Tag Archives: infectious dose

Low levels of Salmonella may be associated with foodborne outbreaks

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A significant data gap exists with respect to the levels of pathogens in foods implicated in foodborne outbreaks. These data are essential for the quantification of pathogen exposure via the ingestion of contaminated food.

Here we report the levels of the foodborne pathogen Salmonella in comminuted raw chicken products that had been breaded and then frozen. The products investigated were collected during four food safety investigations of foodborne outbreaks that occurred in Canada from 2014 to 2016. Most-probable-number (MPN) distribution analysis of the food samples revealed Salmonella levels of 0.0018 to 3 MPN/g, which is equivalent to 1 MPN per 0.33 to 556 g of product. These data suggest low levels of Salmonella may be associated with foodborne outbreaks.

Enumerative analysis of Salmonella in outbreak-associated breaded and frozen comminuted raw chicken products

Journal of Food Protection – May 2017

Angela Catford, Kyle Ganz, and Sandeep Tamber

http://www.jfoodprotection.org/doi/abs/10.4315/0362-028X.JFP-16-496?code=fopr-site

 

What is the infectious dose of Listeria? Who are susceptible?

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The relationship between the number of ingested Listeria monocytogenes cells in food and the likelihood of developing listeriosis is not well understood.

listeria4Data 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.

Infectious dose of listeria monocytogenes on outbreak linked to ice cream, United States, 2015

Emerging Infectious Diseases, December 2016, Volume 22, Number 12, https://dx.doi.org/10.3201/eid2212.160165

http://wwwnc.cdc.gov/eid/article/22/12/16-0165_article