Hunting Practices Increase the Prevalence ofTrichinellaInfection in Wolves From European Russia

Abstract

From 1998 to 2000, 184 animals (82 wolves, 29 red foxes, 55 mustelids, 5 raccoon dogs, and 13 domestic dogs), mainly shot by hunters in the Tvier and Smoliensk regions of northwest European Russia, were tested for Trichinella larvae; 98 animals (53.3%) were found to be positive. The highest prevalence was detected in wolf (97.5%). Trichinella nativa was the most common species detected (98%). The diet of wolves was investigated by examining the stomach contents of 62 animals (75.6% of the total number of wolves examined for Trichinella). It consisted mainly of dog (36.4% of the total number of occurrences of all food items, PFO) and moose (31.2 PFO); however, during the hunting seasons of 1998-1999 and 1999-2000, skinned wolf carcasses were left in the forest as bait (567 carcasses, about 18,000 kg). This very high prevalence of Trichinella infection, the highest ever detected in a natural population of carnivores, could be explained by carnivore-carnivore transmission, influenced by the hunting practices adopted in the study area.

Seroprevalence of Trichinella spp. infection in bank voles (Myodes glareolus) – A long term study

“…Since the prevalence of Trichinella spp. in Polish red foxes is high (10%) (Cybulska et al, 2016), leaving the skinned carcasses of foxes and other carnivores after a hunt in the forest creates a risk factor for spreading of Trichinella infections to both wild rodents and other susceptible wild animals (Pozio et al, 2001). Furthermore, cannibalism is well recorded among rodent species (Reperant and Deplazes, 2005), especially in association with aggressive behavior (Marchlewska-Koj et al, 1989) linked to dominance hierarchies (Gustafsson et al, 1980), protection of nests and competition for mates (Horne and Ylönen, 1996; Marchlewska-Koj et al, 1989; Ylönen and Horne, 2002) and this may contribute also to dissemination of Trichinella spp.…”

Hunting dogs as sentinel animals for monitoring infections with Trichinella spp. in wildlife

“…the ecological niche of the larvae of Trichinella spp. In many areas of the world where hunting is practiced, hunting dogs have easy access to muscle samples of game including carnivore carcasses (e.g., foxes, mustelids, bears, walruses), left on the ground by hunters after skinning, or removing and discarding the entrails [ 41 – 46 ].…”

Trend analysis of Trichinella in a red fox population from a low endemic area using a validated artificial digestion and sequential sieving technique

“…None of these studies however, stated the number of single larvae tested per host animal, or the success rate. One study by Pozio et al [ 30 ] on wildlife samples frozen at −20 and −80 °C, used 5 to 10-fold single larva multiplex PCRs to identify the Trichinella species, but did not mention how many of these larvae actually were identified. The use of multiple attempts in that study implicated that it was at least anticipated to have a low success rate.…”

“…prevalence of 29% in foxes in Latvia. In that publication, individual larvae were identified with PCR according to Pozio et al [ 30 ], which showed a distribution of 78% T. britovi , 8.5% T. nativa and 9.3% mixed infection of the two species in 129 Latvian foxes. Although our sample size of Latvian foxes is much lower and primarily aimed at the validation of our method, we found a comparable distribution of T. britovi and T. nativa .…”

“…DNA was isolated from 3-4 individual ML per Latvian red fox before and after freezing, from three individual larvae from the Latvian wild boar and from the single isolated larva from Dutch red fox according to the protocol described by Pozio et al [ 30 ]. Briefly, 2 μL of 0.05 M TRIS-HCL pH 7.6 was added to each larva in 5 μL H2O, which was overlaid with mineral oil and heated to 90 °C for 10 min.…”