April 27, 2006 -- There is no guaranteed safe way to reuse face masks as protection against flu in the event of a pandemic, a government panel's report concluded Thursday.
The conclusion was a mild setback to U.S. efforts to prepare for an influenza caused by the H5N1 bird flu virus or another flu pathogen. Bush administration officials asked for the report to determine whether stockpiles of surgical masks and respirators could be used multiple times to extend their reach during an emergency.
"There is currently no simple, reliable way to decontaminate these devices to enable people to use them more than once," said John C. Bailar, co-chairman of the Institute of Medicine (IOM) panel that issued the report.
Use of facial masks exploded several years ago during a worldwide but limited SARS outbreak. Government planners are worried about having enough of the masks for federal stockpiles and also about likely runs by consumers on retail supplies in the event of a new outbreak. The U.S. government has contracted to purchase 100 million masks for use by health care workers in a pandemic, a spokesperson for the Health and Human Services Department said.
The IOM panel did not address issues of manufacturing capacity, distribution, or the price of masks -- all factors that would likely play an important role in national supplies during an outbreak.
Health workers use a variety of different masks to protect themselves and patients from infections. Standard surgical masks protect well against saliva droplets that can carry flu virus, while more sophisticated "N-95" respirator masks protect against aerosolized viruses floating in the air. Neither protects against viruses transmitted by hand-to-hand contact.
While both kinds of masks can be effective, scientists don't know which transmission routes are the most common for flu. That makes recommending a particular mask impossible, the panel said.
Experts also said that no mask is effective unless it is properly worn, fitting tightly over the face.
Many consumers are also likely to fashion their own masks out of fabric or clothing in the event of an emergency. Experts stressed that washable cloths have not been adequately tested for their ability to block flu viruses.
"The committee hesitates to discourage their use," said Donald S. Burke, a professor of public health at Johns Hopkins University and the panel's other co-chairman. However, "we are concerned that their use may give the users a false sense of protection."
Firms told the committee during deliberations that it would take time to increase their manufacturing capacity. "The answers varied between six months and about two years to boost capacity," said Bailar, an emeritus professor at the University of Chicago.