Nosocomial outbreak of Serratia marcescens in a neonatal intensive care unit.
OBJECTIVE
To investigate and describe an outbreak of Serratia marcescens in a neonatal intensive care unit (NICU) and to report the interventions leading to cessation of the outbreak.


METHODS
A 2,168-bed, tertiary-care, university teaching hospital in Vienna, Austria, with an 8-bed NICU.


METHODS
We conducted a case-control study to identify risk factors for colonization and infection with S. marcescens. A case-patient was defined as any neonate in the NICU with a positive culture for S. marcescens between October 1, 2000, and February 28, 2001. Polymerase chain reaction was applied to type isolates.


METHODS
During unannounced observations, the NICU was examined and existing policies were reviewed. Staff were reinstructed in hand antisepsis and gloving policies. Admissions were halted on December 27. During previously planned technical maintenance of the ward, the NICU was closed for 10 days and thorough aldehyde-based disinfection of the NICU was performed.


RESULTS
Ten neonates met the case definition: 6 with infections (among them 3 with cerebral abscesses) and 4 with asymptomatic colonization. Previous antibiotic treatment of the mothers with cefuroxime was the single significant risk factor for colonization or infection (P = .028; odds ratio, 17; 95% confidence interval, 1.3 to 489.5).


CONCLUSIONS
S. marcescens can cause rapidly spreading outbreaks associated with fatal infections in NICUs. With aggressive infection control measures, such outbreaks can be stopped at an early stage. Affected neonates themselves may well be the source of cross-infection to other patients on the ward. Antibiotic treatment of mothers should be reevaluated to avoid unnecessary exposure to antibiotics with the potential of over-growth of resistant organisms.
Assadian
Ojan
O
Division of Hospital Hygiene, Clinical Institute for Hygiene and Medical Microbiology, University of Vienna Medical School, Austria.
Berger
Angelika
A
Aspöck
Christoph
C
Mustafa
Stefan
S
Kohlhauser
Christina
C
Hirschl
Alexander M
AM
D019072:Antibiotic Prophylaxis / Q000009:adverse effects; D001317:Austria / Q000453:epidemiology; D002444:Cefuroxime / Q000009:adverse effects; D002511:Cephalosporins / Q000009:adverse effects; D003428:Cross Infection / Q000453:epidemiology* / Q000517:prevention & control; D004196:Disease Outbreaks / Q000517:prevention & control; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D017053:Infection Control / Q000379:methods; D007363:Intensive Care Units, Neonatal; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control; D012189:Retrospective Studies; D012307:Risk Factors; D016868:Serratia Infections / Q000453:epidemiology* / Q000517:prevention & control; D012706:Serratia marcescens
D002511:Cephalosporins; D002444:Cefuroxime