By GREG GORDON
November 18, 2005
The decision, which officials at the Centers for Disease Control and Prevention say is only a first line of defense, is nonetheless drawing sharp criticism from labor unions and some public health experts.
Critics also question the CDC's recommendation that, when in close contact with flu victims, health care personnel wear disposable respirators - the lowest-grade mask that the government certifies as able to filter out toxins and germs.
Hospitals and CDC officials say it's impractical to outfit doctors and nurses with more expensive and unwieldy respirators absent evidence that a virus will remain airborne and infectious for lengthy periods.
Labor unions and some health experts say the risks of disease and of a panic among workers are too great to rely on inexpensive masks, especially given research suggesting virus particles can remain active in the air for hours and can penetrate disposable masks.
"This is a program that will assure that health care workers either get sick or decide not to show up for work because they don't have adequate protection," said Bill Borwegen, health and safety director for the Service Employees International Union, which represents 875,000 medical employees.
Margaret Seminario, the AFL-CIO's health and safety director, warned that the CDC is "laying the seeds for a further disaster" by failing to recommend more protective respirators for criminal frong-line responders.
Officials of the CDC and the Association for Professionals in Infection Control and Epidemiology, a group dominated by hospital officials, stressed that they will take more aggressive steps to protect workers, if needed.
If illness patterns "in an unfolding pandemic suggested that additional steps were warranted, we would certainly ... make changes accordingly," CDC spokesman Tom Skinner said. He said, for example, that workers also could be protected with antiviral medicine, such as the drug Tamiflu.
The respirator controversy draws attention to some of the calculated risks government policymakers have taken in devising a strategy to fight a still-unknown virus feared to be so potent that millions, even hundreds of millions of people could die worldwide.
Until a human-to-human version of the avian flu virus surfaces and spreads, public health officials won't know how deadly it is, the dose needed to transmit disease or how long virus particles stay active.
Mary Ellen Bennett, infection control manager at the Hennepin County Medical Center in Minneapolis and the chair of APIC's public policy committee, said experts "are telling us that there's no evidence to suggest that these (virus particles) would have a different route of transmission than general influenza.
"I think we have to go with what we know now and not go over the deep end," she said.
CDC's comprehensive contingency plan, laid out last week, describes three means in which a flu virus could be transmitted between people: by tiny droplets that travel about 3 feet when a sick person coughs, sneezes or talks; by skin contact with germs, or by inhaling virus particles.
The CDC plan concludes that droplets would be the main avenue for transmission. Since the level of transmission by inhalation was "uncertain" in past flu outbreaks, the plan says, it relies on surgical masks and "N95" disposable respirators certified to filter out 95 percent of microscopic particles.
Two public health experts challenged that thinking.
Mark Nicas, a University of California adjunct associate professor of environmental health sciences, recommended that health care workers be outfitted with powered air purifying respirators (PAPRs), a piece of equipment that can cost $500.
Eugene Cole, a health sciences professor at Brigham Young University, said he would equip most workers with N95s, and those who get within a few feet of flu victims with masks with rubberlike seals that fit more snugly, cost $20 to $35 and are more effective.
At a recent nanotechnology conference in Minneapolis, a University of Cincinnati environmental health professor presented research suggesting that N95s may not be as effective as thought. Sergey Grinshpun said the study showed that some masks that were given an electrostatic charge to improve their efficiency failed to screen out 95 percent of virus-size particles - particles six times smaller than those used to certify the masks.
BYU's Cole said his 1998 study showed that many virus particles will die within seconds of becoming airborne, perhaps via a sneeze or cough, either from drying out or from being exposed to ultraviolet light from the sun. But other particles, drying and shrinking in size, can stay active and suspended in air currents for hours, he said.
Spokeswoman Donna Fleming of Minnesota-based 3M, the nation's leading respirator maker, said that no respirator "eliminates the risk of infection or illness."
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