چکیده (انگلیسی):

Zoonotic Echinococcus spp. cestodes are present in almost all circumpolar nations, and have historically
posed a risk to health of indigenous as well as other northern residents. However, surveillance
data on both alveolar (AE) and cystic (CE) echinococcosis remains incomplete
throughout the circumpolar region: Russia, Fennoscandia, Iceland, Greenland, Canada and
Alaska (USA). Prevalence of Echinococcus spp. varies considerably in definitive canid hosts, animal
intermediate hosts and accidental hosts like humans. Yet despite the high prevalence reported
in canids in some geographic locations, human AE and CE are much less common than
in endemic Asian and central European countries. This paper explores knowledge gaps and future
challenges posed by Echinococcus spp. in eight circumpolar countries, a region where rapid
environmental and social change are rewriting the boundaries, transmission, and impact of
many pathogens, including zoonotic Echinococcus spp.
Genotypes G6, G8 and G10 of Echinococcus canadensis are causative agents of human CE and
have been identified in sylvatic (wild animal) and synanthropic (ecological association with
humans) cervid-canine life cycles in the following northern regions: Alaska and northern
Canada - G8 and G10; northern Russia - G6, G8, G10; and Fennoscandia - G10 in Finland -
with no recent reports from Norway or Sweden. Echinococcus multilocularis, which causes AE,
has been identified in a sylvatic arvicoline rodent-canine lifecycle in Alaska, Canada, Russia,
Sweden and Svalbard (Norway). Asian, Mongolian, European and North American strains of
E. multilocularis are found in Russia, with the North American N1 strain predominating in the
north. The N1 strain is also found in Alaska, as well as Svalbard, whilst Asian strains have
been identified in western Alaska. Central North American (N2) strain and European-type
strains of E. multilocularis are present in Canada. Typing of the strain in Sweden is still pending.
Individual human cases of AE with N2 and European-type strains are reported in North
America, as well as multiple cases with Asian strains in Russia and historically on St Lawrence
Island, Alaska (although genotyping of human cases was not available at the time). Echinococcus
spp. have not been detected in Greenland and have been eliminated from Iceland.