Prevalence, susceptibility testing and multi drug resistance risk factors to methicillin resistant Staphylococcus aureus in nasal carriage of hospitalized patients and medical staff in selected hospitals in Cameroon

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a major hospital acquired pathogen. In Cameroon, there is limited data on nasal carriage of MRSA and its antibiotic susceptibility testing and risk factors for multi resistance to antibiotics in hospitalized patients and medical staff . A prospective, qualitative, cross-sectional hospital-based study was carried out. Anterior nasal swabs were taken from 579 participants and bacterial strains were identified by conventional method and antibiotic susceptibility testing. Methicillin resistance was confirmed with cefoxitin and oxacillin disks. Of the 579 samples analysed, 53.0% were positive for S. aureus, 45.4% were MRSA. MRSA constituted 85.7% of all the S. aureus identified. The prevalence of MRSA in nasal carriage was significantly higher in females (49.6%) than in males (34.0%). The overall prevalence of MRSA in nasal carriage in both medical staff and hospitalized patients was 45.4%. The prevalence of MRSA in nasal carriage was significantly higher in RHL (49.0%) and RHB (48.5%) compared to the UTHY (36.3%). The prevalence of MRSA in nasal carriage was significantly higher in the surgical ward (59.7%) and paediatric ward (45.2%) compared to the other units. Among the MRSA isolates, the maximum sensitivity was observed with vancomycin (97.0%) and minocycline (95.1%), while the least sensitivity was observed with penicillin (0.0%) and ampicillin (0.8%). Binary logistic regression model showed that being aged 35 years an above and being hospitalized for more than 15 days were strongly associated with MDR to MRSA. Nasal carriage of MRSA is increasing rapidly and call for urgent preventive measures.