title: An outbreak of gastroenteritis and fever due to Listeria monocytogenes in milk.
abstract: BACKGROUND
  After an outbreak of gastroenteritis and fever among persons who attended a picnic in Illinois, chocolate milk served at the picnic was found to be contaminated with Listeria monocytogenes.
  
  
  METHODS
  In investigating this outbreak, we interviewed the people who attended the picnic about what they ate and their symptoms. Surveillance for invasive listeriosis was initiated in the states that receive milk from the implicated dairy. Stool and milk samples were cultured for L. monocytogenes. Serum samples were tested for IgG antibody to listeriolysin O.
  
  
  RESULTS
  Forty-five persons had symptoms that met the case definition for illness due to L. monocytogenes, and cultures of stool from 11 persons yielded the organism. Illness in the week after the picnic was associated with the consumption of chocolate milk. The most common symptoms were diarrhea (present in 79 percent of the cases) and fever (72 percent). Four persons were hospitalized. The median incubation period for infection was 20 hours (range, 9 to 32), and persons who became ill had elevated levels of antibody to listeriolysin O. Isolates from stool specimens from patients who became ill after the picnic, from sterile sites in three additional patients identified by surveillance, from the implicated chocolate milk, and from a tank drain at the dairy were all serotype 1/2b and were indistinguishable on multilocus enzyme electrophoresis, ribotyping, and DNA macrorestriction analysis.
  
  
  CONCLUSIONS
  L. monocytogenes is a cause of gastroenteritis with fever, and sporadic cases of invasive listeriosis may be due to unrecognized outbreaks caused by contaminated food.
authors.affiliation: Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Dalton
authors.forename: C C
authors.initials: CC
authors.lastname: Austin
authors.forename: J
authors.initials: J
authors.lastname: Sobel
authors.forename: P S
authors.initials: PS
authors.lastname: Hayes
authors.forename: W F
authors.initials: WF
authors.lastname: Bibb
authors.forename: L M
authors.initials: LM
authors.lastname: Graves
authors.forename: B
authors.initials: B
authors.lastname: Swaminathan
authors.forename: M E
authors.initials: ME
authors.lastname: Proctor
authors.forename: P M
authors.initials: PM
authors.lastname: Griffin
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D002099:Cacao; D004196:Disease Outbreaks; D005243:Feces / Q000382:microbiology; D005334:Fever / Q000453:epidemiology / Q000382:microbiology; D005506:Food Contamination; D005759:Gastroenteritis / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D007087:Illinois / Q000453:epidemiology; D008089:Listeria monocytogenes / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D008088:Listeriosis / Q000453:epidemiology* / Q000382:microbiology; D008892:Milk / Q000382:microbiology / Q000506:poisoning*; D012703:Serotyping
chemical_list: D000907:Antibodies, Bacterial