Trichinella spp. biomass has increased in raccoon dogs (Nyctereutes procyonoides) and red foxes (Vulpes vulpes) in Estonia

Abstract

BackgroundRaccoon dogs and red foxes are well-adapted hosts for Trichinella spp. The aims of this study were to estimate Trichinella infection prevalence and biomass and to investigate which Trichinella species circulated in these indicator hosts in Estonia.MethodsFrom material collected for evaluating the effectiveness of oral vaccination program for rabies eradication in wildlife, samples from 113 raccoon dogs and 87 red foxes were included in this study. From each animal, 20 g of masseter muscle tissue was tested for the presence of Trichinella larvae using an artificial digestion method. The Trichinella larvae were identified to species level by multiplex polymerase chain reaction method.ResultsThe majority of tested animals were infected with Trichinella spp. The parasite species identified were T. nativa and T. britovi. The apparent infection prevalence was 57.5% in raccoon dogs and 69.0% in red foxes, which were higher than previous estimates. In addition, the larval burden had also increased in both hosts. We estimated that in 2011–2012, the Trichinella spp. biomass was more than 15 times higher in raccoon dogs and almost two times higher in red foxes than in 1992–2000 (based on mean larval burden), and almost 20 times higher in raccoon dogs and almost five times higher in red foxes than in 2000–2002 (based on median larval burden).ConclusionsRaccoon dogs and red foxes are relevant reservoirs for Trichinella spp. in Estonia. The biomass of Trichinella circulating in sylvatic cycles was substantial and had increased: there is substantial infection pressure in the sylvatic cycle.

The occurrence and muscle distribution of Trichinella britovi in raccoon dogs (Nyctereutes procyonoides) in wildlife in the Głęboki Bród Forest District, Poland

“…T. spiralis , T. britovi , T. nativa and T. pseudospiralis , as single or mixed infection. However, the prevalence varies between different European regions, from 0% in Denmark and Austria, 1.9% and 4% in Germany, 28% and 33.2% in Finland, 29.3% and 32.5% in Lithuania, and 35.5% in Latvia, to 42% and 57.5% in Estonia (Malakauskas et al, 2007; Airas et al, 2010; Pannwitz et al, 2010; Bružinskaitė-Schmidhalter et al, 2011; Al-Sabi et al, 2013; Mayer-Scholl et al, 2016; Duscher et al, 2017; Kärssin et al, 2017; Antti et al, 2018).…”

“…However, raccoon dogs from the Głęboki Bród Forest District tested in the present study were infected with T. britovi alone; this is not surprising as it is well documented that carnivorous mammals are preferential hosts for T. britovi (Pozio and Zarlenga, 2013). T. britovi infection has been described in 74% of raccoon dogs examined in Lithuania, and in 40.5% and 24.8% of tested individuals in Estonia (Malakauskas et al, 2007; Kärssin et al, 2017). In contrast, the most commonly-identified Trichinella species identified in raccoon dogs in Finland was T. nativa , followed by T. spiralis and T. britovi (Airas et al, 2010); this contrasts with Antti et al (2018) who found T. nativa to be prevalent among raccoon dogs in Finland, followed by T. britovi .…”

“…In Europe, the raccoon dog is known to be an important vector of various parasites which can infect domestic and wild animals (Al-Sabi et al, 2013; Laurimaa et al, 2016); it is well documented that some of these parasites can be highly hazardous to human health, such as Echinococcus multilocularis or Trichinella spp. (Mayer-Scholl et al, 2016; Kärssin et al, 2017).…”

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

“…Trichinella spp. are endemic in wildlife in Estonia [ 6 ]. A high proportion, 42.1%, of investigated wild boars that were hunted in 2012–2013 tested positive for antibodies against Trichinella [ 7 ], and the biomass of Trichinella has increased in the main reservoir hosts raccoon dogs ( Nyctereutes procyonoides ) and red foxes ( Vulpes vulpes ) [ 6 , 8 ].…”

Molecular identification of Sarcocystis lutrae (Apicomplexa: Sarcocystidae) from the raccoon dog, Nyctereutes procyonoides, and the common raccoon, Procyon lotor, in the Czech Republic

“…These hosts are native to East Asia and North America and have been introduced across Europe, including the Czech Republic, where they have spread zoonotic parasites and other pathogens (e.g. Echinococcus or Trichinella) [7][8][9][10].…”