Nasopharyngeal carriage of antimicrobial-resistant Streptococcus pneumoniae among young children attending 79 kindergartens and day care centers in Hong Kong

Resistance to penicillin and multiple antimicrobial agents among Streptococ cus pneumoniae strains is becoming an increasing problem worldwide and in A sia. To determine the prevalence of carriage of S. pneumoniae isolates not susceptible to penicillin in young children, we obtained nasopharyngeal swa b specimens from 1,978 children (ages, 2 to 6 years) attending 79 day care centers or kindergartens. Three hundred eighty-three strains of S. pneumoni ae were isolated from these children. Fifty-eight percent of these isolates had reduced susceptibility to penicillin, 123 (32.1%) were intermediate, a nd 100 (26.1%) were resistant. A very high penicillin MIC (4 mug/ml) was fo und in 3.3% of the isolates. The isolates also demonstrated high rates of r esistance to other antimicrobial agents (51.2% to cefaclor, 50.2% to cefuro xime, 42.8% to cefotaxime, 80.7% to trimethoprimsulfamethoxazole, 77% to er ythromycin, 60% to clindamycin, and 33.7% to chloramphenicol). No isolate w as resistant to fluoroquinolone. Multidrug resistance (not susceptible to t he beta -lactams and three or more other classes) was found in 39.4% of the isolates. Risk factors for the carriage of S. pneumoniae not susceptible t o penicillin were multiple physician visits in the preceding 3 months and u se of antimicrobial agents by the individual or by household members in the preceding 3 months. In the logistic regression analysis, only the use of a ntimicrobial agents in the preceding 3 months was an independent risk facto r (P = 0.004; odds ratio, 2; 95% confidence interval, 1.2 to 3.2). This stu dy demonstrated the high prevalence of antibiotic-resistant S. pneumoniae i n healthy young children in the community in Hong Kong.