OUTBREAK OF TUBERCULOSIS IN A PUBLIC-SCHO OL

Background. At school there are special circumstances of living togeth er and a particular susceptibility, which favour the emergence of tube rculosis microepidemics. We report here the microepidemic ocurred at a school among 9-year old children. Methods. After ruling out a possibl e familiar source in a child with pulmonary tuberculosis, we detected a case with high bacillar shedding in a female teacher and conducted a tuberculin search among children and teachers, initially outlining th e theoretical groups at risk. Tuberculin positive children underwent c hest-X-ray and when abnormalities were found, children were derived to the pediatrician for chemotherapy. All converters received secondary chemoprophylaxis and all non-respondents primary chemoprophylaxis. Res ults. The classroom where the teacher spent most of het time had a hig her rate of converters (70%) than other classroom, where the index tea cher spent only a partial time (40%; RR: 1.75; CI: 1.06-2.88) or the c ollective of teachers (45.4%; RR: 1.45; CI: 0.94-2.23). Three addition al cases of secondary disease were detected, all of them children. The initial compliance with chemoprophylaxis was greater among (for) chil dren (97.0%) than among teachers (41.6%). Among children there was one case of tuberculin conversion compared with three cases among teacher s. No additional cases were detected; also, an abnormal rate of reacto rs outside the initially studied groups was also not detected. Conclus ions. Our results somehow agree with those reported from other school outbreaks. To note the anergy and lack of symptoms in the index case a nd the suggestion to delineate the degree of spending hours together t o identify groups with a higher theoretical risk of being infected. Th us, an unnecessary expense of resources and a social alarm would be av oided.