Post by Watchman on Apr 5, 2007 11:42:52 GMT -5
Banning public gatherings could save lives in pandemic: study
Shutting down subways and schools, and banning weddings and other gatherings could be the key to damage control in the event of a communicable disease pandemic, two new research studies conclude.
Scientists with their eye on the possible outbreak of a bird-flu epidemic found from studying past practice that by intervening early and aggressively to restrict the public's freedom of movement, they may be able to curb the transmission of a virus in the early phase of an epidemic and buy time for investigators to come up with a vaccine.
The findings come from two analyses of US cities in the 1918 Spanish influenza pandemic that killed 600,000 people in the United States and tens of millions around the world.
The study could provide important lessons for agencies tasked with planning for the next global pandemic.
In 1918, many US cities sought to contain the epidemic by closing schools, theatres, churches and dance halls. Kansas City banned weddings and funerals involving more than 20 people while San Francisco and Seattle ordered their citizens to wear face masks.
But researchers have always puzzled over why the early death toll varied so much between cities which used the same tactics.
Going back over the data, US researchers found that in cities where officials responded to the epidemic early and with numerous bans on social or other gatherings, the peak weekly death rate was about 50 percent lower than it was in cities that responded more slowly.
In St. Louis, the peak mortality rate was one-eighth that of Philadelphia, the worst hit city of all the 17 metropolises included in the survey.
Officials in St. Louis moved with broad public health measures within two days of the first reported influenza cases, while their counterparts in Philadelphia waited two weeks to act.
Most metropolises relaxed the measures after two to eight weeks, in part because of pressure from businesses and tradesmen, according to Richard Hatchett of the National Institute of Allergy and Infectious Diseases, and an author of one of the papers.
As a result, some cities experienced a second peak in mortality, presumably because the first wave was stopped so effectively that once controls were lifted, a substantial number of individuals who had not developed immunity fell ill.
In San Francisco and St. Louis, the controls were imposed early and maintained through January 1919, reducing deaths by an estimated 25 percent, according to researchers at Imperial College, London, and the University of Utrecht.
"Our results show that non-pharmaceutical interventions may substantially slow the spread of a pandemic," said Neil Ferguson, a researcher at Imperial College London, who led the European research team.
"However, if we want these measures to save substantial numbers of lives, they really need to be kept in place until we have enough vaccine to immunize the population."
But he cautioned that there would be "huge social and economic consequences of imposing such measures for the three or more months that would be required for optimal effect."
The World Health Organisation has been bracing for another global influenza pandemic since bird flu first surfaced in Asia in 2004. To date, it has infected 288 people, killing 170, but scientists fear that the H5N1 bird flu strain could mutate into a form more easily spread among humans, leading to a global pandemic with the potential to kill millions.
US authorities have already incorporated many of the lessons of 1918 into planning, drawing up guidelines for closing schools, canceling public gatherings, teleworking strategies and voluntary isolation of cases.
But as one infectious disease specialist noted, much will depend on the political will to make unpopular decisions that could cost the economy a bundle.
"There are good arguments for closing the borders," said John Bartlett, an infectious disease expert at the John Hopkins School of Medicine.
"There are good arguments for closing the New York subway. You don't get much closer to other human beings than you do on the subway, but that would prevent millions of people from going to work, including hospital workers," he said.
"And if you close the schools, how do you prevent the kids from just regrouping at the mall? Maybe you send the parents home from work too so they can keep an eye on the kids. Well, that has an impact on businesses."
"It sounds simple, but it's not simple. It's not easy."
The two studies were funded by the National Institutes of Health, the UK Medical Council and the European Union and appear in the Proceedings of the National Academy of Sciences.
rawstory.com/news/afp/Banning_public_gatherings_could_sav_04032007.html