Epidemic of community-acquired methicillin-resistant Staphylococcus aureus infections: a 14-year study at Driscoll Children's Hospital

Abstract

Background: Previously we reported the rapid emergence and exponential increase of community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) infections in South Texas children.

Objective: To assess whether changes have occurred in the frequency, types, susceptibility, and treatment of CAMRSA infections at Driscoll Children's Hospital.

Methods: Data from 1990 through 2001 were collected during 2 previous studies. Data from 2002 through 2003 were collected and compared with data from 1990 through 2001. All S aureus isolates were identified by a computer-assisted search of culture results, and the medical records were reviewed for all patients with MRSA infections.

Results: A total of 1002 MRSA cases were identified from 1990 through 2003 of which 928 (93%) were community-acquired. The number of CAMRSA cases ranged from 0 to 9 per year from 1990 through 1999 and then increased exponentially from 36 in 2000 to 459 in 2003. The most common type of CAMRSA infection in children without (94%) and with (72%) risk factors was cellulitis and abscess. A higher percentage of children with risk factors had invasive CAMRSA infections (26% vs 3%; P<.001). From 2002 through 2003, there was a significant difference in clindamycin susceptibility between CAMRSA isolates from children without and with risk factors and nosocomial isolates (97% and 86% vs 62%; P<.005). A higher percentage of patients admitted for treatment of CAMRSA infections received an empirical intravenous antibiotic to which the organism was susceptible when comparing 2002-2003 with 1990-2000 (96% vs 15%; P<.001). During this 14-year study, all patients recovered, including those with life-threatening CAMRSA infections.

Conclusion: The rapid emergence of CAMRSA as a cause of noninvasive and invasive infections in children, which started occurring in the 1990s, has reached epidemic proportions.