Series of incidents of Listeria monocytogenes non-invasive febrile gastroenteritis involving ready-to-eat meats.
OBJECTIVE
A series of cases and outbreaks of febrile noninvasive gastrointestinal disease involving 31 identified cases was investigated in terms of the numbers and types of Listeria monocytogenes present in the suspect foods (ready-to-eat meats) and clinical samples from cases.


RESULTS
Foods and faecal samples involved in the incidents were tested for the presence and number of L. monocytogenes. Isolates were typed by macrorestriction analysis using pulsed-field gel electrophoresis. The foods contained high levels of L. monocytogenes, in one case 1.8 x 10(7) g-1. Faecal samples contained L. monocytogenes for up to 15 d after the contaminated food was consumed. All isolates from the food and faecal samples were of serotype 1/2 and were indistinguishable from one another by macrorestriction typing.


CONCLUSIONS
It is likely that the meats were contaminated either during their manufacture after they had been cooked or by underprocessing. The long shelf lives on these products would have allowed the contaminating L. monocytogenes to grow to the high numbers measured in this study, causing food poisoning as described.


CONCLUSIONS
Outbreaks of febrile noninvasive listeriosis are relatively rare. This report adds ready-to-eat meats to the range of foods that have acted as vehicles for such outbreaks.
Sim
J
J
Ministry of Health, Wellington, New Zealand.
Hood
D
D
Finnie
L
L
Wilson
M
M
Graham
C
C
Brett
M
M
Hudson
J A
JA
D015373:Bacterial Typing Techniques / Q000379:methods; D015331:Cohort Studies; D015169:Colony Count, Microbial; D004196:Disease Outbreaks; D005516:Food Microbiology; D005759:Gastroenteritis / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D008089:Listeria monocytogenes / Q000235:genetics / Q000302:isolation & purification*; D008461:Meat Products / Q000009:adverse effects / Q000032:analysis / Q000382:microbiology*; D008462:Meat-Packing Industry / Q000592:standards; D013997:Time Factors