Epidemiology and successful control of a large outbreak due to Klebsiella pneumoniae producing extended-spectrum beta-lactamases.
An outbreak due to extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) was detected from May 1993 to June 1995. A total of 145 patients, particularly patients in intensive care units (ICUs) (107 patients [72%]), were colonized or infected. Infection developed in 92 (63%) patients, and primary bacteremia caused by ESBL-KP was the most frequent infection (40 of 92 patients [43%]). A single clone of ESBL-KP was identified by pulsed-field gel electrophoresis analysis throughout the whole period, and no molecular epidemiological relationship could be found between the epidemic strain and non-ESBL-KP isolates. To determine risk factors for ESBL-KP infection weekly rectal swabs were obtained in three serial incidence surveys (470 patients); the probabilities of carriage of ESBL-KP in the digestive tract were 33% (October and November 1993), 40% (May and June 1994), and 0% (October and November 1995) at 10 days of ICU admission. A logistic regression model identified prior carriage of ESBL-KP in the digestive tract (odds ratio, 3.4; 95% confidence interval 1.1 to 10.4) as an independent variable associated with ESBL-KP infection. A statistically significant correlation was observed between the restricted use of oxyimino-beta-lactams (189 defined daily doses [DDD]/ 1,000 patient-days to 24 DDD/1,000 patient-days) and the trends of ESBL-KP infection (r = 0.7; P = 0.03).
Peña
C
C
Infectious Disease Service, Hospital de Bellvitge, Universidad de Barcelona, Spain. mpujol@csv.scs.es
Pujol
M
M
Ardanuy
C
C
Ricart
A
A
Pallares
R
R
Liñares
J
J
Ariza
J
J
Gudiol
F
F
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology*; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007525:Isoelectric Focusing; D007710:Klebsiella Infections / Q000188:drug therapy* / Q000453:epidemiology*; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010641:Phenotype; D012307:Risk Factors; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases