Researchers model avian flu outbreak, impact of int...( ng countries. It tested the effectivene...),Health

The results suggest that an international stockpile of 3 million courses of flu antiviral drugs, combined with other interventions, could contain a pandemic. Treating infected individuals and everyone in their vicinity, along with closing schools and workplaces, could have more than a 90 percent chance of stopping the spread of a pandemic virus, according to the model. Ferguson emphasized that successful containment would depend on the early detection of the first cases and the rapid implementation of public health measures.

The model described in Science simulated 500,000 people living in rural Southeast Asia and relied on information about how those individuals move within their communities. Containment strategies included giving antiviral medication to people in the same social networks, vaccinating before an outbreak with a vaccine that is not well matched to the strain that emerges, quarantining the houses or neighborhoods of infected people, and combinations of these approaches.

Giving a low-efficacy vaccine to just half the population before the start of a pandemic would greatly enhance the success of other containment strategies, according to the model. Longini reported that a combination of targeted antiviral treatment and quarantine introduced two weeks after the first case had the potential to successfully contain disease spread, resulting in less than one case per 1,000 people.

Both models demonstrated that the need for additional public health measures greatly increased as the virus became more contagious. "Each measure can have a significant effect, but it can't contain spread on its own," said Ferguson, adding that targeted antiviral treatment was a crucial componen
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Contact: Emily Carlson
carlsone@nigms.nih.gov
301-496-7301
NIH/National Institute of General Medical Sciences
3-Aug-2005