Capsular serotypes and antibiotic sensitivity of Streptococcus pneumoniae isolated from primary-school children

A total of 1049 primary-school children in 18 schools were screened for carriage of Streptococcus pneumoniae. Data on family size, antibiotic use, travel and hospital admissions were collected. Pneumococcal serotyping and sensitivity tests were performed. One third of children were found to be pneumococcal carriers. Ten of 344 isolates were penicillin-resistant (2.9%). Apart from resistance to trimethoprim and ciprofloxacin, resistance rates in penicillin-sensitive strains were low. Among penicillin-resistant strains (PRP), co-resistance to trimethoprim, chloramphenicol and tetracycline was common. Cefotaxime-resistance was seen in 90% of PRP. Although 24 serotypes were represented, groups 6, 19 and 23 accounted for 55% of strains. Serogroup 23 strains were significantly more likely to be penicillin-resistant than other groups/types. Clustering of strains by serotype and antibiotic resistance was seen in several schools. No association with foreign travel, family size or age of siblings was seen and penicillin resistance was not associated with prior antibiotic use. However, hospital admission was significantly associated with carriage of PRP. The implications of detecting PRP in the community are discussed.