Arctic Medical Research, Vol. 4 7: Suppl. 1, pp. 693- 696, 1988

PARASITIC ZOONOSES IN RELATION TO FISH AND WILDLIFE HARVESTING BY INUIT COMMUNITIES IN NORTHERN QUEBEC, CANADA

M. A. Curtis, M. E. Rau, C. E. Tanner, R. K. Prichard, G. M. Faubert, S. Olpinski and C. Trudeau

Institute of Parasitology, Macdonald College of McGill University, Quebec, Canada

Abstract. During 1983-86 we conducted necropsies on fish and game harvested by the Inuit communities of Kuujjuaq and Salluit to determine parasite prevalences. Several parasites of human health significance occur in the region: Trichinella spiralis in polar bear, walrus, wolf, red fox and arctic fox; and Diphyllobothrium spp. salmon, in arctjc char, brook trout, lake trout and whitefish. Antibody tests on 264 human sera samples obtained from Kuujjuaq and Salluit revealed diagnostic titres for toxo­ plasmosis, trichineflosis, echinococcosis and toxocariasis. Traditional dietary pre­ ferences and food preparation practices by the Inuit of northern Quebec ensure that risk of infection by zoonotic disease organisms is generally low, but the sporadic and unexpected appearance of parasites in atypical hosts (eg. Trichinella in walrus) remains a problem for community health.

Arctic Medical Research, vol. 47: suppl. 1, pp. 693-696, 1988.

Parasitic zoonoses are likely to occur anywhere in the As a part of land claims settlements established dur­ circumpolar north where human populations depend ing the 1970's by native people living in northern for their subsistence upon local wildlife and fish (3, 9). Quebec, very extensive documentation on subsistence In northern native communities where hunting and harvests for each community in the region were carried fishing are important activities, zoonotic risks can be out in order to form a baseline for possible future com­ a significant factor for community health. pensation in the event of adverse affects by hydroelec­ The objective of the research described here is to tric power projects or other modern developments. document and quantify the status of actual and poten­ This detailed information on fish and wildlife usage by tial parasitic zoonoses in two representative Inuit set­ the native settlements of northern Quebec was tlements in northern Quebec, and on the basis of our gathered during a five year study period, and provides findings to recommend control measures compatible an unusually complete record which can be utilized for with traditional Inuit culture. The emphasis of the assessing the risk of zoonotic disease transmission in study was primarily focussed upon sampling wildlife communities where hunting, fishing and trapping are and fish harvested by the two communities in order to of paramount importance to daily life (6, 7, 8). evaluate the prevalence and abundance of parasites During 1983-1986 we collected samples for parasite which can be transmitted to man. In addition to carry­ diagnoses from wildlife and fish taken during the nor­ ing out necropsies for detection of parasites in the mal harvests of two communities, Kuujjuaq and harvest itself, dogs were examined for possible pres­ Salluit, in order to obtain data on the occurrence of ence of Echinococcus granulosus and Toxocara canis. parasites of possible zoonotic significance in those Local people from both communities were interviewed settlements. The study sites were chosen such that one to give information about food preferences, handling was representative of a coastal area where people were and preparation methods, and awareness of patho­ primarily dependent upon marine mammals and fish genic parasites. We also carried out serodiagnoses of for their subsistence, while the other represented a blood samples obtained during hospital or clinic visits more inland locality where caribou were the principal from inhabitants of the two communities as well as source of food. from other areas along the northern Quebec coast. The parasite diseases of greatest potential zoonotic

Cirr:umpolar Health 87 694 Nonviral infectious diseases signifince in northern Quebec, as throughout the arc­ tion on traditional and contemporary means by which tic, are trichinellosis, echinococcosis and diphyllo­ zoonotic disease risks are minimized (11). bothriasis. Five outbreaks of trichinellosis caused by the consumption of infected walrus meat occurred in RESULTS the Salluit region in the two years immediately Trichinellosis. Trichinella spiralis was found in polar preceding our study (13). Diphyllobothriasis is not bears (60%), walrus (2%), red foxes (16%), arctic foxes commonly reported in local clinics serving the region, '(6%) and dogs (10%). The single infected walrus out but it is known to have been important in the past with of the 49 sampled was taken during autumn 1984 by up to 80 % of the inhabitants of coastal villages in­ Salluit hunters at Nottingham Island in Hudson Strait. fected (1). Echinococcosis has not yet been recorded in Only 6 nonviable larvae were obtained after digestion a clinically patent infections, but Echinococcus of 500 g of the walrus muscle tissue. On the other granulosus is commonly found in the caribou and. hand, larvae from the polar bears were viable and wolves of northern Quebec. The relatively small total could be passaged into laboratory mice even though size of the Inuit population, the sporadic nature of the samples had been frozen for several months. parasite transmission, and the vague clinical symp-. Serodiagnosis for T. spiralis revealed 26% and 2% of tomatology of most of these diseases are all factors patients from Salluit and Kuujjuaq respectively had tQat combine to reduce the probability of detection antibody responses above the diagnostic titres. and it is likely that prevalences are higher than regional clinical records would indicate as parasitological tests Echinococcosus. Of the 286 caribou lungs examined, are not routinely done in remote areas .. 9.5% contained hydatid cysts (&hinococcus granu­ /osus) but most were infertile and only 2.1 OJo of the MATERIAL AND METHODS caribou carried cysts containing viable protoscolices. Some information on the selected study sites is given here as E. granu/osus adults were found in the intestines of 10 a background for the study. Kuujjuaq is the largest communi­ of the 21 wolves examined. However, no adults were ty in northern Quebec with a total population of approx­ detected in any of the red foxes, arctic foxes, lynx or imately 1200, including some 163 Inuit who are active in hun­ dogs which were necropsied. Anti-hydatid antibody ting, trapping and fishing. Situated on the banks of the Koksoak river about 40 km from Ungava Bay, the principal levels were above diagnostic titers for 2% and 4% of sources of regional foods are caribou (440Je) and freshwater the patients included in the serodiagnostic tests for the and anadromous fish (salmon, arctic char, brook trout and Salluit and Kuujjuaq regions respectively. lake trout) (3311/o), but marine marnmaj8 (mainly seals) from Ungava Bay also comprise an importlllit part of the local diet Dipbyllobothriasis. Tho species of Diphyllobothrium, (1611fo ). Salluit, with about 600 inhabitants including 115 D. ditremum and D. dentriticum were found to occur active subsistence hunters, is located beside a small fiord on in the salmon, char, trout and whitefish harvested by the south coast of Hudson Strait. About 881170 of the Salluit harvests by weight consists of marine mammals (seals, beluga the communities studied. Only D. dendriticum is whales, walrus, polar bears) and fish (mostly arctic char). known to be infective to man (4). Because the fish Arctic fox is the most important fur animal for both com­ samples had been frozen prior to necropsy, identifica­ munities. tions to the species level were not feasible and so results Partial or complete necropsies were performed on a are presented as grouped totals for the occurrences of number of terrestrial and marine mammals from both com­ munities. The smaller animal species were subjected to com­ both species in the fish analysed from each sampling plete necropsies while only critical organs were examined for site. Diphyllobothrium prevalences in salmon and the larger ones {eg. muscle samples for trichinellosis in polar anadromous or river dwelling arctic char, brook trout bear and marine mammals; lungs for echinococcosis in and lake trout were consistently lower than for fish caribou). Replicate stool samples were obtained for 80 dogs in Kuujjuaq and 14 necropsies of dogs from that community species sampled in lakes in the vicinity of the two com­ were conducted. Approximately 1200 fish were examined for munities. Stool sample analyses revealed the presence Diphyllobothrium from the freshwater and marine fisheries of Diphyllobothrium eggs in two of the 87 patients ex­ of both communities. A total of 264 serum samples from out­ amined. Prevalence of the eggs in fecal samples of 80 patients or patients from Kuujjuaq and Salluit were examined dogs from Kuujjuaq was 44 %. for antibodies to trichinellosis, echinococcosis, toxocariasis, amoebiasis, and toxoplasmosis using ELISA or haernag­ Toxoplasmosis. An unanticipated finding of the glutination techniques. Details of the methods for each of these studies are provided in separate reports (2, 5, 10, 12). serological study was the detection of diagnostic titres Selective interviews with 19individuals from each community for Toxoplasma gondii in 69% of the patients examin­ were conducted during April 1986 in order to obtain inforrna- ed from the Salluit district and 610fo of those from

Cimmrpq/ar Hes/th 87 Curtis et al.: Parasitic zoonoses 695

Kuujjuaq, of which 14% and 10% possessed anti­ Echinococcus eggs which are voided by wolves and Toxoplasma titres at dilutions exceeding 1:1000. The other canids which have become infected by feeding percentage of individuals above the DT steadily in­ upon caribou. Viable diphyllobothrium larvae are creased with age within the populations. One possible recognized when they occur in fish viscera and their source of toxoplasmosis in northern Quebec would be consumption is normally avoided. Furthermore, the the consumption of raw caribou meat. practice of generally selecting fish in good condition and avoiding those which have been dead m the nets Toxocariasis. On the basis of stool sample analyses for a lengthy period reduces the possibility of consum­ and necropsy findings, Toxocara canis was not present ing fish flesh that has been contaminated by plerocer­ in the dogs of the two settlements. However, Toxascaris coids migrating from the viscera. It is also recognized /eonina was detected in 40% of the Kuujjuaq dogs, as that gutting the fish immediately after their removal weli as in arctic foxes (82 %), red foxes (73 %), wolves from nets serves to further diminish the possibility of (14 OJo) and lynx (100 %). In Salluit 20% of the patients infection. However, tJ:ie preference of some individuals tested for anti-Toxocara antibody were positive, and 7 for consumption o(raw fish livers or stomach tissue, OJo were positive in Kuujjuaq. The cause for this is both primary sites for D. dendriticum plerocercoids, unclear, but it may arise from a cross reaction with can lead to infection in circumstances when the pres­ another antigen of parasite origin. ence of the parasites is undetected. The individuals in­ Other parasites of possible zoonotic signifince. An­ terviewed during our study emphasized the important responsibility of hunters, fishermen and those who cyclosU>ma sp., found in the intestine of one of the SO arctic foxes necropsied, is a hookworm known to cause prepare food to ensure the health and communal well cutaneous larval migrans in human infections. Larval being of those for whom they provide sustenance. Anisakine nematodes present in marine fish in the nor­ thern Quebec region, with adults occurring in marine DISCUSSION mammals from the area, are also capable of infecting local people who consume raw or undercooked marine Significant exposure to parasites of zoonotic impor­ fish, although at present there is no real evidence that tance is a natural consequence of contemporary life in anisakiasis commonly occurs as a zoonosis in northern northern communities where subsistence harvesting of Quebec. wildlife and fish provides foods that are essential to good nutrition and serve special cultural purposes. Dietary practices and zoonotic disease. Interviews with Our research has shown that two Inuit settlements in local people from Salluit and Kuujjuaq consistently in­ northern Quebec deal for the most part quite effective­ dicated a high degree of shared knowledge with regard ly with the zoonotic disease risks through their own to dietary practices and perceptions of risk associated traditions of discrimination in selecting and preparing with the consumption of certain foods. Avoidance of subsistence foods, but there are clearly some cir­ trichinellosis is for the most part assured by thorough cumstances for which improved protective measures cooking of polar bear and fox (eaten rarely), and wolf can be implemented. Local health committees have ad­ is presently not consumed at all. Walrus, by virtue of vised people of the inherent dangers of consuming un­ its low prevalence of parasitism, constitutes the main cooked walrus meat, and there have been no outbreaks source of infection as there are no indigenous rules to of trichinellosis from this source in the past three avoid exposure. There is an awareness that raw walrus years. There is also an increased awareness of the risk or igunak and purtak, fermented delicacies, can cause from dogs which may carry Echinococcus after having illness but the sporadic nature of the epidemics and the eaten caribou entrails, but it has not yet been feasible range of individual responses to a dose of Ttichinella to enforce strict rules to more significantly diminish are such that protective measures were not incor­ the possibility of transmission to local people. If the porated into traditional food preparation. Hydatid more highly pathogenic hydatid species, £. multilocu­ cysts in caribou are well known to local people in both laris, were to spread into the region from western communities and infected organs are not consumed, North America, the implementation of protective although this is a matter of natural fastidiousness measures would become a greater priority. rather than because of any associated zoonotic risk, Other parasitic zoonoses in northern Quebec may be for protoscolicies are not infective to man. There is no of less critical importance for public health but general awareness of the dangers of the microscopic nonetheless warrant further research and monitoring.

Circumpolar Health 87 6% Nonviral infectious diseases

Diphyllobothriasis caused by D. dendriticum rather publicizing relevant information at appropriate times than D. latum is poorly understood from a clinical of year, such as prior to an organized walrus hunt, viewpoint and its appearance in northern communities reasonably effective protection can be achieved in a seems to be highly seasonal, meaning that current manner compatible with support of traditional life­ prevalence estimates may be considerably underesti­ styles. mated. The surprisingly large percentage of the nor­ thern Quebec native population which exhibits high REFERENCES anti-Toxoplasma antibody levels constitutes a serous matter for investigation wnh regard to transmission 1. Arh I. Fish tapeworm in Eskimos in the Port Harrison pathways and implications for health. Similarly, fur­ area, Canada. Can J Public Health 1960; 51: 268-271. 2. Berube M, Curtuis MA. Occurrence of metazoan ther work is required to establish the reasons for a rela­ parasites in the fishes of northern Quebec. In press. tively high percentage of the population possessing 3. Cameron TWM. Northern sylvatic helminthiasis. Arch diagnostic titres for toxocariasis despite the absence of Environ Health 1968; 17: 614-621. Toxocara can is from the area. This finding implies that 4. Curtis M. Problems in reporting Diphylllobothrium latum (fish tapeworm) in Canada on the basis of stool there may be additional zoonoses caused by some of sample analyses. Can Dis Wkly Rpt 1980; 6-11: 49-50. the other parasitic nematodes which are common in 5. Desrochers F, Curtis MA. The occurrence of gastro­ the: endemic northern species of wildlife and fish. intestinal helminths in dogs from Kuujjuaq (Fort The Inuit of northern Quebec have successfully re­ Chimo), Quebec, Canada. Can J Public Health. In press. tained their traditional knowledge as it applies to 6. James Bay and Northern Quebec Native Harvesting Research Committee. Research to establish present levels harvesting and food preparation protocols and to a of native harvesting. Harvests by the Inuit of Northern degree this cultural inheritance serves them well as a Quebec. Phase II (Yr. 1976). Northern Quebec Inuit protection from certain parasitic diseases. Unfor­ Association. Montreal, 1979. tunately, this circumstance is not a universal feature of 7. James Bay and Northern Quebec Native Harvesting Research Committee. Research to establish present levels native peoples living today in all areas of the circum­ of native harvesting. Harvests by the Inuit of northern polar north, and wherever detailed knowledge has Quebec. Phase II (Yr. 1977 and 1978). Northern Quebec become altered or lost the population may be placed at Inuit Association. Montreal, 1982. greater risk. In the past, periods of privation led to the 8. James Bay and Northern Quebec Native Harvesting consumption of foods not normally acceptable or the Research Committee. Research to establish present levels of native harvesting. Harvests by the Inuit of northern ingestion of raw meat that would otherwise have been Quebec. Phase II Yrs. 1979 and 1980. Northern Quebec cooked, sometimes with fatal coirsequences. Expe­ Inuit Association. Montreal, 1982. diency, although under less stressful conditions today, 9. Lantis M. Zoonotic diseases in the Canadian and could also engender a similar result. Human nature be­ Alaskan North. Etudes Inuit Studies, Laval University ing what it is, even a heightened personal awareness 1981; 5: 83-107. 10. Rau ME, Trudeau C. Parasites of potential zoonotic im­ regarding the hazards of eating certain foods uncook­ portance in game and furbearers harvested by the Inuit of ed will never entirely ensure protection in a remote nor- northern Quebec. Can J Public Health. In press. them community, any more than an urban inhabitant 11. Ross P, Olpinsky S. The relationship between dietary in the South can necessarily be dissuaded from tobac­ practices and zoonotic disease in northern Quebec. Etudes Inuit Studies, Laval University. In press. co and alcohol abuse despite his or her familiarity with 12. Tanner CE, Staudt M, Adamowski R, Lussier M, Ber­ the risks entailed. trand S, Prichard RK. Seroepidemiological study for five The nutritional value of traditional foods in nor­ different zoonotic parasites in northern Quebec. Can J thern settlements is obviously high, and many food Public Health. In press. types eaten uncooked are of particular dietary impor­ 13. Yaillet J, Maclean JD, Goresky CA, Staudt M, Routhier G, Law C. Arctic trichinosis presenting as prolonged tance. Under these circumstances it is clear that public diarrhea. Gastroenterol 1986; 91: 938-946. health workers giving advice about the avoidance of parasite diseases must adopt a cautious approach which will not be rr>Jsinterpreted as a general condem­ Associate professor Mark A. Curtis, M.D. nation of raw or uncooked foods. Undue emphasis on Institute of Parasitology the presence of parasites normally found in northern MacDonald College of McGill University wildlife and fish is certainly not warranted, for the ma­ 21,111 Lakeshore Road Ste-Anne-de-Bellevue jority of such organisms are of no zoonotic signifince. Quebec H9X !CO By working through community health boards and Canada

Circumpolar Health 87