High prevalence ofTrichinella nativainfection in wolf(Canis lupus)populations of Tvier and Smoliensk regions of European Russia

Abstract

Summary:Domestic and sylvatic trichinellosis have frequently been documented in European regions of Russia, with the highest prevalence reported in wolves (Cam's lupus). From 1998 to 2000, 75 carcasses of wolves shot by hunters were tested for Trichinella larvae, and 73 (97.3 %) of them were found to be positive. This very high prevalence of infection, the highest ever detected in a natural population of carnivores, could be explained by the human impact on the natural ecosystem. In fact, the diet of wolves living in the region under study mainly consists of carcasses of dogs and wolves, which are left in the forest or used as bait by hunters. KEY WORDS :Trichinella naliva, wolf, European Russia, human influence. MATERIALS AND METHODSD omestic and sylvatic trichinellosis have frequently been documented in European regions of Russia (Bessonov, 1985 ;. The highest prevalence (i.e., up to 61 %) has been reported in wolves (Cants lupus), which is the most abundant large predator in Russia, where it is still considered as a pest species (Bibikov, 1994). In the Tvier and Smoliensk regions, the wolf is persecuted with many killing methods and governmental hunting offices pay a bounty for each kill. The ecology of the wolf varies with the specific environment. In recent years, the human impact on the natural ecosystem of Russia has changed as a result of social and economic changes.The aim of the present study was to investigate the prevalence of Trichinella infection in wolves in an area of European Russia where previous surveys showed a high hunting pressure on wildlife and to determine the correlation between prevalence and trophism. Trichinella nativa was the most common species detected in wolves, whereas T. britovi was detected in only one animal. Diet was investigated in 63 wolves.The PFO was 38 % for wolf and dog, 30 % for moose, 5 % for small rodents, 4 % for wild boar, domestic S88

Wolf Is Back: A Novel Sensitive Sentinel Rejoins the Trichinella Cycle in the Western Alps

“…To our knowledge, the Trichinella prevalence in this survey (11.53%) is amongst the lowest ones reported in wolves in Europe (see Table 1 ). In particular, most studies found a prevalence of over 30%, even much higher up to 60–97%, as in Western Russia [ 29 , 44 ], Estonia [ 30 ] and Latvia [ 45 ]. We cannot exclude that, to some extent, the prevalence we found may be underestimated, since only diaphragm samples were collected, and muscle samples have been stored at −20 °C in some cases for more than two weeks, with possible alteration of larvae sedimentation characteristics.…”

Red fox (Vulpes vulpes) cannibalistic behaviour and the prevalence of Trichinella britovi in NW Italian Alps

“…Casulli et al (2001), examining the stomach contents of wolves (Canis lupus) killed in north-western European Russia, attributed the high rates of infection found to the consumption of domestic dogs and wolf carcasses left as baits by hunters. In central Italy, the prevalence of the nematode in wolves has been compared to the available data about their diet, finding no evidence of cannibalism or predation of foxes, which, in the same area, showed rates of infection lower than wolves (Scaramozzino et al 1993).…”

Trichinellosis survey in the wild boar from the Toledo mountains in south-western Spain (2007–2008): molecular characterization of Trichinella isolates by ISSR-PCR

“…The size of the wild boar population is greatly regulated by humans and larger predators, such as the wolf (Järvis et al , 2007). The sylvatic cycle is interrupted when carnivores rely on food sources other than those derived from cannibalistic and scavenging behaviour (Pozio, 1998) and the human impact on the natural ecosystem can either favour or impede the sylvatic cycle (Casulli et al , 2001). Thus, the marked character of the area as a place for hunting, where the present study was carried out, may limit the distribution of foxes and wolves as main predators, thus perhaps lowering the flow of T. britovi .…”