An outbreak of febrile gastroenteritis associated with delicatessen meat contaminated with Listeria monocytogenes.

In June 2001, the Los Angeles County Department of Health Services/Public Health conducted a cohort study of an outbreak of acute febrile gastroenteritis among 16 of 44 healthy attendees of a catered party. The median age of the attendees who became ill was 15.5 years. Symptoms included body aches (in 88% of attendees), fever (81%), headache (81%), diarrhea (63%), and vomiting (56%). Illness was associated with ingestion of precooked, sliced turkey (P=.000004). Six stool specimens yielded Listeria monocytogenes. Leftover turkey yielded L. monocytogenes, 1.6x10(9) cfu/g. All isolates were serotype 1/2a and had matching molecular fingerprints. Clusters of suspect cases were identified among attendees at 2 other catered events, but no additional cases were confirmed. This is only the third reported outbreak of L. monocytogenes-associated gastroenteritis in the United States. In cases of febrile gastroenteritis for which routine cultures for enteric pathogens are negative, clinicians should suspect listeriosis and should consider asking laboratories to retain stool specimens to expedite testing for Listeria organisms.

Campylobacter upsaliensis: Another pathogen for consideration in the United States.

While evaluating quinolone resistance in a sample of Campylobacter isolates recovered from patients with campylobacteriosis in Los Angeles County, California, in 1998, we discovered that the second most frequently isolated species was Campylobacter upsaliensis (6 [4%] of 155 isolates). The ability of laboratories to recover this species may be dependent on the culture conditions and the media used. Three dogs living in the households of 2 of these 6 patients had C. upsaliensis isolated in their stool specimens.

Botulism due to Clostridium baratii type F toxin.

Botulism results from consumption of preformed toxin or in vivo toxin elaboration in wounds or intestine. Of U.S. food-borne botulism cases since 1950, the majority were due to toxin A, but a significant number of suspect cases were never confirmed by culture or toxin detection. We report here a possible case of food-borne botulism attributed to toxin F production by a Clostridium baratii organism isolated from food consumed by the patient. The isolation of a toxin-producing Clostridium species other than Clostridium botulinum from food and stool requires deviation from the usual laboratory protocols, which may account for the lack of complete laboratory confirmation of clinically diagnosed cases.