CDC guidelines in a bureaucratic limbo as TB takes new guise
Fit-testing issue not going away though
Even as tuberculosis threatens to take an insidious new appearance in the United States, draft federal guidelines for TB control in health care settings remain mired in controversy and bureaucratic limbo.
Developed over four years, the 269-page draft TB guidelines by the Centers for Disease and Prevention (CDC) most recently were slated for publication June 15, 2005.
However, that deadline has passed, and the document now may be subject to new requirements for external peer review by other federal agencies, a CDC consultant said recently in Baltimore at the annual meeting of the Association for Professionals in Infection Control and Epidemiology (APIC).
"So now, nobody knows when this guideline is really going to come out," said Rachel Stricof, MT, MPH, an epidemiologist at the bureau of TB control at New York State Department of Health. Stricof consulted in the creation of the guidelines as a liaison member of the CDC’s Healthcare Infection Control Practices Advisory Committee (HICPAC). As a liaison member on the panel, she represents the Advisory Committee for Elimination of TB (ACET).
She expressed doubt the draft guidelines would be finalized this year, but urged ICPs to consult the "frequently asked questions" section of the document to get a gist of the CDC’s latest take on TB.
A veteran TB controller, Stricof warned that current historic lows of TB in the United States may smooth over a striking undercurrent in the epidemiological data: a continuing increase in infections among minority groups and the foreign-born. For example, U.S. public health officials were caught off-guard recently when a group of refugees threatened to spread TB and multidrug-resistant TB in the various states where they were resettled. "I have been in infection control and working at the health department for decades now, and this is an organism that just won’t go away," Stricof said.
"It keeps resurrecting itself in different ways. We know that once we see an introduction of TB into a homeless shelter, into a correctional facility, or any high-risk population, we get explosive results," she explained.
"You need to know the patients your facility serves and what is going on in their communities in order to follow this, because things can change just like that," Stricof added.
Still, a certain level of complacency is understandable. After surging dramatically in the late 1980s and early 1990s, TB in the United States has been beaten back with a vengeance.
"We now have the lowest number of TB cases every recorded," she said. "In 2004, we were down to 14,511 cases in this country. We have the lowest rate — 4.9 cases per 100,000. But we are seeing definite changes in the epidemiology that you have to be aware of. There are areas where there are major disparities — even in this country among our own U.S.-born citizens."
For example, the shifting trends in the United States find the majority of TB cases in the foreign born, a group that represented some 54% of infections in 2004.
There are also alarming disparities within ethic and racial groups in the United States. Hispanics and African Americans have an eightfold higher rate than whites. Asians have 20 times the incidence of TB as Caucasians in the United States, she noted.
"Our world is definitely getting much smaller," Stricof told APIC attendees. "During the resurgence of TB in this country in the mid-1980s and early 90s, the number of TB cases rose about 20%. Since 1992, because of the efforts of a lot of the people in this room, that trend has been reversed, but the decline has slowed down in the past couple of years, and again there are disparities for ethnic, racial, and foreign-born populations. We have to keep in mind that about one-third of the world’s populations [is TB-infected]."
Again, the key is to keep a watchful eye on trends in your local community.
"Have a high index of suspicion, keep up all the training that you are doing, follow those environmental control measures, and keep information flowing between the laboratory and public health partners in the community that you serve," she continued.
MDR-TB, which can require regimens of multiple drugs to clear, has declined sharply in the United States. Noted, but again, Stricof was wary.
"I warn you not to let your guard down," she added. "We are still paying the price. In New York state, I am still seeing health care workers all of a sudden break down with active TB disease, and it’s drug-resistant. Why? Because they were infected in the early ’90s. We had them as converters, but we didn’t have an effective treatment for latent MDR-TB infection for these individuals who were previously infected. The cycle can go on."
Why should ICPs worry that TB vanquished to record low levels will arise again to cause disruption, infections, and even death? Because that is the history of the disease. In what has been famously called "the U-shaped curve of concern," TB historically drops sharply when it is the focus of prevention efforts. The disease sits dormant while the interventions evaporate, diagnostic expertise wanes, and money goes to other problems. TB then arises like a fire in an abandoned building with the introduction of new cases.
It’s already happening, Stricof said, noting that recently an undiagnosed TB case caused havoc in New York as the patient moved in and out of the medical system. When an infectious disease physician finally was called in and gave the TB diagnosis, disruptive follow-up contact investigations had to be undertaken in a variety of settings.
"My fear is that we are going to forget everything we learned in the late ’80s and early ’90s," she said.
"When the number of cases go down, people stop thinking TB. It goes off the radar screen, and lo and behold, we are going to be back to where we were. The most critical component is early identification. Although we all have policies in the emergency department, probably, we’re back to nobody having read or thought about them for a very long time. It’s going to be hard to maintain those clinical competencies. [And] as some of you have seen, we no longer have microbacteriology lab services in [some of] our hospitals," Stricof added.
The message can be confusing, because the draft CDC guidelines reduce the frequency of worker TB skin testing in low incidence areas. Even though there always is the risk of new TB introduction anywhere, high-frequency testing in low incidence areas is most likely to set off a string of false-positives. "The risk classification is going to change," she said. "Low-risk facilities [will] only need to get a baseline TB skin test on hire. Then only post-exposure [testing] will be called for in the guidelines. Really, the decision to test should be a decision to treat people. You don’t want to be testing a lot of people who are very likely to be uninfected and then find out that you are getting more false-positives then true positives."
From complacency to overkill
While sounding the alarm against complacency, Stricof joined the chorus of ICPs who have protested what is widely regarded as a labor-intensive and unnecessary effort at TB infection control: annual or "periodic" respirator fit-testing.
The CDC guidelines may be in limbo, but the thinking is that when they eventually are finalized a controversial and confusing recommendation for "periodic" fit-testing of respirators will remain intact. The CDC recommends in the draft document that health care workers be fit tested "during the initial respiratory protection program training and periodically thereafter based on the risk assessment for the setting."
The Occupational Safety and Health Administration (OSHA) was requiring annual fit-testing, but APIC successfully lobbied to kill the funding to enforce the measure. APIC and individual ICPs have asked the CDC to cite clear evidence of the fit-testing benefit or drop the confusing periodic recommendation.
"[The CDC TB draft] says — and tell me this is not a problem, an inherent inconsistency — There are insufficient evidence-based data to make a recommendation on the periodicity of fit-testing,’" Stricof said.
In essence, the frequency of fit-testing would be based on the ICP’s assessment of risk within the facility and community. "So you try and figure it out," she said. "We have pointed out to them that this poses a dilemma for us. We would really like to see CDC come out with evidence-based guidance and to show us the evidence for doing this."
That apparently is not going to be the case, as the gray-area guidance has remained intact through various iterations of the document. "In the final wording, do I think it is going to change?" Stricof asked. "We have been told, Don’t be optimistic.’ . . . Quite frankly, I’m not sure I want to see the new version of the guidelines if that’s what we have to interpret. But so be it."
The whole issue of respirators and fit-testing has been a thorn in the ICP’s side since TB resurged more than a decade ago. Part of the problem is a diametrical world view with those in industrial occupational health, who have the most experience with respirators.
Overgeneralized, this means ICPs tend to focus on finding and treating the unrecognized TB case; occupational health types lean toward controlling the air around the worker treating the diagnosed case, and never the twain shall meet.
The issue is complicated because once you include respirators, you must have a respiratory protection program, and that raises the unpopular subject of fit-testing the employees face to make sure the mask fits.
The National Institute of Occupational Safety and Health (NIOSH) has "yet to find a [fit-testing] method that is reproducible and reliable," yet the onus of doing fit-testing is being put on ICPs, Stricof said. "[NIOSH] published data have suggested the chance of failing a fit-test — even though the respirator would actually fit you — was anywhere from about 40% to 90%. The chance of passing a fit-test — with a respirator that really doesn’t fit you — is anywhere from 3% to 11%. In more recent studies, it is up to 19%. So we don’t have a method that works and is reproducible and reliable."
Moreover, the fit and the quality of respirator brands are definitely different, she said. "If you have a good fitted respirator to begin with, you will have much better success at blocking out particulates then you will even after fitting some of our poorer respirators," she added.
For their part, respirator manufacturers have to show the filters will protect against certain size particles, but actually don’t have to have a fit-test component in the production process, she said.
"What we in APIC and the ACET have recommended now is that NIOSH reintroduce [fit-testing] into the [approval] process, and that that information be publicly available to you as users so that you can select respirators based on their fit-testing characteristics," Stricof said.
"Let the onus of that responsibility be placed on the manufacturers rather than each of us. I don’t know of any of you who can do a fit-test better than the NIOSH investigators can, and yet, we are being asked to do that. . . . The key to all of this in my mind is to select a respirator with inherently good fit-testing characteristics. Some of you already know what some of these are because you have actually had experience fit-testing people," she noted.
There is another respirator element in the guidelines that puts the whole fit-testing issue in the harsh light of political compromise. (Suggesting here that the CDC included the fit-testing component as a compromise with OSHA). The CDC draft guidelines note that visitors also can be offered N95 respirators to enter TB patient’s rooms, but that no evaluation or fit-testing is required.
"If you think about it, visitors have much more intense and prolonged contact than our employees do," Stricof said. "Our employees go in, take a temperature, take the blood pressure, and leave the room. Visitors stay with them all day and overnight. . . . No medical assessment or fit-testing is required for visitors. Remember, OSHA only regulates employees."