Invasive pneumococcal disease in children aged <5 years admitted to 3 urban hospitals in Ibadan, Nigeria.

BACKGROUND: Streptococcus pneumoniae remains a major cause of childhood morbidity and mortality in the world. The introduction of pneumococcal conjugate vaccine in developing countries will be facilitated by a clearer understanding of the disease burden for bacterial causes of pneumonia and meningitis and the prevalent serotypes of S. pneumoniae. METHODS: We conducted a prospective, hospital-based surveillance for a 2-year period involving children aged 2-59 months at 3 urban hospitals in Ibadan, Nigeria, using standard microbiological methods with confirmation and further testing of isolates at the Medical Research Council Laboratories in The Gambia. RESULTS: There were 1210 cases overall: 481 (39.8%) were meningitis, 399 (33.0%) were pneumonia, and 330 (27.2%) were bacteremia clinical syndromes. There were 24 cases of definite meningitis, of which 9 were caused by S. pneumoniae, 11 by Haemophilus influenzae type b, and 4 by Klebsiella species. Of the 90 culture-positive pneumonia cases, 9 were caused by S. pneumoniae, 2 by H. influenzae type b, and 79 by other species. Among cases of bacteremia, the pathogen isolation rate was 28.8% (95 of 330); the isolated species included S. pneumoniae (3 isolates), Staphylococcus aureus (20 isolates), Klebsiella species (13 isolates), Salmonella species (15 isolates), and Escherichia coli (6 isolates). Of the 23 S. pneumoniae isolates, 11 were serotyped; the serotypes found were 5 (5 isolates), 19F (3 isolates), and 4 (3 isolates), and 1 isolate was nontypeable. These isolates were all susceptible to penicillin. Eight of 9 patients with definite pneumococcal meningitis died, whereas all patients with pneumococcal pneumonia and septicemia survived. CONCLUSIONS: Of the pneumococcal serotypes identified, 55% were covered by the licensed 7-valent pneumococcal conjugate vaccine, whereas all are covered by the 10- and 13-valent vaccines.

Enhanced diagnosis of pneumococcal meningitis with use of the Binax NOW immunochromatographic test of Streptococcus pneumoniae antigen: a multisite study.

BACKGROUND: Accurate etiological diagnosis of meningitis in developing countries is needed, to improve clinical care and to optimize disease-prevention strategies. Cerebrospinal fluid (CSF) culture and latex agglutination testing are currently the standard diagnostic methods but lack sensitivity. METHODS: We prospectively assessed the utility of an immunochromatographic test (ICT) of pneumococcal antigen (NOW Streptococcus pneumoniae Antigen Test; Binax), compared with culture, in 5 countries that are conducting bacterial meningitis surveillance in Africa and Asia. Most CSF samples were collected from patients aged 1-59 months. RESULTS: A total of 1173 CSF samples from suspected meningitis cases were included. The ICT results were positive for 68 (99%) of the 69 culture-confirmed pneumococcal meningitis cases and negative for 124 (99%) of 125 culture-confirmed bacterial meningitis cases caused by other pathogens. By use of culture and latex agglutination testing alone, pneumococci were detected in samples from 7.4% of patients in Asia and 15.6% in Africa. The ICT increased pneumococcal detection, resulting in similar identification rates across sites, ranging from 16.2% in Nigeria to 20% in Bangladesh. ICT detection in specimens from culture-negative cases varied according to region (8.5% in Africa vs. 18.8% in Asia; P< .001), prior antibiotic use (24.2% with prior antibiotic use vs. 12.2% without; P< .001), and WBC count (9.0% for WBC count of 10-99 cells/mL, 22.1% for 100-999 cells/mL, and 25.4% for >or=1000 cells/mL; P< .001 by test for trend). CONCLUSIONS: The ICT provided substantial benefit over the latex agglutination test and culture at Asian sites but not at African sites. With the addition of the ICT, the proportion of meningitis cases attributable to pneumococci was determined to be similar in Asia and Africa. These results suggest that previous studies have underestimated the proportion of pediatric bacterial meningitis cases caused by pneumococci.