Is asymptomatic bacteriuria a risk factor for prosthetic joint infection?
BACKGROUND
Infection is a major complication after total joint arthroplasty. The urinary tract is a possible source of surgical site contamination, but the role of asymptomatic bacteriuria (ASB) before elective surgery and the subsequent risk of infection is poorly understood.


METHODS
Candidates for total hip or total knee arthroplasty were reviewed in a multicenter cohort study. A urine sample was cultured in all patients, and those with ASB were identified. Preoperative antibiotic treatment was decided on an individual basis, and it was not mandatory or randomized. The primary outcome was prosthetic joint infection (PJI) in the first postoperative year.


RESULTS
A total of 2497 patients were enrolled. The prevalence of ASB was 12.1% (303 of 2497), 16.3% in women and 5.0% in men (odds ratio, 3.67; 95% confidence interval, 2.65-5.09; P < .001). The overall PJI rate was 1.7%. The infection rate was significantly higher in the ASB group than in the non-ASB group (4.3% vs 1.4%; odds ratio, 3.23; 95% confidence interval, 1.67-6.27; P = .001). In the ASB group, there was no significant difference in PJI rate between treated (3.9%) and untreated (4.7%) patients. The ASB group had a significantly higher proportion of PJI due to gram-negative microorganisms than the non-ASB group, but these did not correlate to isolates from urine cultures.


CONCLUSIONS
ASB was an independent risk factor for PJI, particularly that due to gram-negative microorganisms. Preoperative antibiotic treatment did not show any benefit and cannot be recommended.
Departments of Orthopaedics.
Ricardo
R
Sousa
Department of Orthopaedics, Bone and Joint Infection Unit.
Ernesto
E
Muñoz-Mahamud
Department of Orthopaedics.
Jonathan
J
Quayle
Departments of Orthopaedics.
Luis
L
Dias da Costa
Department of Orthopaedics, Bone and Joint Infection Unit.
Cristina
C
Casals
Department of Orthopaedics.
Phylip
P
Scott
Departments of Orthopaedics.
Pedro
P
Leite
Department of Orthopaedics, Bone and Joint Infection Unit.
Paz
P
Vilanova
Department of Orthopaedics, Bone and Joint Infection Unit.
Sebastian
S
Garcia
Microbiology, Centro Hospitalar do Porto-Hospital de Santo António.
Maria Helena
MH
Ramos
Department of Biostatistics, Administração Regional de Saúde do Norte, Porto, Portugal.
Joana
J
Dias
Department of Infectious Diseases, Hospital Clínic of Barcelona, Spain.
Alex
A
Soriano
Department of Microbiology, Frimley Park Hospital, Frimley, United Kingdom.
Andrea
A
Guyot
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001170:Arthritis, Infectious / Q000453:epidemiology*; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D001437:Bacteriuria / Q000150:complications*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016459:Prosthesis-Related Infections / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
bacteriuria; incidence; prosthesis-related infections; risk factors