N95 Respirators Best Defense Against Flu for Health Care Workers

The Institute of Medicine, or IOM, has endorsed the CDC's recommendation that health care workers who interact with patients with novel influenza A (H1N1) infection or influenza-like illnesses should use fit-tested N95 respirators.

Kenneth Shine, M.D., chairman of the IOM committee that evaluated use of the respirators at the request of the CDC and the Occupational Safety and Health Administration, or OSHA, said in a Sept. 3 news release that well-fitted N95 respirators offer health care workers the best protection against inhalation of viral particles.

He pointed to the report Respiratory Protection for Healthcare Workers in the Workplace Against Novel H1N1 Influenza A: A Letter Report, which found that, when properly fitted to users' faces, N95 respirators are designed to filter out at least 95 percent of particles as small as 0.3 micrometers, which is smaller than influenza viruses.

The report also notes that although some N95 respirators allow a little more than 5 percent particle penetration, they still have protection factors that are eight to 12 times greater than those of traditional medical masks, which do not seal to the face.

"But there is a lot we still don't know about these viruses, and it would be a mistake for anyone to rely on respirators alone as some sort of magic shield," said Shine, who is executive vice chancellor for health affairs at the University of Texas System, Austin. "Health care organizations and their employees should establish and practice a number of strategies to guard against infection, such as innovative triage processes, hand-washing, disinfection, gloves, vaccination and antiviral drug use."

The report notes that human transmission of influenza virus is thought to occur primarily in three ways:

However, the report acknowledges that the relative contribution of each of these possible routes of transmission is unknown and urges that more research be pursued in this area. The report also calls for the design and development of improved protective equipment to enhance workers' comfort, safety and ability to perform their jobs.

Some health care workers may not come to work during a pandemic if they do not feel safe, the report says. Therefore, health care facilities and physician offices should create a culture of worker safety that mirrors their commitment to patient safety. Doing so will require planning; education; personal protective equipment, or PPE; materials; organization; and patient isolation.

"Employees should feel uncomfortable when not wearing PPE during appropriate situations," the report says, "and supervisors should reinforce the importance of PPE and enforce policies so that noncompliance is a rare exception rather than the rule."

The IOM committee did not recommend that all health care workers use N95 respirators; rather, they limited their guidance to workers in initial contact with patients who present with unidentified febrile respiratory illnesses and those in close contact with patients with confirmed or suspected novel H1N1.

The committee focused on the efficacy of the equipment and was not asked to consider issues associated with implementing the recommendations, such as costs and supplies.