Diversity of Trichinella species in relation to the host species and geographical location.

Trichinella nematodes still circulate in various hosts in both domestic and sylvatic environments. Recently, in Europe, the transmission of Trichinella spp. to humans has been attributed more to wild animals than to domestic animals. However, domestic animals could still be a source of human infections in some regions. Therefore, our aim was to determine the species composition of Trichinella and the prevalence and intensity of infections in animal populations from the domestic cycle, namely pigs (Sus scrofa f. domestica); the synantropic cycle, in the form of rats (Rattus norvegicus); and the sylvatic cycle, namely wild boars (Sus scrofa) and red foxes (Vulpes vulpes), in Poland. The findings showed that the nematode prevalence in pigs (0.0002 %) and wild boars (0.3 %) was lower than it was in red foxes (4 %). A very high prevalence was found in rats (23.3 %), but it must be emphasized that the investigated rat samples were collected from farms where pigs were infected with Trichinella spp. The mean larval burden was found to be higher in wild boars and pigs (11.48 lpg and 10.19 lpg) than in red foxes and rats (4.09 and 2.30). Trichinella spiralis was the predominant species in pigs (98.6 %), wild boars (77.3 %) and rats (100 %), while in red foxes, this species occurred less frequently (15.5 %). The most frequently occurring species in red foxes was Trichinella britovi (73.2 %). Moreover, in wild boar and red fox coinfections, T. spiralis/T. britovi were detected (3.1 and 9.9 %, respectively). In addition, Trichinella pseudospiralis was detected in a few wild boars (0.5 %) and Trichinella nativa was found in one red fox and one wild boar. Furthermore, different T. spiralis and T. britovi prevalence ratios in various geographical regions were found. In the wild boar population, a higher frequency of T. spiralis (70-85 % of infected animals) was observed in the western and central parts of Poland, while in the eastern part, this dominance was not as evident (46-59 %). In the red fox population, T. britovi was abundant throughout the entire territory; however, its highest prevalence was in the east (90-100 %).

First case of Trichinella spiralis infection in beavers (Castor fiber) in Poland and Europe.

BACKGROUND: This is the first report of the finding of Trichinella spiralis in beaver meat (Castor fiber) in Poland and Europe. In Poland, the beaver is a strictly protected animal species, except the few regions where high population density leads to economic losses. In these areas, the reduction culling of the animals was introduced. This uncommon hunting game animal is consumed and treated as a delicacy by hunters. However, currently, there is a lack of knowledge on possible risk factors for humans associated with the consumption of beaver meat. This paper presents the result of the study on the occurrence of nematodes of the genus Trichinella in beavers. METHODS: In total, 69 beavers were examined for the presence of Trichinella spp. The 50g samples were taken from each animal and digested separately, according to a procedure based on the EU reference method. The larva DNA was examined by PCR and sequencing. RESULTS: One of the 69 examined beavers was infected. Only one Trichinella larva was detected by the digestion method. The result of PCR confirms the presence of T. spiralis in beaver meat. CONCLUSIONS: This case further confirms the ability of these typical herbivores to be infected with Trichinella spp. This is the second confirmed case of Trichinella spp. infection in beavers in Europe and the first of T. spiralis.

Occurrence of Trichinella spp. in rats on pig farms.

INTRODUCTION: The highest risk of trichinellosis for human is considered in eating meat products containing live larvae, mostly from wild boars or pigs. Spreading of Trichinella spp. may occur in various ways, one of which is transmission by vectors. The rat is considered to be the most common vector for Trichinella parasite. The population of rats living on pig farms can play an important role in maintaining or spreading the parasite to other animals. OBJECTIVE: The aim of presented survey was to investigate the occurrence of Trichinella spp. in rats on farms with pigs infected with this parasite. MATERIAL AND METHODS: From pig farms selected for study, the muscles of collected rats were investigated by magnetic stirrer digestion method to assess occurrence of Trichinella in the rat population. Isolated Trichinella parasites were identified under stereomicroscope and multiplex PCR were performed for species identification. RESULTS: Rats infected with Trichinella spp. were discovered on three of five investigated pig farms. The mean extent of invasion in rats from the studied farms was 23.33%. The calculated medium intensity of invasion was 4.09 lpg (larvae per gram) (SD 5.41). All larvae of Trichinella discovered from rats were identified as T.spiralis. CONCLUSIONS: The results obtained indicate that in farms with a high prevalence of Trichinella invasion in pigs there are very likely to be found rats infected by this nematode. This suggests possibility to maintain the invasion in herd and spread into neighborhood farms.

First case of Trichinella nativa infection in wild boar in Central Europe-molecular characterization of the parasite.

The examination of wild boars gained in Poland shows for the first time occurrence of Trichinella nativa, freeze-resistant species of Trichinella in this host from the central Europe region. This finding is not only one of several cases of T. nativa invasion in wild boars all over the world but also one of the very few cases of T. nativa detected so far beyond the known boundary of occurrence of this species. The molecular characterization of discovered larvae based on analysis of partial genes: 5s rDNA-ISR and CO1 confirm the findings. Moreover, the analyzed DNA sequences of both genes present new haplotypes of T. nativa in comparison to that described previously.