Surveillance of extended-spectrum-beta-lactamase-producing Enterobacteriaceae in a Swiss Tertiary Care Hospital.
BACKGROUND
Extended spectrum beta-lactamase producing enterobacteriaceae (ESBL-E) are increasing worldwide, but there is sparse data on patient-to-patient transmission and the prevalence among risk groups in Switzerland. A prospective, observational cohort study was performed to: 1) assess the prevalence of ESBL-E at admission among at-risk groups; 2) evaluate nosocomial cross-transmission in acute care (ACF) versus long-term care facilities (LTCF); and 3) evaluate prevalent mutations of the detected beta-lactamase genes.


METHODS
Predefined risk groups were screened either on admission or after having been in contact with index patients diagnosed with ESBL-E by clinical cultures. Three patient categories were distinguished: patients previously known to be ESBL-E carrier (category I); patients transferred from countries with known high ESBL-E prevalence and thus at risk for ESBL-E carriage (category II); and roommates of index patients (category III).


RESULTS
A total of 93 patients with ESBL-E were identified: Sixty-two percent (31/50) of category I patients were positive when screened upon rehospitalisation (category I); eighteen percent (22/124) of category II patients; and eight out of 177 category III patients (4.5%) of which five showed identical ESBL-E strains or shared the same beta-lactamase gene as their index cases. The incidence density of transmission was 0.9/1000 exposure-days, with more transmissions in ACF than in LTCF (4.2 vs 0.4/1000 exposure days). CTX-M-15 was the predominant beta-lactamase gene (60%) among the index patients.


CONCLUSIONS
The prevalence of ESBL-E carriage among patients coming from regions with endemic rates or those previously identified as carriers is high; on-admission screening should be considered for these high risk populations. Documented nosocomial ESBL-E transmission was low.
Fankhauser
C
C
Infection Control Programme, University of Geneva Hospitals, Geneva, Switzerland.
Zingg
W
W
Francois
P
P
Dharan
S
S
Schrenzel
J
J
Pittet
D
D
Harbarth
S
S
D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000453:epidemiology; D015331:Cohort Studies; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology / Q000472:pathogenicity*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012189:Retrospective Studies; D013557:Switzerland; D055815:Young Adult; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000378:metabolism*
D001618:beta-Lactamases