The most serious flu pandemic should immediately prompt strict isolation measures, including sending students home from school for up to three months and quarantining households with sick members, according to new federal guidelines issued Thursday.
Because it would take four to six months to prepare a vaccine to protect against a pandemic flu, the guidelines are considered critical to restricting the virus in the interim.
The next best thing to a vaccine "is to try slow down the spread and buy some time," said Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention.
The guidelines were created in part because of continuing concerns over bird flu, which has spread through Asia, Europe, the Middle East and parts of Africa. The virus, which so far rarely infects humans, has not been detected in North America.
The guidelines from the CDC and the Department of Health and Human Services rank the severity of flu epidemics like hurricanes.
The most serious type of outbreak, a Category 5, would be on par with the 1918 Spanish flu pandemic, which killed tens of millions of people worldwide. Such pandemics would call for the most severe measures, including postponing or canceling public gatherings, such as sport and theatrical events; closing child-care centers; and staggering work schedules to thin out crowded offices.
A regular seasonal flu, which has a fatality rate of less than 0.1%, would be a Category 1. The guidelines' only recommendation is that sick people voluntarily stay home until they recover, possibly up to 10 days.
"This seems like a reasonable response," said Dr. David Pegues, a hospital epidemiologist who wrote UCLA Medical Center's pandemic flu plan. "There had not been a threshold in place for when to cancel a hockey game or a Lakers game."
Local health officials would have the ultimate authority to implement the measures, but the CDC recommended that the first cluster of confirmed cases in a state or region trigger a quick reaction.
The definition of a region is intentionally nebulous, said Dr. Marty Cetron, who helped develop the guidelines at the CDC.
"L.A. may be more connected to Hong Kong than some suburban areas," he said. "If there's an epidemic in Hong Kong that feels like an immediate threat, then L.A. officials can consider that a trigger."
Dr. Jonathan Fielding, Los Angeles County's public health director, said guidelines appeared to be appropriately measured.
"We always want to err on the side of caution," he said. "This document, on first reading, appears to do that."
But he said the restriction could cause some serious social and economic problems.
A poll by the Harvard School of Public Health conducted in conjunction with the report found that 57% of people surveyed said they would have serious financial problems if they had to miss work for more than a month. About a third said they would ignore the restrictions if their employers asked them to come to work.
Ninety-three percent of adults said that if schools and day cares closed for a month, they could arrange for child care, but about 60% said that at least one employed person would have to stay home to provide the care.
Economic concerns led to the notable omission of travel restrictions, Cetron said.
"The trucks that cart the chlorine we need to purify water may have to move across state lines," he said. "We want to preserve the functioning of civil society and work to the extent possible.... If we are in the setting of a Category 5, then we can reevaluate."
(BEGIN TEXT OF INFOBOX)
Storm-like ratings for outbreaks
New federal guidelines rank flu epidemics from Category 1 to 5 and recommend community actions.
Recommendations: Keep ill
people at home until they are no longer contagious, about seven to 10 days; treat them with
antiviral drugs if available.
Potential U.S. deaths: Fewer than 90,000.
Example: A typical flu season.
voluntary quarantine of
households with ill people;
dismiss students from schools; postpone or cancel large public gatherings, such as sporting
and theatrical events; modify workplace practices, including encouraging telecommuting and staggered schedules.
Potential U.S. deaths: 90,000 to 450,000.
Example: Asian flu pandemic
of 1957 and Hong Kong flu
pandemic of 1968.
Recommendations: Same as
Potential U.S. deaths: 450,000 to 900,000.
students from schools and close child-care programs for up to three months; reduce contact among children and teens in the community.
Potential U.S. deaths: 900,000 to 1.8 million.
Recommendations: All of the above.
Potential U.S. deaths: 1.8 million or more.
Example: Spanish flu pandemic of 1918.
Sources: Department of Health and Human Services, Reuters and Times research
Los Angeles Times