Would closing offices and schools lessen the severity of a flu pandemic, should one strike the United States? Could isolating infected people in their homes slow the spread of a lethal virus?
During a pandemic, public health and government officials could use a range of potential strategies to try to reduce the spread of infection, including quarantines and other containment interventions at the community level. These interventions form the cornerstone of newly released federal guidelines that advise states and local municipalities on how to proceed until more drugs and vaccines become available. In the event of a severe flu pandemic, schools should close for up to three months and all members of any household with an infected person should stay isolated voluntarily for up to 10 days, the guidelines say.
In December, a report by the Institute of Medicine said communitywide interventions have a role in controlling illnesses and deaths during a pandemic, but it cautioned officials to not overstate the certainty of their effectiveness to the public. Given that these strategies would have negative consequences as well as benefits, community leaders should exercise caution in implementing them, the report adds.
These conclusions emerged from examination of computer models that simulate different actions and forecast their implications, in addition to analyses of historical records on past flu outbreaks. Government officials invoked community containment interventions during previous flu pandemics. In 1918, for example, some city and town leaders closed schools and theaters and banned public gatherings in an effort to keep the pandemic at bay.
Early action has been associated with flatter epidemic curves and may have lowered the peak death rate during previous outbreaks. But at the same time, some cities that took such steps still experienced high rates of illness and mortality.
Computer models can help officials organize available information about a pandemic situation and inform discussions about the options available. However, the models are inherently limited and provide only an aid -- not a roadmap -- for decision-making, the report says.
Reducing exposure to infection through many community interventions will come with a price. For example, closing workplaces could lead to loss of income that would be devastating to families living from paycheck to paycheck. School closures would mean loss of access to free, nutritional meals for some children. The report urged public officials to consider all possible outcomes and use community containment strategies only when the potential benefit outweighs the likely harms. -- Christine Stencel
Modeling Community Containment for Pandemic Influenza: A Letter Report. Committee on Modeling Community Containment for Pandemic Influenza, Board on Population Health and Public Health Practice, Institute of Medicine (2006, 47 pp.; available only on the Internet).
The committee was chaired by Adel Mahmoud, former president, Merck Vaccines, Princeton, N.J. The study was funded by the U.S. Department of Health and Human Services.