Multistate outbreak of Listeria monocytogenes infection linked to delicatessen turkey meat.
BACKGROUND
Despite a decreasing incidence of listeriosis in the United States, molecular subtyping has increased the number of recognized outbreaks. In September 2000, the New York City Department of Health identified a cluster of infections caused by Listeria monocytogenes isolates with identical molecular subtypes by pulsed-field gel electrophoresis (PFGE) and ribotyping.


METHODS
To determine the magnitude of the outbreak and identify risk factors for infection, we notified state health departments and conducted a case-control study. A case was defined as a patient or mother-infant pair infected with Listeria monocytogenes whose isolate yielded the outbreak PFGE pattern. Controls were patients infected with Listeria monocytogenes whose isolate yielded a different PFGE pattern. Patients were asked about food and drink consumed during the 30 days before the onset of illness.


RESULTS
Between May and December 2000, there were 30 clinical isolates of Listeria monocytogenes with identical PFGE patterns identified in 11 US states. Cases of infection caused by these isolates were associated with 4 deaths and 3 miscarriages. A case-control study implicated sliced processed turkey from a delicatessen (Mantel-Haenszel odds ratio, 8.0; 95% confidence interval, 1.2-43.3). A traceback investigation identified a single processing plant as the likely source of the outbreak, and the company voluntarily recalled 16 million pounds of processed meat. The same plant had been identified in a Listeria contamination event that had occurred more than a decade previously.


CONCLUSIONS
Prevention of persistent L. monocytogenes contamination in food processing plants presents a critical challenge to food safety professionals.
Olsen
Sonja J
SJ
Foodborne and Diarrheal Diseases Branch, Centers for DiseaseControl and Prevention, Atlanta, USA. sco2@cdc.gov
Patrick
Mary
M
Hunter
Susan B
SB
Reddy
Vasudha
V
Kornstein
Laura
L
MacKenzie
William R
WR
Lane
Kimberly
K
Bidol
Sally
S
Stoltman
Gillian A
GA
Frye
Douglas M
DM
Lee
Irene
I
Hurd
Sharon
S
Jones
Timothy F
TF
LaPorte
Tracy N
TN
Dewitt
Wallis
W
Graves
Lewis
L
Wiedmann
Martin
M
Schoonmaker-Bopp
Dianna J
DJ
Huang
Ada J
AJ
Vincent
Curt
C
Bugenhagen
Al
A
Corby
Joe
J
Carloni
Edmund R
ER
Holcomb
Mara E
ME
Woron
Raymond F
RF
Zansky
Shelley M
SM
Dowdle
Gerrie
G
Smith
Forrest
F
Ahrabi-Fard
Susann
S
Ong
Anna Rae
AR
Tucker
Nicole
N
Hynes
Noreen A
NA
Mead
Paul
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D016022:Case-Control Studies; D004196:Disease Outbreaks; D005260:Female; D005516:Food Microbiology; D006801:Humans; D008088:Listeriosis / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D011202:Poultry Products / Q000382:microbiology*; D014422:Turkeys / Q000382:microbiology*; D014481:United States / Q000453:epidemiology