Rise in Number of Listeriosis Cases – August 21, 2008

Dear Colleagues,

You are likely aware that we are currently experiencing an increase in the number of cases of Listeriosis in Ontario, with a possible link to contaminated deli meats. To date there have been 30 outbreak cases across 17 Public Health Units, with 1 death. There has not been a significant increase in cases locally, however, within the period of interest there have been two confirmed cases of Listeriosis in Ottawa; one case has a confirmed link to the provincial outbreak and the other is a probable case. Cases have also been reported in British Columbia, Saskatchewan and Quebec. Ottawa Public Health is working in conjunction with the Ministry of Health and Long Term Care and other Ontario health districts to investigate this outbreak.

As you know, Listeriosis is a rare but serious infection caused by consumption of food contaminated with the bacteria Listeria monocytogenes. Listeria can be found in unpasteurized dairy products, and uncooked meats, as well as processed foods such as deli meats and hot dogs. Listeria contaminated food may look, smell and tastes normal. To read more about Listeriosis: http://www.health.gov.on.ca/english/public/pub/disease/listeria.html

The Canadian Food Inspection Agency (CFIA) and Maple Leaf Consumer Foods have advised the public not to consume several varieties of ready-to-eat deli meat products as they may be contaminated with Listeria. At the moment, a direct link between the outbreak cases and these products has not been found. Investigations are continuing. The up-to-date listing of the voluntarily recalled products can be found on the CFIA website: http://www.inspection.gc.ca/english/corpaffr/recarapp/2008/20080819e.shtml

In light of the outbreak, we ask that you keep a heightened clinical suspicion for Listeriosis. Severe illness can present as sepsis, meningitis, or encephalitis. Milder cases may cause flu-like symptoms, fever, muscle aches, nausea, vomiting or diarrhea. Pregnant women, newborns, the elderly, and immunocompromised are especially susceptible to developing Listeriosis. Infection in pregnancy can cause mild symptoms, but can lead to miscarriage, stillbirth or neonatal disease.

Listeriosis is a reportable disease under Ontario Health Protection and Promotion Act. Please report all suspected and confirmed cases of Listeriosis to Ottawa Public Health immediately at 613-580-6744, ext. 23748 from 8:30 am to 4:30 pm, Monday to Friday. For after hour emergencies, please call 3-1-1 and ask for the Public Health Officer on call.

Lab testing is required for diagnosis of Listeriosis through isolation of Listeria monocytogenes from blood, CSF, amniotic fluid, placenta, meconium or other sites of infection. All positive samples must be sent to the Central Public Health Laboratory for Pulse Field Gel Electrophoresis (PFGE) typing to confirm outbreak status.

Your assistance in this matter is greatly appreciated,

Original signed by

Isra G. Levy, MB BCh, MSc, FRCPC, FACPM

Medical Officer of Health