Aetiology of pneumonia in hospitalized children

One-hundred-and-thirty-two children with clinical and radiological evidence of bronchopneumonia/pneumonia were studied over a 1-year period for isolation/detection of bacterial and viral aetiological pathogens. Throat swab, nasopharyngeal aspirate (NPA), and lung aspirate were studied for bacterial and viral cultures. NPA was also subjected to latex agglutination test (LA) for H. influenzae and S. pneumoniae; and immunofluorescent technique (IFAT) and enzyme immunoassay (EIA) for respiratory syncytial virus (RSV). Blood culture for bacterial pathogens, and LA of blood and urine was also undertaken. Haemophilus influenzae was the commonest organism (15 per cent) isolated as the sole pathogen followed by RSV (14 per cent), Klebsiella (13 per cent) and S. pneumoniae (12 per cent). E. coli was the commonest organism (50 per cent) in infants <3 months and was closely followed by RSV (44 per cent), Klebsiella (25 per cent), and S. pneumoniae (18 per cent). Isolation rate of E. coli gradually declined with age. RSV (47 per cent) and H. influenzae (31 per cent) were the commonest organisms between 7 and 24 months. S. pneumoniae and Staph. aureus were common bacterial pathogens identified in all age groups with maximum isolation of 20 and 40 per cent, respectively, in children more than 5 years. Isolation of E. coli, Klebsiella and Staph. aureus was highest from NPA culture, while as S. pneumoniae and H. influenzae were most often detected by LA. Out of 12 cases from whom a lung aspirate was collected, bacterial pathogen could be isolated in six cases (50 per cent). Detection of RSV by EIA was higher than by culture or IFAT. Most of the organisms were resistant to chloramphenicol except for H. influenza. All the isolates of S. pneumoniae were sensitive to all the antibiotics. Bacterial pathogens were isolated/detected in 74 per cent of cases and RSV was the aetiological agent in 49 per cent of cases investigated for viral aetiology. Higher detection rate of RSV is attributed to selection of cases in winter months during a period of suspected epidemic of RSV.