Viral respiratory infections in young children attending day care in urban Northeast Brazil.

A cohort of children attending a day care center in Salvador (Bahia, Brazil) was studied prospectively to determine the incidence of viral respiratory infectious episodes and to identify the viruses associated with them. Two hundred seventy-one nasopharyngeal samples were collected over a 1-year period for examination, using indirect immunofluorescence with monoclonal antibodies against adenovirus, influenza A and B, parainfluenzae 1-3, and respiratory syncytial virus, and reverse transcriptase-polymerase chain reaction for picornavirus. Examination yielded positive results in 116 samples (42.8%). Rhinovirus was identified alone in 56 samples (48.3%) and was observed along with other viruses in 11 additional samples. Incidence density of viral respiratory infectious episodes was 7.66 episodes/1,000 child-days.