Parasitic Zoonoses in Relation to Fish and Wildlife Harvesting by Inuit Communities in Northern Quebec, Canada
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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