Staphylococcus aureus and methicillinresistant Staphylococcus aureus nasal carriage and infection in children with varicella

Abstract

Objective: To study the prevalence of nasal colonization with CA-MRSA in children with chickenpox treated at hospital level, assessing the presence of secondary infection and clinical outcome.
Methods: Cross-sectional study. A questionnaire assessing risk factors for colonization and infection with S. aureus was applied and nasal swab was collected. The resistance to methicillin was confirmed by detection of the mecA gene by PCR. The severity of cases was estimated using the Pediatric Risk of Mortality score (PRISM) and the clinical outcome of hospitalized
patients was assessed. Categorical variables were compared using the chi-square or the Fisher’s exact test, and p-value< 0.05 was considered statistically significant.
Results: 55 patients were included in the study. The prevalence of S. aureus nasal colonization was 34.5% and CA-MRSA was 7.3%. Bivariate analysis showed statistical significance between colonization with S. aureus and male gender, infectious complications, skin infection, use of beta-lactams and health worker in the family (p < 0.05). The median PRISM of the patients colonized with MRSA was 4.3% and in the non-colonized was 0.7%. Clinical outcome of 26 inpatients was evaluated. The median PRISM of patients colonized with MRSA was 23.6% and non-colonized was 0.8%.
Conclusions: There is evidence that the increase in rates of colonization with CA-MRSA contributes to an increase in the severity of cases of secondary infection in pediatric patients with chickenpox suggesting that the initial empirical antimicrobial therapy in severe cases should include an anti-MRSA agent.