Macracanthorhynchus hirudinaceus in expanding wild boar (Sus scrofa) populations in Eastern Spain

Morphometric, histopathological and molecular findings of Macracanthorhynchus hirudinaceus infection in wild boar (Sus scrofa) from continental Italy

Although Macracanthorhynchus hirudinaceus is a neglected acanthocephalan of suids occasionally responsible for severe infections in humans, the spread of wild boar (Sus scrofa) populations in Europe could promote the circulation. Herein, we report the first morphometric, histological and molecular characterization of a severe M. hirudinaceus infection in a boar from continental Italy. The boar's intestine displayed granulomatous enteritis due to 24 helminths (14 females, 10 males), identified as adults of M. hirudinaceus by a combined morphometric/molecular approach. The phylogenetic analysis of the cox1 gene revealed a close relationship of the M. hirudinaceus sequence type found herein with those from Hungary and insular Italy. The high haplotype diversity and low nucleotide diversity of M. hirudinaceus specimens would suggest its rapid demographic expansion in the Mediterranean basin. More research is needed to assess the presence of M. hirudinaceus in susceptible beetle species and the role of boars in the epidemiology of infection.

First molecular description of Macracanthorhynchus hirudinaceus in wild boars from Italy with pathomorphological and epidemiological insights

Macracanthorhynchus hirudinaceus is a zoonotic parasite affecting suids worldwide which are the definitive hosts for this helminth species. Macracanthorhynchus hirudinaceus is of significant economic and management concern due to its pathogenicity, causing intestinal obstruction and perforation in the definitive hosts. Current study is the preliminary investigation from Sardinia, Italy, reporting the pathomorphological findings and molecular characterization of M. hirudinaceus in the wild boars (Sus scrofa meridionalis). A total of 59 wild boars were examined showing acanthocephalan infection in 8 (13.6%) animals. In total, 49 parasites were collected with a mean intensity of 6.1. Comparatively higher infection levels were observed for males (16.7%) and young boars (14.3%); however, these epidemiological differences were statistically non-significant. Histopathological examination revealed the presence of a variable number of nodules (∼5 mm) in the intestine of M. hirudinaceus infested animals surrounded by a hyperemic-hemorrhagic halo. Several parasites were recovered from the intestinal lumen attached by the means of characteristic hooks showing necrosis in muscle layers. A moderate number of plump reactive fibroblasts and lesser numbers of fibrocytes were embedded with and at the borders of the inflammatory nodules in a moderate amount of homogeneous intensely eosinophilic fibrillary material rupturing the cell membrane. For molecular characterization, six isolated worms were amplified for the partial mitochondrial cox1 gene showing distinct interindividual variations. This first pathological and molecular description from southern Europe provided new knowledge about the diffusion of M. hirudinaceus in wild boars, furthering the research into the origin and transmission status of M. hirudinaceus in endemic localities.

Human and environmental factors driving Toxoplasma gondii prevalence in wild boar (Sus scrofa)

As one of the most relevant foodborne diseases, it is essential to know the factors related to the transmission, persistence and prevalence of Toxoplasma gondii infection. Eurasian wild boar (Sus scrofa) might play a relevant role in T.gondii's life cycle. This species is the most consumed big game animal in Spain and may act as a source of infection if the meat is eaten raw or undercooked or due to cross-contaminations. Additionally, wild boar can act as an excellent bioindicator of T.gondii circulation in the ecosystem, because its natural behaviour leads to exposure to oocysts from the soil when rooting and tissular bradyzoites when scavenging. A total of 1003 wild boar were sampled from 2010 to 2017 in Mediterranean Spain. Blood samples were tested with an indirect ELISA test giving a total of 14.1% (95% confidence interval 12.0-16.4%) positive results. The prevalence was not homogeneous in neither the animals nor the sampled districts. Significant differences were found regarding age, climatic conditions and human space occupancy. Human population aggregation, assessed by Demangeon's index, was identified as an influential factor in T.gondii infection risk. This multiple approach allows us to evaluate local risks for human and environmental contamination.

A Neglected Parasite: Macracanthorhynchus hirudinaceus, First Report in Feral Pigs in a Natural Park of Sicily (Southern Italy)

Sanitary management and population control of feral pigs remains a major problem in public health, particularly in natural parks where hunting is prohibited and the extensive farming of livestock is common. Macracanthorhynchus hirudinaceus is a zoonotic parasite species with a worldwide distribution of which the natural definitive hosts are primarily pigs and wild boars (Sus scrofa). The present study describes the main anatomo-pathological and parasitological findings in the first case of M. hirudinaceus in feral pigs in the Madonie park in Sicily (Southern Italy). Overall, 52 acanthocephalans were collected from the small intestine of four infected feral pigs. The prevalence among the 36 examined animals was 11.1% with a mean Abundance (mA) and mean Intensity (mI) of 1.4 and 13, respectively. Pathological examination revealed grossly visible nodules on the external surface of the intestines, corresponding to the proboscis of M. hirudinaceus attached deeply into the intestinal wall. In these sites, severe inflammatory reactions in the tissue involved and the destruction of normal intestinal architecture, as well as necrosis and ulceration in the mucosa, submucosa, and part of the muscolaris mucosae were described. This is the first official report of this neglected zoonosis in Italy, in particular in a natural park where the extensive farming of domestic pigs is practiced. This could favor the spread of this parasite in domestic animals and the environment, increasing the accidental risk of infection in human residents of these areas.