Is community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) an emerging pathogen among children in Brazil?

Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is spreading worldwide, but little is known about the epidemiology of this pathogen in Brazil. Objective: To evaluate clinical and microbiological features of children with S. aureus infections admitted to a university hospital. Methods: This was a cross-sectional study evaluating the potential risk factors for CA-MRSA, and a retrospective cohort evaluating in-hospital clinical outcomes. To include patients with both community and hospital-associated infections, we screened the results of the microbiological laboratory tests from January 1, 2012, to December 31, 2016. According to the phenotype, we classified the isolates in Methicillin-Susceptible S. aureus (MSSA), Hospital-Associated Methicillin-Resistant S. aureus (HA-MRSA), and CA-MRSA. Clinical data were collected from the patients' medical records. Results: We identified 279 cases of S. aureus infections (MSSA = 163, CA-MRSA = 69, HA-MRSA =41). Overall, the incidence density of CA-MRSA and MSSA infections increased while the HA-MRSA incidence density decreased over the study period. CA-MRSA infected patients were more likely to present with skin and soft tissue infections (OR: 2.83, 95%Cl: 1.54-5.33, p <0.001) and osteomyelitis (OR: 4.76; 95%CI: 1.16-22.71, p = 0.014) when compared to MSSA and HA-MRSA infections. Unadjusted case fatality rates were similar between MSSA-infected patients (3.14%, 5/159) and CA-MRSA infected patients (3.80%, 3/79, p = 0.792), while HA-MRSA infected patients were more likely to die in the hospital (12.20%, 5/41, p = 0.013). Conclusions: CA-MRSA is an emergent pediatric pathogen in Brazil. Our results highlight the relevance of choosing an appropriate initial antimicrobial drug for treating children with severe S. aureus infections. (C) 2018 Sociedade Brasileira de Infectologia. Published by Elsevier Espana, S.L.U.