Cystic echinococcosis in wild boars (Sus scrofa) from southern Italy: Epidemiological survey and molecular characterization

Abstract

Cystic Echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is one of the most important parasitic zoonotic diseases in the world and it represents an important public health and socio-economic concern. In the Mediterranean basin, CE is widespread and it is endemic in Italy, with major prevalence in southern areas. Several studies have investigated CE in domestic pigs, however, such data in wild boars are scant. In the last decades the wild boar population in Italy has increased and this ungulate could play an important role in the spreading of CE in the wild. Here we report on the prevalence and fertility rate of hydatid cysts in wild boars that were shot during two hunting seasons (2016–2017) in the Campania region of southern Italy. For each animal, a detailed inspection of the carcass and organs (lungs, liver and spleen) was performed and when cysts were found, their number, morphology and fertility were determined by visual and microscopic examination. Cysts were classified morphologically as fertile, sterile, caseous and calcified. Protoscoleces and germinal layers were collected from individual cysts and DNA was extracted to identify different strains/genotypes of E. granulosus s.l. Out of a total of 2108 wild boars 93 (4.4%) were found positive for CE. Infected animals were 45 males and 48 females, aged between 1 and 8 years. The average number of cysts per wild boar was 1.3 (min 1 - max 13). The total number of cysts collected was 123, of which 118 (95.9%) in the liver, 4 (3.3%) in the lungs and 1 (0.8%) in the spleen. Of all analyzed cysts, 70 (56.9%) were fertile and 53 (43.1%) sterile/acephalous. The presence of fertile cysts in 19.4% of CE-positive animals is noteworthy. Overall, molecular diagnosis showed 19 wild boars infected with the pig strain (G7).

Genotyping of Toxoplasma gondii in wild boar (Sus scrofa) in southern Italy: Epidemiological survey and associated risk for consumers

“…This hunting practice supports the hypothesis that main cause of infection in boar could be due to the ingestion of muscles containing bradyzoites from infected animals (omnivorous and carnivores) (Battisti et al., 2018; Ferroglio et al., 2014). In addition to the fact that hunters frequently leave boar's offal and muscle pieces on the ground during the evisceration in the field (Sgroi, Varcasia, Dessì, et al, 2019; Sgroi, Varcasia, Dessi, et al, 2019), several wild boar that may have been involuntary injured could die a long away from the hunting area, thus providing prey for other wild animals.…”

Taenia hydatigenacysticercosis in wild boar (Sus scrofa) from southern Italy: an epidemiological and molecular survey

“…Adult boars showed higher exposure to infection (9.1% – χ 2 = 50.9; P = <0.05) compared to sub-adults (4.7%), and there were no cases in piglets, suggesting that older animals are significantly more likely to ingest parasite eggs (ie: through coprophagy), and their infection intensity may be a reflection of accumulation of parasites over the animals' lifespan. Indeed, this is consistent with observations from the same study area for another metacestodosis (cystic echinococcosis) in wild boar (Sgroi et al ., 2019 b ), as well as in domestic ruminants (Veneziano et al ., 2004 ).…”

“…19.0% in lambs) due to massive hepatic and pulmonary infections (Scala et al ., 2016 ). The risk factors involved in the occurrence of metacestodosis include access of stray dogs to sheep pastures, extensive grazing methods, home slaughtering practices and improper disposal of offal; these factors may also favour the spread of cysticercosis and other important metacestodoses, such as coenurosis and cystic echinococcosis, not only in domestic animals (Varcasia et al ., 2009 , 2011 ; Scala et al ., 2016 ) but also in wildlife species, such as red foxes and wild boar (Varcasia et al ., 2015 ; Sgroi et al ., 2019 a , b ).…”

Molecular Epidemiology of Staphylococcus aureus Lineages in Wild Animals in Europe: A Review

“…In the last few years, the wild boar (Sus scrofa) population has been increasing in several European countries and it has been hypothesized that these animals could play an important role in the dissemination of several diseases [147]. Wild boars are one of the most studied wild animals in Europe and there are several studies investigating the S. aureus colonization of these animals.…”