Nasopharyngeal carriage and susceptibility patterns of Streptococcus pneumoniae in Kumasi, Ghana

Penicillin resistant Streptococcus pneunmoniae poses an increasing problem in paediatrics, particularly in less developed countries. Outside of South Africa, little is known about S. pneumoniae susceptibilities in Sub-Saharan Africa. The objective of this study was to determine the prevalence of pneumococcal colonization and antimicrobial susceptibility among children in urban Ghana. Nasopharyngeal pneumococcal colonization was examined in 311 children attending a polyclinic for sick children and an immunization clinic in Kumasi, Ghana. Isolates were tested for antibiotic susceptibility to penicillin, tetracycline, erythromycin, chloramphenicol, cefuroxime, cefotaxime, ceftriaxone, and trimethoprim-sulfamethoxazole. Over half (51.4%) of subjects were colonized with S. pneumoniae and 17% of isolates were resistant to penicillin, all demonstrating intermediate resistance. S. pneumoniae strains were also frequently resistant to trimethoprim-sulfamethoxazole and tetracycline, less so to chloramphenicol and cefuroxime and were almost uniformly sensitive to cefotaxime, cefriaxone and erythromycin. Our study shows a high rate of pneumococcal nasopharyngeal colonization and a concerning level of penicillin resistance although at a less alarming rate than seen in some other countries. Multiple antimicrobial resistance was also noted especially among drugs readily available and commonly used. These data impact treatment choices in pneumococcal disease. Vaccine may play an important role in disease limitation. An effort to curtail the misuse of antibiotics, by prescription and otherwise, may prevent further increases in resistance rates.