School Closings May Not Slow Flu Pandemic

According to British researchers, closing schools during an influenza pandemic could prevent one in seven cases of flu. The study suggests such action would have less impact than some other estimates.

However, school closings would create significant hardships for working parents, who might be forced to create informal daycare arrangements that would undo efforts to contain the spread of flu.

Dr. Simon Cauchemez of Imperial College London says school closings would be less effective than some studies have suggested.

"The main effect would be to slow and flatten the outbreak””so the numbers becoming ill in the worst week of the outbreak might be reduced by up to 40 percent, reducing peak demand on health-care systems," Cauchemez said.

Most health experts agree that a global epidemic (pandemic) of influenza is well overdue and the most likely strain to create a pandemic is the H5N1 avian influenza, which could evolve into a form that passes easily from person to person.

Vaccines and drugs will not be enough to slow or prevent a flu pandemic, according to government estimates. Closing schools and implementing strategies to limit social contact as a way to limit transmission are the recommendations of the U.S. pandemic plan.

One estimate suggests that, if done quickly, such widespread measures combined with drugs and vaccines might reduce transmission in a large city by as much as 80 percent.

“Such estimates are often based on widely varying assumptions,” Cauchemez said.

He and colleagues instead used public health data from France that compared flu transmission when school was in session and during school holidays.

They found school holidays prevent 16 to 18 percent of seasonal influenza cases.

When extrapolated to a pandemic, they said prolonged school closure might reduce the cumulative number of cases by 13 to 17 percent and peak attack rates by 39 to 45 percent.

"If we want the policy to have an impact, children must be kept relatively isolated and not cared for in groups," Cauchemez said.

One recent study showed that U.S. cities that quickly closed schools and discouraged public gatherings during the great flu pandemic of 1918″”which killed tens of millions of people globally””had as many as 50 percent fewer deaths than cities that took less decisive measures.

“An especially deadly pandemic might provide strong incentives for people to keep their children at home. It might nonetheless be difficult for a lot of working parents to be absent from their work for months to look after their kids," Cauchemez said.

He added: “A prolonged outbreak might force working parents to put their children into informal daycare settings””a risk governments should consider when they formulate pandemic flu plans.”

"We can’t predict how people will behave, but we need to be aware that if this happens, school closings might have no effect at all on flu transmission," he said.

The World Health Organization says H5N1 bird flu has killed 239 out of 379 infected but only rarely infects people now.

However, they say it could easily mutate into a form that one person could pass to another, and governments around the world are preparing for the possibility.