Carriage Rate of Methicillin-Resistant Staphylococcus aureus among Workers in Critical Care Units of a Tertiary Hospital in Southwestern Nigeria

Background: Carriage of methicillin-resistant Staphylococcus aureus (MRSA) among Healthcare workers (HCWs) who serves as agent of pathogen transmission in hospital settings portends danger to critical care patients.

Aim: To determine the carriage rate of MRSA among HCWs in the critical care units of the hospital, to identify the factors associated with carriage, and to determine the antibiotic resistance pattern of isolates.

Study Design: A cross sectional descriptive study.

Materials and Methods: A total of 135 randomly selected consenting HCWs from critical care units were studied. Data on demographic characteristics and infection control practices were obtained from participants with the aid of questionnaire. Swabs of the anterior nares and hands of participants were cultured on oxacillin-containing mannitol salt agar (MSA), S. aureus was identified using convectional criteria and MRSA was identified by cefoxitin disc diffusion technique. Antibiotic susceptibility testing was carried out on all isolated MRSA.

Results: Carriage rate of MRSA was high (26.7%). Poor handwashing practices (P=.008) and presence of wound or skin infection (P=.003) were associated with higher isolation rate. None of the age, gender, profession and duration of unit stay of workers was associated with carriage rate of MRSA. Isolation rate was higher from the nose (18.5%) than the hands (8.1%). Isolates demonstrated high resistance to antibiotics: penicillin (100%), amoxicillin/clavulanate (66.7%), cefuroxime (61.1%), ceftriaxone (63.9%), erythromycin (55.6%). All isolates were sensitive to vancomycin.

Conclusion: Carriage rate of MRSA among critical care unit staff was high in this study. There is urgent need for formulation of infection control policies and enforcement, to prevent MRSA spread among critical care patients.