Table 2.
Zoonotic pathogens of Arctic and boreal systems that can be transmitted to humans through hunting, consumption or other use of wildlife, noting pathogen potential for local outbreak clusters, human-to-human transmission, and epidemic/pandemic spread.
| Type of pathogen | Disease/Pathogen | Wild Host(s)* in arctic and boreal biomes | Route of infection to humans | Disease in humans | Local outbreak clusters possible? | Human to human transmission? | Epidemic or pandemic potential? |
|---|---|---|---|---|---|---|---|
| Parasites | Anisakidosis/Roundworms of genus Anisakis (73, 74) | Definitive host: Bearded seals, ringed seals and beluga whale Intermediate: Fish and squid |
Consumption of raw fish | Gastritis with ulcerative lesions of stomach wall | Possible through consumption of shared contaminated product | No | No |
| Fluke infection Cryptocotyle lingua (fish trematode) (75, 76) | Intermediate host: Fish Reservoir hosts: Fish-eating birds and mammals including foxes, gulls, terns, and herons |
Ingestion of raw or improperly cooked fish from fresh and brackish water | Liver and intestinal damage | Possible through consumption of shared contaminated product | No | No | |
| Cystic Echinococcosis/Echinococcus canadensis (22, 77–83) | Definitive host: Wolf, coyote (dog) Intermediate host: Mainly caribou/reindeer and moose (also muskox, elk, bison, and white-tailed and mule deer) |
Canids: Ingestion of viscera of infected intermediate host. Humans: Via accidental ingestion of eggs shed in canid feces (e.g., from fur during fox skinning), or from a water or food source (e.g., plants, berries) contaminated with eggs |
Relatively benign cyst formation in liver and lung | Possible through contaminated water source | No | No | |
| Alveolar Echinococcosis/Echinococcus multilocularis (79, 84, 85) | Definitive host: Fox, felid, wolf, and coyote (also dog) Intermediate host: rodents e.g., vole, deer mice, lemming, muskrat (ground squirrels and shrews on St. Lawrence Island) |
Canids: Ingestion of viscera of infected intermediate host. Humans: Accidental ingestion of eggs shed in canid or felid feces (e.g., from fur during fox skinning); or from contaminated water or food source (e.g., plants, berries) |
Alveolar hydatid disease with parasitic tumor growth in liver, lungs, brain, and other organs and much higher mortality than for Echinococcus canadensis infection | Possible through contaminated water source | No | No | |
| Tapeworms/Diphyllobothrium latum & Diphyllobothrium dendriticum & Diphyllobothrium nihonkaiense (73, 86) |
Diphyllobothrium latum: Fish-eating mammals (e.g., bear, wolf, otters, and mink) Diphyllobothrium dendriticum: Fish, fish-eating mammals, and birds Diphyllobothrium nihonkaiense: Wild salmon |
Consumption of undercooked fish meat or livers | Asymptomatic or causes mild chronic intermittent diarrhea | Possible through consumption of shared contaminated product | No | No | |
| Toxocariasis/Toxocara canis (primarily) & Toxocara cati** (79, 82, 83, 87–90) |
Toxocara canis: Wolves, coyotes, and foxes (small mammals), (dog) Toxocara cati: Felids (e.g., lynx) and rodents |
Mainly through accidental ingestion of eggs from contaminated; possible via consumption of uncooked meat of small mammal paratenic hosts | Ocular and visceral larval migrans | Possible through contaminated water source | No | No | |
| Toxoplasmosis/Toxoplasma gondii (79, 84, 91–101) | Definitive host: Felids (e.g., lynx) Intermediate hosts: many northern animals including caribou, walrus, birds and seal |
Consumption of raw or undercooked meat; or via water or soil contaminated with felid feces containing infective oocysts | Often asymptomatic, possible association with mental health issues e.g., depression; severe disease in immune- compromised individuals (e.g., encephalitis/chorioretinitis); fetal morbidity and mortality during pregnancy | Possible through consumption of shared contaminated product | No | No | |
| Trichinellosis/Trichinella native (30, 73, 79, 82, 84, 102–106) | Walrus, seal, bear (polar, black and grizzly), fox, wolf, and wolverine | Ingestion of raw or undercooked meat | From asymptomatic to nausea, diarrhea, vomiting, abdominal pain, muscle pain, fever swelling of eyes, weakness/fatigue, headache, and (rarely) fatality if heart affected | Possible through consumption of shared contaminated product | No | No | |
| Giardiasis (Giardia spp.) & Cryptosporidiosis (Cryptosporidium spp.) (107) | Mammals including beaver, muskrats, muskoxen, and others | Via water contaminated with feces containing infective oocysts | Diarrheal disease | Possible through contaminated water source | No | No | |
| Bacteria | Anthrax/Bacillus anthracis (108–111) | Wild ungulates (e.g., white-tailed and mule deer, bison, moose, and reindeer) | Ingestion or inhalation, or contamination of wounds by, bacterial spores | Cutaneous: skin sores Inhalational: chest pain, shortness of breath, cough, nausea, vomiting, stomach pains, headache, sweats, fatigue, body aches Gastrointestinal: Fever, swelling of neck glands, sore throat, nausea, vomiting and diarrhea, headache, fainting, swelling of abdomen. All types have potential, if untreated, to spread throughout body, causing severe illness and even death |
Possible through shared contaminated water or food source. Rarely direct human-to- human transmission | Very rare reports from cutaneous form. Not considered contagious | No |
| Brucellosis/Brucella spp. (81, 84, 112, 113) | Wild mammals including: caribou/reindeer, elk, muskoxen, bison, white-tailed and mule deer, goats, sheep, moose, wolf, fox, rodents, hares, mink, and marine mammals | Handling of carcasses, fetuses, and newborn calves from infective animals; or consumption of raw (including frozen or dried) meat and marrow Dogs: Consumption of uncooked infected tissue |
Systemic bacterial disease (acute or insidious): intermittent fever with headache, weakness, sweating, chills, joint pain and weight loss; also cerebral forms; can be fatal | Possible, through consumption of shared contaminated product | Extremely rare (e.g., through breastmilk) | No | |
| Botulism/Clostridium botulinum*** (114–119) | Fish (especially salmon) and many mammals Main source in north is marine mammals, especially seals and whales |
Consumption of raw or parboiled seal meat, fish, seal oil, or other wild meat that has undergone faulty fermentation or aging | Multiple clinical symptoms including: blurred vision, nausea, vomiting, paralysis of the motor nerves, and respiratory paralysis in fatal cases | Possible, through consumption of shared contaminated product | No | No | |
| Erysipelas/Erisipelothrix rhusiopathiae (56, 120–128) | Terrestrial and aquatic mammals including muskoxen, white-tailed and mule deer, caribou, birds, fish, and arthropods | Exposure to infected animals or fish or animal products via skin wounds or via ingestion; environmental sources of infection also reported | Localized skin infections; or severe cases with diffuse cutaneous or systemic disease, septicemia, endocarditis; infrequently pneumonia, abscesses, meningitis, arthritis | Unlikely | No | No | |
| Leptospirosis/Leptospira interrogans (129–131) | Beavers, coyotes, white-tailed and mule deer, foxes, opossums, otters, raccoons, skunks, and Northern fur seals | Direct contact with contaminated urine or animals | From no symptoms, to kidney damage, meningitis, liver failure, respiratory distress, and death | Possible through contaminated water source | No | No | |
| Lyme disease/Borrelia burgdorferi (132, 133) | Seabirds, song birds, and wild ungulates | Bites from ticks that have fed on an infected animal | Fever, rash, facial paralysis, arthritis | Possible if infected host and tick densities high | No | No | |
| Pasteurellosis/Pasteurella multocida; Bisgaardia hudsonensis (others) (134–137) | Pinnipeds, including seals and walruses, many terrestrial mammals, birds, and reptiles | Animal bites or contact with nasal secretions of infected animal | Skin and soft tissue infections: rapidly spreading edema, erythema and tenderness at site of the bite or scratch; abscessation; enlarged local lymph nodes | No | No | No | |
| Q fever/Coxiella burnetii (138–140) | Northern fur seals and sea birds | Inhalation of dust contaminated by infected animal feces, urine, milk, or birth products; contaminated water source; or ingestion of infected animal products e.g., milk or cheese | Mild: Fever, fatigue, headache, muscle aches, vomiting, diarrhea, chest or stomach pain, weight loss, cough Severe: pneumonia or hepatitis. Infection during pregnancy can cause miscarriage, stillbirth, pre-term delivery, low infant birth weight |
Occasionally, through shared contaminated water or food source, or human-to-human transmission | Rare: although highly transmissible from animal-human it is not highly transmissible from human-human | No | |
| Seal finger/Mycoplasma spp. (114, 134, 141) | Seals and whales | Marine mammal bites; or broken skin contact with infectious material from marine mammal | Swollen, painful, and suppurative lesion on finger; rarely systemic, with fever and lymphangitis | No | No | No | |
| Tuberculosis and Mycobacteriosis/Mycobacterium bovis, M. tuberculosis, M. pinnipedii & others (114, 142–144) | Marine mammals: Wild seals (more commonly) and cetaceans (rarely) Terrestrial mammals: bison, elk, moose, white-tailed deer, mule deer and wolves |
Multiple routes: inhalation, ingestion of raw/undercooked meat or unpasteurized milk products, and direct contact with breaks in the skin e.g., when dressing infected ungulates | Pulmonary (cough, shortness of breath) and cutaneous (localized skin infections) disease | Possible, through consumption of shared contaminated product and direct human- to-human transmission | Yes | Yes | |
| Tularemia/Francisella tularensis (84, 145–148) | Muskrats, beavers, hares, voles, squirrels, wolves, bears, and other northern wildlife | Consumption of insufficiently cooked meat or contaminated water and dust; or through bites from infected vectors such as mosquitoes and ticks; and through direct contact i.e., skinning; touching hare carcasses | Skin lesions or ulcerations, lymphadenomegaly, vomiting, diarrhea, abdominal pain, conjunctivitis, pneumonia, septicemia, and hepatosplenomegaly | Rare, but possible through consumption of shared contaminated product or contaminated water source or vector abundance | No | No | |
| Yersiniosis****/Yersinia pseudotuberculosis & Y. enterocolitica (94, 142, 149–151) | Reservoirs in rodents (beaver, muskrat, ground squirrels), lagomorphs (snowshoe hare), and outbreaks in muskoxen | Ingestion of raw or undercooked meat, or water contaminated with infected fecal matter | Fever, abdominal pain, and diarrhea | Possible through consumption of shared contaminated product or contaminated water source | Very rarely; not highly transmissible | ||
| Viruses | Avian influenza/Influenza A viruses (114, 152–155) | Wild birds, especially waterfowl | During preparation of infected birds for eating (plucking, cleaning, butchering) or consumption of raw meat from infected bird | Mild to severe illness, sometimes death. Fever, chills, cough, sore throat, congestion, body aches, headache, fatigue; vomiting, and diarrhea in children | Yes | Yes | Yes |
| Caliciviruses/(marine caliciviruses: serotypes of vesicular exanthema of swine virus) (114, 156) | Arctic marine mammals, including fur seals, elephant seals, walrus, and whales (including bowhead and gray) | Broken skin contact with infectious animal or their secretions | Fluid-filled blisters on the extremities | Rare, but possible through handling same animal | Possible but rare, through broken skin contact with blister fluid | Not for marine serotypes | |
| Sealpox/Parapox virus (114, 157, 158) | Harbor and gray seals | Direct contact via pox lesions on infected mammals | Painful, nodular lesions | Rare, but possible through handling same animal | No | No | |
| Orf/Parapox virus (157–159) | Muskoxen, mountain goats, Dall's sheep, caribou and white-tailed, and mule deer | Direct contact via pox lesions on infected mammals | Painful, nodular lesions | Rare but possible through handling same animal or if multiple animals infected in herd | No | No | |
| Rabies (38, 81, 160–170) |
Principle reservoir hosts: Arctic foxes, red foxes, wolves, and bats Less commonly: Caribou, beaver, black and polar bears, racoons, lynx, and wolverine) |
Humans and domestic dogs: via bites from infected wildlife | Almost always fatal if untreated. Affects central nervous system: general weakness or discomfort, fever, headache; prickling sensation at site of the bite, anxiety, confusion, agitation, delirium, hallucinations, hydrophobia (fear of water), and insomnia | Possible through rabid animal in community | Extremely rare: through bite or organ transplant | No | |
| Hepatitis E***** N.B. transmission from wildlife to humans not yet confirmed in Arctic or boreal regions, but suspected (171–173) | Free-ranging deer, possibly caribou | Humans via undercooked meat or food contaminated with feces from infected animal | Acute viral hepatitis, mortality a concern in pregnant women | Possible through consumption of shared contaminated undercooked meat or shared contaminated water source | Rare: mainly via maternal-infant transmission | Outbreaks possible via fecal contamination of drinking water source | |
| Fungal | None as yet | Future concern in warming Arctic and boreal systems. Dearth of data for fish (174) | Future concern in warming Arctic and boreal systems | N/A | N/A | N/A | No |
| Prion Diseases | Chronic Wasting Disease (CWD)****** (175, 176) | Wild cervids: Moose, white-tailed and mule deer, elk and reindeer in Fennoscandia (potentially caribou) | No documented transmission to humans as yet, but experimental evidence of CWD transmission to non-human primates. Other TSEs have spread from animals to humans via consumption of infected offal, so public health officials still advise caution | N/A | Potentially possible through consumption of shared contaminated product | N/A | No |
*
Definitive or final host = host organism in which a parasite reaches maturity (adult stage) and reproduces sexually; Intermediate host = host organism that harbors the sexually immature parasite and is required by the parasite to undergo development and complete its life cycle; Reservoir host: primary host that maintains a pathogen in a system and that serves as a reservoir of infection for other species.
**
Toxocara cati is rarely zoonotic.
***
Not strictly a zoonosis, but of concern in Indigenous communities and contracted via raw/fermented wild meat.
****
Yersinia pestis discussed in Appendix 1 as a future concern; not yet reported from humans in the Arctic.
*****
There is currently no confirmed transmission of Hepatitis E virus from wildlife to humans in the Arctic and boreal regions, however one study found serological evidence of HEV infection in 3% of the observed Canadian Inuit population (171).
******
As yet, there has been no documented transmission of CWD to humans, but caution is still advised: other Prion diseases have spread from animals to humans e.g. Bovine Spongiform Encephalopathy/Mad Cow Disease, and have a very prolonged incubation period in people; experimental research has shown potential for transmission to non-human primates and ability of CWD to convert human prion protein to a misfolded state; CWD is an emerging disease and more longitudinal research is warranted (176).