Major emerging vector-borne zoonotic diseases of public health importance in Canada

Abstract

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.

Climatic changes and their role in emergence and re-emergence of diseases

“…Similar reports documented the extension of the habitat of the tick species Ixodes scapularis (transmit Lyme borreliosis), Amblyomma americanum (vector of Amblyomma americanum transmitted Ehrlichia chaffeensis and Ehrlichia ewingii) and Amblyomma maculatum (transmit Rickettsia parkeri, potted fever agent, and the canine a p i c o m p l e x i a n ( H e p a t o z o o n a m e r i c a n u m ) ) a n d Hemaphysalis longicornis to involve new land in North America (Eisen and Eisen 2018;Ogden and Lindsay 2016;Paddock and Goddard 2015;Sonenshine 2018). Human cases of tick-borne babesiosis were recently reported in Canada, Europe and Japan (Kulkarni et al 2015;Krause 2012, 2020).…”

Prioritization of High Consequence Viruses to Improve European Laboratory Preparedness for Cross-Border Health Threats

“…Highly infectious diseases can spread rapidly across borders through travel or trade, and international coordination is essential to a prompt and efficient response. Public health systems must be on the alert and ready to deal with new emergencies that may arise anywhere in the world, therefore developing strategies to identify priorities for intervention measures, rational allocation of resources for research and surveillance, and preparedness planning has been the focus of a large body of research in recent years (Balabanova et al 2011, Witt et al 2011, Brookes et al 2015, Dahl et al 2015, Kulkarni et al 2015, Krause et al 2008, Matthiessen et al 2016, Ng and Sargeant 2013, Xia et al 2013, Wallinga et al 2010. At the start of its activity, the EMERGE consortium set out to develop its own strategy to prioritize pathogens for its 3-year EQAEs planning, in order to improve diagnostic capabilities.…”

Northern forest winters have lost cold, snowy conditions that are important for ecosystems and human communities

“…Conversely, the trend toward fewer Mosquito Kill Days (i.e., when daily minimum temperatures are <À5°C) and more frequent Thaw Days (i.e., when daily maximum temperature >0°C) suggests the potential for increased exposure to insect vectors and other human health risks. The emergence and spread of vector-borne diseases is complex and can involve interactions among the introduction of invasive vector species, land use change, and alterations in human behavior (Allan et al 2003, Kulkarni et al 2015, Beard et al 2016. However, numerous studies have demonstrated a linkage between milder winter temperatures and the spatial distribution of insect vectors such as the endemic blacklegged tick (Ixodes scapularis Say) that carries the Borrelia burgdorferi bacteria that causes Lyme disease (Brownstein et al 2003, Leighton et al 2012, Levi et al 2015, and the invasive Asian tiger mosquito, an important vector for dengue and chikungunya fevers and eastern equine encephalitis (Platonov et al 2008, Rochlin et al 2013, Ogden et al 2014).…”