Australian doctor awarded for uncovering smallpox bioterrorism risk

Sep 18 2007

A University of Sydney professor who developed a system to combat bioterrorism has received a major award from the US military.

Professor Raina Maclntyre has won the 2007 Sir Henry Wellcome Medal and Prize from the Association of Military Surgeons of the US (AMSUS) for developing the world's first system to comprehensively rank the different types of bioterrorism risks - an honour for a non-US and non-military person.

Professor Maclntyre's risk-priority scoring system for the most severe (category A) bioterrorism agents, published in the journal Military Medicine, will help governments prepare for potential attacks.

"Traditionally government decisions about the risk of attack by a particular agent have been made simply on the basis of the probability of attack," said Professor MacIntyre, from the University's National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases and the Faculty of Medicine.

"We hypothesised that multiple factors should be considered other than probability of attack - including the severity of an attack's consequences, the potential for person-to-person transmission, the potential for an agent to genetically modify, the relative ease of decontamination, and the availability of vaccinations."

Professor MacIntyre and her team exhaustively reviewed the history of bioterrorist incidents, the known science about each agent, and the transmission potential of each category A agent. Synthesising this information into a matrix of 10 different categories of threat allowed them to create a "priority score" for each agent.

"We found that anthrax and smallpox are the highest priority, followed by viral haemorrhagic fevers, botulism, plague and tularaemia," she said. "Anthrax topping the list is not a surprise, because it is widely available globally and easy to weaponise, but smallpox scoring highly is a surprise."

The high priority for smallpox flies in the face of the low priority governments have given to it on the basis of probability of attack alone, according to Professor MacIntyre. Although the global supply of the smallpox virus is limited, it has high person-to-person transmission rates, high fatality rates, and it has the potential for high numbers of infections and to be genetically modified into more virulent strains.

"Governments will benefit from this research in that it provides a framework and a tool for rationally and efficiently assigning priority for bioterrorism agents - and therefore planning stockpiles of drugs, vaccines and other supplies," Professor MacIntyre said.

Professor MacIntyre will receive the award in November at the AMSUS conference in Salt Lake City.

Background notes on bioterrorism:

The use of biological agents ("Biowarfare", "bioterrorism") dates back at least to 300 B.C, when the Greeks, Romans and Persians used cadavers to contaminate the water supplies of their enemies.

The Japanese used biowarfare with plague and anthrax agains the Chinese in Manchuria in the 1930s and 1940s. The former Soviet Union had an unparalleled bioweapons program which developed sophisticated weaponised anthrax, plague, smallpox and viral heamorrhagic fevers, and continued large scale work well into the 1990s despite signing the Biological Weapons Convention.

Bioterrorism is still a concern - in 2001 in the USA, anthrax spores were mailed to several cities and resulted in 11 cases of inhalational anthrax and five deaths. The economic consequences of this attack were disproportionate to the number of cases, with the shut-down of essential services such as the US Postal Service.

Potential bioterrorist agents are classified by there severity into category A (the most severe) and category B (less severe). Category A agents include anthrax, smallpox, tularaemia, plague, botulism and viral hameorrhagic fevers (eg. Ebola and Marburg viruses).