WASHINGTON — A clonal outbreak of community-acquired methicillin-resistant Staphylococcus aureus in Los Angeles County led to a high rate of hospitalizations among children in 2003, Elizabeth Bancroft, M.D., reported in a poster at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
Following four skin infection outbreaks due to a particular clone of MRSA (USA 300; ST:8) in 2002, the Los Angeles County Department of Health Services made community-acquired methicillin-resistant S. aureus (CAMRSA) infections in hospitalized children less than 18 years of age a reportable condition for 6 months during 2003. A total of 140 cases were reported between May 5 and Nov. 7, said Dr. Bancroft of the county health department.
Mean age of the children was 6.25 years (range 0-17), 51% were female, 66% were Hispanic, 16% white, 15% black, and the remainder said they were “other.” Their mean length of stay was 5.13 days (range 1-30). Diagnoses included cellulitis in 44%, abscess in 36%, and a combination of the two in 11%.
In 23%, chart notes indicated a misdiagnosis of possible insect or spider bites, and 75% of the total 135 who had been treated with antibiotics were initially treated inappropriately with β-lactams, she said at the conference, sponsored by the American Society for Microbiology.
Among 82 for whom a caregiver was interviewed, 24 (29%) had a household contact with a skin infection within a month of the child's infection.
Other nosocomial risk factors were present in 29 (35%), while risk factors for community-acquired infection were present in 38 (46%), including 9 (11%) who had contact with a recently incarcerated person.
Of 83 isolates analyzed, 79 (96%) were consistent with the USA 300; ST:8 CAMRSA genotype, even though many of the children had nosocomial risk factors. During the 6 months, the 140 pediatric CAMRSA cases in Los Angeles far outnumbered other common reportable diseases, including salmonella (99) and invasive pneumococcal disease (84), she noted.