Community-acquired methicillin resistant Staphylococcus aureus infections of the hand

Background: The purpose of this study was to determine the incidence and patterns of community-acquired methicillin resistant Staphylococcus aureus (MRSA) hand infections in patients that required hospital admission and surgical drainage at a large urban, county hospital. Methods: A retrospective chart review of 247 patients treated with surgical debridement of hand infections from January 2003 to December 2006 was done. Nosocomial infections were excluded, leaving 192 patients with community-acquired infections. Each surgical specimen was cultured and tested for antibiotic susceptibility. A database was created to track each culture along with each patient's demographics. Particular attention was paid to infections with Staphylococcus aureus. Patient demographics were analyzed using Chi-square and Student t-test when appropriate. Results: Of 192 patients, 94 had MRSA (48.9%), 30 had methicillin sensitive Staphylococcus aureus MSSA (15.6%) and 68 (35.4%) had other organisms. Over 4 years, both the total number of hand infections and the number of MRSA infections increased. Incarceration and history of mental illness were the most significant predictors for community-acquired MRSA with an odds ratio of 3.85 (95% CI of 1.22-12.11) and 3.42 (95% CI of 1.04-11.23), respectively. Smokers and spider bite injuries were more likely associated with community-acquired MRSA than other organisms (P-values=0.027 and 0.018, respectively). Although not statistically significant, the mean length of stay for community-acquired MRSA patients was 6.82 days compared with 5.17 days for MSSA patients (P=0.07). Conclusions: The number of community-acquired MRSA hand infections is on the rise in our community and orthopaedic population. Risk factors associated with community-acquired MRSA infections include a history of incarceration, mental illness, smoking and spider bites.