Climate and 
communicable disease

Discussion paper

2024



Citation and authorship

CSIRO (2024) Climate and communicable disease: Discussion 
paper. CSIRO, Canberra.

CSIRO Futures

At CSIRO Futures we bring together science, technology 
and economics to help governments and businesses 
develop transformative strategies that tackle their biggest 
challenges. As the strategic and economic advisory arm 
of Australia’s national science agency, we are uniquely 
positioned to transform complexity into clarity, uncertainty 
into opportunity, and insights into action.

The Australian Climate Service

The Australian Climate Service is a partnership between 
the Bureau of Meteorology, CSIRO, the Australian Bureau of 
Statistics and Geoscience Australia. CSIRO has undertaken 
this project as part of the National Climate Risk Assessment, 
in partnership with the Department of Climate Change, 
Energy, the Environment and Water. 

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Acknowledgements

CSIRO acknowledges the Traditional Owners of the land, 
sea and waters, of the area that we live and work on across 
Australia. We acknowledge their continuing connection to 
their culture, and we pay our respects to their Elders past 
and present.

The project team is grateful to the stakeholders who 
generously gave their time to provide advice and feedback 
on this report through interviews and report reviews. 

Copyright notice

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Organisation 2024. To the extent permitted by law, all 
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Contents

Executive summary...................................................................................................................................2Glossary..........................................................................................................................................................51 Introduction...........................................................................................................................................62 Climate sensitive communicable diseases...............................................................................7Vector borne diseases........................................................................................................................................................8Food and water borne diseases.......................................................................................................................................10Zoonotic diseases.............................................................................................................................................................11Soil borne diseases...........................................................................................................................................................113 Assessing priority communicable disease risks in 2050 ...............................................13Australian surveillance systems.......................................................................................................................................13Prioritisation framework.................................................................................................................................................13Example priority diseases................................................................................................................................................154 Priority needs for further analysis..............................................................................................21Prioritisation framework rating validation....................................................................................................................22Preliminary scoping of a national vulnerability, capacity and adaptation assessment..............................................22Early warning system needs assessment........................................................................................................................23Appendices................................................................................................................................................24A.1 Consulted organisations........................................................................................................................................24A.2 Assessed communicable diseases.........................................................................................................................25A.3 Additional needs for further analysis ..................................................................................................................27A.4 Pathogen climate sensitivity – applied research findings...................................................................................30

Executive summary

This report

Climate changes such as rising temperatures, changing 
rainfall patterns and extreme weather events are driving a 
shift in the types and geographic spread of communicable 
disease in Australia. This report explores the differences in 
climate sensitivity across communicable diseases, provides 
a framework for assessing priority communicable disease 
risks for Australia in 2050, and outlines research and 
analyses that will support Australia in further understanding 
priority risks. The insights presented in this report were 
compiled through desktop research and engagement with 
57 experts across research, industry and government.

CSIRO has undertaken this project as part of the National 
Climate Risk Assessment, in partnership with the 
Department of Climate Change, Energy, the Environment 
and Water.

Mosquito borne diseases are 
the most climate sensitive. 

Mosquito borne diseases are the most climate sensitive 
transmission type of communicable disease in Australia, 
with other vector borne diseases, food and water borne 
diseases, zoonotic diseases and environmental diseases also 
aggravated by multiple climate conditions (Figure 1). 

Figure 1: Summary of climate condition impacts on communicable disease transmission categories in Australia.

CLIMATE CONDITION 

Warming

Rainfall 

Flooding

Drought

Extreme 
storms, 
winds and 
cyclones 

Bushfires 
and 
grassfires 

Coastal 
erosion, 
shoreline 
change 
and ocean 
warming 

Vector borne – mosquito

Vector borne – other

Food and water borne

Zoonotic 

Soil borne 

Air borne

Blood borne

Sexually transmitted 





CLIMATE CONDITION IMPACT

No published 
climate-link

Moderately 
diminishing

Low/little 
climate 
sensitivity

Moderately 
aggravating

Strongly 
aggravating





Projected warming, rainfall and flooding changes are 
expected to aid the proliferation of mosquito borne 
diseases through shortened pathogen incubation periods, 
additional geographies with suitable habitats, and 
longer seasons for mosquito survival and reproduction. 
These changes will be experienced most in Australia’s 
tropical (Northern Territory, northern Western Australia, 
and Queensland) and subtropical (northern New South 
Wales and southern Queensland) regions to 2050. 
Projected decreases in rainfall and increases in temperature 
in southern Australia (South Australia, southern New South 
Wales, southern Western Australia and Victoria) may also 
alter mosquito breeding and survival. 



Prioritising national investments 
in communicable disease resilience 
should consider climate sensitivity, 
disease severity, and the degree to 
which Australia’s health systems are 
prepared to respond to outbreaks. 

While surveillance and investment should remain focused 
on high incidence diseases, considering other criteria 
may help to direct additional investment and policy 
support towards communicable diseases that are currently 
under‑monitored and under-evaluated based on their 
future risk profile. 

Figure 2 presents a set of criteria that could be used to 
comprehensively assess future communicable disease 
risk in Australia. Preliminary assessments were made for 
93 communicable diseases considered to be potential 
national health risks by 2050. By considering diseases 
that rate high or moderate across most criteria in the 
framework, and those most frequently raised as national 
2050 risks of concern by engaged stakeholders, five were 
selected as example priority diseases. These were avian 
influenza, dengue, Japanese encephalitis, melioidosis 
and salmonellosis. 

Figure 2: Criteria for assessing future communicable disease risks in Australia.

Climate sensitivity 

Which diseases are most likely to 
increase in incidence or impact 
due to climate projections?

Transmissibility

Which diseases have high 
transmissibility and have the 
potential to rapidly spread?

Vaccine availability risk

Which diseases do not have 
effective vaccines that are 
available in Australia?

Disease severity 

Which diseases result in severe 
illness or death in an infected 
person?

Impact on Indigenous health

To what extent do diseases 
disproportionately impact 
Aboriginal and Torres Strait 
Islander peoples?

Novelty in Australia 

To what extent does Australia lack 
experience with responding to 
outbreaks of the disease? 



Further research and analyses are 
required to sufficiently understand 
climate impacts on future 
communicable disease risks. 

These needs fall under four broad objectives: 
understanding climate sensitivity, predicting disease 
incidence, projecting health and health system impacts, 
and monitoring, detection and surveillance (Figure 3). 
Activities that target these objectives can inform each other, 
ideally forming an ongoing cycle of data collection and 
insight gathering that ensures the nation’s prioritisation 
of communicable disease risk is responsive to the ever-
evolving global context. 

Efforts in these areas will need to be tailored for 
key variables including disease, climate projections, 
epidemiology, and geography, and consider cultural, 
behavioural, economic, and genetic differences across 
communities. They should be undertaken with a One 
Health approach, and consider indirect factors like food 
security, mental wellbeing, social and environmental 
determinants of health, socioeconomic impacts, ecology, 
and population demographics. 

Figure 3: Summary of further research and analysis needs grouped by objective. 

Understanding climate 
sensitivity

• Pathogen sensitivity
• Vector sensitivity
• Zoonotic sensitivity
• Host sensitivity


Predicting disease incidence

• Modelling changing 
climate and disease


Projecting health and health 
system impacts

• Disease burdens 
• Healthcare demand
• Economic costs


Monitoring, detection and surveillance

• Prioritisation framework rating validation 
• Preliminary scoping of a national vulnerability, capacity and adaption assessment
• Early warning detection system needs assessment


While each of the examples presented in Figure 3 are 
important for informing comprehensive national risk 
assessments, those most frequently raised in stakeholder 
consultations, and with the potential to provide valuable 
short-term insights, fall under the monitoring, detection 
and surveillance objective. These could be considered 
nearer term priorities for establishing a strong foundation 
for the other activities. 



Glossary

TERM

DEFINITION 

Air borne disease 

A disease transmitted through the air by droplets or dust particles. Within the context of this report, 
only communicable air borne diseases were considered.

Blood borne disease

A disease transmitted through contact with infected blood, blood products or body fluids.

Bushfires and grassfires 

Uncontrolled fire event that occurs in vegetation, including forests, grasslands and shrublands.

Climate condition 

Climate events and trends which have been derived from the climate hazard categories defined in the 
National Climate Risk Assessment Methodology.1 For example, warming, rainfall and flooding. 

Climate variables 

Physical, chemical or biological variables that contribute to climate conditions. For example, land surface 
temperature, precipitation and sea surface temperature. 

Coastal erosion, 
shoreline change and 
ocean warming

Includes impacts from sea level rise, changing tides, wave action, storm surge, high winds, marine 
heatwaves, coral bleaching, changes in biogeochemical cycles, ocean acidification, changes in ocean 
productivity, currents and overturning. 

Communicable disease 

An infectious disease that can be transmitted from one person, animal, or vector to a person. 

Congenital disease 

A disease that is transmitted from birthing parent to child during pregnancy, birth or breastfeeding. 

Drought 

A prolonged period of abnormally low rainfall. Includes broadscale changes in atmospheric circulation 
resulting in short (years) and long (decades) term drought, increases in aridity, and flash drought associated 
with high evapotranspiration.

Endemic 

The consistent presence or usual prevalence of a disease within a specific population or geographic area, 
without significant fluctuation in its occurrence over time.

Epidemic 

The widespread occurrence of a disease within a specific population or geographical area.

Extreme storms, winds 
and cyclones 

Intense weather events characterised by high winds, heavy rainfall (and flash flooding), thunderstorms, storm 
surges and cold fronts.

Flooding

The overflow of water onto land caused by abnormally heavy rainfall. Includes pluvial (flash) and fluvial 
(riverine) floods, soil moisture and river/dam levels. 

Food borne disease 

A disease caused by the ingestion of contaminated food. Within the context of this report, only 
communicable food borne diseases were considered.

Infectious disease

A disease caused by an infectious agent or pathogen. 

One Health 

An integrated multi-sector and transdisciplinary approach to health that considers the interconnected 
relationships between human, animal, plant and environmental health.

Pathogen 

An organism that causes disease in its host (e.g., bacteria, virus, parasite, fungi).

Sexually transmitted 
disease

A disease transmitted through sexual contact. 

Soil borne disease 

A disease acquired through exposure to a pathogen that lives in soil or passes through soil. Within the 
context of this report, only communicable soil borne diseases were considered. 

Vectorial capacity

A measure of the potential of an insect population to transmit disease, similar to the daily reproductive 
number (R0 value) of other infectious diseases. 

Vector borne disease

A disease transmitted to humans or other animals by vectors (insects that can transmit infectious pathogens, 
e.g., mosquitoes and ticks). Many vector borne diseases are also zoonotic as they originate in animals or 
involve animals as intermediate hosts.

Water borne disease 

A disease caused by the ingestion of contaminated water. Within the context of this report, only 
communicable water borne diseases were considered.

Zoonotic disease

A disease caused by a pathogen that has crossed species from an animal to a human. Zoonotic diseases can be 
transmitted directly through animals or indirectly through contaminated sources. Within the context of this 
report, zoonotic diseases that rely on vectors for transmission to humans are considered vector borne diseases. 

Zoonotic spillover

A cross-species transmission event where a pathogen, which originated in an animal, moves from an animal 
to a human. Spillover generally involves a source host, intermediate host and recipient host.2 





1 Australia Government Department of Climate Change, Energy, the Environment, and Water (2023) National Climate Risk Assessment Methodology. <https://
www.dcceew.gov.au/sites/default/files/documents/national-climate-risk-assessment-methodology.pdf> (accessed 16 May 2024). 

2 Ellwanger JH, Chies JA (2021) Zoonotic spillover: Understanding basic aspects for better prevention. Genetics and Molecular Biology 44(1 Suppl), 1–18.



1 Introduction

Communicable diseases cause significant impacts on 
individual health, public health and health systems in 
Australia. For example, the total health system spending 
in response to COVID‑19 in Australia from 2019 to 2022 
was $47.9 billion, and campylobacteriosis is estimated to 
cost Australia $365 million per year.3 Aside from the direct 
costs associated with mortality, morbidity, and disease 
prevention and treatment, communicable diseases also 
cause productivity loss and can lead to the onset of chronic 
disease.4 

Economic and social costs associated with communicable 
disease are disproportionately felt by priority populations 
including Aboriginal and Torres Strait Islander people, 
rural and remote communities, young children, pregnant 
people, the elderly and immunocompromised people.5 The 
spread and incidence of communicable diseases also differ 
by geography, season and climate in Australia, further 
contributing to their varied impacts.6 

Climate changes have the potential to exacerbate the 
impacts of communicable diseases by creating more 
favourable conditions that increase pathogen virulency, 
change human behaviour, and increase the geographic 
range, seasonality and intensity of disease transmission.7 
By 2050, changes in Australia’s climates are projected 
to increase the incidence and severity of communicable 
diseases.8 

There are limited Australian-specific analyses exploring 
the link between climate and communicable diseases and 
comparing the future risks that these relationships could 
pose. This discussion paper examines climate sensitivity 
of communicable disease, proposes criteria that could be 
used to prioritise and assess communicable disease risks 
in Australia, and outlines research and analyses that will 
support Australia in further understanding priority risks. 

3 Australian Institute of Health and Welfare (2023) Health system spending on the response to COVID-19 in Australia 2019–20 to 2021–22. <https://www.
aihw.gov.au/reports/health-welfare-expenditure/health-system-spending-on-the-response-to-covid-19/contents/spending-by-area> (accessed 14 June 2024); 
Australia National University (2022) The annual cost of foodborne illness in Australia. <https://www.foodstandards.gov.au/sites/default/files/publications/
Documents/ANU%20Foodborne%20Disease%20Final%20Report.pdf> (accessed 14 May 2024).

4 Crosland et al. (2019) The economic cost of preventable disease in Australia: a systematic review of estimates and methods. Australian and New Zealand 
Journal of Public Health 43 (5), 484–495; O’Connor et al. (2006) Emerging Infectious Determinants of Chronic Diseases. Emerging Infectious Diseases 12(7), 
1051–1057. 

5 Australian Institute of Health and Welfare (2021) Significant improvements in the burden of disease experienced by Aboriginal and Torres Strait Islander 
people. <https://www.aihw.gov.au/news-media/media-releases/2021-1/october/indigenous-burden-of-disease> (accessed 15 April 2024).

6 Australian Department of Health (2021) National Preventive Health Strategy. <https://www.health.gov.au/sites/default/files/documents/2021/12/national-
preventive-health-strategy-2021-2030_1.pdf> (accessed 14 June 2024).

7 Semenza JC, Rocklov J, Ebi KL (2022) Climate Change and Cascading Risks from Infectious Disease. Infectious Diseases and Therapy 11(4), 1371–1390.

8 Mora et al. (2022) Over half of known human pathogenic diseases can be aggravated by climate change. Nature Climate Change 12, 869–875. 



2 Climate sensitive 
communicable diseases

The mechanisms and magnitude of climate impacts on 
communicable disease (climate sensitivity) vary significantly 
across climate conditions, pathogens, geography 
and demography. 

Given the large number of communicable disease 
pathogens and complex nature of their relationship 
to climate, Figure 4 attempts to summarise climate 
sensitivity to key climate conditions by grouping diseases 
by forms of transmission. The ratings in this figure were 
informed by Australian-relevant literature and stakeholder 
consultation. To reflect Australian-specific climate 
sensitivities as best as possible, the ratings also factored 
in Australia’s infrastructure (including water supply and 
sanitation standards, and healthcare system) that reduce 
certain disease transmission risks compared to low- and 
middle-income countries. 

These ratings did not consider the secondary impact of 
climate on disease, for example where a climate condition 
may exacerbate the symptoms of a communicable disease 
or where extreme weather events may cause infrastructure 
destruction that disrupt healthcare and emergency services. 

Figure 4: Summary of climate condition impacts on communicable disease transmission categories in Australia.

Mosquito borne diseases are the most climate sensitive 
transmission type of communicable disease in Australia, 
with other vector borne diseases, food and water borne 
diseases, zoonotic diseases, and soil borne diseases also 
aggravated by multiple climate conditions. While air borne 
diseases are aggravated by some climate conditions, the 
impact is indirect. For example, multiple climate conditions 
can increase the spread of air borne disease due to 
increased congregation of people inside, poor ventilation 
and increased air conditioning use.9 This section provides 
further discussion of the transmission types that were 
determined to have high and direct climate sensitivity 
through stakeholder consultation and literature review. 

CLIMATE CONDITION 

Warming

Rainfall 

Flooding

Drought

Extreme 
storms, 
winds and 
cyclones 

Bushfires 
and 
grassfires 

Coastal 
erosion, 
shoreline 
change 
and ocean 
warming 

Vector borne – mosquito

Vector borne – other

Food and water borne

Zoonotic 

Soil borne 

Air borne

Blood borne

Sexually transmitted 





CLIMATE CONDITION IMPACT

No published 
climate-link

Moderately 
diminishing

Low/little 
climate 
sensitivity

Moderately 
aggravating

Strongly 
aggravating





9 He et al. (2023) Viral respiratory infections in a rapidly changing climate: the need to prepare for the next pandemic. EBioMedicine 93(104593); Huan Minh 
Tran et al. (2023) The impact of air pollution on respiratory diseases in an era of climate change: A review of the current evidence. Science of The Total 
Environment 898, 1–7. 



Vector borne diseases

The most climate sensitive communicable diseases in 
Australia are vector borne; with warming, rainfall and 
flooding the main aggravating climate conditions for 
vectors (e.g., mosquitoes and ticks).10 The relationship 
between climate variables and mosquito borne disease is 
particularly complex because disease incidence is impacted 
by species-specific factors, such as vector seasonality, 
geographic distribution, survival rates, biting rates, 
pathogen incubation periods and vectorial capacity.11 

Warming can have significant impacts on mosquitoes, 
including extended transmission seasons and geographical 
range expansion.12 Warming can also impact the survival 
of mosquitoes and the pathogens they transmit, as they 
have specific temperature ranges for development. 
Meta-analysis of the transmission of 10 viruses (including 
Ross River, Murray Valley encephalitis and dengue) in 
15 mosquito species (including Culex, Anopheles and Aedes 
species, all found in Australia) show precise temperature 
boundaries. Transmission peaks at 23–29°C and drops to 
zero above 32–38°C, with malaria and Ross River virus 
peaking at lower optimal temperatures (25–26°C) than 
Zika or dengue (29°C).13 

Warmer climates also impact specific vector-pathogen 
mechanisms. For example, increased temperature can 
shorten the time between a vector’s exposure to a 
pathogen and becoming infectious (extrinsic incubation 
period). In Aedes aegypti and albopictus mosquitoes 
(species that carry dengue), this extrinsic incubation period 
reduces from 15 days to 6.5 days as mean temperature 
increases from 25°C to 30°C.14 General temperature 
related increases in dengue incidence is greater in tropical 
monsoon climate zones and humid subtropical climate 
zones; conditions found predominantly in Queensland.15 
By 2050, Australia’s tropical monsoon zones are projected 
to expand by 50%, which may increase dengue risk over 
greater geographical areas.16 

Predicted increases in the frequency of heavy rainfall 
and flooding events is likely to increase the incidence 
of some vector borne diseases by increasing the extent 
and longevity of larval mosquito habitats, expanding 
geographical range and boosting populations.17 
The Western Australian government releases warnings 
most years regarding the heightened risk of mosquito 
borne diseases, including Ross River virus, Murray Valley 
encephalitis and Barmah Forest virus, due to periods of 
non-seasonal and increased rainfall and flooding creating 
ideal mosquito breeding conditions and lengthening 
disease risk periods.18 

10 Rocklov J, Dubrow R (2020) Climate change: an enduring challenge for vector-borne disease prevention and control. Nature Immunology 21, 479–483. 

11 Colón-González et al. (2021) Projecting the risk of mosquito-borne diseases in a warmer and more populated world: a multi-model, multi-scenario 
intercomparison modelling study. The Lancet Planetary Health 5(7), e404–e414.

12 Colón-González et al. (2021) Projecting the risk of mosquito-borne diseases in a warmer and more populated world: a multi-model, multi-scenario 
intercomparison modelling study. The Lancet Planetary Health 5(7), e404-e414.; Russell RC (2009) Mosquito-borne disease and climate change in Australia: 
time for a reality check. Australian Journal of Entomology 48(1), 1–7.

13 Mordecai et al. (2019) Thermal biology of mosquito-borne disease. Ecology Letters 22(10), 1690–1708.

14 Chan M, Johansson MA (2012) The incubation periods of dengue viruses. Public Library of Science One 7(11), e50972.

15 Australian Bureau of Meteorology (2005) Climate classification maps. <http://www.bom.gov.au/climate/maps/averages/climate-
classification/?maptype=kpngrp> (accessed 16 May 2024). 

16 Crosbie et al. (2012) Changes in Koppen-Geiger climate types under a future climate. Hydrology and Earth Systems Science Discussions 9(6), 7415–7440.

17 Harley et al. (2011) Climate change and infectious diseases in Australia: Future prospects, adaptation options, and research priorities. Asia Pacific Journal of 
Public Health 23(2 suppl), 54S–66S.

18 WA Department of Health (2023) New Murray Valley encephalitis case prompts mosquito warning for the Kimberley <https://www.health.wa.gov.au/Media-
releases/2023/July/New-Murray-Valley-encephalitis-case-prompts-mosquito-warning-for-the-Kimberley> (accessed 17 May 2024).



For many mosquito species, high temperatures combined 
with increased rainfall (i.e., high humidity) typically 
increase mosquito population development, survival, and 
biting rates; expanding their suitable habitats, extending 
reproductive seasons, and altering migration patterns.19 
The 2023 Intergovernmental Panel on Climate Change Sixth 
Assessment Report reported increasing global average 
temperatures, relative humidity, and rainfall, are making 
larger geographic areas more suitable for the increased 
transmission and vectorial capacity of mosquito borne 
diseases.20 This is likely to be most relevant to mosquito 
borne disease transmissions in northern Australia 
(Northern Territory, northern Queensland and northern 
Western Australia). In these areas, expected temperature 
increases and changes to rainfall patterns are likely to 
extend seasonal wetlands (impacting diseases like Murray 
Valley encephalitis) and create longer seasons of peak 
vector activity (impacting diseases like Ross River virus).21 
In contrast, areas of southern Australia (South Australia, 
southern New South Wales and northern Victoria) are 
projected to see a decrease in average rainfall and increase 
in temperature, which may see a decrease in transmission 
due to a reduction in suitable larval habitats and higher 
temperatures compromising adult mosquito survival.22 

Less literature exists around the climate sensitivity of other 
vectors. However, it has been proposed that long periods 
of moderate rainfall significantly increase tick survival, 
spread and population size; and high severity in rainfall 
can wash away ticks, eggs and larvae, thereby reducing 
their population.23 While this indicates a strong aggravating 
impact for some climate conditions, especially in tropical 
settings, Australian health systems are comparatively well 
equipped to manage common tick diseases (predominantly 
rickettsial infections).24 

19 Rocklov J, Dubrow R (2020) Climate change: an enduring challenge for vector-borne disease prevention and control. Nature Immunology 21, 479–483. 

20 IPCC (2023) Summary for Policymakers. Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report 
of the Intergovernmental Panel on Climate Change. Geneva, Switzerland.

21 Russell RC (2009) Mosquito-borne disease and climate change in Australia: time for a reality check. Australian Journal of Entomology (48)1, 1–7.

22 Russell RC (2009) Mosquito-borne disease and climate change in Australia: time for a reality check. Australian Journal of Entomology (48)1, 1–7.

23 Ma et al. (2022) Climate change drives the transmission and spread of vector-borne diseases: An ecological perspective. Biology 11(11), 1628.

24 Stewart et al. (2019) The epidemiology and clinical features of rickettsial diseases in North Queensland, Australia: Implications for patient identification and 
management. Public Library of Science Neglected Tropical Diseases 13(7).



Food and water borne diseases

Several climate conditions increase the risk of food and 
water borne diseases in Australia. Warming can increase 
the growth, virulence and survival of food and water borne 
pathogens. For example, warming is associated with the 
virulence of water borne vibrio parahaemolyticus bacteria 
that causes gastroenteritis,25 and increases in food borne 
salmonellosis incidence.26 Positive correlations have been 
found in most Australian States and Territories regarding 
temperature and salmonellosis notifications, with a 
1°C mean temperature increase associated with a 3.4% 
increase in salmonellosis cases the following month.27 
In contrast, some food and water borne diseases survive 
best in cooler conditions, like rotavirus. For each 1°C rise in 
mean temperature, rotavirus hospital admissions decrease 
by 2–5%.28 

Recreational exposure to water borne disease, which is the 
most common cause of Australian outbreaks (as opposed 
to exposure from drinking water), is also correlated with 
warming.29 Both salmonellosis and campylobacteriosis 
cases peak in spring and summer, due to higher 
ambient temperatures and higher rates of recreational 
water activities.30 

Rainfall also significantly impacts the transmission of 
several food and water borne diseases. Outbreaks of 
cryptosporidiosis, salmonellosis and campylobacteriosis 
have strong correlations with seasonal rainfall.31 
Further, heavy rainfall facilitates the leaching of pathogens 
into water bodies and the contamination of water 
supplies.32 Rainfall in combination with other climate 
variables also changes pathogen dynamics. For example, 
heavy rainfall and ocean warming reduces coastal water 
salinity, facilitating rapid growth and virulent mutations 
of vibrio parahaemolyticus in oysters and mussels.33 
Further, the 2018 Australian rockmelon listeriosis outbreak 
(resulting in 22 cases and 7 deaths) has been attributed 
to heavy rainfall and dust storms, which enabled 
disease-causing levels of bacteria despite above-average 
sanitation practices.34 

Extreme weather events can also increase pathogen 
presence in water and agricultural systems. In recent 
years, storms and bushfires have damaged water 
infrastructure causing widespread contamination.35 
Fire related vegetation loss in water catchments also 
makes soil vulnerable to erosion, increasing the long-term 
possibility of contaminated runoff entering water supplies.36 
Further, floodwater can transport bacteria to growing 
crops and processing facilities and has been implicated 
in Escherichia coli and Salmonella contamination of 
vegetable crops.37 

25 Zhang et al. (2023) The impact of global warming on the signature virulence gene, thermolabile hemolysin, of Vibrio parahaemolyticus. Microbiology 
Spectrum 11(6), e01502–01523. 

26 Davis et al. (2022) Climate variability and change are drivers of salmonellosis in Australia: 1991 to 2019. Science of The Total Environment 843(156980). 

27 David et al. (2022) Climate variability and change drivers of salmonellosis in Australia: 1991 to 2019. Science of The Total Environment 843(15), 156980.

28 Harley et al. (2011) Climate change and infectious diseases in Australia: Future prospects, adaptation options, and research priorities. Asia Pacific Journal of 
Public Health 23(2 suppl), 54S–66S.

29 Dale et al. (2010) Reported waterborne outbreaks of gastrointestinal disease in Australia are predominantly associated with recreational exposure. 
Australian and New Zealand Journal of Public Health 34(5), 527–530.

30 Harley et al. (2011) Climate change and infectious diseases in Australia: Future prospects, adaptation options, and research priorities. Asia Pacific Journal of 
Public Health 23(2 suppl), 54S–66S.

31 Harley et al. (2011) Climate change and infectious diseases in Australia: Future prospects, adaptation options, and research priorities. Asia Pacific Journal 
of Public Health 23(2 suppl), 54S-66S; Semenza et al. (2012) Climate Change Impact Assessment of Food- and Waterborne Diseases. Critical Review 
Environmental Science and Technology 42(8), 857–890. 

32 Ghazani et al. (2018) Temperature variability and gastrointestinal infections: A review of impacts and future perspectives. International Journal of 
Environmental Research and Public Health 15(4), 766.

33 Burge et al. (2014) Climate Change influences on marine infectious diseases: implications for management and society. Annual Review of Marine Science 6, 
249–277; Scanes et al. (2023) Emerging diseases in Australian oysters and the challenges of climate change and uncertain futures. Australian Zoologist 15.

34 NSW Government Department of Primary Industries (2018) Biosecurity and Food Safety: Listeria Outbreak Investigation. NSW Government Department 
of Primary Industries, Biosecurity and Food Safety. <https://www.foodauthority.nsw.gov.au/sites/default/files/_Documents/foodsafetyandyou/listeria_
outbreak_investigation.pdf> (accessed 12 June 2024).

35 Calyton R (2020) Melbourne suburbs served by Yarra Valley Water, South East Water warned to boil water after wild weather. ABC News, 28 August. 

36 Landow S (2020) Drinking water under threat: water contamination risks this bushfire season. UNSW Sydney, Newsroom. 

37 Singh SP (2023) Flooding adversely affects fresh produce safety. Microbiology Australia 44(4), 185–189.



Zoonotic diseases

Zoonotic pathogens have the potential to be aggravated by 
all climate conditions. A major driver of zoonotic disease in 
Australia is the reduction in habitable conditions for wildlife 
species and biodiversity loss, which alters interaction 
patterns with humans and other animals. For example, 
in subtropical Australia, climate-driven food shortages 
have driven bats to migrate and feed in agricultural areas, 
potentially infecting horses and pigs that come into contact 
with humans.38 This mechanism has facilitated Hendra virus 
transmission in Queensland and New South Wales.39 As an 
indication of how these drivers are spreading south; Hendra 
virus was reported for the first time during 2019 in southern 
New South Wales, despite its endemicity in Queensland.40 

Animals that act as intermediary pathogen hosts for 
vector borne diseases will also be impacted by climate 
change, demonstrating the interaction between different 
disease transmission types and ecology. Seasons of 
high temperatures and rainfall boost vegetation for the 
animal hosts of Ross River virus and Barmah Forest virus 
(marsupials such as possums, kangaroos and wallabies).41 
In contrast, longer and more intense fire seasons will 
instead limit the food sources of animal hosts, lead to 
biodiversity loss, and reduce the ability of mosquito 
vectors to spread the pathogen.42 For example, Japanese 
encephalitis is thought to have emerged in Australia 
because of drought conditions in 2015–2019 followed 
by flooding events in 2020; drought conditions brought 
together wetland bird populations (the amplifying host) 
with mosquito vectors around shrinking water reserves, 
and subsequent flooding events created optimal breeding 
conditions for both species.43

Soil borne diseases

Rainfall and flooding events strongly aggravate the 
transmission of soil borne diseases. Up to 25% of the 
bacteria emitted from soil globally are attributed to rain 
and floods, with excess water bringing bacteria to the 
surface for increased exposure.44 In Australia, 81% of 
melioidosis cases occur during the wet season and more 
severe symptoms are associated with heavier rainfall.45 
Increases in melioidosis cases are also associated with 
storms and cyclone events, which may disperse pathogens 
to previously unaffected regions.46 

Warming also aggravates soil borne diseases, with higher 
temperatures providing a more favourable environment 
for the survival of anthrax spores in soil.47 Incidence of 
soil-transmitted helminthiases and strongyloidiasis are also 
expected to increase with warming, as higher temperatures 
accelerate the development of parasitic worms that cause 
these diseases.48

38 Eby et al. (2023) Pathogen spillover driven by rapid changes in bat ecology. Nature 613, 340–344. 

39 Australian Government Department of Agriculture, Fisheries and Forestry (2023). Hendra virus. < https://www.agriculture.gov.au/biosecurity-trade/pests-
diseases-weeds/animal/hendra-virus#:~:text=Since%201994%2C%20Hendra%20virus%20(HeV,New%20South%20Wales%20(NSW)> (accessed 17 June 2024). 

40 Yuen et al. (2021) Hendra virus: Epidemiology dynamics in relation to climate change, diagnostic tests and control measures. One Health 12, 100207. 

41 Kain MP et al. (2021) Physiology and ecology combine to determine host and vector importance for Ross River virus. eLife 10(e67018), 1–40.

42 Harley et al. (2011) Climate change and infectious diseases in Australia: Future prospects, adaptation options, and research priorities. Asia Pacific Journal of 
Public Health 23(2 suppl), 54S–66S.

43 Purnell, C (2022) The role of waterbirds in Australia’s 2022 Japanese Encephalitis outbreak Unpublished – a rapid synthesis. Birdlife Australia, Carlton.

44 Joung YS, Ge Z, Buie CR (2017) Bioaerosol generation by raindrops on soil. Nature Communications 14668. 

45 Chakravorty A, Heath CH (2019) Melioidosis: An updated review. Australian Journal of General Practice 48(5); Currie et al. (2000) Endemic Melioidosis in 
Tropical Northern Australia: A 10-year prospective study and review of the literature. Clinical Infectious Diseases 31(4), 981–986; Currie BJ, Jacups SP (2003) 
Intensity of Rainfall and Severity of Melioidosis, Australia. Emerging Infectious Diseases 9(12), 1538–1542.

46 NT Health Department (2021) Melioidosis Fact Sheet. <https://health.nt.gov.au/__data/assets/pdf_file/0006/1303386/melioidosis-nt-health-factsheet.pdf> 
(accessed 30 April 2024). 

47 Walsh MG, Smalen AW, Mor SM (2018) Climatic influence on anthrax suitability in warming northern latitudes. Nature Scientific Reports 8(9269). 

48 Weaver HJ, Hawdon JM, Hoberg EP (2010) Soil-transmitted helminthiases: implications of climate change and human behaviour. Trends in Parasitology 
26(12), 574–581.



3 Assessing priority 
communicable disease risks 
in 2050 

Australian surveillance systems

Australia has a range of existing national, state and 
territory surveillance programs for tracking communicable 
diseases across human, animal and environmental health.49 
The National Notifiable Disease Surveillance System 
(NNDSS) coordinates national surveillance by collecting and 
tracking incidence, trends, and several impact metrics for 
diseases that present risks to public health.50 In 2023, the 
most frequently reported cases of communicable diseases 
in Australia were for COVID-19 (864,564 reports), influenza 
(288,989), and respiratory syncytial virus (128,013).51 While 
the specific pathogens may vary, it is likely that these 
types of respiratory viruses will continue to cause seasonal 
epidemics and be among the most frequently reported 
diseases in Australia by 2050. 

Diseases tracked by the NNDSS are determined using an 
established decision-making protocol,52 however, this 
process is not designed to be used as a risk assessment 
tool. In the context of building national resilience to future 
communicable disease risks, pairing surveillance system 
insights with information on climate impacts, disease 
severity, and health system preparedness for both notifiable 
and non-notifiable diseases is required. 

Prioritisation framework

This section introduces a framework that investigates a 
range of criteria for determining future communicable 
disease risks (Table 1). This may help to direct additional 
investment and policy support towards communicable 
diseases that are under-monitored and under-evaluated 
based on their future risk profile. The framework 
may also support the early assessment of emerging 
diseases and pathogens that have not previously been 
encountered globally. 

The proposed framework builds on existing national and 
international prioritisation frameworks,53 by (i) focussing 
on communicable diseases, (ii) considering a future 
(2050) state rather than exclusively looking at present day 
risks, and (iii) incorporating Australian-specific criteria. 
Each criterion is assessed independently of the others to 
highlight their influence on potential priority diseases; 
however, it would be reasonable to combine and weight 
them based on the prioritisation objectives of a given 
stakeholder group. 

A total of 93 communicable diseases were assessed through 
the framework (see Appendix A.2). These diseases were 
identified by combining national, state and territory 
notifiable disease registers, notable climate health literature, 
and stakeholder insights, to arrive at a comprehensive list 
of potential risks to Australia in 2050. These preliminary 
assessments focus on the direct health and health system 
impacts of each disease and were developed to aid 
discussion. More comprehensive analysis (as outlined in 
Section 4) for each disease-criterion combination would be 
required to support government decision making. 

49 Australian Government (2024) National Notifiable Diseases Surveillance System. <https://www.health.gov.au/our-work/nndss#about-the-nndss;%20https://
nahis.animalhealthaustralia.com.au/public.php;%20https://www.agriculture.gov.au/abares/research-topics/social-sciences/making-general-surveillance-
work/listing-stocktake-general-surveillance-initiatives> (accessed 17 May 2024); Wildlife Health Australia (2024) Our work: Surveillance. <https://
wildlifehealthaustralia.com.au/Our-Work/Surveillance> (accessed 11 June 2024).

50 Australian Government Department of Health and Aged Care (2023) National Communicable Disease Surveillance Dashboard. <https://nindss.health.gov.au/
pbi-dashboard/> (accessed 11 June 2024).

51 Australian Government Department of Health and Aged Care (2023) National Communicable Disease Surveillance Dashboard. <https://nindss.health.gov.au/
pbi-dashboard/> (accessed 11 June 2024).

52 Australian Government Department of Health and Aged Care (2015) Protocol for making a change to the National Notifiable Diseases List (NNDL) in 
Australia. <https://www.health.gov.au/sites/default/files/documents/2022/06/protocol-for-making-a-change-to-the-national-notifiable-diseases-list-in-
australia.pdf> (accessed 11 June 2024).

53 Australian Government Department of Health and Aged Care (2015) Protocol for making a change to the National Notifiable Diseases List in Australia. 
Canberra, Australia; United Nations Framework Convention on Climate Change (2021) Handbook on Vulnerability and Adaptation Assessment, Chapter 8: 
Human Health. Bon, Germany; World Health Organisation (2017) Methodology for Prioritizing Severe Emerging Diseases for Research and Development. 
Geneva, Switzerland; World Health Organisation (2021) Climate Change and Health Vulnerability and Adaptation Assessment. Geneva, Switzerland. 



Table 1: Criteria for identifying priority communicable disease risks for further analysis.

CRITERIA

ASSESSMENT CATEGORIES 

COUNT OF 
DISEASES 
RATED ‘HIGH’

EXAMPLES OF DISEASES 
RATED ‘HIGH’

Climate sensitivity

Which diseases are most 
likely to increase in incidence 
or impact due to climate 
projections?

Low: No evidence or a diminishing/protective link

Moderate: Low to moderate aggravating link 

High: Moderate to strong aggravating link

60 

Dengue 

Japanese encephalitis 

Melioidosis

Ross River virus 

Salmonellosis

Transmissibility 

Which diseases have high 
transmissibility and have the 
potential to rapidly spread?

Low: No or low potential for disease to cause 
widespread transmission

Moderate: Disease has previously caused, or has the 
potential to cause, an epidemic 

High: Disease has previously caused multiple 
epidemics or a pandemic

23

COVID-19

Cryptosporidiosis

Dengue 

Influenza

Salmonellosis 

Vaccine availability risk

Which diseases do not have 
effective vaccines that are 
available in Australia?

Low: Effective vaccine available and a national 
program dedicated to access in Australia 

Moderate: Vaccine available but ineffective or low 
acceptability/uptake in Australia

High: No vaccine available either on the market or 
approved for use in Australia

63

Avian influenza 

Barmah Forest virus 

Hendra virus

Murray Valley encephalitis 

Ross River virus 

Disease severity

Which diseases result in 
severe illness or death in 
an infected person?

Low: Short-term illness, complete recovery in most 
cases, or case-fatality <1%

Moderate: Long-term illness requiring treatment, 
long-term disability likely, or case-fatality 1-10%

High: Severe and long-term illness or case fatality 
10-100%

22 

Australian bat lyssavirus 

Avian influenza 

Hendra virus 

Murray Valley encephalitis 

Viral haemorrhagic fevers 
(e.g., Ebola, Lassa and 
Marburg viruses)

Impact on Indigenous health

To what extent do diseases 
disproportionately impact 
Aboriginal and Torres Strait 
Islander peoples?

Low: Disease severity or disease rates for Aboriginal 
and Torres Strait Islander peoples are similar 
to disease severity or rates for non-Indigenous 
Australians

Moderate: Disease severity or disease rates are 
somewhat higher for Aboriginal and Torres Strait 
Islander peoples 

High: Disease severity or disease rates are 
significantly higher, or the disease nearly exclusively 
impacts Aboriginal and Torres Strait Islander peoples

12 

Chlamydial trachomatis 
infection (trachoma)

HTLV-1

Melioidosis

Pneumococcal disease 
(Streptococcus pneumoniae)

Soil-transmitted helminthiases 
and strongyloidiasis 

Novelty in Australia

To what extent does Australia 
lack experience with 
responding to outbreaks 
of the disease? 

Low: Disease is endemic in Australia or Australia has 
experience with addressing widespread outbreaks of 
this disease

Moderate: Australia has experience with addressing 
small outbreaks of this disease (or very localised 
experience)

High: Australia does not have experience dealing 
with widespread outbreaks of this disease 

12

Chikungunya 

Middle East respiratory 
syndrome (MERS) infection

Viral haemorrhagic fevers 
(e.g., Ebola, Lassa and 
Marburg viruses)

West Nile/Kunjin virus 

Yellow fever







Example priority diseases

Five example priority diseases were selected by considering diseases that rate high or moderate across most 
criteria in the framework (see Table 2). These diseases were also the most frequently raised as 2050 disease 
risks of national concern by consulted stakeholders. The following summaries seek to outline the drivers, 
impacts and magnitude of these potential priority disease risks for 2050. 

Table 2: Prioritisation framework assessment ratings for example priority diseases

CLIMATE 
SENSITIVITY

TRANSMISSIBILITY

VACCINE 
AVAILABILITY 
RISK

DISEASE 
SEVERITY

IMPACT ON 
INDIGENOUS 
HEALTH

NOVELTY IN 
AUSTRALIA

Avian influenza 
(HPAI H5N1)

High

Moderate

High

High

Low

High

Dengue

High

High

Moderate

Moderate

Moderate

Moderate

Japanese 
encephalitis

High

Moderate

Moderate

High

Moderate

Moderate

Melioidosis

High

Moderate

High

Moderate

High

Moderate

Salmonellosis 

High

High

High

Low

Moderate

Low







Avian influenza (HPAI H5N1) 

Avian influenza is a zoonotic disease caused by strains of 
type A influenza. The Highly Pathogenic Avian Influenza 
(HPAI) H5N1 strain is transmitted by birds, for which it is 
highly contagious and deadly. HPAI H5N1 can infect a range 
of species including humans, pigs, cats and dairy cattle. 
While transmission from birds to humans is rare and relies 
on close contact, it can cause serious viral pneumonia.54 

Between 1 January 2003 and 3 May 2024, 889 human 
cases of HPAI H5N1 were reported to the World Health 
Organization; these incidents span 23 countries and had 
a 52% fatality rate.55 In March 2024, the first human case 
of H5N1 was detected in Australia, relating to a returned 
traveller who acquired the infection in India.56 In April 2024, 
the first case of cattle-to-human transmission was recorded 
in the United States of America, further demonstrating the 
virus’ changing epidemiology.57 

Recent global surges of HPAI pandemics in bird populations 
have paralleled climate change patterns.58 In Australia, 
wild waterbirds – the natural reservoir for avian influenza 
– move according to drought and rain cycles and transmit 
the virus to domesticated birds in the industrialised poultry 
sector.59 As a result, avian influenza has been linked to 
irregular, non-seasonal rainfall, which causes shifts in 
waterbird breeding and creates temporary wetlands.60 
For example, poultry outbreaks of non-H5N1 avian influenza 
surge after periods of high rainfall in southeastern Australia 
(the Murray-Darling Basin and southern Queensland).61 

No human vaccines are available for HPAI H5N1 (or other 
avian influenza strains). While the public health risk in 
Australia is low, occupational groups like poultry workers 
have a higher risk of exposure.62 

54 New South Wales Government (2023) Avian Influenza ("bird flu") fact sheet. New South Wales Health. <https://www.health.nsw.gov.au/Infectious/
factsheets/Pages/avian-influenza.aspx> (accessed 15 May 2024).

55 Food and Agriculture Organisation of the United Nations (2024) Global avian influenza viruses with zoonotic potential situation update. United Nations, 
Rome <https://www.fao.org/animal-health/situation-updates/global-aiv-with-zoonotic-potential/en> (accessed 15 May 2024); World Health Organisation 
(2024) Cumulative number of confirmed human cases for avian influenza A(H5N1) reported to WHO, 2003-2024, 3 May 2024. <https://www.who.int/
publications/m/item/cumulative-number-of-confirmed-human-cases-for-avian-influenza-a(h5n1)-reported-to-who--2003-2024-3-may-2024> (accessed 23 May 
2024). 

56 Victoria Department of Health (2024) Human case of avian influenza (bird flu) detected in returned traveller to Victoria. <https://www.health.vic.gov.
au/health-advisories/human-case-of-avian-influenza-bird-flu-detected-in-returned-traveller-to-victoria?utm_source=social&utm_medium=twitter&utm_
campaign=CHO_Advisory&utm_content=Bird_Flu> (accessed 23 May 2024).

57 World Health Organisation, Disease Outbreak News (2024) Avian Influenza A(H5N1) - United States of America, 28 March 2024. World Health Organisation. 
<https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON512> (accessed 15 May 2024).

58 Prosser et al. (2023) Climate change impacts on bird migration and highly pathogenic avian influenza. Nature Microbiology 8, 2223–2225.

59 CSIRO (2022) Understanding bird flu dynamics in Australia. CSIRO, Australia. <https://www.csiro.au/en/news/all/articles/2022/september/understanding-
bird-flu-dynamics-in-australia> (accessed 12 June 2024); Gilbert M, Slingenbergh J, Xiao X (2009) Climate change and avian influenza. Revue scientifique et 
technique 27(2), 459-466.

60 Ferenczi M, Beckmann C, Klaassen M (2021) Rainfall driven and wild-bird mediated avian influenza virus outbreaks in Australian poultry. BMC Veterinary 
Research 17(1), 306.

61 Queensland Government, Department of Agriculture and Fisheries (2022) Outbreaks of avian influenza. <https://www.daf.qld.gov.au/business-priorities/
biosecurity/animal-biosecurity-welfare/animal-health-pests-diseases/notifiable/outbreaks> (accessed 12 June 2024); South Australia Department of Primary 
Industries and Regions (2024) Avian influenza. <https://pir.sa.gov.au/biosecurity/animal_health/animal_species/poultry/avian_influenza> (accessed 12 June 
2024).

62 Communicable Disease Network Australia (2016) Avian influenza in humans: CDNA national guidelines for public health units. Communicable Disease 
Network Australia. <https://www.health.gov.au/sites/default/files/2023-08/avian-influenza-in-humans-cdna-national-guidelines-for-public-health-units_1.
pdf> (accessed 15 May 2024).



Dengue

Dengue is a vector borne disease transmitted by Aedes 
species mosquitoes, which can also spread Zika and 
chikungunya. Dengue is endemic in more than 100 
countries, and the World Health Organization reported 
a ten-fold surge from 2000–2019 amounting to 
approximately 5.2 million cases per year.63 In April 2024, 
Brazil classified dengue as a public health emergency, with 
3 million cases occurring due to rising temperatures and 
El Niño-associated heatwaves and rainfall.64 

Australia reports around 1,000 notifications of dengue 
annually, however, 95% of these cases are acquired 
overseas.65 Locally acquired cases (confined to Far North 
Queensland) have decreased from 236 in 2013 to zero in 
2021 and 2022 following widespread Wolbachia rollouts.66 

The future rates of dengue vector and virus distribution in 
Australia are difficult to project and will be influenced by 
many factors including warming, increased domestic water 
storage (due to regional drying) and human population 
growth. While some research implies these drivers 
are likely to see an increased risk of dengue into more 
southern and inland regions of Australia,67 other modelled 
scenarios indicate a reduced risk is possible.68 Further 
adding to the uncertainty of future risk is the potential for 
the dengue-transmitting Aedes albopictus species to enter 
mainland Australia (currently found in the Torres Strait as 
well as North and South America, Africa, Europe and the 
Middle East). 

Between 2020 and 2050, public health costs of dengue are 
estimated to rise from $1.35m to $1.87m per year, with an 
additional 900 lost workdays per year.69 While controls like 
the Wolbachia bacteria are demonstrating effectiveness 
in some contexts, there are no licensed antivirals for 
dengue treatment and limited vaccines for prevention.70 
The development of effective universal therapeutics is 
complicated by the existence of four distinct dengue 
variants; with therapies for one variant impacting the 
safety and efficacy of therapies for others. This presents 
additional challenges for regions where more than one 
variant establishes. 

63 World Health Organization (2023) Disease Outbreak News; Dengue – Global situation. <https://www.who.int/emergencies/disease-outbreak-news/
item/2023-DON498> (accessed 9 May 2024).

64 Glatter RD, Ferreira JSD (2024) An Escalation of Dengue in Brazil Echoes a Global Crisis. <https://www.medscape.com/viewarticle/escalation-dengue-brazil-
echoes-global-crisis-2024a10006js?form=fpf> (accessed 10 May 2024).

65 Sohail A et al. (2024) The epidemiology of imported and locally acquired dengue in Australia, 2012-2022. Journal of Travel Medicine 31(2).

66 Sohail A et al. (2024) The epidemiology of imported and locally acquired dengue in Australia, 2012-2022. Journal of Travel Medicine 31(2).

67 Russell RC et al. (2009) Dengue and climate change in Australia: predictions for the future should incorporate knowledge from the past. Medical Journal of 
Australia 190(5), 265–268.

68 Williams et al. (2016) Projections of increased and decreased dengue incidence under climate change. Epidemiology and Infection 144(14), 3091-3100.

69 Bambrick HJ, Woodruff RE, Hanigan IC (2009) Climate change could threaten blood supply by altering the distribution of vector-borne disease: an Australian 
case-study. Global health action 2(1). 

70 Kwek SS, Ooi EE (2024) Race against dengue. Elife 13(e96018), 1–2.



Japanese encephalitis 

Japanese encephalitis is a vector borne disease most 
commonly transmitted by Culex species mosquitoes. 
The virus is endemic in 24 countries in the Western Pacific 
and South-East Asia, with an estimated 70,000 annual 
cases.71 Less than 1% of cases experience severe symptoms. 
However, of those that do, roughly one-third are fatal, and 
another third are left with permanent injury to the brain 
and nervous system.72 

In 2022, mainland Australia experienced its first ever 
Japanese encephalitis outbreak. There were 45 reported 
cases associated with this outbreak including 7 fatalities.73 
The outbreak followed months of intense rainfall that 
resulted in the creation of inland wetlands, the migration 
of wading birds (disease hosts) to the south, and a 
surge in mosquito populations. Viral amplification in 
pig populations also facilitated virus spread to southern 
Australia. Japanese encephalitis was identified in more than 
80 piggeries in Queensland, New South Wales, Victoria 
and South Australia.74 With the establishment of Japanese 
encephalitis in mainland Australia, there is a high likelihood 
of endemic circulation and future outbreaks.75 

The emergence of Japanese encephalitis in mainland 
Australia underscores the need for One Health approaches 
to tackle zoonotic diseases, coordinating human, animal 
and environmental health sectors. In 2022, the Australian 
Government recognised these risks and committed 
$69 million to control Japanese encephalitis spread 
including vaccines, mosquito surveillance and control, 
and agricultural support.76 

71 World Health Organization (2019) Japanese encephalitis. World Health Organisation. <https://www.who.int/news-room/fact-sheets/detail/japanese-
encephalitis> (accessed 14 May 2024).

72 Queensland Government (2024) Japanese encephalitis. Queensland Health, Australia. <https://www.qld.gov.au/health/condition/infections-and-parasites/
viral-infections/japanese-encephalitis> (accessed 14 May 2024).

73 Australian Government, Department of Health and Aged Care (2023) Statement on the end of Japanese encephalitis virus emergency response. <https://
www.health.gov.au/news/statement-on-the-end-of-japanese-encephalitis-virus-emergency-response> (accessed 15 May 2024).

74 Australian Government, Department of Agriculture, Fisheries and Forestry (2023) Japanese encephalitis virus. Department of Agriculture, Fisheries and 
Forestry, Australia. <https://www.agriculture.gov.au/biosecurity-trade/pests-diseases-weeds/animal/japanese-encephalitis> (accessed 14 May 2024).

75 Australian Government, Department of Agriculture, Fisheries and Forestry (2023) Japanese encephalitis virus. <https://www.agriculture.gov.au/biosecurity-
trade/pests-diseases-weeds/animal/japanese-encephalitis> (accessed 12 June 2024); McGuinness SL, Lau CL, Leder K (2023) The evolving Japanese 
encephalitis situation in Australia and implications for travel medicine. Journal of Travel Medicine 30(2), 1–4; Pendrey CG, Martin GE (2023) Japanese 
encephalitis clinical update: Changing diseases under a changing climate. Australian Journal of General Practice 52(5).

76 Australian Government, Department of Health and Aged Care (2022) $69 million for Japanese encephalitis virus (JEV) response. <https://www.health.gov.au/
ministers/the-hon-greg-hunt-mp/media/69-million-for-japanese-encephalitis-virus-jev-response> (accessed 15 May 2024).



Melioidosis

Melioidosis is caused by exposure to the Burkholderia 
pseudomallei bacteria in contaminated soil or water, or 
more rarely, by direct contact with an infected person. 
The disease is endemic in the tropical north of Australia 
including the Kimberly region of Western Australia, 
Northern Territory and North Queensland; however, 
sporadic cases have been reported in other states.77 
Approximately 400 cases of human infection have been 
reported in Queensland between 2019 and 2023,78 with 
the majority of infected individuals having one or more 
associated risk factors such as diabetes, cancer, chronic 
lung or kidney disease.79 Fatality rates vary but are as high 
as 50% in Far North Queensland.80 With early diagnosis 
and treatment, fatality can be reduced to less than 10%, 
but fatality remains high in regional areas where there is 
reduced access to health services.81 

Melioidosis disproportionately affects Aboriginal and Torres 
Strait Islander peoples. Between 2012–2016, there was an 
average of 5.7 cases per 100,000 Aboriginal and Torres 
Strait Islander peoples. For non-Indigenous Australians the 
rate was 0.4 cases per 100,000 people.82 

Climate conditions strongly aggravate the transmission 
of melioidosis, with increased incidences and severity 
associated with heavy rainfall and extreme weather events 
like windstorms and cyclones, all of which are expected to 
become more frequent and intense by 2050. 

Salmonellosis 

Salmonellosis is caused by the ingestion of food or water 
contaminated with Salmonella bacteria, or less commonly, 
by direct contact with an infected person or animal. 
Salmonellosis is the most common cause of food borne 
disease outbreaks in Australia.83 Each year there are around 
55,000 cases of non-typhoidal salmonellosis in Australia, 
amounting to an estimated $140 million in total public 
health costs.84 

Warming is likely to increase the incidence of salmonellosis 
in Australia. A 1°C increase in mean temperature is 
associated with an up to 15% increase in incidences of 
salmonellosis.85 

77 Inglish TJ (2021) Melioidosis in Australia. Microbiology Australia 42(2), 96–99. 

78 Queensland Government (2024) Notifiable conditions annual reporting <https://www.health.qld.gov.au/clinical-practice/guidelines-procedures/diseases-
infection/surveillance/reports/notifiable/annual> (accessed 12 June 2024).

79 Currie et al. (2021) The Darwin Prospective Melioidosis Study: a 30–year prospective, observational investigation. Lancet Infectious Disease 21(12), 1737–
1746. 

80 Smith S, Hanson J, Currie BJ (2018) Melioidosis: An Australian Perspective. Tropical Medicine and Infectious Disease 3(1), 27. 

81 Currie et al. (2021) The Darwin Prospective Melioidosis Study: a 30–year prospective, observational investigation. Lancet Infectious Disease 21(12), 1737–
1746.

82 Queensland Department of Health (2017) Melioidosis in Queensland 2012–2016. <https://www.health.qld.gov.au/__data/assets/pdf_file/0026/671183/
melioidosis-qld-2012-2016.pdf> (accessed 17 May 2024). 

83 OzFoodNet Working Group (2021) Monitoring the incidence and causes of diseases potentially transmitted by food in Australia: Annual report of the 
OzFoodNet network, 2013–2015. Communicable diseases Intelligence (45); OzFood Working Group (2022) Monitoring the incidence and causes of disease 
potentially transmitted by food in Australia: Annual report of the OzFoodNet network, 2017. Communicable Disease Intelligence (46). 

84 Australia National University (2022) The annual cost of foodborne illness in Australia. <https://www.foodstandards.gov.au/sites/default/files/publications/
Documents/ANU%20Foodborne%20Disease%20Final%20Report.pdf> (accessed 14 May 2024); Hall et al. (2008) Estimating community incidence of 
Salmonella, Campylobacter, and Shiga toxin-producing Escherichia coli infections, Australia. Emerging Infectious Disease 14(10), 1601–1609. Queensland 
Health Department (2017) Foodborne disease outbreaks. <https://www.health.qld.gov.au/clinical-practice/guidelines-procedures/diseases-infection/
diseases/foodborne/outbreaks> (accessed 14 May 2024).

85 Milazzo et al. (2015) The effect of temperature on different Salmonella serotypes during warm seasons in a Mediterranean climate city, Adelaide, Australia. 
Epidemiology and Infection 144(6) 1231–1240; Zhang Y, Bi P, Hiller JE (2010) Climate variations and Salmonella infection in Australian subtropical and 
tropical regions. Science of The Total Environment 408(3), 524–530.



4 Priority needs for further 
analysis

A range of research activities and analyses are needed 
to better understand climate impacts on communicable 
diseases within the Australian context. Examples were 
developed in collaboration with consulted stakeholders 
and fall under four broad objectives: understanding climate 
sensitivity, predicting disease incidence, projecting health 
and health system impacts, and monitoring, detection and 
surveillance (see Figure 5). 

Activities that target these objectives can inform 
each other, ideally forming an ongoing cycle of data 
collection and insight gathering that ensures the nation’s 
prioritisation of communicable disease risk is responsive 
to the ever-evolving global context. Each of these activities 
can inform the structure, weightings, and ratings of the 
prioritisation framework presented in Section 3 and should 
link with upstream disease prevention activities and 
downstream outbreak response activities. 

Figure 5: Summary of further research and analysis needs grouped by objective. 

While these activities are all important for informing 
comprehensive national risk assessments, those most 
frequently raised in stakeholder consultations, and with 
the potential to provide valuable short-term insights, fall 
under the monitoring, detection and surveillance objective. 
These could be considered nearer term priorities for 
establishing a strong foundation for the other activities. 
This section provides an overview of three forms of analysis 
that were suggested within this context. Further research 
and analysis examples that map to the other objectives 
from Figure 5 can be found in Appendix A.3. 

Understanding climate 
sensitivity

• Pathogen sensitivity
• Vector sensitivity
• Zoonotic sensitivity
• Host sensitivity


Predicting disease incidence

• Modelling changing 
climate and disease


Projecting health and health 
system impacts

• Disease burdens 
• Healthcare demand
• Economic costs


Monitoring, detection and surveillance

• Prioritisation framework rating validation 
• Preliminary scoping of a national vulnerability, capacity and adaption assessment
• Early warning detection system needs assessment




Prioritisation framework rating 
validation

While this discussion paper is a start, the assessment 
of 93 communicable diseases against the prioritisation 
framework in Section 3 was developed rapidly for 
discussion purposes only. More robust analysis and 
validation of the disease assessments against the criteria 
is needed to build a sufficient evidence base for the 
prioritisation of national policy and investment decisions. 

Comprehensive assessment could help guide 
evidence-informed investments in health service delivery, 
adaption efforts, infrastructure, information systems, 
and workforce education and skills to support Australia’s 
resilience against future communicable disease risks. 
The results of more robust analysis and validation 
could also inform a national vulnerability, capacity and 
adaptation assessment, and identify priority diseases for 
the development of early warning systems. 

Rating validation could be undertaken by comprehensively 
assessing each criterion from Section 3 for each of the 
93 communicable diseases through further desktop 
research and validation from Australian communicable 
disease experts. This validation process could also involve 
expanding the analysis to capture non-communicable 
infectious diseases (e.g., tetanus or legionellosis), as well 
as diseases that are not notifiable or frequently reported 
in notable climate health literature. 

Preliminary scoping of a national 
vulnerability, capacity and 
adaptation assessment

The National Health and Climate Strategy notes the intent of 
the Australian Government to undertake a National Health 
Vulnerability, Capacity and Adaptation (VCA) Assessment, 
starting with an analysis of the Health and Social Support 
System within the National Climate Risk Assessment.86 
VCA assessments are a useful tool for holistically evaluating 
a nation’s capacity to manage the impacts of climate 
change on health and wellbeing, and can be used to 
consolidate the outputs of a breadth of analyses into a 
single coherent national narrative and plan. 

To inform the planning process of the National Health 
VCA Assessment, an initial piece of work could involve 
adapting existing frameworks and guidance to the 
Australian context. A particularly relevant example is the 
World Health Organization’s Vulnerability and Adaptation 
Framework,87 which several countries have used as a guide 
for assessing the impact of climate on all health conditions. 
The framework provides guidance on assessing the current 
burden of climate sensitive health outcomes, the capacity of 
health systems to manage these burdens, baseline analysis 
against which changes in disease risks and protective 
measures can be monitored, and pairs risk assessments with 
policy-relevant insights and actions for addressing current 
and future risks. 

Adapting existing frameworks to the Australian context 
would require consideration of the geographic, 
demographic and climatic diversity of Australia, as well 
as the wide variation in health system capacity and 
capability. This Australian-specific VCA framework could 
then be tested and refined through the rapid assessment 
of a selection of priority communicable diseases, prior to 
national implementation. Outputs from the other analyses 
described in this report could also feed into this process. 
For example, there would be synergies (information 
flows, efficient stakeholder engagement) in conducting 
this analysis alongside the validation of ratings from the 
prioritisation framework. 

86 Australian Government Department of Health and Aged Care (2023) National Health and Climate Strategy. Canberra, Australia. 

87 World Health Organization (2021) Climate Change and Health Vulnerability and Adaptation Assessment. Geneva, Switzerland. 



Early warning system needs 
assessment

Early warning systems provide essential information about 
the likelihood of disease outbreaks before they occur and 
allow for implementation of mitigating activities to reduce 
the impact of a potential outbreak or prevent an outbreak 
entirely.88 The data collected through early warning systems 
can also inform ongoing analyses to ensure Australia’s 
communicable disease risk prioritisation is responsive 
and reflective of evolving global contexts. Early warning 
systems are routinely used for predicting extreme weather 
events and have been adapted across Europe, Africa and the 
Asia‑Pacific to anticipate the emergence of zoonotic and 
vector borne diseases,89 and extreme weather-related food 
and water borne diseases.90 

To identify the highest value early warning system needs for 
Australia, a gap analysis and needs assessment of Australia’s 
surveillance systems could be conducted for the priority 
diseases identified through the other analyses described in 
this section. This could include evaluating existing systems 
across human, animal and environmental sectors, including 
the data collection and processing requirements of each.

88 Hassan OA, Balogh K, Winkler AS (2023) One Health early warning and response system for zoonotic diseases outbreaks: Emphasis on the involvement 
of grassroots actors. Veterinary Medicine and Science 9(4) 1881–1889; National Research Council (US) Committee on Climate, Ecosystems, and Infectious 
Disease (2001) Under the Weather: Climate, Ecosystems, and Infectious Disease. National Academies Press, Washington DC, United States. 

89 European Climate Adapt (2023) Early warning systems for vector-borne diseases. <https://climate-adapt.eea.europa.eu/en/metadata/adaptation-options/
early-warning-systems-for-vector-borne-diseases> (accessed 17 May 2024); Inter-American Institute for Global Change Research: IAI and Wellcome Trust 
(2022) Landscape mapping of software tools for climate-sensitive infectious disease modelling. <https://www.iai.int/admin/site/sites/default/files/
Landscape_mapping_of_software_tools_for_climate_sensitvie_infectious_disease_modelling_0.pdf> (accessed 20 June 2024); Pley et al. (2021) Digital and 
technological innovation in vector-borne disease surveillance to predict, detect, and control climate-driven outbreaks. Lancet Planet Health 5, e739–756. 

90 ENBEL Project (n.d.) Addressing Extreme Weather Related Diarrheal Disease Risks in the Asia Pacific Region Project Page <https://www.enbel-project.eu/
projects-page/award-apr> (accessed 17 May 2024).



Appendices

A.1 Consulted organisations

CSIRO would like to thank the 57 experts from across the following organisations for their contributions to 
the project through interviews and reviews. The insights expressed throughout this report were developed by 
considering the collective views obtained alongside independent desktop research. Insights may not always align 
with the views of the consulted individuals or organisations. This list is not to be interpreted as an endorsement 
or promotion of this report. 

• Australian Climate Service
• Australian Government Department of Agriculture, Fisheries and Forestry
• Australian Government Department of Climate Change, Energy, the Environment and Water
• Australian Government Department of Foreign Affairs and Trade
• Australian Government Department of Health and Aged Care
• Australian Partnership for Preparedness Research on Infectious Disease Emergencies
• Charles Darwin University
• Communicable Diseases Network Australia
• Commonwealth Scientific and Industrial Research Organisation
• Healthy Environments and Lives (HEAL) National Research Network
• Monash University
• NT Health
• OzFoodNet Central
• The Australian National University
• The Climate and Health Alliance
• The Kirby Institute Biosecurity Program
• The Public Health Association of Australia
• The Royal Australian College of Physicians
• The University of Adelaide
• The University of Canberra, HEAL Global Research Centre
• The University of Queensland
• The University of Sydney Infectious Diseases Institute
• The University of Sydney School of Public Health
• The University of Washington
• The University of Wisconsin-Madison




A.2 Assessed communicable diseases

By combining national, state and territory notifiable disease registers,91 notable climate health literature,92 
and insights from consultation with communicable disease experts, a total of 93 communicable diseases 
were identified that represent a potential risk to Australia in 2050. These diseases were assessed in the 
Section 3 analysis. 

• Amoebiasis
• Anthrax (cutaneous and pulmonary)
• Australian bat lyssavirus
• Avian Influenza in humans (HPAI H5N1)
• Barmah Forest virus
• Botulism
• Brucellosis
• Campylobacteriosis
• Candida auris
• Carbapenemase-producing enterobacterales 
• Chancroid
• Chikungunya virus 
• Chlamydial trachomatis infection (trachoma and non-
trachoma)
• Cholera
• Coronavirus Disease 2019 (COVID-19/SARS-CoV-2)
• Creutzfeldt-Jakob disease (all forms)
• Cryptosporidiosis
• Dengue 
• Diphtheria
• Donovanosis
• Echinococcosis (hydatid)
• Flavivirus infection (unspecified; including Alfuy, 
Kokobera, Edge Hill, Stratford, New Mapoon and Zika)
• Gan Gan virus 
• Getah virus
• Giardiasis
• Gonococcal infection
• Haemophilus influenzae type b infection (Hib)
• Hendra virus 
• Hepatitis A
• Hepatitis B
• Hepatitis C
• Hepatitis E
• HTLV-1
• Human African trypanosomiasis (sleeping sickness)
• Human immunodeficiency virus (HIV)
• Influenza
• Invasive group A streptococcal disease (iGAS)
• Japanese encephalitis
• Leishmaniasis
• Leprosy
• Leptospirosis
• Listeriosis
• Lymphogranuloma venereum (LGV)
• Malaria
• Mapputta virus
• Measles


91 ACT Health (2022) Disease surveillance and public health response. <https://www.act.gov.au/directorates-and-agencies/act-health/our-business-areas/
population-health/disease-surveillance-unit> (accessed 17 May 2024); Australian Government Department of Health and Aged Care (2024) List of nationally 
notifiable diseases. <https://www.health.gov.au/topics/communicable-diseases/nationally-notifiable-diseases/list> (accessed 17 May 2024); QLD Health 
(2023) List of notifiable conditions. <https://www.health.qld.gov.au/clinical-practice/guidelines-procedures/diseases-infection/notifiable-conditions/list> 
(accessed 17 May 2024); NSW Health (2024) Disease notification. <https://www.health.nsw.gov.au/Infectious/Pages/notification.aspx> (accessed 17 May 
2024); NT Health (2024) Surveillance and Response Unit. <https://health.nt.gov.au/professionals/centre-for-disease-control/surveillance-response-unit> 
(accessed 17 May 2024); SA Health (2023) Notifiable disease reporting <www.sahealth.sa.gov.au/wps/wcm/connect/public+content/sa+health+internet/
clinical+resources/health+notifications/notifiable+disease+reporting/notifiable+disease+reporting > (accessed 17 May 2024); TAS Department of Health 
(2024) Infectious diseases guides and fact sheets. <https://www.health.tas.gov.au/health-topics/infectious-diseases/infectious-diseases-guides-and-fact-
sheets> (accessed 17 May 2024); VIC Department of Health (2024) Notifiableinfectious diseases conditions and micro organisms. <https://www.health.
vic.gov.au/infectious-diseases/notifiable-infectious-diseases-conditions-and-micro-organisms> (accessed 17 May 2024); WA Department of Health (2023) 
Notification of infectious diseases and related conditions. <https://www.health.wa.gov.au/Articles/N_R/Notification-of-infectious-diseases-and-related-
conditions> (accessed 17 May 2024).

92 Australian Government Department of Health and Aged Care (2023) National Health and Climate Strategy. Canberra, Australia; Centre for Disease 
Control (2024) Climate and Infectious Diseases <https://www.cdc.gov/ncezid/priorities/climate-infectious-disease.html?CDC_AAref_Val=https://www.
cdc.gov/ncezid/what-we-do/climate-change-and-infectious-diseases/index.html> (accessed 17 May 2024); European Centre for Disease Prevention 
and Control (2010) Climate change and communicable diseases in the EU Member States <https://www.ecdc.europa.eu/sites/default/files/media/en/
publications/Publications/1003_TED_handbook_climatechange.pdf> (accessed 17 May 2024); Mora et al. (2022) Over half of known human pathogenic 
diseases can be aggravated by climate change. Nature Climate Change 12, 869–875; UK Health Security Agency (2023) Health Effects of Climate 
Change (HECC) in the UK: 2023 report. Chapter 7. Effect of climate change on infectious diseases in the UK <https://assets.publishing.service.gov.uk/
media/657087777469300012488921/HECC-report-2023-chapter-7-infectious-diseases.pdf> (accessed 17 May 2024); World Health Organization (2024) 
Neglected tropical diseases <https://www.who.int/data/gho/data/themes/neglected-tropical-diseases> (accessed 17 May 2024). 



• Melioidosis
• Meningococcal disease (invasive)
• Methicillin resistant Staphylococcus aureus (MRSA) 
infection/colonisation
• Middle East respiratory syndrome coronavirus 
(MERS‑CoV)
• Mpox (Monkeypox virus)
• Mumps
• Murray Valley encephalitis
• Mycobacterium ulcerans (Buruli ulcer)
• Onchocerciasis (river blindness)
• Paratyphoid fever
• Pertussis (whooping cough)
• Plague
• Pneumococcal disease (Streptococcus pneumoniae)
• Poliovirus infection (poliomyelitis)
• Psittacosis (ornithosis)
• Q fever
• Rabies
• Respiratory syncytial virus (RSV) 
• Rickettsia infection (including spotted fevers and all 
forms of typhus fever)
• Ross River virus 
• Rotavirus infection
• Rubella
• Salmonellosis
• Scabies (crusted)
• Schistosomiasis (bilharzia)
• Severe acute respiratory syndrome (SARS)
• Shigatoxin and verotoxin producing Escherichia coli 
• Shigellosis (shigella) 
• Sindbis
• Smallpox
• Soil-transmitted helminthiases and strongyloidiasis
• Syphilis
• Taeniasis and cysticercosis
• Termeil virus
• Toxoplasmosis
• Trubanaman virus
• Tuberculosis
• Tularaemia
• Typhoid fever
• Vancomycin Resistant Enterococcus (VRE) 
infection/colonisation
• Varicella zoster infection (unspecified; including 
chickenpox and shingles)
• Vibrio parahaemolyticus 
• Viral haemorrhagic fevers (all forms; including 
Crimean-Congo, Ebola, Lassa fever and Marburg viruses) 
• West Nile/Kunjin virus 
• Yaws (endemic treponematoses)
• Yellow fever
• Yersiniosis




A.3 Additional needs for further 
analysis 

This appendix provides additional examples of research and 
analysis activities that can advance national understanding 
around the impact of climate on communicable disease 
risk. They were developed in collaboration with consulted 
stakeholders and are not intended to be an exhaustive list. 
They do not cover all concepts listed in Figure 5. 

Planning discrete projects that map to these concepts 
will require tailoring for key variables including disease, 
climate projections, epidemiology, and geography, and 
consider cultural, behavioural, economic, and genetic 
differences across communities. Efforts should also draw 
on multisectoral and transdisciplinary expertise and utilise 
One Health approaches, recognising the interconnection 
of human, animal and environmental health. Additionally, 
indirect factors of climate change, like the social and 
environmental determinants of health, socioeconomic 
impacts, food security, population demographics and 
mental wellbeing should also be considered. 

Understanding climate sensitivity

Pathogen climate sensitivity 

Climate change can induce mutations in pathogens, 
affecting pathogen survival, replication and virulence. 
Conducting analyses to examine mutation rates, their 
location on the genome, and the resulting functional 
change is valuable to understand pathogen sensitivity in 
relation to different climate conditions. 

One approach to exploring pathogen climate sensitivity 
could include utilising machine learning and statistical 
approaches to conduct genome sequence alignments 
of pathogen species from different climates around the 
world. Once correlations between pathogen mutations 
and climate conditions have been identified, these studies 
can then seek to understand the direction and degree to 
which they might impact pathogen survival, replication 
and virulence within the Australian context by focussing 
on Australian-relevant pathogen species, samples and 
climate variables. 

For example, using these methods, CSIRO identified 
340 mutations in the dengue virus that are associated 
with warmer climates (see Appendix A.4 for further detail). 
Of note, most of these observed mutations were in a 
gene previously implicated as temperature sensitive in 
laboratory settings. In contrast, the opposite was observed 
for Salmonella bacteria, where heat resistant mutations 
were not observed in real-world samples. These findings 
highlight the need for more research to better understand 
the mechanisms of how heat might drive mutations in 
pathogens as they may occur differently in laboratory 
settings compared to the real world. 

Vector climate sensitivity – mosquitoes 

Mosquito borne diseases are the most climate sensitive 
of all transmission types (see Section 2). Approximately 
40 species in Australia are known to bite humans and 
can spread disease.93 While some studies have explored 
the impact of climate on Aedes mosquitoes (dengue 
vector),94 and Anopheles mosquitoes (malaria vector),95 
more Australian-specific insights are needed, including for 
Culex mosquitoes (Japanese encephalitis, Barmah Forest 
virus, Ross River virus and Murray Valley encephalitis 
vector). Understanding the impact of climate variables 
on different mosquito species, the diseases they have the 
potential to carry, and inter-species dynamics within the 
Australian context, will be critical for informing priority 
2050 risk assessments. 

A prioritisation framework for mosquito specific pathogens 
has been established within the African context,96 and a 
similar method could be applied to the Australian context. 
These methods utilise expert elicitation to develop a 
ranking of priority pathogens based on a range of criteria 
to measure their risk and impact on socioeconomics and 
human health. 

New analysis should integrate data from field surveillance, 
modelling and laboratory experiments on field-collected 
mosquitoes to assess the impact of climate changes on 
mosquito fitness, population abundance, and vectorial 
capacity. The resulting transmission models and data 
could then be used to validate the mosquito species that 
pose high risk to Australia, and the relevant diseases. This 
will help identify at-risk regions and inform early warning 
systems to support targeted surveillance and interventions. 

93 Claflin SB, Webb CE (2015) Ross River Virus: Many Vectors and Unusual Hosts Make for an Unpredictable Pathogen. Public Library of Science Pathogen 11(9), 
e1005070.

94 Rezza G (2024) Climate change and the spread of Aedes mosquito-borne viruses in Europe. Pathogen Global Health. 1–2. 

95 Siraj et al. (2013) Altitudinal Changes in Malaria Incidence in Highlands of Ethiopia and Colombia. Science 343(6171), 1154–1158. 

96 Hayes et al. (2020) Structured prioritisation of human and animal pathogens for the purpose of scoping risk assessments of genetic control strategies for 
malaria vectors in sub-Saharan Africa. CSIRO, Hobart, Tasmania. 



Zoonotic climate sensitivity 

Over 60% of infectious diseases in humans have originated 
in animals,97 and some recent outbreaks of diseases in 
Australia have been zoonotic in origin, such as COVID-19 
and Mpox. Further, many vector borne diseases also rely 
on one or more intermediary animal hosts. Understanding 
the impact of climate on animal distribution, ecological 
change (including change in land use) and animal to human 
transmission is crucial for predicting the risk of current and 
novel zoonotic diseases. 

Analysis in this field involves integrating ecological, 
biological and climatic data to understand how climate 
changes influence the transmission dynamics of zoonotic 
diseases.98 One method of analysis is ecological niche 
modelling, which models current habitat suitability 
based on several factors including climate data, to 
estimate the geographic distribution of animal species. 
Future geographic distributions can be determined 
based on current habitat suitability and projected climate 
changes.99 Outcomes of this analysis can highlight regions 
in Australia that are expected to experience changes 
in animal populations and consequently the diseases 
they carry. 

This analysis can be conducted in tandem with zoonotic 
spillover modelling to quantify the likelihood of spillover 
risk (when an infectious agent jumps from an animal host 
to a human) in high priority animal and disease ecology 
hotspots.100 This method considers factors such as human 
population density and zoonotic virus diversity to estimate 
the spatial distribution of spillover risk. This spillover risk 
can be correlated with climatic variables and projected to 
various climate scenarios in 2050. Efforts could focus on 
high-risk pathogen families known to cross into humans, 
such as coronaviridae, flaviviridae, orthomyxoviridae, 
paramyxoviridae and togaviridae.101 These approaches are 
critical to ensure Australia is well prepared for diseases that 
the nation is yet to have experienced. 

Predicting disease incidence

Modelling changing climate and disease 

Once robust climate sensitivity data exists for pathogens 
of interest and their vectors, hosts and reservoirs, disease 
projections will require consideration of Australia’s unique 
geographic and climate variability, and how these factors 
change over time. Currently, literature in this field is limited 
to discrete regions in Australia and for limited diseases. 
Comprehensive analyses that encompass all Australian 
regions and address all priority diseases are needed to 
better inform national risk. 

Statistical and process-based spatio-temporal models 
offer these forms of analyses. Spatio-temporal models 
use disease incidence and climate variables, while 
accounting for additional factors that influence disease 
transmission. These factors include geographic location, 
vectors and animal reservoirs distribution, intermediate 
hosts distribution, seasonality, lag time effects, the effects 
of existing medical countermeasures and mitigation 
strategies, herd immunity, socioeconomic status and 
demographic shifts. By modelling these variables to 
projected climate scenarios, spatio-temporal analyses can 
provide a more holistic and accurate projection of disease 
incidence and geographic spread across Australia to 2050. 

97 Ellwanger JH, Chies JAB (2021) Zoonotic spillover: Understanding basic aspects for better prevention. Genetics and Molecular Biology 44(1 suppl), 
e20200355. 

98 Gibb et al. (2020). Ecosystem perspectives are needed to manage zoonotic risks in a changing climate. BMJ 371:m3389, 1–7.

99 Graham et al. (2019). Climate change and biodiversity in Australia: a systematic modelling approach to nationwide species distributions. Australian Journal 
of Environmental Management 26(2), 112–123.

100 Golchin et al. (2024) Prediction of viral spillover risk based on the mass action principle. One Health 18 (100737); Plowright et al. (2024) Ecological 
countermeasures to prevent pathogen spillover and subsequent pandemics. Nature Communication 15 (2577). 

101 CSIRO Futures (2022) Strengthening Australia’s Pandemic Preparedness: Science and technology-enabled solutions. CSIRO, Canberra. 



Projecting health and health system impacts

Projecting disease burdens 

Many analyses focus on the correlation of climate and 
disease, but there is a gap in understanding how much of 
the burden of communicable diseases can be attributed 
to climate changes. By quantifying the burden of 
communicable disease due to key climate variables, health 
systems can more appropriately prioritise efforts based on 
projected climate conditions. 

Future burden of disease analyses could focus on priority 
communicable diseases that lack burden of disease data 
(e.g., dengue, melioidosis, cryptosporidiosis), addressing 
the gaps as outlined in the Australian Institute of Health 
and Welfare’s Climate and Environmental Health Report.102 
Inputs of this analyses could include climate risk factors as 
well as additional variables that influence burdens of disease 
such as acuteness, existing medical countermeasures, 
socioeconomic status, and demographic shifts. These 
analyses can model disability-adjusted-life-years (DALYs), 
years of life lost (YLLs) and years lived with disability (YLDs) 
data to different climate variables over time. Once a baseline 
relationship between burden of communicable disease 
and climate conditions is established, these models can 
project the associated burden of communicable diseases 
for different climate scenarios in 2050. 

Projecting healthcare demand

Several forms of healthcare demand are linked to climate. 
One example being hospital and intensive care unit 
admissions for respiratory conditions which show a 
correlation with climate changes.103 Understanding the 
climate variables that are linked to health care demand for 
communicable diseases can help to assess future healthcare 
demand and effectively prepare the Australian healthcare 
system for the challenges anticipated in 2050. 

These analyses could involve using historical hospital 
admission and primary health care demand, climate 
forecast and climate projection data to model the 
relationship between climate variables and health system 
demand for various communicable diseases and potential 
outbreak scenarios. These analyses can be region, disease, 
and time specific, and can be applied to project the demand 
for a range of health services including primary healthcare, 
specialist and hospital services. 

Projecting economic costs

Climate change will likely increase the incidence of many 
communicable diseases, increasing the associated economic 
cost in the future. There is a lack of modelling outputs on 
the current indirect economic costs of many communicable 
diseases, although there are comprehensive data on 
the direct health system spending for various diseases 
across Australia.104 While previous studies assessed the 
economic costs of select diseases,105 they have not covered 
the full spectrum of communicable diseases in Australia. 
Understanding the current economic cost to Australia for 
priority communicable diseases, their projected incidence 
in 2050 due to climate change, and the economic cost of 
different outbreak scenarios, is critical to helping prioritise 
investments and preventative measures. 

The economic cost of communicable diseases under 
a baseline global warming scenario in 2050 could 
be estimated by applying the projected burden of 
communicable diseases (measured as DALYs, YLLs and YLDs) 
to the current economic cost of that disease. Costs should 
include direct costs (e.g., public health expenditures) and 
indirect costs (e.g., absenteeism, workplace productivity, 
government subsidies, the cost of DALYs and change in 
tourism). Future economic costs could then be estimated 
based on projected disease burdens for different scenarios. 

102 Australian Institute of Health and Welfare (2024) Climate change and environmental health indicators: reporting framework. Australian Government, 
Canberra. <https://www.aihw.gov.au/reports/environment-and-health/climate-change-and-environmental-health-indicators/summary> (accessed 22 May 
2024)

103 Poon et al. (2023) Projecting Future Climate Impact on National Australia Respiratory-Related Intensive Care Unit Demand. Heart Lung and Circulation 32(1), 
95–104.

104 Australian Institute of Health and Welfare (2023) Health system spending on disease and injury in Australia, 2020-21. <https://www.aihw.gov.au/reports/
health-welfare-expenditure/health-system-spending-on-disease-and-injury-in-au/contents/summary> (accessed 17 May 2024).

105 Crosland et al. (2019) The economic cost of preventable disease in Australia: a systematic review of estimates and methods. Australian and New Zealand 
Journal of Public Health. 43(5), 484–495; PwC (2015) Weighting the cost of obesity: A case for action.



A.4 Pathogen climate sensitivity 
– applied research findings

As outlined in Appendix A.3, analysing pathogen sensitivity 
to changing climate conditions will be valuable in informing 
the ongoing assessment and prioritisation of communicable 
disease risks in Australia. To demonstrate methodologies 
that could contribute to this form of analysis, CSIRO 
researchers studied the link between genetic mutations 
and temperature for influenza, dengue and Salmonella. 

Two separate methodologies were explored: (i) machine 
learning to identify heat sensitive mutations, and (ii) 
statistical analysis for validating laboratory insights with 
Australian samples. The intent of these analyses was to 
better understand the suitability of these approaches and to 
identify challenges within the data or the approach that will 
need to be addressed to apply the methodologies to other 
diseases or conduct further analysis that can validate causal 
relationships. 

Machine learning to identify heat 
sensitive mutations

Before studies can explore the transmission risk impacts 
of temperature and temperature related mutations, 
it is first necessary to identify temperature sensitive 
mutations. CSIRO researchers designed machine learning 
algorithms to identify temperature sensitive mutations 
from the genomes of influenza and dengue. This involved 
pairing global pathogen genomic data sets with global 
temperature data sets. 

For dengue, 340 temperature sensitive mutations 
were identified that would be suitable candidates for 
causality and impact related analyses. Consistent with the 
literature, these are clustered in a specific genomic region 
(NS5), which was previously implicated in temperature 
sensitive mutations.106 For influenza, similar patterns 
of mutation were found across regions with varied 
average temperatures. It is likely that considering average 
temperature alone is too simplistic for this disease. 
Previous research has indicated several other factors 
associated with influenza mutations that may need 
to be controlled for, including minimum temperature, 
precipitation, social development index, and population 
density.107 However, more quality sample data is needed, 
especially from warmer climates (average temperatures 
above 25oC). Without more balanced sample data, it is 
difficult to identify statistically significant differences 
between hot and cold climates.

These results indicate that the machine learning algorithms 
are proficient at navigating vast data series to detect 
temperature sensitive mutations and can be used to identify 
promising candidates for further investigation across a wide 
range of diseases. These candidates may also be suitable for 
surveillance activities. 

Researchers also attempted to examine Salmonella using 
this approach but were unable to do so due to the time 
taken to convert relevant data into its necessary form. 
Tools for converting assembly information to standard 
mutation data are needed to apply this machine learning 
approach to Salmonella. 

The next step for the analysis would be to investigate the 
functional effects of the mutations. Understanding how 
the mutations impact the pathogen (e.g., strengthening the 
cell wall) can inform medical countermeasure development 
(e.g., developing antimicrobials that target these features). 

106 Alcaraz-Estrada et al. (2010) Construction of a dengue virus type 4 reporter replicon and analysis of temperature-sensitive mutations in non-structural 
proteins 3 and 5. Journal of General Virology, 91(11), 2713–2718; Cheng et al. (2022) Impact of intrahost NS5 nucleotide variations on dengue virus 
replication. Frontiers in Microbiology 13, 894200. 

107 Jiang et al. (2020) Could Environment Affect the Mutation of H1N1 Influenza Virus? International Journal of Environmental Research and Public Health 17(9), 
3092. 



Statistical analysis for validating laboratory 
insights with Australian samples

Validating laboratory derived hypotheses around 
temperature sensitivity requires detecting the phenomena 
in the wild. A 2024 study identified 14 mutations in 
Salmonella associated with increased growth at higher 
temperatures in a laboratory setting.108 CSIRO researchers 
aimed to identify the presence of these mutations 
(or analogous mutations) in Australian Salmonella samples 
and evaluate whether their emergence correlated with 
environmental temperature changes. 

Upon analysis, no direct link was observed between these 
specific mutations and the yearly average temperature of 
Australia. This suggests that if Australian Salmonella strains 
adapt to heat, they may achieve this through currently 
unreported mutations. One of the implicated genes, dnaj, 
was however found to accumulate mutations at a higher 
rate than comparative regions in the Salmonella genome. 
This may be indicative of increased selection pressure 
warranting further analysis. Future studies could aim to 
incorporate more fine grain temperature information and 
a more in-depth quantification of mutations; potentially 
expanding to global Salmonella samples. 

One challenge experienced was that evolutionary speed 
makes it difficult to obtain a common reference genome 
and therefore difficult to compare the locations between 
strains. As such, a reference free approach may be more 
appropriate for Salmonella data.

108 Berdejo et al. (2024) Evolutionary trade-off between heat shock resistance, growth at high temperature, and virulence expression in Salmonella 
Typhimurium. American Society for Microbiology 15(3), e3105–3123. 



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+61 3 9545 2176
csiro.au/contact
csiro.au

For further information

Greg Williams
Associate Director, CSIRO Futures
+61 03 9545 2138
greg.williams@csiro.au 
csiro.au/futures