Evolving epidemiology of pediatric Staphylococcus aureus cutaneous infections in a Baltimore hospital

To examine the epidemiology, antibiotic susceptibility profiles, and outcomes in pediatric Staphylococcus aureus (SA) cutaneous infections at a time when community-associated (CA) methicillin-resistant SA (CA-MRSA) infections seemed to be increasing in our community.

The hospital microbiology database was searched for unique skin and wound SA isolates among pediatric patients between November 2002 and October 2003. Demographic and clinical data were abstracted from medical records. Cases were classified as either health care-associated (HA) or CA.

Among 181 pediatric SA cutaneous infections, 81 (45%) were caused by MRSA. Most (84%) of these MRSA were CA. Between the first 6 months and second 6 months of the study period, CA-MRSA increased from 15% to 45% (P < 0.001) of all SA cutaneous infections. Ninety-eight percent and 94% of CA-MRSA were susceptible to trimethoprim/sulfamethoxazole and clindamycin (confirmed by D test), respectively. Hospitalization occurred for 25% of CA-MRSA and 75% of HA-MRSA (P = 0.004). Drainage procedures were performed for 70% of CA-MRSA. No cases of CA-MRSA skin infections were accompanied by bacteremia.

The CA-MRSA cutaneous infections increased in children in our urban Baltimore hospital in 2003. These CA-MRSA were erythromycin resistant, clindamycin susceptible, and trimethoprim/sulfamethoxazole susceptible. The CA-MRSA cutaneous infections frequently required drainage and were not associated with bacteremia. Children with cutaneous MRSA infections were less likely to have traditional health care risk factors than children with cutaneous methicillin-sensitive SA infections--an inversion of past patterns of MRSA infections--but were equally likely to be hospitalized when other factors were considered. These CA-MRSA cutaneous infections can be managed with abscess drainage and culture, careful follow-up, and empirical clindamycin therapy when clinically indicated.