Carriage and Antibiogram of Methicillin Resistant Staphylococcus Aureus among Admitted Patients of a Surgical Ward in A Tertiary Hospital, South Western Uganda

Abstract

Background: Methicillin Resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial infections affecting post-surgery patients. Antimicrobial resistance prolongs the duration of hospitalization. We sought to determine the MRSA carriage among patients admitted to surgical ward in a tertiary hospital in South Western Uganda. Methods: Total of 46 participants were included in the study, swabbed at four different sites: nares, hands, perineum and surgical wound site. Identification of Staphylococcus aureus was done by standard conventional microbiological methods. Antibiotic susceptibility testing was done using disk diffusion method, except for Vancomycin were MIC was used as per CLSI guidelines. Using these results, prevalence of MRSA was determined. The on admission were followed up for 7days to determine the incidence of MRSA. Site carriage rate of MRSA was determined using drug susceptibility test (DST) test results. Questionnaire was used to collect data on factors associated with MRSA. Results: The prevalence of MRSA carriage at admission was 18/46 (39.1%). Among patients who were MRSA negative at admission, the incidence of MRSA carriage during hospitalization was13/26 (50%). Of the 122 S. aureus isolates, resistance to Oxacillin was 55(45.1%), Ciprofloxacin 50(41.0%), Ceftriaxone 46(37.7%), Methicillin 44(36.1%), Levofloxacin 39(32.0), Imipenem 13(10.7%) and Vancomycin 3(2.5%). The site with the highest carriage rate was the Nares 16/77 (20.8%), Hands 14/77(18.2%), Perineum 15/77(19.5%), surgical wound site 9/77(11.7%). 80% of the isolates were MDR. The factors measured were not statistically associated to MRSA carriage outcome. Conclusion: There was high MRSA carriage among patients on surgical ward. Resistance to commonly used antibiotics was high, 80% of the isolates were MDR. Therefore, there is the need for continuous surveillance to monitor aetiology and antimicrobial susceptibility patterns in order to guide the empirical use of antimicrobials. Sex was the only factor associated with MRSA carriage. Further studies should be done to fully assess factors associated to MRSA.