Bird Flu Could Be Stopped -- If Everything Is Aligned Right
Thursday, August 4, 2005
An emerging bird flu pandemic with the potential to kill millions of people around the world could be nipped in the bud if it were discovered within a week or so of its initial eruption and battled intelligently with drugs and quarantines, according to the first computer models to show how the disease would spread and what it would take to stop it.
The computations offer a modicum of hope amid a din of alarming predictions about the catastrophic outbreak now thought to be brewing in South Asia.
"The models show that if you combine well-directed, targeted treatment with some social interventions like closing schools, ideally together with some vaccination, it's conceivable you'd be able to stop the epidemic," said Anthony S. Fauci, chief of infectious diseases at the National Institutes of Health, which funded much of the work through its National Institute of General Medical Sciences.
But the odds of success are tempered by many "ifs," Fauci and others warned.
The plan would work only if authorities recognized very quickly that the flu virus had morphed into the contagious form that can trigger a pandemic.
It would work only if health officials around the world immediately shipped to the outbreak area as many as 30 million tablets of the one medication scientists expect could be helpful.
It would work only if local agencies managed to distribute those drugs to the vast majority of people who may have had recent contact with the victims -- schoolmates and workmates at a minimum but, better yet, anyone who may have gone to the same restaurants, ridden the same buses, or shopped or prayed in the same venues.
And it would work only if most residents over a potentially sprawling region obeyed orders to stay home as the emergency blossomed.
"If we get to the point where there are thousands of cases, we just have no chance of containing it," said Neil M. Ferguson of Imperial College in London, lead author of one of the studies, which appears in today's issue of the journal Nature.
"Basically, you contain it at the source or you fail," agreed Ira M. Longini Jr., a biostatistician at Emory University's Rollins School of Public Health in Atlanta, who led the other study, published in today's online edition of the journal Science.
At issue is the H5N1 strain of avian flu virus that is spreading among birds and other animals in Asia. Of more than 100 people reported to have been infected in the past 18 months, about half have died. But the virus has the potential to cause global devastation if, as many scientists expect, it gains the ability to spread easily from person to person.
No vaccine exists against the virus, though experimental versions are being raced into development. The one drug that seems able to prevent infection and reduce the virus's spread is oseltamivir (sold as Tamiflu). More than two dozen countries and the World Health Organization (WHO) are stockpiling the drug. But supplies are so limited that it would be impossible to treat everyone in the event of an outbreak.