Active surveillance to determine the impact of methicillin resistance on mortality in patients with bacteremia and influences of the use of antibiotics on the development of MRSA infection.
BACKGROUND
Methicillin-resistant Staphylococcus aureus (MRSA) is among the most important pathogens of nosocomial infections, mainly in intensive care units (ICUs), and accounts for 40-60% of all healthcare-associated S. aureus infections. We evaluated the incidence of nosocomial infection by S. aureus, identified the risk factors for MRSA infection, and evaluated the effect of resistance to methicillin on mortality in patients.


METHODS
We conducted MRSA surveillance at a university hospital in Brazil from January 1, 2010, to December 31, 2010, and performed a retrospective case-control matched study to evaluate the frequency of subsequent MRSA bacteremia and death among patients. We evaluated and compared the risk factors between patients with MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) infection.


RESULTS
Sepsis was the most common cause of infection (17.7/1,000 patient-days), followed by surgical site (11.4/1,000 patient-days), pneumonia (4.1/1,000 patient-days), and urinary tract infection (2.4/1,000 patient-days). The significant risk factors were time of hospitalization, use of central vascular catheter (CVC), urinary catheter, nasogastric tube, parenteral nutrition, tracheostomy, mechanical ventilation, and previous antibiotic administration, the latter of which was the only independent risk factor for MRSA infection. Mortality was significantly higher in patients with MRSA. The number of antibiotics tested was not related to increases in the frequency of MRSA/1,000 patient-days. The incidence of mortality attributable to MRSA (bloodstream infection) BSI was 50%.


CONCLUSIONS
Surveillance results showed that the use of high levels of antibiotics was directly related to the development of MRSA infection, and the mortality attributable to MRSA in patients with bacteremia was significant.
Curso de graduação em Enfermagem, Faculdade de Medicina, Universidade Federal de Uberlândia(FAMED/UFU), UberlândiaMG.
Juliana Pena
JP
Porto
Programa de Pós-Graduação em Imunologia e Parasitologia Aplicadas, Universidade Federal de Uberlândia, UberlândiaMG.
Rosana Oliveira
RO
Santos
Programa de Pós-Graduação em Imunologia e Parasitologia Aplicadas, Universidade Federal de Uberlândia, UberlândiaMG.
Paulo Pinto
PP
Gontijo Filho
Programa de Pós-Graduação em Imunologia e Parasitologia Aplicadas, Universidade Federal de Uberlândia, UberlândiaMG.
Rosineide Marques
RM
Ribas
D000328:Adult; D016470:Bacteremia / Q000382:microbiology / Q000401:mortality*; D001938:Brazil / Q000453:epidemiology; D003428:Cross Infection / Q000382:microbiology / Q000401:mortality*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D013203:Staphylococcal Infections / Q000382:microbiology / Q000401:mortality*