Changing microbiology of pediatric neck abscesses in Iowa 2000-2010.

Objectives/hypothesis: To examine the changing microbiology of pediatric neck abscesses over a 10-year period with particular interest in methicillin-resistant Staphylococcus aureus (MRSA) infections and their associated antibacterial-resistance patterns, including resistance to clindamycin, a frequently used antibiotic for Staphylococcus aureus.

Study Design: Retrospective chart review at a tertiary academic medical center.

Methods: One hundred and twenty-two consecutive pediatric patients managed between January 2000 and June 2010 with incision and drainage of a proven neck abscess.

Results: Seventy-four patients with 76 abscesses were identified. A microorganism was found in 65 (85%) of the 76 abscesses. Forty-three percent grew Staphylococcus aureus (SA), 12% were methicillin-resistant Staphylococcus Aureus (MRSA), and 31% were methicillin-susceptible Staphylococcus aureus (MSSA). There was a significant increase in the incidence of MRSA infections during the study period, with only one case of MRSA diagnosed in the first half of the study (from 2000-2004) compared with seven in the second half (from 2005-2010) (P = 0.023). The second most common bacterial etiology or isolate was Streptococcus pyogenes in 27%, while the remaining 30% grew mixed oral flora and other microorganisms.

Conclusions: These findings demonstrate a statistically significant rise in the proportion of MRSA neck infections in pediatric patients in Iowa. Resistance to clindamycin was highest among MSSA isolates. Clindamycin-resistant S. aureus and Streptococcus pyogenes are established pathogens in neck infections. In communities with similar microbiology patterns, empiric treatment with combination therapy of a beta lactam and vancomycin or trimethoprim/sulfamethoxazole should be initiated until culture results are available.