RESUMO
BACKGROUND: Acute lower respiratory tract infections are the primary cause of morbidity in developing countries. POPULATION AND METHODS: Six hundred and sixty seven children (379 boys, 288 girls, aged 0-30 months) admitted for lower respiratory tract infections from January 1990 to March 1991 were included in the study. Immediate medical history was collected from the mother. The weight, height, temperature and clinical manifestations, plus the results of chest X-rays, parasitologic and bacteriological examination of stools, and blood smear for malaria were recorded for each patient. Sero-immunologic study for HIV infection of 473 of the patients aged 12-36 months and their mothers also took part in a sero-immunological study for HIV infection. RESULTS: Lower respiratory tract infections were the second major cause of admission (16.8%) after malaria (28.7%). Infections peaked between 6 and 11 months of age (29.5%). The main diseases were pneumonia and bronchial pneumonia (54%) followed by bronchiolitis (21.7%). Almost half the patients were admitted during the hot, dry season. Two hundred and eighty seven patients (43.4%) were referred only after they had been suffering from the disease for 3 to 9 days, partly explaining the high level of mortality. One hundred and twenty one patients (20.9%) died; the main cause of death was staphylococcal pneumonia (57.9%), followed by pneumonia and bronchial pneumonia (29.3%). Some criteria for severity could be identified, based on pulmonary signs and symptoms and associated manifestations (dehydration, malnutrition, convulsions, anemia). Twenty two patients were positive for HIV-1 infection. CONCLUSIONS: This study confirms that acute lower respiratory tract infections remain a public health problem. Early diagnosis and treatment are necessary to reduce mortality.