Nasal carriage of methicillin resistant Staphylococcus aureus among health care workers at a tertiary care hospital in Western Nepal

Background: Staphylococcus aureus is a frequent cause of infections in both the community and hospital. Methicillin-resistant Staphylococcus aureus continues to be an important nosocomial pathogen and infections are often difficult to manage due to its resistance to multiple antibiotics. Healthcare workers are important source of nosocomial transmission of MRSA. This study aimed to determine the nasal carriage rate of S. aureus and MRSA among healthcare workers at Universal College of Medical Sciences and Teaching Hospital, Nepal and to determine antibiotic susceptibility pattern of the isolates. Methods: A cross-sectional study involving 204 healthcare workers was conducted. Nasal swabs were collected and cultured on Mannitol salt agar. Mannitol fermenting colonies which were gram positive cocci, catalase positive and coagulase positive were identified as S. aureus. Antibiotic susceptibility test was performed by modified Kirby-Bauer disc diffusion method. Methicillin resistance was detected using cefoxitin disc diffusion method. Results: Of 204 healthcare workers, 32 (15.7 %) were nasal carriers of S. aureus and among them 7 (21.9 %) were carrier of MRSA. Overall nasal carriage rate of MRSA was 3.4 % (7/204). Highest MRSA nasal carriage rate of 7.8 % (4/51) was found among nurses. Healthcare workers of both surgical wards and operating room accounted for 28.6 % (2/7) of MRSA carriers each. Among MRSA isolates inducible clindamycin resistance was observed in 66.7 % (2/3) of erythromycin resistant isolates. Conclusions: High nasal carriage of S. aureus and MRSA among healthcare workers (especially in surgery ward and operating room) necessitates improved infection control measures to be employed to control MRSA transmission in our setting.