Background:This article continues the annual series on tick surveillance in Canada, tracking two of the primary tick vectors of concern in the country, Ixodes scapularis and Ixodes pacificus, which can transmit the agent of Lyme disease alongside several other tick-borne pathogens. Objective:This study analyzed passive and active tick surveillance data, including geographic distribution, pathogen prevalence and other characteristics to inform public health prevention. Methods:Passive and active surveillance data were compiled from eTick (an online, image-based platform), the National Microbiology Laboratory (Public Health Agency of Canada), provincial and local public health authorities and the Canadian Lyme Disease Research Network. Descriptive statistics of ticks and their associated pathogens are presented, including infection prevalence estimates. Results:In 2022, a total of 7,030 I. scapularis were submitted through passive surveillance from all provinces, while 911 I. pacificus were submitted from British Columbia (n=909) and Yukon (n=2). Ixodes scapularis submissions peaked in May and again in October. For I. pacificus, submissions peaked in May with a second, smaller peak in November. Six tick-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Borrelia miyamotoi, Babesia microti, Babesia odocoilei, Powassan virus) were identified from the I. scapularis collected by dragging in Manitoba, Ontario, Québec, New Brunswick or Nova Scotia. Conclusion:This report provides a summary of tick surveillance data collected in 2022. Tick characteristics and tick-borne pathogen infection prevalence were similar to previous years. Tick surveillance continues to play an important role in monitoring infection prevalence among ticks and their geographic distribution, which will help inform public health prevention and intervention efforts.

Background:Ixodes scapularis and Ixodes pacificus ticks pose risk of infection with tick-borne diseases in Eastern and Pacific Western Canada, respectively. Objective:In 2021, passive and active tick surveillance programs collected ticks and associated data elements, including location, infection and other characteristics, to monitor their populations and inform public health prevention and mitigation activities. Methods:Surveillance data for ticks were compiled from the National Microbiology Laboratory (Public Health Agency of Canada), provincial public health, Canadian Lyme Disease Research Network and eTick (an image-based online platform). A descriptive analysis of tick records and infection prevalence of tick-borne pathogens is presented. Seasonal trends are described. Results:During 2021, 6,892 I. scapularis ticks were identified across all ten provinces via passive surveillance with 777 I. pacificus ticks collected from British Columbia. Most were adult female ticks, collected from human hosts in the spring (March-May) or fall (October-November) seasons. The most common pathogen, Borrelia burgdorferi, was detected in 18.6% (95% CI: 17.2%-20.1%) of samples. Active surveillance resulted in 1,929 I. scapularis and 18 I. pacificus ticks collected in six provinces. Among I. scapularis, 22.3% were infected with B. burgdorferi, 11.8% with Babesia odocoilei and 4.3% with Anaplasma phagocytophilum. Fewer than 1% were infected with each of Borrelia miyamotoi (0.7%), Babesia microti (0.1%) and Powassan virus (0.1%). Conclusion:As the risk of infection with tick-borne diseases continues to grow in many parts of Canada, monitoring trends in infection prevalence and the geographical range expansion of ticks provides essential data to inform public health actions and messaging.

To estimate rates of hospitalizations for tick-borne diseases (TBDs) in Canada, retrospective analysis was conducted to determine the incidence of patients diagnosed with TBDs during their hospital stay in Canada, and describe demographic characteristics, temporal trends and geographic distributions, from 2009 through 2021. Codes from the International Classification of Diseases, Tenth Revision (ICD-10-CA) were used to capture diagnoses of TBDs in the Discharge Abstract Database (DAD) in Canadian hospitals. From 2009 through 2021, 1,626 patients were diagnosed with TBDs during their hospital stay. Of these, 1,457 were diagnosed with Lyme disease (LD), 162 with other TBDs, and seven were diagnosed with more than one TBD. Annual hospitalization counts for LD showed a significant increase from 50 in 2009 to 259 in 2021 (incidence rate per 100,000 population of 0.1 and 0.7, respectively). Epidemiologic patterns for hospitalized LD cases, including increases and variation in annual incidences, seasonality, demographics and geographic distribution, are consistent with those elucidated in national LD surveillance data. Amongst 162 patients diagnosed with other tick-borne diseases, discharge diagnoses were: rickettsiosis (32.7%), spotted fever due to rickettsia rickettsii (23.5%), tularemia (21.0%), babesiosis (8.6%), other tick-borne viral encephalitis (6.2%), tick-borne relapsing fever (4.9%), and Colorado tick fever (0.6%). Annual incidence increased only for rickettsiosis from 3 to 12 patients over the study period. Monitoring the data of hospitalizations using the DAD provided insights into the burden of emerging TBDs, the severity of illnesses and the population most at risk.

National West Nile virus (WNV) surveillance was established in partnership with the federal, provincial and territorial governments starting in 2000, with the aim to monitor the emergence and subsequent spread of WNV disease in Canada. As the disease emerged, national WNV surveillance continued to focus on early detection of WNV disease outbreaks in different parts of the country. In Canada, the WNV transmission season occurs from May to November. During the season, the system adopts a One Health approach to collect, integrate, analyze and disseminate national surveillance data on human, mosquito, bird and other animal cases. Weekly and annual reports are available to the public, provincial/territorial health authorities, and other federal partners to provide an ongoing national overview of WNV infections in Canada. While national surveillance allows a jurisdiction-by-jurisdiction comparison of data, it also helps to guide appropriate disease prevention strategies such as education and awareness campaigns at the national level. This paper aims to describe both the establishment and the current structure of national WNV surveillance in Canada.

Background:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease 2019 pandemic, is capable of infecting a variety of wildlife species. Wildlife living in close contact with humans are at an increased risk of SARS-CoV-2 exposure and, if infected, have the potential to become a reservoir for the pathogen, making control and management more difficult. The objective of this study is to conduct SARS-CoV-2 surveillance in urban wildlife from Ontario and Québec, increasing our knowledge of the epidemiology of the virus and our chances of detecting spillover from humans into wildlife.Methods:Using a One Health approach, we leveraged activities of existing research, surveillance and rehabilitation programs among multiple agencies to collect samples from 776 animals from 17 different wildlife species between June 2020 and May 2021. Samples from all animals were tested for the presence of SARS-CoV-2 viral ribonucleic acid, and a subset of samples from 219 animals across three species (raccoons, Procyon lotor; striped skunks, Mephitis mephitis; and mink, Neovison vison) were also tested for the presence of neutralizing antibodies.Results:No evidence of SARS-CoV-2 viral ribonucleic acid or neutralizing antibodies was detected in any of the tested samples.Conclusion:Although we were unable to identify positive SARS-CoV-2 cases in wildlife, continued research and surveillance activities are critical to better understand the rapidly changing landscape of susceptible animal species. Collaboration between academic, public and animal health sectors should include experts from relevant fields to build coordinated surveillance and response capacity.

In Canada, the emergence of vector-borne diseases may occur via international movement and subsequent establishment of vectors and pathogens, or via northward spread from endemic areas in the USA. Re-emergence of endemic vector-borne diseases may occur due to climate-driven changes to their geographic range and ecology. Lyme disease, West Nile virus (WNV), and other vector-borne diseases were identified as priority emerging non-enteric zoonoses in Canada in a prioritization exercise conducted by public health stakeholders in 2013. We review and present the state of knowledge on the public health importance of these high priority emerging vector-borne diseases in Canada. Lyme disease is emerging in Canada due to range expansion of the tick vector, which also signals concern for the emergence of human granulocytic anaplasmosis, babesiosis, and Powassan virus. WNV has been established in Canada since 2001, with epidemics of varying intensity in following years linked to climatic drivers. Eastern equine encephalitis virus, Jamestown Canyon virus, snowshoe hare virus, and Cache Valley virus are other mosquito-borne viruses endemic to Canada with the potential for human health impact. Increased surveillance for emerging pathogens and vectors and coordinated efforts among sectors and jurisdictions will aid in early detection and timely public health response.

What is already known on this topic?Q fever is a zoonotic disease caused by Coxiella burnetii and is usually transmitted through inhalation of air contaminated with animal excreta.The disease is considered to be underdiagnosed because symptoms are nonspecific and can vary from patient to patient, making diagnosis difficult. What is added by this report?During September-October 2014, the New York State Department of Health identified Q fever in five patients with exposure to a treatment known as live cell therapy, an alternative medicine practice involving injections of fetal sheep cells, which is a type of xenotransplantation.Investigation revealed that a group of U.S. residents traveled to Germany twice a year to receive this treatment. What are the implications for public health practice?Clinicians should consider zoonotic diseases, such as Q fever, in patients whose history includes receipt of a treatment known as live cell therapy.International travel for xenotransplantation procedures can facilitate transmission of zoonotic disease.

This study evaluated the use of house sparrow (Passer domesticus) nestlings as sentinels of West Nile virus (WNV) in the prairie grasslands of Saskatchewan. In the summer of 2006, 600 house sparrow nestlings were collected and pooled tissues tested by reverse transcriptase-polymerase chain reaction. All tested negative for WNV. During the same period, no WNV was detected by mosquito surveillance in the study area and 15 WNV-infected pools were collected from the nearby city of Estevan. Six percent of avian carcasses collected from Regina, a city 100 km from the study area in the same ecozone, were infected with WNV. In 2007, 200 house sparrow nestlings were collected and 4 tested positive for WNV, a prevalence of 2%. Ninety-seven house sparrow eggs were also collected and WNV antibodies were measured in the yolk. Seven eggs had measurable titers, a prevalence of 7.2%. Combined WNV surveillance showed high levels of WNV transmission in 2007; 112 WNV-infected mosquito pools were collected from nearby cities of Estevan and Weyburn, and the proportion of WNV infected avian carcasses from Regina was 78%. There were 1456 human cases of WNV in Saskatchewan in 2007, compared to 19 cases in 2006. The study concluded that house sparrow nestlings are not useful as an early warning of WNV circulation, or as a measure of the intensity of WNV activity in the prairie grasslands. Also, the study determined that maternally derived antibody did not have a significant limiting effect on WNV transmission to house sparrow nestlings in 2007, a year of epidemic WNV activity in the study area.

Of 4,268 wild ducks sampled in Canada in 2005, real-time reverse transcriptase-PCR detected influenza A matrix protein (M1) gene sequence in 37% and H5 gene sequence in 5%. Mallards accounted for 61% of samples, 73% of M1-positive ducks, and 90% of H5-positive ducks. Ducks hatched in 2005 accounted for 80% of the sample.

To respond to emerging public health threats such as West Nile virus, an advanced geographic information systems (GIS) -driven Web-based real-time surveillance system was developed to serve the National West Nile virus dead bird surveillance programme in Canada. The development of this system uses real-time Web GIS technologies and services to enhance conventional real-time surveillance systems based on real-time GIS requirements. The system has three modules: QuickTrack, QuickMap and QuickManage. QuickTrack is the real-time surveillance module that supports data collection, edit and transfer. QuickMap is the real-time Web GIS module that provides comprehensive real-time GIS supports and services in public health surveillance and information sharing. The QuickManage module is a Web-based system management package used to manage the entire system. This system offers an effective approach to enhance real-time public health surveillance systems by integrating real-time Web GIS technologies and services. The system demonstrates that real-time Web GIS technologies can play an important role in enhancing public health surveillance systems.

Background An extensive West Nile virus surveillance program of dead birds, mosquitoes, horses, and human infection has been launched as a result of West Nile virus first being reported in Canada in 2001. Some desktop and web GIS have been applied to West Nile virus dead bird surveillance. There have been urgent needs for a comprehensive GIS services and real-time surveillance. Results A pilot system was developed to integrate real-time surveillance, real-time GIS, and Open GIS technology in order to enhance West Nile virus dead bird surveillance in Canada. Driven and linked by the newly developed real-time web GIS technology, this integrated real-time surveillance system includes conventional real-time web-based surveillance components, integrated real-time GIS components, and integrated Open GIS components. The pilot system identified the major GIS functions and capacities that may be important to public health surveillance. The six web GIS clients provide a wide range of GIS tools for public health surveillance. The pilot system has been serving Canadian national West Nile virus dead bird surveillance since 2005 and is adaptable to serve other disease surveillance. Conclusion This pilot system has streamlined, enriched and enhanced national West Nile virus dead bird surveillance in Canada, improved productivity, and reduced operation cost. Its real-time GIS technology, static map technology, WMS integration, and its integration with non-GIS real-time surveillance system made this pilot system unique in surveillance and public health GIS.

West Nile virus (WNV) causes severe neurological disease in less than 1% of infections. However, meningoencephalitis may be more common in immunosuppressed transplant patients. In 2002, a WNV outbreak occurred in our region. To determine the spectrum of disease of community acquired WNV infection and assess public health behavior patterns in transplant recipients, we carried out a seroprevalence study. Patients were enrolled from outpatient transplant clinics in October 2002 and sera were screened for WNV. Questionnaires about WNV were provided to patients. Eight hundred sixteen organ transplant patients were enrolled. The seroprevalence of WNV IgM was 2/816 (0.25%; 95% CI 0.03-0.88%). By extrapolation to our entire transplant population of 2360 patients, and using data from hospital-based surveillance, the risk of meningoencephalitis in a transplant patient infected with WNV is estimated to be 40% (95% CI 16-80%). With regards to knowledge and behavior, 56% patients knew of and 47% used at least one protective measure against WNV. Only 33% used insect repellent. The risk of meningoencephalitis in transplant recipients is much higher than in the general population. There is incomplete knowledge and poor rates of compliance amongst patients with regards to WNV prevention.

A surveillance program has been in place since 2000 to detect the presence of West Nile virus (WNV) in Canada. Serological assays are most appropriate when monitoring for human disease and undertaking case investigations. Genomic amplification procedures are more commonly used for testing animal and mosquito specimens collected as part of ongoing surveillance efforts. The incursion of WNV into this country was documented for the first time in 2001 when WNV was demonstrated in 12 Ontario health units during the late summer and fall. In 2002 WNV activity was documented by avian surveillance in Ontario by mid-May with subsequent expansion of the virus throughout Ontario and into Quebec, Manitoba, Saskatchewan and Nova Scotia. Human cases were recorded in both Ontario and Quebec in 2002 with approximately 800 to 1000 probable, confirmed and suspect cases detected. The possible recurrence and further spread of WNV to other parts of Canada in 2003 must be anticipated with potential risk to public health. The continued surveillance and monitoring for WNV-associated human illness is necessary and appropriate disease prevention measures need to be in place in 2003.