Extensive hospital-wide spread of a multidrug-resistant enterobacter cloacae clone, with late detection due to a variable antibiogram and frequent patient transfer.
A hospital-wide increase in the number of patients with aminoglycoside-resistant Enterobacter cloacae (AREC) isolated from clinical cultures was detected in December 2002 using a classical surveillance system (CSS). CSS refers to a strategy based on the recognition of an increased incidence of a species with a particular antibiogram at certain wards in a limited period. Since clonal spread was suspected, hospital records were reviewed for E. cloacae culture-positive patients. Based upon genotyping of 139 clinical E. cloacae isolates from 80 patients, it was concluded that 53 patients had had clinical cultures with a single AREC clone since April 2001. Determinants for unnoticed spread were investigated retrospectively, as was the possibility that a computer-assisted surveillance method would have detected this outbreak at an earlier stage. Determinants associated with late detection of clonal spread were the following: (i) the absence of a hospital-wide increase in incidence of E. cloacae cases for 1.5 years, (ii) the long time interval between cases, (iii) the hospital-wide occurrence of new cases, due to a high number of patient transfers between wards, (iv) the large variety of clinical sites, and (v) the high variability of antibiograms (n = 33). Retrospective application of a recently described computer-assisted surveillance method as well as an "in-house"-developed algorithm resulted in earlier detection of the outbreak of 6 and 12 months, respectively. These findings suggest that computerized tools for surveillance may recognize resistance trends that are too complex to be detected by manual review and indicate the need for prospective evaluation of such algorithms.
Leverstein-van Hall
Maurine A
MA
Eijkman-Winkler Institute for Microbiology, Infectious Disease and Inflammation, University Hospital Utrecht, Rm. G 04.614, PO 855000, 3508 GA Utrecht, The Netherlands. M.LeversteinvHall@lab.azu.nl
Blok
Hetty E M
HE
Paauw
Armand
A
Fluit
Ad C
AC
Troelstra
Annet
A
Mascini
Ellen M
EM
Bonten
Marc J M
MJ
Verhoef
Jan
J
D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D016972:Enterobacter cloacae / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D006801:Humans; D015994:Incidence; D008826:Microbial Sensitivity Tests; D011159:Population Surveillance; D012621:Seasons; D012984:Software
D000900:Anti-Bacterial Agents