Serosurvey for Toxoplasma gondii in arctic foxes and possible sources of infection in the high Arctic of Svalbard

Prestrud, Kristin Wear; Åsbakk, Kjetil; Fuglei, Eva; Mørk, Torill; Stien, Audun; Ropstad, Erik; Tryland, Morten; Gabrielsen, Geir Wing; Lydersen, Christian; Kovacs, Kit M.; Loonen, Maarten J. J. E.; Sagerup, Kjetil; Oksanen, Antti

doi:10.1016/j.vetpar.2007.09.006

Cited by 84 publications

(67 citation statements)

References 36 publications

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“…Theoretically, however, T. gondii could become established in a new population in the absence of cats, if it was transferred there within an intermediate host. Evidence to support this idea has been found in the cat-free Svalbard Islands, Norway, where the parasite has been detected in the arctic fox [18]. It is thought that T. gondii might have been introduced to these islands by migratory geese that became infected elsewhere and were eaten by arctic foxes when they returned to Svalbard.…”

Section: The Sexual Cycle Is Not Essential For Transmission or Maintementioning

confidence: 98%

“…It is thought that T. gondii might have been introduced to these islands by migratory geese that became infected elsewhere and were eaten by arctic foxes when they returned to Svalbard. Once introduced, T. gondii infection could be maintained on these islands by vertical transmission and carnivory [18].…”

Section: The Sexual Cycle Is Not Essential For Transmission or Maintementioning

confidence: 99%

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Adaptive host manipulation by Toxoplasma gondii: fact or fiction?

Worth

Lymbery

Thompson

2013

Trends in Parasitology

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Section: The Sexual Cycle Is Not Essential For Transmission or Maintementioning

confidence: 98%

Section: The Sexual Cycle Is Not Essential For Transmission or Maintementioning

confidence: 99%

Adaptive host manipulation by Toxoplasma gondii: fact or fiction?

Worth

Lymbery

Thompson

2013

Trends in Parasitology

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“…One route for walruses to be infected could be from eating seals. Although no other investigation has found seropositive seals in the North Atlantic, this is a common finding among various seal species from Alaska and northern Canada (see Prestrud et al 2007 for details).…”

Section: Health and Diseasesmentioning

confidence: 88%

“…The biological significance of the lower inorganic phosphate is unknown (Tryland et al 2009). Blood samples from these same 17 adult male walruses from Svalbard were part of a larger serosurvey for Toxoplasma gondii, primarily in arctic foxes (Alopex lagopus) but also in various birds and mammals from Svalbard (Prestrud et al 2007). T. gondii is a protozoan parasite for which felids are the final host; a wide range of birds and mammals serve as intermediate hosts.…”

Section: Health and Diseasesmentioning

confidence: 99%

“…gondii has been implicated as a mortality factor for arctic foxes in Svalbard (dead foxes with toxoplasmosis have been recorded multiple times) and since no felids are present in the Archipelago samples from various other species, including walruses, were analyzed to shed light on other possible transmission routes (Prestrud et al 2007). One of the investigated walruses was seropositive showing that T. gondii is present in the marine food chain in Svalbard.…”

Section: Health and Diseasesmentioning

confidence: 99%

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Walrus <i>Odobenus rosmarus</i> research in Svalbard, Norway, 2000-2010

Lydersen

Kovacs

2014

NAMMCOSP

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Herein we report results from studies on walruses in Svalbard conducted in 2000-2010. Data from newly developed satellite relay data loggers (SRDLs) revealed seasonal differences in habitat use of adult male walruses. During winter, they moved into areas of >90% ice concentration, traveling as far as 600 km from ice-free water. Breeding areas deep into the pack ice were identified based on timing of the occupancy and diving behaviour. When the breeding season was over, walruses with SRDLs that were still transmitting locations returned to the coast, showing high site fidelity to the previous year’s summering area. Haul-out data from the SRDLs provided correction factors for an aerial survey of walruses that covered all known haul-out sites within the Svalbard Archipelago. This survey estimated 2,629 (95 % CI; 2,318 – 2,998) walruses to be in Svalbard during August 2006. Blubber biopsies from adult male walruses analyzed for fatty acids (FAs) showed vertical stratification similar to that observed in many other marine mammals. However, differences between layers were less pronounced, possibly because the thick dermis of walruses provides an insulating shield, affecting the FA composition of the outer blubber. The FA composition of the inner blubber most closely resembled the lipids in Mya truncata and Buccinum spp., which are considered the most important walrus prey in Svalbard. A study investigating the use of skin biopsies for assessing levels of organochlorines (OCs) in walruses found a significant relationship between OC levels in skin and blubber. Another contaminant study found a significant decrease in levels of PCBs and DDE in walruses in Svalbard from 1993 to 2002-04. Large inter-individual variation in OC levels was found, although all of the study animals were adult males from roughly the same location. In FA analyses of the inner blubber this variation appeared to be diet-related, with high OC levels having FA compositions in the inner blubber that closely matched seal tissues, while those with low levels matched typical invertebrate prey. Various enzymes, proteins, metabolites, minerals, and hormones were measured in blood samples to serve as baseline data for future health-related studies of both wild and captive walruses. Historical sex-distribution of walruses in southern Svalbard was investigated based on mandible measurements of individuals hunted during the 19^th century.The analyses showed that female walruses were once more common in south-eastern Svalbard than they are today.

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