Trichinella spiralis prevalence among wildlife of a boreal region rapidly reduced in the absence of spillover from the domestic cycle.

Carnivore and omnivore animals are the main reservoir hosts of nematodes of the genus Trichinella. Out of the twelve taxa identified so far in the world, four, namely Trichinella spiralis, Trichinella nativa, Trichinella britovi and Trichinella pseudospiralis, are circulating in Europe. All these four species were detected in Finnish wild animals and T.

Synanthropic Trichinella infection in Finland.

The first three human trichinellosis cases in Finland were recorded around 1890, and altogether eight cases were registered until 2008. The first infected Finnish swine was found in 1954. From the early 1980s, an increasing trend in the number of infected swine was seen, with the highest number registered in 1996, after which a decrease has been observed.

The prevalence of Trichinella infection in domestic dogs in Finland.

In this study, we examined the prevalence of Trichinella infection in domestic dogs in Finland, which is known to have a high prevalence of Trichinella infection in sylvatic hosts. Altogether 727 dog serum samples were tested serologically by ELISA with ES-antigen in dilutions 1:50, 1:100, 1:200, and 1:400. Additionally, muscle samples from 102 dogs' front leg extensors were tested parasitologically by HCl-pepsin-digestion.

Persistence of Trichinella spiralis in rat carcasses experimentally mixed in different feed.

Trichinella spiralis infected rat carcasses were incubated for 6 weeks in several animal feeds to assess how long Trichinella can present a risk for an outbreak in contaminated feeds. In groups of 6, 24 infected target rats were placed in silage, grained barley, propionic acid-preserved feed, and also into simulated pasture conditions. Test environments were sampled after one-, 2-, 4-, and 6-week-incubations.

Associations between Trichinella species and host species in Finland.

Examination of 627 wild animals--raccoon dogs (Nyctereutes procyonoides), red foxes (Vulpes vulpes), European lynxes (Lynx lynx), brown bears (Ursus arctos), wolves (Canis lupus), and badgers (Meles meles)--revealed Trichinella spp. The prevalence varied according to geographical region of Finland (north; southwest, SW; and southeast, SE) and was the highest among lynxes (70%, SW). The risk of trichinellosis was higher in the SE (odds ratio, OR, 19.

Trichinella nativa and T. spiralis induce distinguishable histopathologic and humoral responses in the raccoon dog (Nyctereutes procyonoides).

Three experimental groups of six male raccoon dogs (Nyctereutes procyonoides) each were formed by placing one of three littermates from six litters into each group. One group was inoculated with pig-origin Trichinella spiralis, the second was inoculated with raccoon dog-origin T. nativa, and the third served as a control group.

Predilection muscles and physical condition of raccoon dogs (Nyctereutes procyonoides) experimentally infected with Trichinella spiralis and Trichinella nativa.

The predilection muscles of Trichinella spiralis and T. nativa were studied in 2 experimental groups of 6 raccoon dogs (Nyctereutes procyonoides), the third group serving as a control for clinical signs. The infection dose for both parasites was 1 larva/g body weight.

Evaluation of two PCR-based techniques for molecular epidemiology in Finland, a high-endemic area with four sympatric Trichinella species.

Trichinella larvae collected from wildlife, domestic and synanthropic animals in Finland were identified to species by two molecular techniques: Random amplified polymorphic DNA (RAPD) polymerase chain reaction (PCR) and the recently described multiplex PCR. The RAPD-PCR was very sensitive to the sub-optimal preservation muscle larvae and resulting in weak and smeared bands on the gels for such material. However, the same samples yielded easily recognizable bands in the multiplex PCR; this latter technique is then recommended for epidemiological studies, especially when the preservation of the samples is sub-optimal.

Trichinellosis in farmed wild boar: meat inspection findings and seroprevalence.

A reflection of highly prevalent endemic wildlife trichinellosis is seen in wild boar farming in Finland. During the last five years, 0.7% (15/2265) of wild boars undergoing official meat inspection have been determined to be Trichinella-positive.

An outbreak of trichinellosis in farmed wild boar in Finland.

Nine farmed wild boar out of 25 slaughtered from a single farm were condemned at meat inspection because of trichinellosis. With RAPD-PCR, Trichinella spiralis was identified in all positive wild boar. Out of the available serum samples (n=7), all wild boar which had failed the meat inspection showed seroconversion in ELISA and Western blotting, as did one additional animal which had passed the inspection.

Experimental trichinellosis in reindeer.

Six female reindeer calves were inoculated intraruminally with various doses of Trichinella muscle larvae. Four calves were inoculated with T. nativa, receiving 15,000 (n = 1), 5,000 (1), and 2,500 (2) larvae each.

Clinical features of experimental trichinellosis in the raccoon dog (Nyctereutes procyonoides).

Three groups of six raccoon dogs (Nyctereutes procyonoides) were provided for the experiment: the first group was infected with pig-origin Trichinella spiralis, the second with raccoon dog-origin Trichinella nativa, and the third served as controls. Infection dose for both parasite species was 1000 larvae/kg of body weight, which led to intense final infection. Clinical signs, haematology and serum biochemistry with repeated blood samples were monitored up to 12 weeks post-infection.