Is a Tuberculosis Exposure a Tuberculosis Exposure If No One Is Infected

If this sounds like a capricious question, understand that I am writing this commentary after a very long day listening to 7 hours of testimony on the proposed Occupational Health and Safety Administration (OSHA) tuberculosis (TB) Standard by the Association of Practitioners in Infection Control (APIC), the American Hospital Association (AHA), and other concerned organizations, followed by 3 hours testifying and questioning on the response of the American Lung Association and the American Thoracic Society, whom I represented. I shouldn't complain. OSHA officials will have listened to 8 days of similar testimony, much of it critical of their proposal, in this the first of four hearing sites around the country. The Society for Healthcare Epidemiology of America representatives will offer testimony at the New York City hearing in June. After more than a decade of debating the protection of healthcare and other institutional workers, visitors, and residents, it is clear that there is as yet no consensus on either the TB risk for institutional workers or the best available means for monitoring and control. The closest thing to a consensus has been the 1994 Centers for Disease Control and Prevention (CDC) guidelines, which also drew heavy fire in its draft form, but which have proven to be flexible enough for use in many institutional settings. Three California hospitals, however, may have been too flexible in their application of the CDC guidelines, with consequent potential exposure of healthcare workers, according to a survey by Sutton et al in this issue of the Journal.1 In what must have been something like a voluntary OSHA inspection, the authors reviewed and compared the written TB infection control plans of two county and one private hospital to actual practices, including, among other components, the measurement of negative pressure, room directional airflow and mixing, and the use of particulate respirators. Unfortunately, all three hospitals had multiple deficiencies in most areas, according to the authors. The findings demonstrate what has long been known to those experienced in indoor air quality-that poor maintenance, more than poor design, is the main barrier to healthful air in most settings. While these deficiencies should not have occurred and should be corrected, that they did occur in presumably well-run institutions is probably more often the rule than the exception. The expectation that ventilaion systems consistently will perform as designed, however desirable, may be unrealistic and part of the problem of achieving TB infection control today. Complex mechanical systems in hospitals that may contain as many as 50 to 75 isolation rooms are difficult to maintain through seasonal changeovers, personnel changes, renovations, competing pressure fluctuations, and system aging. Mustering the administrative will to devote the kinds of resources needed to maintain mechanical systems, as well as fit-test respirators, flawlessly, to educate and skin-test workers, and to maintain the other infection control components usually requires convincing evidence that failing to do so will be linked closely to bad outcomes. This happened in high-prevalence hospitals in New York City, Miami, and Atlanta in the early 1990s, leading to the success stories in TB infection control in those cities that have been cited widely as endorsements for the 1994 guidelines. Under the less-acute, lower-prevalence conditions extant in much of the country today, however, where over 100 patients may be isolated without TB for every case with the disease and where false-positive skin tests may outnumber true conversions, it often is difficult to generate the enthusiasm and resources necessary to implement and maintain infection control practices as currently recommended. As TB case rates fall, at some point it will be necessary to reassess the risk of institutional TB transmission and adjust control strategies accordingly. This is a provocative statement in view of OSHA's current