title: Infectious Dose of Listeria monocytogenes in Outbreak Linked to Ice Cream, United States, 2015.
abstract: The relationship between the number of ingested Listeria monocytogenes cells in food and the likelihood of developing listeriosis is not well understood. Data from an outbreak of listeriosis linked to milkshakes made from ice cream produced in 1 factory showed that contaminated products were distributed widely to the public without any reported cases, except for 4 cases of severe illness in persons who were highly susceptible. The ingestion of high doses of L. monocytogenes by these patients infected through milkshakes was unlikely if possible additional contamination associated with the preparation of the milkshake is ruled out. This outbreak illustrated that the vast majority of the population did not become ill after ingesting a low level of L. monocytogenes but raises the question of listeriosis cases in highly susceptible persons after distribution of low-level contaminated products that did not support the growth of this pathogen.
authors.forename: Régis
authors.initials: R
authors.lastname: Pouillot
authors.forename: Karl C
authors.initials: KC
authors.lastname: Klontz
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Laurel S
authors.initials: LS
authors.lastname: Burall
authors.forename: Dumitru
authors.initials: D
authors.lastname: Macarisin
authors.forename: Matthew
authors.initials: M
authors.lastname: Doyle
authors.forename: Kären M
authors.initials: KM
authors.lastname: Bally
authors.forename: Errol
authors.initials: E
authors.lastname: Strain
authors.forename: Atin R
authors.initials: AR
authors.lastname: Datta
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hammack
authors.forename: Jane M
authors.initials: JM
authors.lastname: Van Doren
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load; D004196:Disease Outbreaks; D005506:Food Contamination; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000453:epidemiology*; D049674:History, 21st Century; D006801:Humans; D007054:Ice Cream / Q000382:microbiology*; D008089:Listeria monocytogenes; D008088:Listeriosis / Q000453:epidemiology* / Q000266:history / Q000382:microbiology* / Q000635:transmission; D011159:Population Surveillance; D014481:United States / Q000453:epidemiology
keywords: Listeria monocytogenes; United States; bacteria; dose-response; food safety; foodborne illness; ice cream; infectious dose; outbreak investigation