Prevalence and Anti-Microbial Susceptibility of Methicillin Resistant Staphylococcus aureus at Moi Teaching and Referral Hospital Eldoret

Background: Methicillin-resistant Staphylococcus aureus (MRSA) are pathogens that have major negative impact in all aspects of patient care and are increasingly being recognized as troublesome pathogens in the community. The MRSA are multi-drug resistant bacteria responsible for higher morbidity, mortality and cost of treatment in the affected patients. Research on MRSA antimicrobial susceptibility and resistance in developing countries is limited;hence accurate burden is not certain. Objective: To determine the prevalence and susceptibility pattern of MRSA in S. aureus isolates from patients treated in various units at Moi Teaching and Referral Hospital. Study Design: Cross-sectional design was used to conduct the study. Methods and Materials: Staphylococcus aureus stored isolates from patients at various units at Moi Teaching and Referral Hospital (MTRH) were identified by laboratory conventional methods. Methicillin resistant Staphylococcus aureus was determined using cefoxitin and oxacillin, discs and confirmed by Penicillin Binding Protein (PBP2a’) latex agglutination test. Susceptibility testing was performed according to the Clinical Laboratory Standards Institute procedures. Control strains used were: ATCC 43300 for Methicillin resistant S. aureus (MRSA) strains and ATCC 29213 for methicillin susceptible S. aureus (MSSA) strains. Nine anti-microbials (Erythromycin, Gentamycin, Tetracycline, Vancomycin, Rifampin, Linezolid, Ciprofloxacin, Clindamycin and Fucidicacid) were used to test the anti-microbial susceptibility patterns. Control organisms were run along with the isolates for quality Assurance. The data was analyzed using STATA version 11. Categorical variables were summarized as frequencies and the corresponding percentages. Results were presented using tables and graphs. Results: A total of 107 isolates of S. aureus were obtained, of which 39 (37%) were MRSA. Most of the MRSA, 13 (33%) and 7 (17%), were found in pus and tracheal aspirate samples respectively. Majority of the MRSA isolates were from surgical wards and intensive care unit. The MRSA isolates were highly resistant to erythromycin (92%;36/39) and tetracycline (92% 36/39) and moderately susceptible to linezolid (77% 30/39), Vancomycin (75% 29/39) and fucidic acid (67% 26/39). A total of 28 (74.4%) MRSA isolates were Clindamycin inducible resistant. Conclusions and Recommendations: This study showed that MRSA is a significant pathogen at MTRH. The MRSA were most detected in pus specimens and least in peritoneal aspirates. Routine Screening of S. aureus isolates for MRSA strains at MTRH is therefore imperative. Infection control measures should be put in place to reduce prevalence and prevent the spread of MRSA at MTRH.

Factors Associated with First-Line Antiretroviral Therapy Failure amongst HIV-Infected African Patients: A Case-Control Study

Background: Since 2001, anti-retroviral therapy (ART) has been provided to over 75,000 HIV-infected patients at the USAID-Academic Model Providing Access to Healthcare (AMPATH) Partnership in western Kenya. Over 1000 of these patients have switched to second-line ART. We therefore set out to determine factors associated with first-line ART failure amongst these patients. Methods: This case controlled study matched patients (in the ratio 1:2) from the electronic AMPATH Medical Record System on the basis of age, gender, and ART initiation date. Cases were adults (≥18 years) who initiated second-line ART between January 1, 2007 and July 31, 2011 after at least one viral load measurement >5000 copies/ml or satisfying the WHO immunological or clinical failure criteria. Controls were those on non-failing first-line ART with a CD4 count > 400 /ml within the last 12 months, at the time of case incidence. Conditional logistic regression for paired data was used to assess association. We evaluated the strength of association of risk factors using stratified Cox model. Results: Of the 1084 cases and 2149 controls included in the analysis, 62% were female. Median age was 36.5 years (IQR = 30.7 - 43.1);median baseline CD4 cell count was 161 /ml (IQR = 72 - 277);Median time to ART failure was 37 months (IQR = 24 - 47). Low baseline CD4 count < 50 /ml (H.R = 7.07, (95% CI = 4.92 - 10.15);Zidovudine based ART (H.R 1.76, 95% CI = 1.25 - 2.48) and imperfect ART adherence (H.R = 2.77, 95% CI = 2.20 - 3.49) were independently associated with treatment failure. Conclusion: In this setting, low baseline CD4 count, zidovudine-based ART and imperfect adherence are associated with first-line ART treatment failure.