ABSTRACT
BACKGROUND: This report describes two L. monocytogenes outbreak investigations that occurred in March and September of 2018 and that linked illness to a food premises located in an Ontario cancer centre. The cancer centre serves patients from across the province. METHODS: In Ontario, local public health agencies follow up with all reported laboratory-confirmed cases of listeriosis to identify possible sources of disease acquisition and to carry out investigations, including at suspected food premises. The Canadian Food Inspection Agency (CFIA) is notified of any Listeria-positive food product collected in relation to a case. The CFIA traces Listeria-positive product through the food distribution system to identify the contamination source and ensure the implicated manufacturing facility implements corrective measures. RESULTS: Outbreaks one and two each involved three outbreak-confirmed listeriosis cases. All six cases were considered genetically related by whole genome sequencing (WGS). In both outbreaks, outbreak-confirmed cases reported consuming meals at a food premises located in a cancer centre (food premises A) before illness onset. Various open deli meat samples and, in outbreak two, environmental swabs (primarily from the meat slicer) collected from food premises A were genetically related to the outbreak-confirmed cases. Food premises A closed as a result of the investigations. CONCLUSIONS: When procuring on-site food premises, healthcare facilities and institutions serving individuals with immuno-compromising conditions should consider the potential health risk of foods available to their patient population.
Subject(s)
Foodborne Diseases , Listeria monocytogenes , Listeriosis , Neoplasms , Humans , Listeria monocytogenes/genetics , Foodborne Diseases/epidemiology , Food Microbiology , Neoplasms/epidemiology , Listeriosis/epidemiology , Disease Outbreaks , Ontario/epidemiologyABSTRACT
In an investigation of a listeriosis outbreak in Ontario, Canada, during November 2015-June 2016, pasteurized chocolate milk was identified as the source. Because listeriosis outbreaks associated with pasteurized milk are rare in North America, these findings highlight that dairy products can be contaminated after pasteurization.
Subject(s)
Chocolate , Food Microbiology , Foodborne Diseases/epidemiology , Foodborne Diseases/microbiology , Listeria monocytogenes , Listeriosis/epidemiology , Listeriosis/microbiology , Milk , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Child , Child, Preschool , Disease Outbreaks , Female , Food Contamination , Humans , Infant , Listeria monocytogenes/classification , Listeria monocytogenes/genetics , Listeria monocytogenes/isolation & purification , Male , Middle Aged , Ontario/epidemiology , Pasteurization , Young AdultABSTRACT
We analyzed travel-associated clinical isolates of Escherichia coli O104:H4, including 1 from the 2011 German outbreak and 1 from a patient who returned from the Philippines in 2010, by genome sequencing and optical mapping. Despite extensive genomic similarity between these strains, key differences included the distribution of toxin and antimicrobial drug-resistance determinants.
