Outbreak of Vibrio parahaemolyticus Associated with Consumption of Raw Oysters in Canada, 2015.

There has been a steady increase in illness incidence of Vibrio parahaemolyticus (Vp). The majority of illnesses are associated with consumption of raw oysters. In the summer of 2015, Canada experienced the largest outbreak associated with the consumption of raw oysters harvested from British Columbia (BC) coastal waters. Case investigation of laboratory-confirmed cases was conducted to collect information on exposures and to assist traceback. Investigations at processors and oyster sampling were conducted. Eighty-two laboratory-confirmed cases of Vp infection were reported between January 1 and October 26, 2015. The majority of the cases were reported in BC, associated with consumption of raw BC oysters in restaurants. Sea surface temperatures were above the historical levels in 2015. This outbreak identified the need to improve surveillance and response to increases in human cases of Vp. This is of particular importance due to the potential for increasing water temperatures and the likelihood of additional outbreaks of Vibrio.

Frequent marijuana use and driving risk behaviours in Canadian youth.

BACKGROUND: A better understanding of the relations between patterns of marijuana use and driving risks in young adulthood is needed. METHODS: Secondary analyses of self-report data from the Victoria Healthy Youth Survey. Youth (baseline ages 12 to 18; N=662; 52% females) were interviewed biannually (on six occasions) from 2003 to 2013 and classified as abstainers (i.e., used no marijuana in past 12 months), occasional users (i.e., used at most once per week), and frequent users (i.e., used more than once a week). RESULTS: In the frequent user group, 80% of males and 75% of females reported 'being in a car driven by driver (including themselves) using marijuana or other drugs in the last 30 days', 64% of males and 33% of females reported that they were 'intoxicated' with marijuana while operating a vehicle and 50% of males and 42% of females reported being in a car driven by a driver using alcohol. In addition, 28% of occasional users and also a small proportion of abstainers reported 'being in a car driven by a driver using marijuana or other drugs in the last 30 days'. INTERPRETATION: The high frequency of driving risk behaviours, particularly for frequent users, suggest that plans for legalization of recreational use should anticipate the costs of preventive education efforts that present an accurate picture of potential risks for driving. Youth also need to understand risks for dependence, and screening for and treatment of marijuana use disorders is needed.

HISTORIQUE: Il est nécessaire de mieux comprendre les liens entre les habitudes de consommation de marijuana et la conduite à risque chez les jeunes adultes. MÉTHODOLOGIE: Les auteurs ont procédé à des analyses secondaires de données autodéclarées tirées du sondage sur la santé des jeunes de Victoria. Dans ce sondage, les jeunes (de 12 à 18 ans en début d'étude, n=662; 52 % de filles) ont participé à une entrevue tous les deux ans (à six reprises) entre 2003 et 2013. Ils ont été classés comme abstinents (aucune consommation de marijuana dans les 12 mois précédents), consommateurs occasionnels (consommation maximale d'une fois par semaine) et consommateurs fréquents (consommation plus d'une fois par semaine). RÉSULTATS: Dans le groupe des consommateurs fréquents, 80 % des garçons et 75 % des filles ont déclaré « avoir été dans une voiture conduite par une personne (y compris eux-mêmes) qui avait consommé de la marijuana ou d'autres drogues dans les 30 jours précédents ¼, 64 % des garçons et 33 % des filles ont affirmé avoir déjà été « intoxiqués ¼ par la marijuana lorsqu'ils conduisaient une voiture et 50 % des garçons et 42 % des filles ont indiqué avoir été dans une voiture conduite par quelqu'un qui consommait de l'alcool. De plus, 28 % des consommateurs occasionnels et une petite proportion d'abstinents ont déclaré « avoir été dans une voiture conduite par une personne qui avait consommé de la marijuana ou d'autres drogues dans les 30 jours précédents. ¼. INTERPRÉTATION: Compte tenu de la forte fréquence de conduite à risque, notamment chez les consommateurs fréquents, le projet de légaliser la consommation récréative devrait tenir compte des coûts de mesures d'éducation préventive qui présenteront un portrait précis des risques potentiels liés à la conduite. Les jeunes doivent également comprendre les risques de dépendance. Enfin, il est important de procéder au dépistage et au traitement des troubles liés à la consommation de marijuana.

Estimating the number of injection drug users in greater Victoria, Canada using capture-recapture methods.

BACKGROUND: Population size estimation is critical for planning public health programmes for injection drug users. Estimation is difficult, as these populations are considered 'hidden' or 'hard to reach'. The currently accepted population size estimate for greater Victoria, Canada is between 1,500 and 2,000 individuals, which is dated prior to the year 2000, and is likely an underestimate. METHODS: We used three mark-recapture methods (the Lincoln-Petersen estimator, Huggins' model, and Pledger's model) to estimate population size using cross-sectional survey data collected in 2003 and 2005. Data come from a closed population with two time-ordered samples from the same source. We compare our estimates with the currently accepted estimate that is based on the registry of a Victoria needle exchange. RESULTS: All methods provided population size estimates that were higher than the currently accepted estimate. Huggins' method produced wider confidence intervals. Point estimates of population size from the three methods ranged from 3,329 to 3,342. CONCLUSIONS: Our estimates will aid health authorities in planning for harm reduction programmes. Repeating the methods as further phases of I-Track data become available will ensure that the population estimates remain up to date.

Methodological approaches to comparing information about bicycle accidents internationally: a case study involving Canada and Germany.

The use of bicycles as a mean of healthy and eco-friendly transportation is currently actively promoted in many industrialized countries. However, the number of severe bicycle accidents rose significantly in Germany and Canada in 2011. In order to identify risk factors for bicycle accidents and possible means of prevention, a study was initiated that analyses bicycle accidents from selected regions in both countries. Due to different healthcare systems and regulations, the data must be selected in different ways in each country before it can be analyzed. Data is collected by means of questionnaires in Germany and using hybrid electronic-paper records in Canada. Using this method, all relevant data can be collected in both countries.

Risk factors for Cryptococcus gattii infection, British Columbia, Canada.

To determine whether particular environmental, medical, or behavioral risk factors existed among Cryptcoccus gattii-infected persons compared with the general population, we conducted a sex-matched case-control study on a subset of case-patients in British Columbia (1999-2001). Exposures and underlying medical conditions among all case-patients (1999-2007) were also compared with results of provincial population-based surveys and studies. In case-control analyses, oral steroids (matched odds ratio [MOR] 8.11, 95% confidence interval [CI] 1.74-37.80), pneumonia (MOR 2.71, 95% CI 1.05-6.98), and other lung conditions (MOR 3.21, 95% CI 1.08-9.52) were associated with infection. In population comparisons, case-patients were more likely to be ≥50 years of age (p<0.001), current smokers (p<0.001), infected with HIV (p<0.001), or have a history of invasive cancer (p<0.001). Although C. gattii is commonly believed to infect persons with apparently healthy immune systems, several immunosuppressive and pulmonary conditions seem to be risk factors.

Development of Policy-Relevant Indicators for Injury Prevention in British Columbia by the Key Decision-Makers.

Indicators can help decision-makers evaluate interventions in a complex, multi-sectoral injury system. We aimed to create indicators for road safety, seniors falls, and 'all-injuries' to inform and evaluate injury prevention initiatives in British Columbia, Canada. The indicator development process involved a five-stage mixed methodology approach, including an environmental scan of existing indicators, generating expert consensus, selection of decision-makers and conducting a survey, selection of final indicators, and specification of indicators. An Indicator Reference Group (IRG) reviewed the list of indicators retrieved in the environmental scan and selected candidate indicators through expert consensus based on importance, modifiability, acceptance, and practicality. Key decision-makers (n = 561) were invited to rank each indicator in terms of importance and actionability (online survey). The IRG applied inclusion criteria and thresholds to survey responses from decision-makers, which resulted in the selection of 47 road safety, 18 seniors falls, and 33 all-injury indicators. After grouping "like" indicators, a final list of 23 road safety, 8 seniors falls, and 13 all-injury indicators were specified. By considering both decision-maker ranking and expert opinion, we anticipate improved injury system performance through advocacy, accountability, and evidence-based resource allocation in priority areas. Our indicators will inform a data management framework for whole-system reporting to drive policy and funding for provincial injury prevention improvement.

Reconciling nutritional geometry with classical dietary restriction: Effects of nutrient intake, not calories, on survival and reproduction.

Dietary restriction (DR) is one of the main experimental paradigms to investigate the mechanisms that determine lifespan and aging. Yet, the exact nutritional parameters responsible for DR remain unclear. Recently, the advent of the geometric framework of nutrition (GF) has refocussed interest from calories to dietary macronutrients. However, GF experiments focus on invertebrates, with the importance of macronutrients in vertebrates still widely debated. This has led to the suggestion of a fundamental difference in the mode of action of DR between vertebrates and invertebrates, questioning the suggestion of an evolutionarily conserved mechanism. The use of dietary dilution rather than restriction in GF studies makes comparison with traditional DR studies difficult. Here, using a novel nonmodel vertebrate system (the stickleback fish, Gasterosteus aculeatus), we test the effect of macronutrient versus calorie intake on key fitness-related traits, both using the GF and avoiding dietary dilution. We find that the intake of macronutrients rather than calories determines both mortality risk and reproduction. Male mortality risk was lowest on intermediate lipid intakes, and female risk was generally reduced by low protein intakes. The effect of macronutrient intake on reproduction was similar between the sexes, with high protein intakes maximizing reproduction. Our results provide, to our knowledge, the first evidence that macronutrient, not caloric, intake predicts changes in mortality and reproduction in the absence of dietary dilution. This supports the suggestion of evolutionary conservation in the effect of diet on lifespan, but via variation in macronutrient intake rather than calories.

Cyclospora spp. in herbs and water samples collected from markets and farms in Hanoi, Vietnam.

OBJECTIVE: To determine the prevalence of Cyclospora spp. oocysts in herb and water samples as well as in fecal specimens of clinical cases of diarrhoea in Hanoi, Vietnam. METHOD: From November 2004 to October 2005, water and herb samples collected from markets and farms in Hanoi were examined for the presence of Cyclospora spp. oocysts in concentrated sediments and washings using UV epifluorescence examination of a wet mount. In addition, hospital based surveillance studies were carried out using a structured questionnaire which focused on potential risk factors for cyclosporiasis. Stool specimens were collected from individuals with diarrhoea attending primary healthcare facilities and examined for Cyclospora spp. oocysts by modified acid fast smear and wet mount examination using both light and UV epifluorescence microscopy. RESULTS: Cyclospora spp. were found in 34/288 (11.8%) market water and herb samples, and in 24/287 (8.4%) farm samples. All varieties of herbs sold at the market and grown in farms were contaminated with Cyclospora spp. oocysts. A marked seasonal increase in Cyclospora spp. contamination was observed before the rainy season (39/288) from November to April compared to the rainy season (19/268) from May to October (chi(2) = 7.593, P = 0.006). However, Cyclospora spp. was not found in any stool samples collected in hospital-based surveillance studies. CONCLUSIONS: These results confirm the presence of Cyclospora spp. which varies seasonally in environmental samples (water and herbs collected from farms and markets) within the Hanoi metropolitan area.

Protecting the public from exposure to secondhand cannabis smoke and vapour following legalization.

The adverse effects of direct cannabis use are well described in the literature; however, researchers are now beginning to expose the health consequences of secondhand exposure. Given the commitment by the federal government to legalize cannabis in Canada by summer 2018, public health officials must build on the successes of existing smoke-free programs and work with provinces and municipalities to develop policies that protect the public from secondhand exposure to cannabis smoke and vapour. While harmonization with existing tobacco laws may offer the simplest approach, other alternatives may allow stricter control of public consumption by different levels of government. Further research will be needed to assess the health implications of secondhand cannabis exposure, as well as the population impacts of legalization.

A bird's eye view: using geographic analysis to evaluate the representativeness of corvid indicators for West Nile virus surveillance.

BACKGROUND: The objective of this evaluation was to determine whether reports of dead corvid sightings and submissions of dead corvids for West Nile virus testing were representative of true corvid mortality in British Columbia in 2004, a year with no West Nile virus activity, in order to ensure the system was accurately describing corvid mortality rather than reflecting regional differences in surveillance methods. RESULTS: Local Health Areas reported 0-159 (median = 3) dead corvid sightings and 0-209 (median = 5) submissions for West Nile virus testing. The expected numbers of dead corvid sightings and submissions for testing from each Local Health Area were 0-232 (median = 3) and 0-258 (median = 4), respectively. Twelve Local Health Areas reported significantly fewer sightings than expected; 21 reported significantly more. Eleven Local Health Areas submitted significantly fewer corvids than expected; 26 submitted significantly more. CONCLUSION: Some Local Health Areas were over-represented and others under-represented in terms of corvid West Nile virus surveillance indicators. Recommendations were made to improve the representativeness of corvid surveillance data. Geographic analysis can be used to evaluate the representativeness of surveillance systems and result in improvements to surveillance.

Physician diagnostic and reporting practices for gastrointestinal illnesses in three health regions of British Columbia.

OBJECTIVES: To estimate seasonal proportions of patient visits due to acute gastrointestinal illness (GI), assess factors influencing physicians' stool sample requests, their understanding of laboratory testing protocols and adherence to provincial stool request guidelines in three British Columbia (BC) health regions. METHODS: During a one-year period, eligible physicians were mailed four self-administered questionnaires used to estimate proportions of patients diagnosed with GI, related stool sample requests in the preceding month, and to assess factors prompting stool sample requests. RESULTS: The response rate overall for the initial comprehensive questionnaire was 18.6%; 7.4% responded to all four questionnaires. An estimated 2.5% of patient visits had a GI diagnosis; of these, 24.8% were asked to submit stool samples. Significant (p < 0.05) regional and seasonal variations were found in rates of GI and stool sample requests. Top-ranked factors prompting stool sample requests were: bloody diarrhoea, recent overseas travel, immunocompromised status, and duration of illness > 7 days; "non-patient" factors included: laboratory availability, time to receive laboratory results, and cost. Physicians' perceptions of which organisms were tested for in a 'routine' stool culture varied. INTERPRETATION: BC physicians appear to adhere to existing standardized guidelines for sample requests. This may result in systematic under-representation of certain diseases in reportable communicable disease statistics.

Population distribution and burden of acute gastrointestinal illness in British Columbia, Canada.

BACKGROUND: In developed countries, gastrointestinal illness (GI) is typically mild and self-limiting, however, it has considerable economic impact due to high morbidity. METHODS: The magnitude and distribution of acute GI in British Columbia (BC), Canada was evaluated via a cross-sectional telephone survey of 4,612 randomly selected residents, conducted from June 2002 to June 2003. Respondents were asked if they had experienced vomiting or diarrhoea in the 28 days prior to the interview. RESULTS: A response rate of 44.3% was achieved. A monthly prevalence of 9.2% (95% CI 8.4-10.0), an incidence rate of 1.3 (95% CI 1.1-1.4) episodes of acute GI per person-year, and an average probability that an individual developed illness in the year of 71.6% (95% CI 68.0-74.8), weighted by population size were observed. The average duration of illness was 3.7 days, translating into 19.2 million days annually of acute GI in BC. CONCLUSION: The results corroborate those from previous Canadian and international studies, highlighting the substantial burden of acute GI.

Enzyme immunoassay of Cryptosporidium-specific immunoglobulin G antibodies to assess longitudinal infection trends in six communities in British Columbia, Canada.

A newly developed enzyme-linked immunosorbent assay (ELISA) that detects immunoglobulin G antibodies to the 27-kDa Cryptosporidium parvum sporozoite surface antigen was used to test 4,097 sera collected from pregnant women in 6 communities in British Columbia, Canada, between January 1996, and December 1997. Waterborne outbreaks of cryptosporidiosis occurred in two of the study communities during the period of follow-up, and ELISA seropositivity was high in all six communities during the study period (77% positive to 92% positive). In the community with the largest outbreak, levels of antibody to the 27-kDa antigen increased rapidly and then decayed to background levels within 3-4 months of the peak of the epidemic curve. Trends in serologic reactivity were complex in all communities, and increased antibody levels not related temporally to known waterborne outbreaks were also observed. Serological assays may provide more accurate information regarding community levels of Cryptosporidium infection.

The prevalence of hepatitis A in children in British Columbia.

BACKGROUND: The risk of hepatitis A virus (HAV) infection during childhood is difficult to estimate without population serosurveys because HAV-related symptoms are often mild at this age. Few serosurveys have been conducted in Canada. The present study surveyed teenagers in two nonurban regions of British Columbia where the historical rate of reported HAV either exceeded (region A) or was less than (region B) the historical provincial rate. METHODS: A point prevalence survey of salivary HAV-specific immunoglobulin G was conducted in high schools among grade 9 students in regions A and B. A questionnaire was used to gather sociodemographic data. The survey was extended to grade 1 and grade 5 students in community 1 of region B. Associations between risk factors and prior infection were evaluated by logistic regression. RESULTS: Eight hundred eleven grade 9 students were tested. Antibody to HAV was detected in 4.7% of students in region A (95% CI 2.9% to 7.2%) and 9.6% of students in region B (95% CI 6.9% to 12.9%). The region B figure reflected HAV antibody prevalence rates of 19.5% in community 1 and 2.5% in the remainder of the region. Younger students in community 1 had low HAV antibody to HAV prevalence rates (3.9% for grade 1 and 3.1% for grade 5), and positive tests in this community were associated with a particular school, foreign travel and brief residence. The risk factors for HAV infection in grade 9 students were not determined. CONCLUSIONS: Children in nonurban areas of British Columbia are generally at low risk of HAV infection during the first decade of life regardless of the reported population rates, thereby permitting the consideration of school-based HAV immunization programs.

Cryptococcus neoformans infections at Vancouver Hospital and Health Sciences Centre (1997-2002): epidemiology, microbiology and histopathology.

An outbreak of infections due to a rare subspecies of Cryptococcus neoformans (var. gattii) was recognized on Vancouver Island (VI), British Columbia, in 2002, which had affected 59, mostly immunocompetent, individuals since 1999. The objectives of this study were to: (1) determine if the outbreak had spread to Vancouver and its surrounding communities and (2) review the epidemiological, clinical and pathological features of all cryptococcal infections in patients admitted to the Vancouver Hospital and Health Sciences Centre (VHHSC) over a 5 year period. VHHSC microbiology and pathology databases were searched for cryptococcal infections from 1 June 1997 to 31 December 2002. Hospital charts of all identified patients were reviewed. Available cryptococcal isolates and histopathological specimens were reviewed. Twenty-six cases of cryptococcosis were identified in both HIV-positive (n = 15) and HIV-negative (n = 11) patients. C. neoformans var. grubii was cultured from 13 patients, of whom 10 were HIV-positive. The outbreak strain, C. neoformans var. gattii, was detected in three patients; all had travelled to VI. C. neoformans var. neoformans was cultured from two patients, Cryptococcus laurentii was cultured from one, and seven patients had cryptococcosis based on histopathology alone, without cultures. The majority (10/15) of the HIV-positive patients developed systemic disease whilst HIV-negative patients (8/11) presented with pulmonary cryptococcosis. Lung biopsies revealed necrotizing and/or fibrosing granulomas, with cryptococcal cells in 5 of 10 specimens. Brain biopsies showed cryptococcal organisms within leptomeninges and deeper structures with minimal associated inflammation. This retrospective study demonstrated a sharp increase in the total number of C. neoformans infections in both immunocompromised and immunocompetent patients at the VHHSC in 2002. There was no evidence of spread of the outbreak strain to the Greater Vancouver area. This is the first correlation of clinical and investigational findings of cryptococcosis in a region in North America where C. neoformans varieties gattii and grubii are endemic.

Frozen chicken nuggets and strips--a newly identified risk factor for Salmonella Heidelberg infection in British Columbia, Canada.

Salmonella enterica var. Heidelberg was isolated from an unusual food source during routine case follow-up, prompting a case control investigation of frozen chicken nuggets and strips. Most frozen nuggets and strips are raw; however, par-frying lends a cooked appearance. As such, suitable food preparation precautions might not be undertaken by consumers. Cases were confirmed in the laboratory between 1 January and 1 April 2003. Controls were generated through forward-digit dialing and individually matched by age category. Telephone interviews were conducted, and limited sampling of unopened product was performed. Eighteen matched pairs were interviewed. The odds of infection were 11 times higher in individuals who had consumed frozen processed chicken nuggets and strips (95% confidence interval, 1.42 < odds ratio < 85.20). One-third of cases and controls considered frozen nuggets and strips to be precooked, and one quarter used the microwave, an ill-advised cooking method. Consumer misconceptions contributed to the risk of infection. Clear labels identifying nuggets and strips as raw poultry are needed.

Ecological niche modeling of Cryptococcus gattii in British Columbia, Canada.

BACKGROUND: Cryptococcus gattii emerged on Vancouver Island, British Columbia (BC), Canada, in 1999, causing human and animal illness. Environmental sampling for C.gattii in southwestern BC has isolated the fungal organism from native vegetation, soil, air, and water. OBJECTIVES: Our aim was to help public health officials in BC delineate where C.gattii is currently established and forecast areas that could support C.gattii in the future. We also examined the utility of ecological niche modeling (ENM) based on human and animal C.gattii disease surveillance data. METHODS: We performed ENM using the Genetic Algorithm for Rule-set Prediction (GARP) to predict the optimal and potential ecological niche areas of C.gattii in BC. Human and animal surveillance and environmental sampling data were used to build and test the models based on 15 predictor environmental data layers. RESULTS: ENM provided very accurate predictions (> 98% accuracy, p-value < 0.001) for C.gattii in BC. The models identified optimal C.gattii ecological niche areas along the central and south eastern coast of Vancouver Island and within the Vancouver Lower Mainland. Elevation, biogeoclimatic zone, and January temperature were good predictors for identifying the ecological niche of C.gattii in BC. CONCLUSIONS: The use of human and animal case data for ENM proved useful and effective in identifying the ecological niche of C.gattii in BC. These results are shared with public health to increase public and physician awareness of cryptococcal disease in regions at risk of environmental colonization of C.gattii.

Protective behavior survey, West Nile virus, British Columbia.

We investigated personal protective behaviors against West Nile virus infection. Barriers to adopting these behaviors were identified, including the perception that DEET (N,N-diethyl-m-toluamide and related compounds) is a health and environmental hazard. Televised public health messages and knowing that family or friends practiced protective behaviors were important cues to action.