[Epidemiological features of multidrug-resistant tuberculosis in a reference service in São Paulo city].

In order to study certain epidemiological features of multidrug-resistant tuberculosis (MDR-TB) carriers and their influence on the control and treatment, a group of patients was evaluated over a four-year period, selected by: Mycobacterium tuberculosis isolation from sputum; resistance to Rifampin, Isoniazid and one more drug, or, failure of reserve regimen, all cases were from a tuberculosis reference unit in the City of S o Paulo. A total of 182 patients were reviewed, with a mean age of 35.7 +/- 6.8 years and 112 (61.5%) were male. These patients was classified according to therapeutic history, as: primary MDR-TB (with initial sensitivity test) 11 (6%); post primary MDR-TB (after irregular use previous treatment) 134 (74%), and indeterminate MDR-TB (failure after regular use of initial and reserve regimens) 37 (20%). Contagion was identified in 41/170 patients, acquired through domiciliary rather than institutional transmission. There were four familial outbreaks and none were institutional. The most frequent condition associated with these cases was abandonment of therapy (45%) followed by alcoholism (27%), sequential failure in the treatment regimens (23%), MDR contagion (15%), drug reaction (6%), HIV positive (4%) and diabetes (3%). There was resistance to Rifampin+Isoniazid in 100%, Streptomycin in 83% and Ethambutol in 47%. Conventional X-ray revealed cavities in all, though only 35 (19%) were unilateral. These cases are discussed and some suggestions presented.