HYPERENDEMIC PULMONARY TUBERCULOSIS IN A PERUVIAN SHANTYTOWN

Estimates of the incidence of pulmonary tuberculosis in developing cou ntries are based on case reporting from local health laboratories or t he annual risk of tuberculin skin test conversion. Because these metho ds are problematic, the authors used a multiple case ascertainment met hod to estimate the incidence of pulmonary tuberculosis from 1989 to 1 993 in a Peruvian shantytown of 34,000 inhabitants. Two methods, face- to-face interview of all local inhabitants and examination of local la boratory smear records, were used for case gathering. The number of mi ssed cases was estimated by capture-recapture analysis. Survey cases w ith positive smears were matched to age- and sex-matched controls and interviewed about socioeconomic conditions. The average annual inciden ce per 100,000 population was 364 (95% confidence interval 293-528) by capture-recapture methods. For the city encompassing the shantytown, the Peruvian Ministry of Heath reported an average annual incidence of 134 cases per 100,000 population. The authors conclude that, in Peru, alarming clusters of pulmonary tuberculosis are masked by government reports that pool zones of disparate incidence. Existing estimators of pulmonary tuberculosis incidence based on tuberculin conversion rates may be invalid in such areas. Within these hyperendemic areas, person s suitable for intensive prophylaxis efforts cannot be reliably identi fied by housing and socioeconomic risk factors.