Prevalence and acquisition of MRSA amongst patients admitted to a tertiary-care hospital in brazil
- Equal contributors
1 Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
2 Pós-Graduação em Epidemiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
3 Instituto de Matemática- Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
4 Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
BMC Infectious Diseases 2010, 10:328 doi:10.1186/1471-2334-10-328Published: 14 November 2010
There are few studies in Brazil that address baseline prevalence of MRSA colonization and associated risk factors at hospital admission, or the incidence of nosocomial colonization. We report a prospective study in a tertiary-care, university-affiliated hospital to implement a new MRSA control policy at the institution.
A cohort of randomly selected patients admitted to emergency and clinical wards at our hospital was followed until discharge. Nasal swabs were taken for identification of MRSA-colonized patients and detection of SCCmecA in positive cultures, at admission and weekly thereafter. Multivariate analysis using a log-binomial analysis was used to identify risk factors for colonization.
After screening 297 adult patients and 176 pediatric patients, the prevalence of MRSA at admission was 6.1% (95%CI, 3.6% to 9.4%), in the adult population and 2.3% (95%CI, 0.6% to 5.7%), for children. From multivariate analysis, the risk factors associated with colonization in adults were: age above 60 years (P = 0.019) and hospitalization in the previous year (P = 0.022). Incidence analysis was performed in 276 MRSA-negative patients (175 adults and 101 children). Acquisition rate was 5.5/1,000 patient-days for adults (95%CI, 3.4 to 8.5/1,000 patients-days), and 1.1/1,000 patient-days for children (95%CI, 0.1 to 4.0/1,000 patients-days).
The identification of MRSA carriers is a step towards establishing a control policy for MRSA, and helps to identify measures needed to reduce colonization pressure and to decrease the high acquisition rate in hospitalized patients.