Parasites in the changing world – Ten timely examples from the Nordic-Baltic region

Deksne, Gunita; Davidson, Rebecca K.; Buchmann, Kurt; Kärssin, Age; Kirjušina, Muza; Gavarāne, Inese; Miller, Andrea L.; Pálsdóttir, Guðný Rut; Robertson, Lucy J.; Mørk, Torill; Oksanen, Antti; Palinauskas, Vaidas; Jokelainen, Pikka

doi:10.1016/j.parepi.2020.e00150

Cited by 24 publications

(18 citation statements)

References 141 publications

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“…One study [42] concluded that above-mean summer temperatures facilitate mass development of infective E. rangiferi larvae in the gastropod intermediate hosts and thus can cause epidemics of cerebrospinal elaphostrongylosis with high mortalities, especially among calves. In the unusually warm summer of 2018, reindeer herders in Norway reported an outbreak of elaphostrongylosis; one herder apparently lost 70 animals of different ages [43]. Under conditions of predicted climate change, such outbreaks of elaphostrongylosis may increase.…”

Section: Discussionmentioning

confidence: 99%

Occurrence of faecal endoparasites in reindeer (Rangifer tarandus) in two grazing areas in northern Norway

et al. 2021

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Background Semi-domesticated reindeer represent an important livestock industry and livelihood for a proportion of the human population in northern Fennoscandia. Reindeer husbandry is considered an extensive animal husbandry, where the animals are kept mostly on natural pastures, although sometimes kept in fenced areas for shorter periods. These reindeer may harbour a variety of parasites that may affect animal health and production. The relatively limited close contact between herds and owners gives limited opportunities for diagnosis and treatment of diseases in general. Furthermore, the effects of subclinical parasitism in livestock are commonly expressed as a reduction in productivity rather than clinical disease and mortality. Thus, specific knowledge of endoparasites and parasitic infections in these herds is scarce. This study investigated the occurrence of various endoparasites in reindeer by analysis of a total of 114 faecal samples from winter-slaughtered reindeer from two different grazing areas in Troms and Finnmark, Norway. Results Using a McMaster method, a Baermann technique, and a direct immunofluorescent antibody test, the following parasites were identified in the faecal samples with the occurrence data given as percentages: Strongylid eggs (62%), Nematodirinae spp. eggs (24%), Capillaria sp. eggs (42%) and Moniezia spp. eggs (17%), Dictyocaulus spp. larvae (14%) protostrongylid larvae (40%), Eimera spp. oocysts (23%), and Giardia duodenalis cysts (5%). Cryptosporidium oocysts were not detected. Parasite eggs, oocysts, and cysts were quantified. Molecular analysis revealed G. duodenalis sub-assemblage AI, a potentially zoonotic genotype not previously reported in reindeer from this region. Morphological analyses of Eimeria oocysts identified two species, Eimeria mayeri and Eimeria rangiferis, and molecular analyses of the cytochrome C oxidase I (coi) gene and 18 s rRNA (18SSU) gene of Eimeria confirmed the presence of Eimeria species that are specific to reindeer. Conclusions A high prevalence, but low burden, of endoparasites was detected in samples from these semi-domesticated reindeer. The samples were collected during winter, when adult gastrointestinal parasites usually produce only low numbers of transmission stages. Therefore, together with the low number of samples, detailed and definitive conclusions regarding parasite status of semi-domesticated reindeer are avoided. Nevertheless, these data provide a snapshot overview of parasite occurrence in a semi-domesticated animal group vulnerable to the various environmental changes to which they are exposed.

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Section: Discussionmentioning

confidence: 99%

Occurrence of faecal endoparasites in reindeer (Rangifer tarandus) in two grazing areas in northern Norway

et al. 2021

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“…Elevated predicted thermal suitability in the Trøndelag region (central Norway, ~63.5°N) over the past decade ( Figure 2 , 2000s and 2010s panels, Thermal Suitability Index 1–3) is supported by recent persistent outbreaks in this region [( 2 ), unpublished data]. These outbreaks were thought to be a result of the unusually warm summer of 2018 and were unusual in that reindeer of all ages were affected ( 10 ), suggesting significant transmission of L3 early in the spring-summer grazing season. Finally, the Norwegian Veterinary Institute diagnosed a 1-year old reindeer with elaphostrongylosis in June 2020 in Nordland, Norway (67°N).…”

Section: Discussionmentioning

confidence: 99%

“…The implications of our predictions for reindeer and their herders is potentially significant. Eighty percent of Norway's semi-domesticated reindeer are herded by the Sámi population in Finnmark county ( 3 ), which is the region predicted to have been most affected since 1950, and new outbreak foci have emerged in recent years ( 10 ). The predicted current thermal suitability could be used to raise awareness of the potential for E. rangiferi transmission on a broad spatial scale, aiding veterinary diagnoses and surveillance.…”

Section: Discussionmentioning

confidence: 99%

“…In light of the importance of reindeer to Sámi culture and livelihoods, the potential transmission to farmed small ruminants, and recent ongoing elaphostrongylosis outbreaks in Norway ( 2 , 10 ), there is a need to improve understanding of how climate change might impact on reindeer health and productivity through altered seasonal forage and disease dynamics to enable mitigation strategies to be put in place.…”

Section: Introductionmentioning

confidence: 99%

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Modeling Thermal Suitability for Reindeer (Rangifer tarandus ssp.) Brainworm (Elaphostrongylus rangiferi) Transmission in Fennoscandia

et al. 2021

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The brainworm, Elaphostrongylus rangiferi, is a nematode which causes neurological disorders (elaphostrongylosis) in reindeer (Rangifer tarandus ssp.). Favorable climatic conditions have been inferred as the cause of sporadic outbreaks of elaphostrongylosis in Norway, supported by positive associations between observed outbreaks/intensity of infection and summer temperatures in the previous years. Climate warming which results in increased transmission of E. rangiferi therefore presents a risk to the health of semi-domesticated and wild reindeer in Fennoscandia (Norway, Sweden, and Finland), the health of co-grazing small ruminants, and the livelihoods of indigenous Sámi herders. As a first step toward developing climate change impact assessments for E. rangiferi, a degree-day model was developed for larval development in a range of gastropod hosts and applied to historic weather data. Predictions were validated by statistical and qualitative comparison against historic parasitological and outbreak records. The model predicted an overall increase in thermal suitability for E. rangiferi, which was statistically significant in the north and along the Scandinavian mountain ranges, where reindeer density is highest. In these regions annual cumulative temperature conditions are suitable for larval development within a single year, potentially changing E. rangiferi epidemiology from a 2-year transmission cycle to a 1-year transmission cycle. This is the first mechanistic model developed for E. rangiferi and could be used to inform veterinary risk assessments on a broad spatial scale. Limitations and further developments are discussed.

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“…Trichinella spp. are important zoonotic parasites in the country and the region [ 17 ], and it is crucial that the One Health approaches addressing them cover not only domestic animals and humans, but also wildlife.…”

Section: Discussionmentioning

confidence: 99%

Trichinella spp. in Wild Boars (Sus scrofa), Brown Bears (Ursus arctos), Eurasian Lynxes (Lynx lynx) and Badgers (Meles meles) in Estonia, 2007–2014

Kärssin

Häkkinen

Vilem

et al. 2021

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In this study, we summarize Trichinella findings from four wild, free-ranging host species from Estonia during 2007–2014. Trichinella spp. larvae were detected in 281 (0.9%, 95% confidence interval (CI) 0.8–1.0) of 30,566 wild boars (Sus scrofa), 63 (14.7%, 95% CI 11.6–18.3) of 429 brown bears (Ursus arctos), 59 (65.56%, 95% CI 55.3–74.8) of 90 Eurasian lynxes (Lynx lynx), and three (60.0%, 95% CI 18.2–92.7) of five badgers (Meles meles). All four European Trichinella species were detected: T. britovi in 0.7% of the wild boars, 7.2% of the brown bears, 45.6% of the lynxes, and 40.0% of the badgers; T. nativa in 0.1% of the wild boars, 5.8% of the brown bears, and 20.0% of the lynxes; T. pseudospiralis in 0.02% the wild boars; and T. spiralis in 0.03% of the wild boars and 4.4% of the lynxes. The results include the first description from Estonia of T. britovi in brown bear and badgers, T. pseudospiralis in wild boars, and T. spiralis in wild boars and lynxes. The results indicate high infection pressure in the sylvatic cycles across the years—illustrating continuous risk of spillover to domestic cycles and of transmission to humans.

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Parasites in the changing world – Ten timely examples from the Nordic-Baltic region

Cited by 24 publications

References 141 publications

Occurrence of faecal endoparasites in reindeer (Rangifer tarandus) in two grazing areas in northern Norway

Occurrence of faecal endoparasites in reindeer (Rangifer tarandus) in two grazing areas in northern Norway

Modeling Thermal Suitability for Reindeer (Rangifer tarandus ssp.) Brainworm (Elaphostrongylus rangiferi) Transmission in Fennoscandia

Trichinella spp. in Wild Boars (Sus scrofa), Brown Bears (Ursus arctos), Eurasian Lynxes (Lynx lynx) and Badgers (Meles meles) in Estonia, 2007–2014

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