Reliable and easy identification of bacterial acute respiratory infections of childhood.

OBJECTIVES: To identify the causative bacteria in childhood acute respiratory infections (ARI) and to determine the usefulness of pus cell counts in differentiating between pathogenic and commensal bacteria, cultured from nasopharyngeal aspirates. DESIGN: Case control prospective study. SETTING: Outpatients' department and the paediatric unit at General Hospital, Colombo South. SUBJECTS: 200 children under 5 years with cough and difficulty in breathing for less than one week who had no history of antibiotic therapy for the current illness, and 50 healthy controls matched for age and sex. RESULTS: 56.5% of cases had bacterial infections. Branhamella catarrhalis (25%), Haemophilus influenzae (12.5%) and Streptococcus pneumoniae (10.5%) were the major pathogens identified. Pus cell counts were found to be significantly higher in cases than in controls (X2 58.28 df = 1 p < 0.001), and the pathogens were more often associated with pus cell counts of more than 10/field. CONCLUSIONS: 56.5% of children with ARI had bacterial infections. B catarrhalis seems to play a major role in childhood ARI. Examination of nasopharyngeal aspirates is a useful way to identify pathogens, provided microscopic examination for pus cells is performed together with culture.