Tuberculosis in healthcare workers at a general hospital in Mexico.

OBJECTIVE: To determine the incidence rate of tuberculosis (TB) disease among healthcare workers (HCWs) at a general hospital. DESIGN: Retrospective analysis of TB cases among HCWs over the course of 5 years. SETTING: A 140-bed general hospital in Tijuana, Mexico. PARTICIPANTS: All hospital employees who developed TB during the 5-year period. RESULTS: From 1 January 1999 through 31 December 2003, 18 TB cases were diagnosed among the hospital personnel. During that period, the mean (+/- standard deviation) annual work force of the hospital was 819+/-21.7 employees. The TB incidence rate was 439.56 cases per 100,000 employees; this rate was 10.98 times higher than the rate for the general population of the city. The TB incidence rate for physicians was 860.21 cases per 100,000 employees, that for nurses was 365.85 cases per 100,000 employees, and that for physicians in training was 1,846.15 cases per 100,000 employees. Physicians in training had a higher risk of acquiring TB than did either physicians (relative risk, 2.14 95% confidence interval, 1.34-35.66) or nurses (relative risk, 5.04 95% confidence interval, 3.16-83.33). Three of the HCWs with TB disease were infected with a drug-resistant strain of Mycobacterium tuberculosis, and one of the infecting strains was multidrug resistant. Asymptomatic TB infection among HCWs was not addressed during this study. CONCLUSIONS: The TB incidence rate among the HCWs at the hospital is extremely high, compared with that in the general population. The implementation of infection control measures is an urgent priority, to reduce this occupational hazard.