Carriage rate of carbapenem-resistant Klebsiella pneumoniae in hospitalised patients during a national outbreak.
During a national outbreak of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Israel, we conducted a point prevalence survey to determine the extent of asymptomatic carriage. Subsequently, a retrospective case-control study was done, comparing carriers of CRKP with non-carriers, in order to detect risk factors for carriage. Oral, perianal and rectal swabs were obtained from all hospitalised eligible and consenting patients. Selective media for carbapenem-resistant Gram-negative bacteria were used and pulsed-field gel electrophoresis (PFGE) helped to determine clonal source. Culture was obtained from 298 patients. Sixteen (5.4%) were carriers of CRKP, with a higher carriage rate in medical and surgical wards. Only 18% of carriers were treated with any carbapenem prior to the survey. Five of the 16 carriers had a positive clinical specimen for CRKP, hence a clinical infection versus asymptomatic carriage ratio of 1:3. The rectum was the most sensitive site sampled, detecting 15/16 carriers, and the overall sensitivity of the method was 94% with a negative predictive value of 99.6%. In a multivariate analysis of risk factors for CRKP carriage, three variables were significantly related to carriage state: diaper use, longer duration of hospital stay and vancomycin use. PFGE demonstrated that all 16 isolates were identical, confirming clonal origin. A point prevalence survey performed at a single medical centre during an outbreak of CRKP demonstrated a carriage rate of 5.4%. The clonal origin of these isolates suggests that strict adherence to isolation procedure may contain this outbreak.
Infectious Disease Unit, Shaare Zedek Medical Center, Jerusalem, affiliated with the Hebrew University - Hadassah Medical School, Jerusalem, Israel.
Y
Y
Wiener-Well
B
B
Rudensky
A M
AM
Yinnon
P
P
Kopuit
Y
Y
Schlesinger
E
E
Broide
T
T
Lachish
D
D
Raveh
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D015780:Carbapenems / Q000494:pharmacology*; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016172:DNA Fingerprinting; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007557:Israel / Q000453:epidemiology; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D012007:Rectum / Q000382:microbiology; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult; D018440:beta-Lactam Resistance
D000900:Anti-Bacterial Agents; D015780:Carbapenems