Pressure ulcers colonized by MRSA as a reservoir and risk for MRSA bacteremia in patients at a brazilian university hospital.

UNLABELLED Pressure ulcers (PU) are a major reservoir of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals. The objectives of this study were to estimate the prevalence of MRSA colonization in PU of hospitalized patients with Stage II or higher PU, to identify risk factors for colonization of these wounds, and to ascertain whether MRSA colonization of PU increases the risk of MRSA bacteremia. METHODS This study was conducted at the Clinical Hospital of Federal University of Uberlandia, MG, Brazil. A prospective cohort study of 145 patients with Stage II or higher PU, colonized or not with MRSA, was conducted over 21 months. Infected ulcers were defined for clinical signs and for positive evaluation of smears of the wound by the ratio of polymorphonuclears to epithelial cells of ≥ 2:1, after Giemsa staining. RESULTS Sixty-three (43.5%) MRSA colonized PU patients were identified, but none of the risk factors analyzed were independently associated with MRSA colonization. Among the patients with positive blood cultures and MRSA colonized PU, the odds ratio for MRSA bacteremia (OR = 19.0, 95% CI = 2.4-151.1, P < 0.001) and mortality rate (OR = 21.9, 95% CI = 1.23-391.5, P = 0.002), were high. Independent risk factors for MRSA bacteremia were: ≥ 2 underlying disease (OR = 6.26, 95% CI = 1.01-39.1, P = 0.05) and prior MRSA infected PU (OR = 12.75, 95% CI=1.22-132.9, P = 0.03). CONCLUSION The present study identifies MRSA colonized PU patients as a potential epidemiologic reservoir for this organism and a high-risk for MRSA bacteremia, which contributes to prolonged hospitalization and poor prognosis. .