AAHL's high containment facility allows work up to the highest designated biosecurity level, physical containment level four (PC4), and includes modern animal facilities that can house a range of animal species.
AAHL is the only laboratory in Australia that can safely handle exotic animal diseases agents, which can pose a major economic threat to the nation’s animal industries and a health threat to animals and humans.
Exotic disease agents are used in the laboratory for:
- researching emergency disease diagnosis
- training veterinarians to recognise diseases they would not normally see.
Procedures and containment facilities at AAHL conform with or exceed the requirements defined in the Australian/New Zealand Standard, Safety in Laboratories, Part 3; Microbiological safety and containment facilities.
A box within a box
Diagram showing AAHL's secure area (click to see larger version).
AAHL’s main building has four levels inside the microbiologically secure barrier. A thick concrete wall forms an airtight ‘box’ around the secure area.
All of this area is held at a lower air pressure than the outside world, to keep any airborne infectious agent inside the laboratory.
Within the secure box are a series of smaller secure boxes, each with a drop in air pressure.
A guiding principle in the design of AAHL is that containment should never be by a single barrier. If one containment system or barrier fails, then at least one other barrier is in place to protect Australia’s livestock.
Better safe than sorry
At AAHL, all physical containment systems are duplicated, and all essential systems, such as electricity generators, steam and compressed air plants, are triplicated. For example, containment would not be at risk from a computer or power failure.
Nothing that goes into the secure area can come out without being decontaminated.
Most things never leave the secure area, but those that do must first be treated:
- the air leaving the building is filtered to remove infectious aerosols
- all sewage is heat-treated and solid waste is incinerated
- equipment leaving the secure area is sterilised by autoclave or gas decontamination
- information is transmitted electronically, as books and papers cannot be removed from inside the secure area
- staff and visitors leaving the secure area must leave behind their laboratory clothes, then shower and exit via a secure airlock. Those wearing glasses must decontaminate them in a chemical solution.
Protecting our staff
Our staff wear special personal protective clothing when working with:
- infected animals that may be excreting viruses potentially fatal to humans. Staff work in whole-body plastic suits that isolate them from the disease hazard.
- agents such as Newcastle disease virus, which humans can carry in the respiratory tract or the eyes. Staff wear breathing-air hoods.
Access to potentially dangerous agents is strictly limited to trained staff who use a range of measures to contain the disease agents.
The personal containment procedures are backed up by compulsory showering out of infected animal rooms and out of the secure area. Once outside the secure area, staff must not have contact with livestock animals for seven days.