ABSTRACT
A multi-province outbreak of listeriosis occurred in Canada from June to November 2008. Fifty-seven persons were infected with 1 of 3 similar outbreak strains defined by pulsed-field gel electrophoresis, and 24 (42%) individuals died. Forty-one (72%) of 57 individuals were residents of long-term care facilities or hospital inpatients during their exposure period. Descriptive epidemiology, product traceback, and detection of the outbreak strains of Listeria monocytogenes in food samples and the plant environment confirmed delicatessen meat manufactured by one establishment and purchased primarily by institutions was the source of the outbreak. The food safety investigation identified a plant environment conducive to the introduction and proliferation of L. monocytogenes and persistently contaminated with Listeria spp. This outbreak demonstrated the need for improved listeriosis surveillance, strict control of L. monocytogenes in establishments producing ready-to-eat foods, and advice to vulnerable populations and institutions serving these populations regarding which high-risk foods to avoid.
Subject(s)
Disease Outbreaks , Food Contamination , Listeria monocytogenes/isolation & purification , Listeriosis/epidemiology , Meat Products/microbiology , Adult , Aged , Canada , Electrophoresis, Gel, Pulsed-Field , Female , Food Microbiology , Humans , Long-Term Care , Male , Middle AgedABSTRACT
We conducted a case-control study to describe the clinical and epidemiologic characteristics of an outbreak of pandemic (H1N1) 2009 at a Canadian military cadet training center. We found that asthma and obesity confer greater risk for infection. Viral shedding was detected by PCR up to 18 days after symptom onset.
Subject(s)
Disease Outbreaks , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Military Personnel , Adolescent , Adult , Asthma/epidemiology , Canada/epidemiology , Case-Control Studies , Cough/diagnosis , Cough/epidemiology , Female , Fever/diagnosis , Fever/epidemiology , Humans , Male , Obesity/epidemiology , Risk Factors , Virus SheddingABSTRACT
Despite a population immunity level estimated at approximately 95%, an outbreak of measles responsible for 94 cases occurred in Quebec, Canada. Unlike previous outbreaks in which most unvaccinated children belonged to a single community, this outbreak had cases coming from several unrelated networks of unvaccinated persons dispersed in the population. No epidemiological link was found for about one-third of laboratory-confirmed cases. This outbreak demonstrated that minimal changes in the level of aggregation of unvaccinated individuals can lead to sustained transmission in highly vaccinated populations. Mathematical work is needed regarding the level of aggregation of unvaccinated individuals that would jeopardize elimination.
