March 22, 2006
School Closings May Not Work in Bird Flu: Study
By Jim Loney
ATLANTA - Closing schools may not help contain the spread of bird flu or other potentially pandemic illnesses, according to U.S. research released on Tuesday.Public health officials are considering school closings, cancellation of big gatherings such as sports events and concerts and other methods to limit contact among people and control the spread of avian influenza.
Urging people to stay at home if they or someone in their household is sick is likely to work better, according to the statistical study unveiled at the International Conference on Emerging Infectious Diseases. The conference, held in Atlanta, brought together experts from some 80 countries.
The H5N1 avian influenza has killed 103 people, most of them in Asia, and infected nearly 200 since it re-emerged in 2003, giving it more than a 50 percent fatality rate. Health officials around the globe are concerned about the possibility of a pandemic if the virus mutates enough to pass easily from person to person.
Because people lack immunity, it could sweep the world in weeks or months and kill millions of people.
The spread of bird flu has accelerated in recent weeks and it is now found across Asia, in Europe, Africa and the Middle East. It has not been found in the United States but top government officials said on Monday it was increasingly likely to reach U.S. shores this year.
Limited stockpiles of drugs that might work against bird flu and delays in creating vaccines for a fast-changing virus have forced public health officials to consider other methods of slowing its spread.
Using statistics and computer models, U.S. researchers simulated an influenza outbreak in a small urban community of several thousand people, where people made contact in a variety of places where disease could be transmitted, including schools, homes, day care centers, work places and long-term care facilities.
The results suggested that closing schools might simply send children to other places where they could encounter a virus.
"When we assume school closing, it doesn't mean the children are sent home. They will meet at the movies or other places in the community," said Michael Haber, the study's author and a professor in the Emory University Department of Biostatistics. "Children who are not ill may become sick outside the school."
Much more likely to help slow the spread of bird flu and other viruses is home confinement of anyone who is ill or exposed. The study found that under certain circumstances, infection rates could be reduced up to 52 percent and death rates up to 60 percent by home confinement.
"If we can convince people to stay at home in the early stages when they are sick or when someone in their home is sick this is likely to slow the spread," Haber said. "People who are obviously sick should stay at home, and this means not going to school or the workplace."
The study also found that reducing contact between vulnerable people in long-term care facilities could reduce the spread of virus and mortality rates by as much as 60 percent.