Nasopharyngeal carriage of community-acquired, antibiotic-resistant Streptococcus pneumoniae in a Zambian paediatric population.

Abstract

The emergence of antibiotic-resistant Streptococcus pneumoniae is an international health problem. Apart from South Africa few data on pneumococcal resistance are available for sub-Saharan Africa. This study examines the nasopharyngeal carriage and prevalence of antibiotic resistance in pneumococci isolated from 260 Zambian children aged < 6 years. Pneumococci were isolated from 71.9% of the children; the odds of carrying organisms were twice as high among children < 2 years of age compared with older children. Antibacterial resistance was found in 34.1% of the isolates; resistance to tetracycline, penicillin, sulfamethoxazole + trimethoprim, and chloramphenicol occurred in 23.0%, 14.3%, 12.7%, and 3.9% of the isolates, respectively. Only 4% of the isolates were resistant to three drugs. High-level resistance was found in all isolates resistant to tetracycline; but only intermediate level penicillin resistance was found. A total of 11.1% of the isolates demonstrated intermediate resistance to sulfamethoxazole + trimethoprim. Children aged < 6 months were less likely to carry antibiotic-resistant organisms. Antibiotic resistance in S. pneumoniae appears to be an emerging public health problem in Zambia, and the national policy for the empirical treatment of pneumococcal meningitis and acute respiratory tract infections may need to be re-evaluated. The establishment of ongoing surveillance to monitor trends in pneumococcal resistance should be considered.