CDC TB guidelines hit fit-testing roadblock over periodic’ testing

Conflict over annual fit-testing delays release

A firestorm over fit-testing has spilled over to another agency, derailing the release of draft tuberculosis guidelines by the Centers for Disease Control and Prevention (CDC). If CDC recommends "periodic" fit-testing, will that be interpreted as annual fit-testing? If the U.S. Occupational Safety and Health Administration (OSHA) requires annual fit-testing, should the TB guidelines be consistent with that?

"If that word [periodic] is maintained, I believe OSHA will have the definition tied up," Rachel Stricof, MT(ASCP), MPH, an epidemiologist who is a liaison member of the Advisory Council for the Elimination of Tuberculosis (ACET), told another CDC advisory panel. "Periodic will equal annual."

Even within CDC, those issues and others are being hotly debated as hospitals await the updated guidelines. Representatives from CDC’s TB division, division of healthcare quality promotion (which deals with infection control), and the National Institute for Occupational Safety and Health (NIOSH) are meeting to work out differences in wording the guidelines.

The agency first is looking into the source of the disagreement, Denise Cardo, MD, director of the division of healthcare quality promotion, told the Healthcare Infection Control Practices Advisory Committee (HICPAC), an expert advisory panel. "If it’s because of a lack of data, where are we going to produce the data?" (The CDC guidelines also have been delayed as the agency considers the use of the QuantiFERON blood test in lieu of skin testing and other issues.)

Infection control and employee health practitioners have flooded OSHA with letters, asserting that annual fit-testing has no proven, scientific merit. CDC also has received its share of feedback from infection control practitioners and others. "Fit-testing is extremely time-consuming, labor-intensive, costly, and of virtually no incremental benefit when good fitting respirators are used," the Association for Professionals in Infection Control and Epidemiology (APIC) wrote to OSHA.

Yet industrial hygienist Mark Nicas, PhD, MPH, CIH, a respiratory protection expert at the University of California-Berkeley, argues that respirator studies are pertinent to tuberculosis.

"M. tb bacilli are carried on airborne particles that behave aerodynamically just like other airborne particles of comparable size, and although health care facilities cannot yet measure airborne M. tb concentrations, they can assess exposure potential," he says. "When you’re in close proximity [to an infectious patient], then wearing a respirator is your first line of defense," adds Nicas, who is industrial hygiene program director in the environmental health sciences division at UC-Berkeley. "If that’s your first line of defense, you should extend the effort to make sure it works."

This debate over fit-testing has been simmering for at least six years — since OSHA implemented a new General Industry Respiratory Protection Standard (1910.134). OSHA was then drafting a tuberculosis standard and announced it would address fit-testing for TB in that document. On Dec. 31, 2003, OSHA revoked its proposed TB standard — and the older respiratory protection standard that had applied specifically to TB.

"OSHA basically did what they said they were going to do," says Michael Tapper, MD, chief of infectious diseases at Lenox Hill Hospital in New York City and a member of HICPAC and a liaison member of ACET. "They said TB was carved out [only] because the TB standard was moving forward at that time."

The CDC guidelines, which date to 1994, recommend hospitals conduct an annual risk assessment. Skin testing and other activities would be based on level of risk. The guidelines did not include much information about fit-testing, but instead referred to OSHA and NIOSH documents. However, the guidelines state that all hospitals — except those with minimal risk of encountering a TB patient — should have a respiratory protection program and health care workers caring for TB patients should wear respirators that have been fit-tested.1

While CDC wrestles over how to address fit-testing in the updated guidelines, there is little indication that OSHA plans to reconsider its position. The agency has not yet responded to letters from APIC, the American Hospital Association, and others. OSHA always intended to include biologic agents in its General Industry Respiratory Standard, an OSHA official notes. The preamble to the 1998 standard states: "Deleting the proposed definition’s examples of air contaminants makes clear that no type of air contaminant, including biological agents, is excluded from the definition."

It references comments made during the public hearings on the General Industry Respiratory Protection Standard, stating, "OSHA emphasizes that this respiratory protection standard does apply to biological hazards."2

One area of agreement has emerged among those opposed to the annual fit-testing and those who support OSHA’s position: Manufacturers should be required to certify the fit of their respirators. "Under current NIOSH certification procedures, manufacturers only have to prove the filtration characteristics, not the fit characteristics," Tapper notes. "A well-designed respirator that has inherently good fit characteristics will fit most health care workers."

A change in NIOSH certification would be an improvement, Nicas concurs. "You’d decrease the likelihood of handing out a poorly fitting respirator. But the only way to know if it fits well or doesn’t fit well would be through fit-testing."

Meanwhile, more research also should be conducted on fit-testing itself — such as how reproducible the fit-test results are, Tapper says. "Everyone wants to protect workers. The only thing we’re disagreeing about is how efficient and how effective these things are."

While employee health and infection control professionals register their objections with the fit-testing requirement, they still face the challenge to comply by July 2. OSHA has stated that hospitals must have a fully functioning respiratory protection program for TB — including medical evaluations of employees and annual fit tests — by that date.

That is a daunting prospect for many hospitals. An informal poll of hospital-based occupational medicine practitioners indicates that hospitals fit test two-thirds of their staff to wear N95 filtering facepiece respirators, says Mark Russi, MD, MPH, director of occupational health at Yale-New Haven (CT) Hospital.

"The burden to hospitals would be substantial [of annual fit-testing], says Russi, a liaison member of HICPAC. "It would inevitably draw resources from activities of proven benefit to an activity of no proven benefit." He stresses that initial fit-testing is crucial and annual training provides reminders to health care workers about the proper use of the respirators.

Some hospitals tackled the fit-testing issue when they prepared for a potential severe acute respiratory syndrome (SARS) outbreak. "SARS has now driven us to fit test," says Steve Gordon, MD, hospital epidemiologist with the Cleveland Clinic Foundation and a member of HICPAC. He notes that many hospitals also have purchased powered air-purifying respirators, which do not require fit-testing.


1. Centers for Disease Control and Prevention. Guidelines for preventing the transmission of Mycobacterium tuberculosis in health care facilities, 1994. MMWR 1994; 43(RR13); 1-132.

2. 63 Fed Reg 1,152 (Jan. 8, 1998).