ABSTRACT
In August 2021, a legionellosis outbreak involving 7 persons occurred within a 500-meter radius in the Montérégie region of Québec, Canada. Near real-time modeling of wind direction along with epidemiologic and environmental investigations identified the possible source. Modeling wind direction could help identify likely Legionella pneumophila sources during legionellosis outbreaks.
Subject(s)
Legionella pneumophila , Legionellosis , Legionnaires' Disease , Humans , Quebec/epidemiology , Legionellosis/epidemiology , Legionella pneumophila/genetics , Disease Outbreaks , Canada , Water Microbiology , Legionnaires' Disease/epidemiologyABSTRACT
A matched case-control study in Quebec, Canada, evaluated consumption of veal liver as a risk factor for campylobacteriosis. Campylobacter was identified in 28 of 97 veal livers collected concurrently from slaughterhouses and retailers. Veal liver was associated with human Campylobacter infection, particularly when consumed undercooked.
Subject(s)
Campylobacter Infections/epidemiology , Campylobacter Infections/microbiology , Campylobacter , Foodborne Diseases/epidemiology , Foodborne Diseases/microbiology , Liver/microbiology , Meat/microbiology , Aged , Aged, 80 and over , Animals , Case-Control Studies , Female , Food Microbiology , Food Safety , Humans , Male , Middle Aged , Public Health Surveillance , Quebec/epidemiology , Risk FactorsABSTRACT
Two patients with no exposure to gardening compost had related Legionella longbeachae infections in Quebec, Canada. Epidemiologic investigation and laboratory results from patient and soil samples identified the patients' workplace, a metal recycling plant, as the likely source of infection, indicating a need to suspect occupational exposure for L. longbeachae infections.
Subject(s)
Legionella longbeachae/isolation & purification , Legionellosis/epidemiology , Legionellosis/microbiology , Occupational Exposure , Humans , Quebec/epidemiology , Risk Factors , Soil MicrobiologyABSTRACT
BACKGROUND: Travel-related shigellosis is not well documented in Canada although it is frequently acquired abroad and can cause severe disease. OBJECTIVES: To describe the epidemiology of travel-related cases of shigellosis for Quebec (Canada) and to identify high-risk groups of travelers. METHOD AND DATA SOURCES: We performed a random sampling of 335 shigellosis cases (from a total of 760 cases) reported in the provincial database of reportable diseases from January 1, 2004, to December 31, 2007. Each case was analyzed according to information available in the epidemiology questionnaire. Total number of trips by region from Statistics Canada was used as denominator to estimate the risk according to region of travel. RESULTS: Annually, between 43 and 54% of the shigellosis cases were reported in travelers, 45% of whom were aged between 20 and 44 years. Children under 11 years accounted for nearly 16% of cases, but represent only 4% of travelers. Most cases in travelers were serogroups Shigella sonnei (50%) or Shigella flexneri (45%). Almost 31% of cases were reported between January and March. The majority (64%) were acquired in Central America, Mexico, or the Caribbean. However, the Indian subcontinent, Africa, and South America had the highest ratio of number of cases per number of trips. Tourists represented 76% of the cases; 62% of them had traveled for <2 weeks. At least 15% of cases among travelers were hospitalized. CONCLUSIONS: In Quebec, travel-related cases of shigellosis represent a large burden of total cases. Short-term travelers are at risk, as well as young children. The majority of cases occur in the winter months, corresponding to the peak of travel to "sunshine destinations." Continuous efforts should be made to encourage all travelers to seek pre-travel care, and to inform primary care practitioners of health risks faced by their patients abroad, even for those going to resorts.
Subject(s)
Dysentery, Bacillary/epidemiology , Travel , Adolescent , Adult , Age Factors , Aged , Child , Child, Preschool , Communicable Disease Control , Cross-Sectional Studies , Databases, Factual , Dysentery, Bacillary/prevention & control , Female , Humans , Infant , Male , Middle Aged , Quebec/epidemiology , Risk Factors , Shigella/isolation & purification , Surveys and QuestionnairesABSTRACT
The analytical studies used to investigate foodborne outbreak are mostly case-control or retrospective cohort studies. However, these studies can be complex to perform and susceptible to biases. This article addresses basic principles of epidemiology, probability, and the use of case-case design to identify the source of an Escherichia coli O157:H7 outbreak linked to raw milk cheese consumption in Quebec, Canada; a small number of cases with the same pulsed-field gel electrophoresis (PFGE) profile were involved. Between 4 December 2008 and 15 January 2009, a cumulative total of 16 E. coli O157:H7 cases with the same PFGE profile were reported to Quebec public health authorities. Among the first six cases reported, three had consumed raw milk cheese from the same producer (cheese A). Raw milk cheese is consumed by about 2 % of the Quebec population. By using the exact probability calculation, it was found that a significantly higher proportion of E. coli O157:H7 cases (with the specific PFGE profile) than expected had consumed cheese A (P < 0.001). These computations were updated during the course of the investigation to include subsequent cases and gave the same results. A case-case study corroborated this result. This article considers alternative statistical and epidemiological approaches to investigate a foodborne outbreak-in particular with an exact probability calculation and case-case comparisons. This approach could offer a fast and inexpensive alternative to regular case-control studies to target public health actions, particularly during a foodborne outbreak.
