According to heath officials in the US and Canada, the 31 cases share a related whole genome sequencing (WGS), but US investigators “did not identify a specific food item, grocery store, food processor, or restaurant chain as the source of infections.”  However, Canadian investigators found their cases to be linked to “Rosemount brand cooked diced chicken meat.”  What is perplexing is that our FSIS reported, “that multiple samples of product produced by Tip Top Poultry, Inc. confirmed positive for the presence of Listeria monocytogenes after being tested in Canada.”  

No connection between the 24 sick, with 2 deaths in the US and Tip Top Poultry?  Really?

CDC, several states, and federal partners investigated a multistate outbreak of Listeria monocytogenes infections. The outbreak investigation is over and did not identify a specific food item, grocery store, food processor, or restaurant chain as the source of infections.

Public health investigators used the PulseNet system to identify illnesses that may have been part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting is performed on Listeria bacteria isolated from ill people by using a standardized laboratory and data analysis method called whole genome sequencing (WGS). CDC PulseNet manages a national database of these sequences that are used to identify possible outbreaks. WGS gives investigators detailed information about the bacteria causing illness. In this investigation, WGS showed that bacteria isolated from ill people were closely related genetically. This means that people in this outbreak were more likely to share a common source of infection.

As of November 7, 2019, a total of 24 people infected with the outbreak strain of Listeria monocytogenes were reported from 13 states.

Listeria specimens were collected from ill people from July 20, 2017, to August 1, 2019. Ill people ranged in age from 35 to 92 years, with a median age of 72. Sixty-three percent of ill people were female. Of 23 ill people with information available, 22 hospitalizations were reported. Two deaths were reported. No additional ill people were reported after the initial investigation notice on August 23, 2019.

State and local public health officials interviewed ill people to ask about what they ate and other exposures they had before their illness started. CDC analyzed the interview data but did not identify a common food or exposure among ill people.

In Canada, a total, there were seven confirmed cases of Listeria monocytogenes illness in three provinces: British Columbia (1), Manitoba (1) and Ontario (5). Individuals became sick between November 2017 and June 2019. Six individuals were hospitalized. Individuals who became ill were between 51 and 97 years of age. The majority of cases (86%) were female.


Based on the investigation findings, Rosemount brand cooked diced chicken was identified as a likely source of the outbreak. Rosemount cooked diced chicken was supplied to institutions (including cafeterias, hospitals and nursing homes) where many of the individuals who became sick resided, or visited, before becoming ill.

On August 18, 2019 the Canadian Food Inspection Agency issued a food recall warning for Rosemount brand cooked diced chicken meat 13mm – ½” (#16305), packdate – 01/21/2019. During the food safety investigation, the CFIA identified additional affected products and updated food recall warnings have been issued. For additional details on all recalled product names and lot codes, please consult CFIA’s website.

The collaborative outbreak investigation was initiated because of an increase of Listeria illnesses that were reported in June 2019. Through the use of a laboratory method called whole genome sequencing, two Listeria illnesses from November 2017 were identified to have the same genetic strain as the illnesses that occurred between April and June 2019. Although the outbreak investigation has been closed, the Public Health Agency of Canada will continue to monitor this event as part of their ongoing surveillance activities for food-related illnesses in Canada.

The U.S. CDC is investigating an outbreak of Listeria illnesses occurring in several states. The type of Listeria identified in the U.S. is closely related genetically (by whole genome sequencing) to the Listeria that was making people sick in Canada.

According to FSIS, Tip Top Poultry, Inc, a Rockmart, Ga., establishment, is recalling an undetermined amount of ready-to-eat (RTE) poultry products that may be adulterated with Listeria monocytogenes, the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) announced today.

The frozen cooked, diced or shredded, RTE chicken products were produced between January 21, 2019 and September 24, 2019. The products subject to recall can be found in this spreadsheet.

The products subject to recall bear establishment number “Est. P-17453” inside the USDA mark of inspection. These items were shipped to institutions nationwide in the United States and Canada (see the recalled products distributed in Canada).

The problem was discovered when the firm notified FSIS that multiple samples of product produced by Tip Top Poultry, Inc. confirmed positive for the presence of Listeria monocytogenes after being tested in Canada. The firm decided to recall all cooked, diced or shredded, RTE chicken products produced from January 21, 2019 through September 24, 2019 with product codes ranging from 10000 to 19999 and 70000 to 79999. Tip Top expanded the dates and the scope of the recall out of an abundance of caution.