Salmonella enterica serovar Heidelberg is the second most frequently occurring serovar in Quebec and the third-most prevalent in Canada. Given that conventional pulsed-field gel electrophoresis (PFGE) subtyping for common Salmonella serovars, such as S. Heidelberg, yields identical subtypes for the majority of isolates recovered, public health laboratories are desperate for new subtyping tools to resolve highly clonal S. Heidelberg strains involved in outbreak events. As PFGE was unable to discriminate isolates from three epidemiologically distinct outbreaks in Quebec, this study was conducted to evaluate whole-genome sequencing (WGS) and phylogenetic analysis as an alternative to conventional subtyping tools. Genomes of 46 isolates from 3 Quebec outbreaks (2012, 2013, and 2014) supported by strong epidemiological evidence were sequenced and analyzed using a high-quality core genome single-nucleotide variant (hqSNV) bioinformatics approach (SNV phylogenomics [SNVphyl] pipeline). Outbreaks were indistinguishable by conventional PFGE subtyping, exhibiting the same PFGE pattern (SHEXAI.0001/SHEBNI.0001). Phylogenetic analysis based on hqSNVs extracted from WGS separated the outbreak isolates into three distinct groups, 100% concordant with the epidemiological data. The minimum and maximum number of hqSNVs between isolates from the same outbreak was 0 and 4, respectively, while >59 hqSNVs were measured between 2 previously indistinguishable outbreaks having the same PFGE and phage type, thus corroborating their distinction as separate unrelated outbreaks. This study demonstrates that despite the previously reported high clonality of this serovar, the WGS-based hqSNV approach is a superior typing method, capable of resolving events that were previously indistinguishable using classic subtyping tools.

Objectives: Preexposure vaccination against rabies is recommended for some travellers and individuals exposed to the virus through their work.At a cost of at least $150 per intramuscular (IM) dose, few follow this recommendation.In Canada, provided certain conditions are met, the National Advisory Committee on Immunization (NACI) and the Comité d'immunisation du Québec allow a more economical alternative, intradermal vaccine administration (ID) which uses 1/10 the IM dose.The purpose of this study is to assess the feasibility and immunogenicity of intradermal preexposure vaccination. Methods:Students and employees at the Faculty of Veterinary Medicine received three doses of ImovaxRage™ (Sanofi Pasteur) inactivated, human diploid cell rabies vaccine at days 0, 7 and 21 or 28.An IM or ID booster dose was administered after two years when indicated.Outcomes: Among the 159 participants who received three doses, 139 underwent serological testing in the year following vaccination and all achieved protective antibody levels.The antibody level was higher when measured within five weeks of the third dose.When the serological control was performed two years later, 65% of participants had a <0.5 IU/ml titre.Of the 22/30 participants who chose an ID booster, 100% responded and the average antibody titres were multiplied by 11, indicating a strong anamnestic response.Discussion: ID rabies vaccination is immunogenic, economic and could be considered for the booster dose.Protective antibodies decline rapidly after primary immunization by ID, so it would seem prudent to perform a serological control one year later on individuals at high risk of occult occupational exposure.An alternative would be to give these individuals a routine ID booster dose one year after primary vaccination, which would simplify initial treatment and reduce related costs (follow-up, blood sampling, serological tests, etc.).The persistence of protective antibodies after this booster dose should be assessed to determine the need for subsequent serological tests and the ideal interval between tests.

Objectifs : La vaccination en préexposition contre la rage est recommandée aux personnes exposées au virus dans le cadre du travail ainsi qu'à certains voyageurs.Avec un coût d'au moins 150$ par dose par voie intramusculaire (IM), cette recommandation est peu suivie.Au Canada, le Comité consultatif national de l'immunisation et le Comité d'immunisation du Québec permettent l'usage de la voie intradermique (ID) qui est une alternative plus économique en utilisant 1/10 de la dose IM, pourvu que certaines conditions soient respectées.Cette étude a pour but d'évaluer la faisabilité et l'immunogénicité de la vaccination en préexposition par voie ID.Méthodologie : Des étudiants et employés d'une faculté de médecine vétérinaire ont reçu 3 doses de vaccin inactivé sur cellules diploïdes humaines ImovaxRage™ (sanofipasteur) aux jours 0, 7 et 21 ou 28.Une dose de rappel par voie IM ou ID était administrée après 2 ans lorsqu'indiquée.Résultats : Parmi les 159 participants qui ont reçu 3 doses, 139 ont fait leur sérologie durant l'année suivant la vaccination et tous ont atteint un titre d'anticorps protecteur.Le niveau d'anticorps est plus élevé lorsqu'il est mesuré en-dedans de 5 semaines après la 3 e dose.Lors de la sérologie de contrôle 2 ans plus tard, 65% des participants présentait un dosage <0,5 UI/ml.Sur les 22/30 qui ont choisi un rappel par voie ID, 100% ont répondu et les titres moyens d'anticorps ont été multipliés par 11, témoignant d'une forte réponse anamnestique. Conclusion :La vaccination antirabique par la voie ID est immunogène, économique et pourrait également être envisagée pour la dose de rappel.Les anticorps protecteurs déclinent rapidement après une primovaccination par voie ID, donc il semblerait prudent d'effectuer une sérologie de contrôle 1 an après aux personnes à risque élevé d'exposition occulte dans leur travail.Une alternative serait d'administrer une dose de rappel par voie ID d'emblée à ces personnes 1 an après la primovaccination, ce qui permettrait de simplifier le suivi initial et de réduire les coûts associés (relance, prise de sang, sérologies, etc.).La persistance des anticorps protecteurs après cette dose de rappel devrait être évaluée afin de déterminer la nécessité et le délai entre les sérologies subséquentes.

Cyclospora cayetanensis is an emerging infectious agent. The aim of this study was to describe an outbreak that occurred in 250 adults exposed to contaminated food, focusing on the duration and relapses of symptoms, complications and evidence of local transmission. This outbreak affected workers who ate in a restaurant in June 2005. Cyclospora sp. was observed in the stools of 20 cases and 122 probable cases were identified. The attack rate was estimated at 89%. Main symptoms were diarrhoea (96%), nausea (88%), fatigue (87%), abdominal cramps (85%), fever (52%) and headaches (45%). Contaminated fresh basil originating from a Mexican farm, used to prepare an uncooked appetizer, was identified as the source. In this non-endemic population of immunocompetent adults, Cyclospora infection presents with watery diarrhoea lasting from 4 to 18 days and fatigue lasting from 11 to 42 days. For a small proportion of affected persons, recovery can be delayed.

Infectious disease epidemics in the community and health care settings have been and will continue to be a major public health problem worldwide. A rapid outbreak detection is the second of ten essential public health functions defined by the Pan American Health Organization/World Health Organization which are required "to improve, promote, protect, and restore the health of the population through collective action".In response to two need assessment studies and according to the core competencies for public health reference guide developed by the Public Health Agency of Canada, we produced a training program aimed at developing abilities and skills in investigation of infectious disease outbreaks. The program reviews and specifies:basic concepts in epidemiology of infections;steps involved in the investigation and key principles for managing an infectious disease outbreak;roles and responsibilities of health organisations to ensure the implementation and follow up of control measures;strategies to effectively communicate health risks and results of outbreak investigations.The training program is designed for professionals working in epidemiology, surveillance and infection control in public health departments or health care centers. It may also be suitable for graduate students or other professionals interested in acquiring skills in field epidemiology. Delivered by public health experts, this program uses a competency-based approach to facilitate learning and integrate theory with practice.The program contains three modules: an introductory and two intermediate level modules which include 60 hours of training with a tutor and 120 hours of individual work. Moodle (TM), an Open Source Course Management System, was used as a tool for creating the online modules. Individual and group exercises, reports, workshops and discussions on selected case studies and topics supplement the training activities. Students that successfully complete the program earn 4 credits from the University of Montreal which can be used towards a masters or doctorate degree.Since 2008, more than 60 individuals have completed the program. Changes have been made to the structure in order to suit the target audience's needs. Presently, we are working on creating a mobile support team to help regional public health organizations or health care centers with limited resources to deal with important infectious disease outbreaks.Our program, which combines different learning techniques, is a suitable and comprehensive model for developing and strengthening field epidemiology competencies among health professionals and graduate students. This allows them to understand that outbreak investigation is more than applying basic concepts of epidemiology but also implicates different parties which work together as a team to finally get to the bottom of things.