CDC releases pandemic flu preparedness plans

March 2007

Updated pandemic flu preparations, from closing schools and workplaces for up to 12 weeks to categorizing outbreak severity, were unveiled last month by the CDC and the Department of Health and Human Services.

“Pandemic flu is not necessarily imminent, but we believe it is inevitable,” Mike Leavitt, Secretary of the Department of Health and Human Services, said during a press conference held at CDC headquarters in Atlanta.

Pandemic flu is characterized by rapid, worldwide spread of a new strain of influenza to which people have no immunity. Despite near-doomsday scenarios including high death tolls, food shortages from quarantine restrictions and the social and economic impact of isolation or “social distancing” tactics, officials were quick to report no immediate concern of pandemic flu. Officials did note that avian flu (H5N1) activity is being closely monitored.

“There is a danger that as avian influenza slips from the headlines that people may begin to believe that the threat is no longer real,” Leavitt said. “The media buzz may have died down, but the H5N1 virus hasn’t.”

Officials said pre-planning is the best way to minimize morbidity and mortality in the wake of pandemic flu because a vaccine to match a strain would likely be unavailable for at least six weeks after the virus outset.

Pandemic Severity Index

The next pandemic will be the first assigned a category under the new Pandemic Severity Index, unveiled Feb. 1. The Pandemic Severity Index assigns categories to pandemic flu similar to those assigned hurricanes.

A category one outbreak designation would signify low mortality and morbidity. In contrast, a category five designation would denote high morbidity and mortality and, in turn, greater risk management. A category five pandemic flu would require drastic measures, including closing schools, postponing public gatherings such as baseball games and movies for more than two months, and shifting work schedules to diminish large gatherings of potentially contagious people, according to proposed plans.

To give a historical perspective, a pandemic with the same or more intensity as the 1918 flu pandemic would be classified as a category five; both the 1957 and 1968 outbreaks – which were more localized and less deadly – would be designated category 2 pandemics.

Public policy

Plans for public policy in the wake of pandemic flu were based on information derived from the last three known pandemics in 1918, 1957 and 1968. Researchers used newspaper accounts and other records from 44 cities to identify which prevention measures were most effective.

“We would like to not reproduce some of the lessons of 1918, which is waiting until the bodies and the morality are so high that it is insufferable,” said Martin Cetron, MD, director of the CDC division of global migration and quarantine.

Officials said the most effective measure for minimizing the effects of pandemic flu is preparedness planning. Researchers found that people in areas with plans in place before outbreak fared better when the pandemic hit. Plans for communities are contained in the CDC community mitigation guides.

“The earlier you initiate an intervention, the more likely the intervention is to make a big impact,” said Julie Gerberding, MD, MPH, director of the CDC.

Non-pharmaceutical interventions designed to limit contact between people and reduce disease spread are also part of the detailed preparedness plans devised by the CDC and Department of Health and Human Services. The goal of intervention is to delay disease spread until the best-matched vaccine is developed and distributed.

Planning for a pandemic

An influenza planning tool for states, communities, businesses and schools is available through the CDC, which encourages each group to start planning using mitigation tools designed by experts.

In the most severe pandemic outbreaks, people would be encouraged to stay home from work and anyone with symptoms and members of their households would be asked to remain at home for up to 10 days. Workplaces and schools could be closed for 10 to 12 weeks in the wake of a category 5 pandemic.

Officials said they are aware of a number of economic and social impact problems arising from these tactics, including how long people can survive without working outside the home and who will take care of the tremendous population of contagious and sick. Keeping school-aged children and adolescents away from each other is also of particular concern in pandemic flu planning.

Actions would have to be made uniformly across a community to be effective; every organization, family and individual would need to have a plan, officials said.

Monitoring virus strains worldwide is an important aspect of planning for pandemic flu, according to experts. Although no one is sure what strain will start the pandemic, experts said early intervention based on trigger identification could make a difference in pandemic mortality and morbidity rates.

“We can’t be certain that the H5N1 virus will be the spark of the next pandemic. We can be sure that pandemics happen,” Leavitt said.

Mandatory flu shots

The Infectious Disease Society of America is also advocating proactive measures to prepare for the potential of pandemic influenza. Citing estimates that a mild flu epidemic could kill 100,000 to 250,000 Americans and a severe pandemic could kill 2 million Americans, the IDSA urged all physicians, nurses and other health care workers to get vaccinated for influenza. The goal of the recommendation is to plug a critical weakness in the nation’s flu preparations, according to IDSA officials.

IDSA further issued a call to Congress to consider the health care worker vaccinations as part of influenza pandemic preparation legislation. Each year fewer than two in five health care workers get flu shots, according to IDSA.

“It’s our professional duty to first do no harm,” Andrew T. Pavia, MD, chairman of IDSA’s National and Global Public Health Committee, said in a prepared statement.

For more information:

• Additional information about pandemic influenza is available online at www.pandemicflu.gov.