Increasing prevalence of nasal and rectal colonization with methicillin-resistant Staphylococcus aureus in children with cancer.

ABSTRACT

BACKGROUND: Infections with methicillin-resistant Staphylococcus aureus (MRSA), in community-settings, especially with strains carrying the Panton-Valentine Leukocidin (PVL) genes, have increased markedly in recent years. Colonization with S. aureus is a risk factor for infection. However, there are few studies that examine colonization and infection with PVL-positive strains of MRSA in cancer patients. PROCEDURE The epidemiology of colonization and infection with MRSA was studied in children with cancer during two time periods 2000/2001 and 2006/2007. PVL genes were screened and spa typing performed on the isolates. RESULTS: The prevalence of colonization with MRSA increased from 0.6% in 2000/2001 to 2.9% in 2006/2007 (P = 0.0003). MRSA colonization at admission was associated with infection (P < 0.0001; RR 38.32; 95% CI 23.36-62.84). The prevalence of infection increased from 0.99% in 2000/2001 to 3.78% in 2006-2007 (P = 0.0002). Of the 32 colonized patients, 18 (56%) had infection. None of the 14 colonized but non-infected patients had dual colonization of nares and rectum, while 8 of the 18 infected patients had colonization of both of these sites (P = 0.004). Ten patients (31%) were colonized with PVL-positive strains. Patients colonized with PVL-positive strains were more likely to be colonized both in the nares and rectum (P = 0.005), and more likely to have infection (P = 0.001). Recurrent MRSA infections were seen in 22% of patients. CONCLUSION: An increasing prevalence of colonization with MRSA was observed in children with cancer at our institution. Colonization with MRSA especially with PVL-positive strains was associated with infection.