Risk factors for nosocomial infections due to Pseudomonas aeruginosa producing metallo-beta-lactamase in two tertiary-care teaching hospitals.
OBJECTIVE
To assess risk factors for nosocomial infections due to Pseudomonas aeruginosa producing metallo-beta-lactamase (MBL-PA) in two teaching hospitals where horizontal dissemination has been demonstrated.


METHODS
A case-control study was performed in both hospitals (assigned as hospital 1 and 2). Cases were patients with MBL-PA infections and controls were those with non-MBL-PA infections. Multivariate analysis was performed to identify independent risk factors.


RESULTS
A total of 86 cases and 212 controls were included in the study. A logistic regression model showed that exposure to beta-lactams [odds ratio (OR) 3.21; 95% confidence interval (CI) 1.74-5.93] or fluoroquinolones (OR 3.50; 95% CI 1.46-8.37) was associated with MBL-PA infections. Other independent risk factors were neurological disease (OR 3.00; 95% CI 1.61-5.58), urinary tract infection (OR 2.48; 95% CI 1.21-5.09) and renal failure (OR 2.29; 95% CI 1.13-4.65). Admission to hospital 1 (OR 5.97; 95% CI 3.45-14.09) and intensive care unit stay (OR 2.07; 95% CI 1.46-3.96) were also associated with increased risk for MBL-PA infections.


CONCLUSIONS
beta-Lactam exposure is an important risk factor for MBL-PA infections even in a setting where patient-to-patient transmission plays a major role in the spread of the isolates. Other risk factors deserve further investigation, particularly exposure to fluoroquinolones.
Zavascki
Alexandre Prehn
AP
Infectious Diseases Service, Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil. apzavascki@terra.com.br
Barth
Afonso Luís
AL
Gaspareto
Patrick Barcelos
PB
Gonçalves
Ana Lúcia Saraiva
AL
Moro
Ana Lúcia Didonet
AL
Fernandes
Juliana Fernandez
JF
Goldani
Luciano Zubaran
LZ
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D024841:Fluoroquinolones / Q000627:therapeutic use; D006784:Hospitals, Teaching; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology*; D012307:Risk Factors; D001618:beta-Lactamases / Q000096:biosynthesis*; D047090:beta-Lactams / Q000627:therapeutic use
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D047090:beta-Lactams; D001618:beta-Lactamases