Methicillin-resistant staphylococcus aureus (mrsa) colonization among Intensive Care Unit (ICU) patients and health care workers at Muhimbili National Hospital, Dar es salaam, Tanzania

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as important nosocomial pathogen worldwide. MRSA may induce clinically manifested diseases, or the host may remain completely asymptomatic. Objective: To determine the magnitude of MRSA colonization among ICU patients and health care workers at Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania. Methodology: A cross-sectional hospital-based study was conducted from October 2012 to March 2013 in the two ICUs at MNH. Admitted patients and health care workers were enrolled in the study. Interviewer administered questionnaires, patient history forms, observation charts and case report forms were used to collect data. Swabs (nostrils, axillary or wounds) were collected. MRSA were screened and confirmed using cefoxitin, oxacillin discs and oxacillin screen agar. Antibiotic susceptibility was performed using Kirby-Bauer disk diffusion method. The risk factors for MRSA were determined using the logistic regression analysis and a p - value of <0.05 was considered as statistically significant. Results: Of the 169 patients and 47 health workers who were recruited, the mean age was 43.4 years SD ± 15.3 and 37.7 years SD ± 11.44 respectively. Among the patients males contributed 108 (63.9%) while in health care worker majority 39(83%) were females. The prevalence of MRSA colonization among patients and health care workers was 11.83% and 2.1% respectively. All (21) MRSA isolates were highly resistant to penicillin and erythromycin, and 18 (85.7%) were highly sensitive to vancomycin. Being male (AOR 6.74, 95% CI 1.31-34.76), history of sickness in past year (AOR 4.89, 95% CI 1.82- 13.12), being sick for more than 3 times in the past year (AOR 8.91, 95% CI 2.32-34.20), being diabetic (AOR 4.87, 95% CI 1.55-15.36) and illegal drug use (AOR 10.18, 95%CI 1.36-76.52) were found to be independently associated with MRSA colonization. Conclusions: A study identified a high prevalence of MRSA colonization among patients admitted in the ICU. MRSA isolates were highly resistant to penicillin and erythromycin. History of illegal drug use was highly associated with MRSA colonization. Recommendations: Patients and health care workers should be screened prior to ICU admission and routinely, respectively, to identify individuals carrying MRSA. MRSA screening should prioritize groups at risk for MRSA colonization. Since MRSA show high resistance to commonly used antimicrobials, antibiotic susceptibility testing is recommended for effective treatment.