Antibiotic Susceptibility, Carrier State and Predictors of Outcome of Staphylococcus aureus Infections in Hospitalized Children

ABSTRACT

Objectives: To evaluate the antibiotic resistance pattern, clinical profile and predictors for adverse outcomes in children hospitalized due to staphylococcal infection; and the frequency of nasal and axillary carrier states in these children. Methods: This descriptive study enrolled 100 symptomatic children (aged 1 month - 12 years) in whom S. aureus was isolated from cultures of blood, pus or cerebrospinal fluid. All samples were processed as per the Clinical and Laboratory Standards Institute (CLSI) standards. Antimicrobial susceptibility was tested using disc diffusion method; minimum inhibitory concentration (MIC) for vancomycin was measured using E strips. Predictors for poor recovery were determined by univariate and multivariable logistic regression analysis. Results: Skin and soft tissue infections were the most common (47%) followed by respiratory infections (37%). Methicillin-resistant Staphylococcus aureus (MRSA) was detected in 62%, out of which 63% (39/62) were multi-drug resistant. Carrier state was present in 49% (93% MRSA); 80% were axillary carriers. High MIC (>1 µg/mL) for vancomycin was seen in 65% of patients, and was the only factor associated with poor recovery [aOR (95%CI) 5.3 (1.6,18.5); P=0.008] on multivariable logistic regression analysis. Conclusion: MRSA is the predominant strain in severe staphylococcal infections requiring hospitalization, and majority of them are multidrug resistant. High MIC to vancomycin among S. aureus is an emerging concern.