Tuberculosis in health-care workers: Results of a surveillance program in Mexico City

Background: Tuberculosis is major public health problem, left untreated, each person with active TB disease will infect on average between 10 and 15 people every year. Preventive strategies are essential for the achievement of the Millennium Development Goal. Methods: In 1992 a HCW’s surveillance program was instituted in our hospital, which consist in an initial evaluation for every worker during their first week of working within the Institute, a questionnaire with demographic and risk variables, PPD application, and a basic risk prevention’s course. PPD Booster is applied for those with an initial PPD negative test, and then annual follow-up is performed. The workers with PPD positive test are evaluated by a physician and a chest-Rx is taken. Prophylaxis is indicated in every HCW who has a PPD positive test during the follow up or risk factors for the disease. Results: A total of 5513 HCW have been evaluated since 1992, 61% were women, and the median age was 27. Forty percent were physicians, 32% nurses, 10% administrative workers and the rest (18%) from other areas. Of the evaluated workers 1932 (38%) had an initial PPD positive test, all of them had a normal chest-Rx. After the Booster application we identified 286 workers with positive test. During the follow up 259 HCW have had a PPD positive test. A total of 169 prophylactic treatments have been provided, 53 workers did not finish the treatment because of mild secondary effects and personal decision. Sixteen HCWs have developed clinical tuberculosis, 9 had a previous PPD positive test and refused prophylactic treatment. Conclusion: The initial PPD positive test prevalence was 43%. HCWs are in risk of this infection especially in developing countries. A a specific program for them is essential in order to reduce nosocomial transmission and identify those in risk of tuberculosis.