DESCRIPTION OF A NEW EIMERIA SPECIES AND REDESCRIPTION OF EIMERIA MAYERI (PROTOZOA: EIMERIIDAE) FROM WILD REINDEER RANGIFER TARANDUS IN ICELAND

A Screening for Virus Infections among Wild Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Iceland, 2017-2019

A winter population of around 4000-5000 wild Eurasian tundra reindeer (Rangifer t. tarandus) in the eastern part of Iceland represents descendants from 35 semi-domesticated reindeer imported to Iceland from Finnmark county, Norway, in 1787. While previous studies have indicated that they host fewer parasite species as compared to reindeer in Fennoscandia, little information exists on their exposure to reindeer viral pathogens. The aim of this study was to investigate blood from hunted reindeer for antibodies against alphaherpesvirus and gammaherpesviruses (malignant catarrhal fever viruses, MCFV), pestivirus, bluetongue virus, and Schmallenberg virus, and to investigate nasal and oral mucosal membrane swab samples for the presence of parapoxvirus-specific DNA. Blood samples collected during the hunting seasons in 2017 (n = 40), 2018 (n = 103), and 2019 (n = 138) were tested for viral antibodies using enzyme-linked immunosorbent assays (ELISA). Screening for parapoxvirus DNA was conducted on swab samples from 181 reindeer by polymerase chain reaction (PCR), targeting the B2L and GIF genes. Antibodies against pestivirus were detected in two animals from 2017, and antibodies against MCFV were detected in two reindeer from 2018. No antibodies were detected against the other viruses tested. Parapoxvirus-specific DNA was detected in nasal swab samples from two animals sampled in 2019. This study suggests that the investigated viral infections are either not present or present at a low prevalence only, probably not representing a major health threat to this reindeer population. The lack of exposure to alphaherpesvirus, an enzootic pathogen in most investigated Rangifer populations, was unexpected.

A new Eimeria coccidian species (Apicomplexa: Eimeriidae) from Père David's deer (Elaphurus davidianus Milne-Edwards, 1866) in Dafeng Milu National Nature Reserve in Jiangsu Province, eastern China

Background

Eimeria coccidiosis is a significant intestinal parasitic disease, which can lead to weight loss, disease and even death of many animals. At present, there is no information about the prevalence of Eimeria among the world’s endangered species of Père David’s deer (Elaphurus davidianus). Therefore, the purpose of this study is to identify an unknown Eimeria genus in the Père David’s deer in Dafeng Milu National Nature Reserve, China.

Results

A new Eimeria species is described from Père David’s deer. Sporulated oocysts (n = 54) are pyriform, with a rough, yellowish brown, 2-layered oocyst wall (2.5 μm thick). A numerous small granules are dispersed randomly on the wall. Oocysts measured 41.2 (39.2–42.8) μm × 29.5 (27.9–30.5) μm, oocyst length/width (L/W) ratio, 1.4. Oocyst residuum, a polar granule and a polar cap are absent. The micropyle (3.5 μm wide) is present. Sporocysts are spindle shaped, 18.2 (16.5–20.0) μm × 10.5 (9.8–11.9) μm, sporocyst L/W ratio, 1.7 (1.5–1.9). A thin convex Stieda body is present and the sporocyst residuum is composed of numerous small granules less than 2.0 μm in diameter dispersed randomly. Each sporocyst contained 2 comma-shaped sporozoites in head-to-tail arrangement. A nucleus is located immediately anterior to the posterior, strong refractive and subspherical refractile body (~ 8 μm). Molecular analysis was conducted at the 18S, ITS-1 and COI loci.

Conclusion

Based on the morphological and molecular data, this isolate is a new species of coccidian parasite, which is named Eimeria davidianusi after its host, the Père David’s deer (Elaphurus davidianus).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03308-2.

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

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.

Gastrointestinal parasites in reindeer (Rangifer tarandus tarandus): A review focusing on Fennoscandia

Reindeer (Rangifer tarandus tarandus) are known to host a wide variety of parasites, including those in the gastrointestinal system. Here, we review the current knowledge of the main gastrointestinal parasites of reindeer focusing on northern Fennoscandia, which comprises parts of Finland, Sweden, Norway and Russia. We explore both the historical baseline data for diversity and distribution and recent advancements in our understanding of parasite faunas in reindeer across this region. It is evident that the balance between reindeer and their gastrointestinal parasites, along with the potential for emergent disease in the changing world warrants careful monitoring and further studies.

A new Eimeria species (Protozoa: Eimeriidae) from caribou in Ameralik, West Greenland

Fecal samples of 11 calves shot in the Ameralik area, West Greenland, in August-September 2014 were examined for coccidian parasites. The calves belonged to a population of interbreeding indigenous caribou Rangifer tarandus groenlandicus and feral semi-domestic Norwegian reindeer Rangifer tarandus tarandus. Two coccidian species were found: Eimeria rangiferis and a coccidium that was identified and described as a new species. The latter's sporulated oocyst is spherical or slightly subspherical. Average size is 25.6 × 24.8 μm. The oocyst has two distinct walls. Wall thickness is ∼1.4 μm. The unicolored outer wall is brown, the inner wall is dark gray. The oocysts contain a small polar granule but are devoid of a microphyle. The oocysts enclose four ovoid-shaped sporocysts with a rounded end opposite to the Stieda body. The average size of sporocysts is 15.2 × 7.8 μm. Sporocysts contain a granular sporocyst residuum that forms a spherical cluster between the sporocysts, one large refractile body is present in each sporozoite. The spherical form easily distinguishes oocysts of the new species from the seven previously described eimerid species in R. tarandus. This is the first eimerid described as a new species to the sciences from caribou in the Nearctic.

Parasites in ungulates of Arctic North America and Greenland: a view of contemporary diversity, ecology, and impact in a world under change

Parasites play an important role in the structure and function of arctic ecosystems, systems that are currently experiencing an unprecedented rate of change due to various anthropogenic perturbations, including climate change. Ungulates such as muskoxen, caribou, moose and Dall's sheep are also important components of northern ecosystems and are a source of food and income, as well as a focus for maintenance of cultural traditions, for northerners. Parasites of ungulates can influence host health, population dynamics and the quality, quantity and safety of meat and other products of animal origin consumed by people. In this article, we provide a contemporary view of the diversity of nematode, cestode, trematode, protozoan and arthropod parasites of ungulates in arctic and subarctic North America and Greenland. We explore the intricate associations among host and parasite assemblages and identify key issues and gaps in knowledge that emerge in a regime of accelerating environmental transition.

The third newly discovered Eimeria species (Protozoa: Eimeriidae) described from wild reindeer, Rangifer tarandus, in Iceland

Fecal samples from 56 adult reindeer from eastern Iceland were examined for coccidian parasites. One Eimeria species was found in an 8-year-old male. Prevalence of infection was 1.8%; oocyst per gram (opg) value was 150. The coccidium was identified and described as a new species. The sporulated oocysts are ellipsoidal and average size is 30.0 x 21.1 microm. The oocyst has two distinct walls. Wall thickness is approximately 1.0 microm, and the outer wall, approximately four-fifths of total thickness, is generally smooth and appears bicoloured. The outermost portion is light blue, and the innermost portion, yellow to pale brown. The inner wall is dark brown. Oocysts contain a prominent polar granule but are devoid of a micropyle. Oocysts enclose four spindle-shaped sporocysts with a rounded end opposite to the Stieda body. The average size of sporocysts is 15.3 x 6.5 microm. Sporocysts contain a granular sporocyst residuum that usually forms a cluster between the sporozoites and one large refractile body in each sporozoite.