Seroprevalence of Toxoplasma gondii and Salmonella in Hunted Wild Boars from Two Different Regions in Switzerland

Abstract

Toxoplasma gondii and Salmonella are zoonotic foodborne pathogens that may be transmitted to humans through the consumption of raw or undercooked meat, including game. The aim of this study was to determine the seroprevalence of T. gondii and Salmonella antibodies in wild boars in two different regions in Switzerland. During the hunting season of 2020, a total of 126 diaphragm muscle samples of hunted wild boars were collected and the meat juice of these samples was analysed for pathogen-specific IgG antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. The overall seroprevalences were 35% for T. gondii and 17% for Salmonella, respectively. In general, seropositivity increased with the age of the animals. Seroprevalences of T. gondii were similar for animals from the northern region (29%) to those from the southern region (36.8%), indicating that T. gondii is widespread in the sylvestrian environment. By contrast, Salmonella seropositivity was remarkably higher in wild boars from the north (52%) compared with those from the south (5.3%). The high occurrence of Salmonella may represent a risk of transmission to compatriot domestic animals such free-range farmed pigs as well as to humans. Further, meat of hunted wild boars may present a source of human toxoplasmosis or salmonellosis.

Presence of Foodborne Bacteria in Wild Boar and Wild Boar Meat—A Literature Survey for the Period 2012–2022

“…The prevalence of Salmonella in the wild boar population has been studied through the analysis of different matrices. Some authors investigated the seroprevalence from blood serum, diaphragm, or muscle samples, achieving different percentages: 1.27% (141/1103) [ 156 ], 3.6% (14/393) [ 157 ], 4.3% (4/94) [ 158 ], 5% (1/20) [ 159 ], 17% (21/126) [ 160 ], 19.3% (52/269) [ 161 ], 38% (69/181) [ 39 ], and 66.5% (255/383) [ 162 ]. Testing of serum samples can reveal the presence of antibodies against Salmonella spp.…”

Molecular detection of Toxoplasma gondii, Neospora caninum and Sarcocystis spp in tissues of Sus scrofa slaughtered in southern Brazil

“…However, because of the smaller number of females evaluated in this study it is not possible to infer data on higher or lower frequency of detection in relation to the sex of the animals. Other studies have however, reported male wild boars with higher detection rates for T. gondii, ranging from 42% (Bassi et al, 2021) to 60% (Machado et al, 2021). This may be explained by the fact that male wild boars have solitary habits, travel longer distances in search of food when compared to females and young ones, thereby increasing the risk of infection (Machado et al, 2021;Rostami et al, 2017), as oocysts of this pathogen survive for long periods in an aquatic environment (Shapiro et al, 2019).…”

Revealing the Prevalence of Toxoplasma in Sierra Morena’s Wild Boar: An ELISA-Based Study Using Meat Juice

“…The prevalence of Toxoplasma infection in wild boar is influenced by factors such as the age and sex of the animals as well as the season and weather conditions [ 29 , 30 ]. Prevalence varies in different European countries: 40% (range 32–59%) in the Czech Republic [ 31 ]; 48% in Poland [ 32 ]; 29% (range 5–45%) in Sweden [ 33 ]; 16.8% in France [ 34 ]; 62% in Slovenia [ 35 ]; 35% in Switzerland [ 36 ]; and 15.5% in Italy [ 37 ]. In Spain, prevalence also varies between different areas: 14.1% in the Valencian Community [ 30 ]; 39% in Doñana National Park [ 29 ]; 19.4% in Andalusia [ 38 ]; 23.88% in the Extremadura Region and 20.8% in the Sierras de Cazorla, Segura, and Las Villas Natural Park [ 39 ]; and 51.16% in Sierra Morena [ 40 ].…”