Community-acquired methicillin-resistant Staphylococcus aureus colonization in healthy children attending an outpatient pediatric clinic

Background. We previously showed that children attending an inner city pedi atric emergency department were sometimes asymptomatically colonized with c lindamycin-susceptible community-acquired methicillin-resistant Staphylococ cus aureus (MRSA) and borderline methicillin-resistant S. aureus (BRSA) as well. We wished to ascertain whether healthy children attending an outpatie nt clinic were colonized with these organisms. Therefore to estimate the pr evalence of community-acquired MRSA and BRSA nasal colonization in a well c hild population, we cultured children attending an inner city pediatric out patient clinic. Study design. This was a prospective cross-sectional study conducted from J anuary to August, 1999, at a primary care outpatient facility at the Univer sity of Chicago. The target population was 500 healthy children less than o r equal to 16 years of age who attended this facility to receive well child care. Results. One hundred twenty-two (24.4%) children were colonized with S. aur eus. Three of the 122 (2.5%) S. aureus isolates were MRSA, they came from c hildren who lacked predisposing risk factors and were susceptible to clinda mycin, gentamicin, trimethoprim-sulfamethoxazole, rifampin and ciprofloxaci n. Two (1.6%) additional S. aureus isolates were BRSA, both children had pr edisposing risk factors for MRSA colonization. The mecA gene was present in the 3 MRSA isolates and absent in both BRSA isolates. Conclusions. These data document that a reservoir of asymptomatic MRSA colo nization exists among healthy children who lack traditional risk factors fo r MRSA infections.