Limits on Social Contact Helped Fight Flu Pandemic

TUESDAY Aug. 7, 2007 -- In a finding that could save countless lives in the next flu pandemic, U.S. researchers have discovered that such public health measures as quarantines, school closings and bans on public gatherings reduced the death toll in the great influenza outbreak of 1918-19.

A pandemic is feared if a flu strain -- such as avian flu, which has killed some people in scattered outbreaks, primarily in Asia -- mutates so that it passes easily from person to person. Current vaccines and people's immune systems aren't prepared to protect against such a new infectious virus -- exactly the situation that occurred when a new strain called Spanish flu struck the world in 1918-19, killing 40 million people, 550,000 of them in the United States.

"Public health people have been talking about the risk of a flu pandemic for some time," said study lead author Dr. Howard Markel, director of the University of Michigan Center for the History of Medicine. "Even though it's now the 21st century, it would still take roughly six months once a pandemic starts to have enough vaccine manufactured and distributed."

Specialists at the University of Michigan worked with experts at the U.S. Centers for Disease Control and Prevention on non-medical protective measures taken in 43 cities. They studied public health records, newspaper reports and other chronicles of activity from Sept. 8, 1918, through Feb. 22, 1919.

"We paired with CDC to see whether things like quarantines and school closings could do anything to reduce the toll," Markel said. "We traveled through the country, looking at state archives, collecting two newspapers a day from each city and getting information from federal and state sources, combing all of this to create a database on incidence. Lo and behold, we found that those cities that responded earliest and sustained their response did best."

For example, St. Louis closed schools and canceled public gatherings early in the pandemic and maintained those measures for 10 weeks. Statistics showed that St. Louis had a markedly lower number of flu deaths than other cities.

The findings are published in the Aug. 8 issue of the Journal of the American Medical Association.

"Here is something we could apply," Markel said. "These old-fashioned methods hopefully could buy us time until a vaccine could be created and put in the arms of people who need it."

But what worked in the United States of 1918-19 might not work today, said Philip Alcabes, associate professor in the School of Public Health at Hunter College in New York City.

"The world is a dramatically different place," Alcabes said. "We don't have people working in big factories where there are a lot of people under one roof. We commonly use private transportation. We have smaller families. We live in suburbs, where the pathogen is not as likely to be transmitted as quickly as it was then."

The new study is "a very, very good piece of historical epidemiology," Alcabes said. But, he added, "It's not clear that the interventions that were effective against the flu in 1918 are relevant to the preparations we are making today."

Markel countered that the world is not that different in basic ways. Children still have runny noses and poor respiratory habits, people still pass the virus from one to another in the same way. The study provides evidence that basic public health measures can slow that passage of germs, he said.

"No one has even gotten any evidence that it works in the past," Markel said. "You don't want to do a multibillion dollar policy unless you're sure it works."

Guidelines on such measures would be recommended by the federal government and carried out by the states, Markel said. The states are working with the federal government to cover implementation, he said.

More information

A vivid history of the Spanish flu pandemic is supplied by Stanford University.

Posted: August 2007


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