Hepatitis E Virus RNA Detection from Hunted Wild Boars in Central Italy: an Epidemiological Investigation

Trichinella spp. detection in hunted wild boar (Sus scrofa) diaphragm biopsies in Central Italy

Trichinellosis is a globally diffused foodborne parasitic disease caused by nematodes of the Trichinella complex. During evolution, guided by ecological interactions, natural selection, and biochemical "intelligence", these parasites developed admirable strategies to infect the host's organism. One of the most fascinating is represented by the nurse cell formation in muscular tissue (e.g., diaphragm, skeletal muscle, extrinsic ocular muscles, etc.). This strategy allowed the parasite to adapt and conquer the wider host species spectrum, including ungulates and humans. Consumption of undercooked meat from infected wild ungulates constitutes the most important source of infection for the human species. In this study, we show the prevalence of Trichinella spp. in hunted wild boars (Sus scrofa) in Central Italy. During the hunting season 2021/2022 in the province of Rieti, 554 wild boar diaphragm biopsies were collected for Trichinella spp. screening, in accordance with Regulation EU 1375/2015. An artificial digestion method was used for the detection of Trichinella spp. larval forms. The results revealed a positivity of 0.18% (1/554), and molecular biology identification demonstrated the presence of Trichinella britovi in the positive sample. This species is the most diffused in wild ungulate populations in Central Italy and the most frequently isolated in human patients with trichinellosis from this area, showing a close epidemiological relation between Homo sapiens and Sus scrofa for Trichinella spp. diffusion in an ecosystem. Epidemiological surveillance, in receptive animal species destined for human consumption and at any One Health level, represents the main "winning" strategy in the control of this worldwide, widespread foodborne parasitic disease.

Prevalence and Risk Factors for Hepatitis E Virus in Wild Boar and Red Deer in Portugal

Hepatitis E virus (HEV) is a zoonotic foodborne virus with an annual infection prevalence of 20 million human cases, which seriously affects public health and economic development in both developed and developing countries. To better understand the epidemiology of HEV in Central Portugal, a cross-sectional study was conducted from 2016 to 2023 with sera samples from wild ungulates. The seroprevalence and risk factors for HEV seropositivity were evaluated in the present study. Specifically, antibodies against HEV were determined by a commercial enzyme-linked immune-sorbent assay (ELISA). Our results show that in the 650 sera samples collected from 298 wild red deer and 352 wild boars in Portugal, 9.1% red deer and 1.7% wild boar were positive for antibodies to HEV. Regarding age, the seropositivity in juvenile wild ungulates was 1.3%, whereas it was 7.2% in adults. Logistic regression models investigated risk factors for seropositivity. The odds of being seropositive was 3.6 times higher in adults than in juveniles, and the risk was 4.2 times higher in red deer than in wild boar. Both wild ungulate species were exposed to HEV. The higher seroprevalence in red deer suggests that this species may make a major contribution to the ecology of HEV in Central Portugal. Further research is needed to understand how wildlife affects the epidemiology of HEV infections in Portugal.