John Chipolombwe, Mili Estee Török, Nontombi Mbelle, Peter Nyasulu

The objective of this study was to evaluate the optimal number of sampling sites for detection of methicillin-resistant Staphylococcus aureus (MRSA) colonization. We performed a Medline search from January 1966 to February 2014 for articles that reported the prevalence of MRSA at different body sites. Studies were characterized by study design, country and period of the study, number of patients and/or isolates of MRSA, specimen type, sites of MRSA isolation, study population sampled, diagnostic testing method, and percentage of the MRSA isolates at each site in relation to the total number of sites. We reviewed 3,211 abstracts and 177 manuscripts, of which 17 met the criteria for analysis (n=52,642 patients). MRSA colonization prevalence varied from 8% to 99% at different body sites. The nasal cavity as a single site had MRSA detection sensitivity of 68% (34%-91%). The throat and nares gave the highest detection rates as single sites. A combination of two swabs improved MRSA detection rates with the best combination being groin/throat (89.6%; 62.5%-100%). A combination of three swab sites improved MRSA detection rate to 94.2% (81%-100%) with the best combination being groin/nose/throat. Certain combinations were associated with low detection rates. MRSA detection rates also varied with different culture methods. A combination of three swabs from different body sites resulted in the highest detection rate for MRSA colonization. The use of three swab sites would likely improve the recognition and treatment of MRSA colonization, which may in turn reduce infection and transmission of MRSA to other patients.