Trichinella infection of wild carnivorans in Primorsky Krai, Russian Far East

Abstract

Nematodes of the genus Trichinella cause trichinosis, which is a zoonotic disease of humans, wild and domestic animals. In the Russian Far East, trichinosis has a natural focal character. Carnivorans (Carnivora), living in natural ecosystems including Protected Areas, are the main hosts of Trichinella. The peculiarities of Trichinella circulation in natural environment and the parasite prevalence in wild animals of different species remain poorly understood as well as the species composition of the Trichinella genus in the studied region. Muscle samples were obtained from 731 specimens belonging to 14 species and four families (Mustelidae, Ursidae, Felidae, and Canidae) in Primorsky Krai (Russia) in 2010-2020 and examined on Trichinella. The parasites were found in 124 specimens belonging to 11 species. The highest Trichinella prevalence was observed in Vulpes vulpes (64%), Ursus arctos (57%), and Lynx lynx (50%). A relatively high ratio of infected animals (30-50%) was found in Nyctereutes procyonoides, Ursus thibetanus, and Prionailurus bengalensis. The parasite prevalence was relatively low in the representatives of the Mustelidae family. Three species of the genus Trichinella (T. nativa, T. spiralis, and T. pseudospiralis) were found for carnivorans inhabiting the study area. Trichinella nativa was found the most frequently in natural ecosystems. Trichinella pseudospiralis was discovered for the first time both for P. bengalensis and for the area of the Primorsky Krai. The Carnivora ecology contributes to a high risk of infection by Trichinella species. The parasite prevalence was high in the species that combined different feeding habits, i.e. they acted as predators, scavengers and cannibals. A relatively long life expectancy also contributed to a higher risk of infection. A relatively high parasite prevalence of Trichinella in wild animals in the Primorsky Krai was caused by the high biological diversity of carnivorans. Our results are important for understanding the trichinosis circulation in natural communities and the possibility of human infestation. These data are also important for managing the carnivorans' populations in the Russian Far East. The issues of nature conservation in regard to the trichinosis circulation are also important for threatened animals, including Panthera tigris altaica.

The genus Trichinella and its presence in wildlife worldwide: A review

“…was identified as another allochthonous host of Trichinella spp., as reported in Poland, Russia and China, with an overall prevalence of 2.07% (Hurníková et al, 2016;Seryodkin et al, 2020;Zhang et al, 2020). The reported hosts for the different Trichinella spp.…”

“…The racoon dog ( Nyctereutes procyonoides ), which presented with an overall prevalence rate of 12.25%, is an allochthonous species introduced in the ex‐Union of Soviet Socialist Republics in 1929; then, its distribution expanded to Europe, and it has rapidly become an important part of the reservoir of Trichinella in the Palearctic (Dudzinski et al., 1963; Pannwitz et al., 2010; Paulauskas et al., 2016). In addition to the raccoon dog in Europe, the American mink ( Neovison vison ) was identified as another allochthonous host of Trichinella spp., as reported in Poland, Russia and China, with an overall prevalence of 2.07% (Hurníková et al., 2016; Seryodkin et al., 2020; Zhang et al., 2020). The reported hosts for the different Trichinella spp.…”

“…A number of articles were identified that reported infection across the septentrional countries, the most common of which were Russia ( n = 9), Estonia ( n = 8), Latvia ( n = 8), Norway ( n = 6), and Finland ( n = 4). Four Trichinella species were reported in these countries, with T. nativa being particularly important in Russia (Deksne et al., 2016; Gozdzik et al., 2017; Kärssin et al., 2016, 2017, 2021; Kirjušina et al., 2015; Naidenko et al., 2019; Segliņa et al., 2015; Seryodkin, 2015; Seryodkin et al., 2020).…”

“…Allochthonous animals can play an interesting role as a reservoir of Trichinella sp. Thus, the American mink ( Neovison vison ), which is native to North America, has reportedly been infected in both the Palearctic and Neotropic regions (Espinoza‐Rojas et al., 2021; Hurníková et al., 2016; Seryodkin et al., 2020). Further, the raccoon dog, which is native to East Asia, has reportedly been infected in Europe, while the wild boar, native to the Palearctic region, was found to be infected in the Nearctic and the Neotropic regions (Almeida et al., 2018; Cybulska et al., 2019; Deksne et al., 2016; Hidalgo et al., 2019; Kärssin et al., 2017; Maas et al., 2016; Mayer‐Scholl et al., 2016).…”

Helminths in Myomorph Rodents (Rodentia, Myomorpha) from the National Park “Smolny” and Its Surroundings (European Russia)

“…Parasitic organisms are an integral part of natural biocenoses. They play an important role in the biosphere and act as one of the factors of biodiversity formation [1][2][3][4][5][6][7]. Helminths live in all vertebrates, including small rodents.…”