Prevalence and distribution of methicillin-resistant staphylococcal infections in a tertiary care hospital: a prospective observational study

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MR-CONS) cause healthcare- and community-associated infection and spread rapidly within hospitals. Local surveillance guides empirical therapy and infection control. This study determined the prevalence, distribution, and outcome of MRSA and MR-CONS infections across areas of a tertiary care hospital.

Methods: A six-month prospective observational study was conducted at S.S. Institute of Medical Sciences and Research Centre, Davangere. Staphylococcal isolates from clinical specimens submitted from different hospital areas were identified by standard methods. Methicillin resistance was detected by cefoxitin disc diffusion per CLSI criteria; susceptibility was tested by the Kirby-Bauer method.

Results: Of 216 staphylococcal isolates, 80 (37.0%) were S. aureus and 136 (63.0%) were CONS. Fourteen isolates (17.5% of S. aureus) were MRSA, and 16 (11.8% of CONS) were MR-CONS, an overall rate of 13.9% (30/216). General wards and the outpatient department contributed the most isolates and highest MRSA/MR-CONS counts, while ICUs contributed few resistant isolates. Blood and pus/wound/tissue specimens yielded the largest share of resistant isolates. No isolate was vancomycin-resistant, and all patients recovered.

Conclusions: Methicillin resistance was relatively low overall, suggesting effective infection control, particularly in critical care areas. The disproportionate burden of resistant isolates in general wards and the OPD highlights the need to strengthen infection control outside ICUs and investigate risk factors for community- and ward-acquired MRSA.