Gastrointestinal Infections

Climate warming during El Niño Southern Oscillation events has been associated with illness in marine mammals, birds, fish and shellfish. These illnesses have included botulism, avian Newcastle disease, duck plague, influenza in seabirds, and a herpes-like virus epidemic in oysters.  Consequently, it is likely that long-term temperature changes resulting from climate change will be associated with changes in the types and incidences of diseases and outbreaks in those species that can transmit disease to humans.

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Many zoonotic diseases currently occur in Arctic host species, such as:

• tularemia in rabbits, muskrats and beavers; rabies in foxes;
• brucellosis in ungulates, foxes and bears;
• echinococcosis in rodents or canine species;
• trichinosis in walruses and polar bears; and
• cryptosporidiosis in both marine (ringed seals) and terrestrial mammals.

Changes in the spatial occurrence of these diseases is likely because they are spread through temperature-mediated mechanisms, such as the movement of animal populations and contamination of surface waters used by Arctic populations.

The most common agents of food and water-borne diseases in the Arctic are:

• giardia from drinking contaminated water, and
• salmonella and campylobacter from contaminated foods such as goose, and food that is eaten raw or poorly cooked.

Some regions have documented significant cases of zoonotic infections in the past. For example, since 1982, 11 outbreaks involving 86 confirmed cases of trichinosis have been documented in Nunavik.

Many Inuit in Iqaluit have also reported to be having outbreaks of hives and other reactions to eating char caught at Sylvia Grinnell river and area. Inuit also report that char is much lighter in colour than the bright red orange flesh in recent years, and a poor taste. 2016 was reportedly a particularly poor year for Arctic char. 

Walrus meat was the source in 97% of cases but no deaths have been recorded from the disease.

Reported cases of Campylobacter and Salmonella have declined in recent years in the North. However, an increase in parasites in caribou has been reported in the central and eastern Arctic in recent years, and local hunters have expressed concerns about the safety of the consumption of this meat. 

Scientists have described the role that a combination of climate warming, shrinking habitats and changes in other ecological factors have played in the emergence of three nematode roundworm or threadworm) species in umingmak/muskoxen in the central and western Arctic, one of which may be important in regulating population numbers of this species on Banks Island, Nunavut.

A study was carried out in two communities in Nunatsiavut, Canada explore associations between weather, water quality and occurrence of infectious gastrointestinal illnesses (IGI). In Nain, Labrador, water volume input (rainfall + snowmelt) peaked in spring and summer and was positively associated with levels of raw water bacteriological variables. The number of IGI-related clinic visits peaked in the summer and fall months. Significant positive associations were observed between high levels of water volume input 2 and 4 weeks prior, and the IGI-related clinic visits. This study is the first to systematically gather, analyze and compare baseline data on weather, water quality and health in the Inuit Nunangat, and illustrates the need for high quality temporal baseline information to allow for detection of future impacts of climate change on regional Inuit human environmental health.

Receiving training on safe food handling including boiling river or ice for a minimum of 2 minutes, will help protect against gastrointestinal infections. 

Similarly, the over-wintering survival and the distribution of some insect species are increased by warming temperatures and create opportunities for the introduction of new diseases into Arctic regions or increased risk from endemic pathogens. Insects are therefore likely to change in their distribution with warming in Arctic regions and increase the incidence of diseases among human populations. Climate change may have already shifted the range of tick-borne encephalitis toward more northern latitudes.  Studies suggest that increasing temperature will continue to favour further northward expansion of the geographic range of Ixodes scapularis, the tick vector of Lyme disease. Temperature conditions suitable for this tick may occur in the NWT by the 2080s. The spread of the spruce bark beetle and its contribution to increasing forest fire risk in the Yukon, and the potential impacts this has on biodiversity and human health.