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

Abstract

Trichinella is a foodborne parasite whose wildlife reservoirs are represented by carnivores and omnivores with predatory and scavenger behavior. The aim of the present study was to investigate the occurrence of Trichinella infection in grey wolves (Canis lupus) that recolonized the Western Alps from the end of the past century, and discuss the epidemiological role played by this apex predator in the early phases of its return. During the period 2017–2022, diaphragm samples were obtained from 130 individuals collected in the frame of a wolf mortality survey. Trichinella larvae were found in 15 wolves (11.53%) with a parasite intensity of 11.74 larvae per gram. Trichinella britovi was the only species identified. This is the first prevalence survey of Trichinella in wolves recolonizing the Alps. Results suggest that, in this particular biotope, the wolf has rejoined the Trichinella cycle and has the potential to play an increasingly important role as maintenance host. Arguments in favor and against this perspective are discussed and knowledge gaps highlighted. The calculated Trichinella larval biomass in the estimated wolf population roaming in Northwest Italy will serve as baseline value to explore possible shifts in the relative importance of wolves as Trichinella reservoir within the regional carnivore community. Finally, wolves re-colonizing the Alps already appear as sensitive sentinels to monitor the risk of Trichinella zoonotic transmission by infected wild boar meat.

Diversity of Trichinella species in carnivores from Bosnia and Herzegovina

“…Moreover, even among grey wolves from the same territory, there was a notable variability in LPG levels. Regarding other animal species, the higher frequency of trichinellosis in grey wolves has been found in other studies [26], where the reasons mentioned are related to their apex predator status and longer lifespan compared to foxes and cats. Several studies on Trichinella spp.…”

From wildlife to humans: The global distribution of Trichinella species and genotypes in wildlife and wildlife-associated human trichinellosis

“…vulpes ) 6/141 (4.3%) Italy Western Alps Wolf ( C . lupus ) Multiplex PCR 9/130 (6.9%) Martínez-Carrasco et al (2023) Italy Province of Rieti Wild boar ( S . scrofa ) Multiplex PCR 1/554 (0.18%) Piccinini et al (2023) Italy Emilia-Romagna Region Wild boar ( S .…”

Identification of Sarcocystis and Trichinella Species in Muscles of Gray Wolf (Canis lupus) from Lithuania

“…infection in gray wolf from Lithuania (80.0%) corresponds to high infection rates established in this host in Latvia (69.7–100%), Estonia (50–79.4%), and Russia (97.3%) [ 10 , 29 , 71 , 72 , 73 ]. Lower values of prevalence of Trichinella parasites in gray wolf had previously been documented in the Central Balkans (46.5%) [ 74 ], Finland (33.33–39.2%) [ 75 ], Croatia (31%) [ 76 ], Poland (54.5%) [ 77 ], Romania (31–40%) [ 78 ], Alaska (28–36%) [ 79 ], Italy (27.1%) [ 80 ], and the Western part of the Italian Alps (11.53%) [ 81 ]. In the current study, no significant differences in lpg were observed in the diaphragm (0.2–17; = 5.79 ± 5.6) and limb (0.7–21; = 5.63 ± 7.3) muscles.…”