Objective: To assess the prevalence of S. aureus nasal carriage in HIV infected adult persons and antibiotic resistance of S. aureus in rural Zambia, data which are largely unknown in developing countries.
Methods: During a 2 months period 129 HIV positive adult patients were included in this cross-sectional study. A questionnaire was filed with potential determinants of S. aureus carriage. Two nasal swabs were obtained to determine S. aureus carrier state: persistent carriage (both cultures positive), intermittent carriage (one culture positive) and non carriage (both cultures negative). All swabs were sent for culture and resistance testing according to standard operating procedures. SPSS 15.0 was used for statistical analysis.
Results: A total of 41 (32%) patients were persistent S. aureus carriers, 33 (26%) intermittent and 55 (42%) were non carriers. No determinants were found to explain this high persistent carriage rate with S. aureus. Twenty-two percent of S. aureus strains were resistant to methicillin, 22% to gentamicin, 85% to co-trimoxazol, 41% to erythromycin, 76% to tetracycline and 96% to penicillin. Only 4% of strains were ciprofloxacin resistant. Over 77 % of the patients carried a S. aureus strain resistant to 3 or more antibiotics.
Conclusion: In rural resource-poor settings, treatment options are very much limited while the impact of improper treatment of S. aureus infections can be considerable. Due to the high prevalence of S. aureus nasal carriage and high level of antibiotic resistance, implementing microbiologic examinations could have a profound impact on improving antibiotic treatment of S. aureus infections in a rural developing country.