Short communicationFarmed wild boars exposed to Toxoplasma gondii and Trichinella spp.
Introduction
The European wild boar (Sus scrofa L.) is a popular game animal species whose meat is also available for consumers as a farmed delicacy. Unfortunately, it can be a source of zoonotic parasites, such as Toxoplasma gondii and Trichinella spp., if enjoyed undercooked (EFSA, 2005, EFSA, 2007). At the slaughterhouse level, meat intended for retail is monitored for Trichinella, but not for T. gondii infections.
Although many epidemiological and parasitological studies of wild boar pertain to free-ranging animals (e.g. for T. gondii, reviewed by Fornazari et al., 2009), investigating the role of farmed wild boars as hosts for zoonotic parasites is also of both public health and veterinary importance. Contrary to expectations for free-ranging game animals, farmed animals could be at least partly protected from such infections. In Finland, approximately 100 free-ranging wild boars are shot by hunters every year, and 600 farmed wild boars are slaughtered for meat. This serological survey aimed to estimate the exposure of the farmed wild boar population to T. gondii and Trichinella spp.
Section snippets
Farms and animals
This survey was part of a nationwide epidemiological study for which a sampling frame was compiled from the official records of Finnish wild boar farmers. All 117 farms were contacted and 32 (45% of active farms) participated in the study. The farmers sampled their wild boars at slaughter and provided the background information on the animals and farms.
For this survey, we selected serum samples from 2007 to 2008 to obtain a sufficient sample size, calculated based on expected seroprevalences of
Prevalences
T. gondii-specific IgG antibodies were detected in 65 (33.0%; 95% CI 26.7–39.8%) sera (Table 1). At least one T. gondii-seropositive animal was found on 15 (60.0%; 95% CI 40.2–77.6%) farms (Fig. 1).
Based on the cut-off that we set, four (2.0%; 95% CI 0.6–4.8%) samples were interpreted as Trichinella-seropositive (Table 1). Three (12.0%; 95% CI 3.1–29.3%) farms had at least one Trichinella-seropositive animal. In general, higher ODs seemed to be clustered on some of the farms (Fig. 2).
Indirect
Discussion
The T. gondii seroprevalence in Finnish farmed wild boars (33%) was seven times higher than the seroprevalence in captive wild boars in Brazil (4.5%) despite our higher threshold for defining a positive sample (Fornazari et al., 2009). The method used in the Brazilian study is fundamentally the same as the direct agglutination test used in our study.
The Trichinella seroprevalence in Finnish farmed wild boars (2%) was lower than the previous estimate (11%) (Sukura et al., 2001). However, that
Conflict of interest statement
The authors declare no conflicts of interest.
Acknowledgements
The authors thank the farmers for their contribution in sampling the animals, the personnel of the Quality Game Farming project for their assistance, and Antti Oksanen for commenting on the manuscript during its preparation. Financial support was provided by the Finnish Ministry of Agriculture and Forestry, the Association for Animal Disease Prevention (ETT), and the Mercedes Zachariassen Foundation.
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Seroprevalence of Toxoplasma gondii in wild boars (Sus scrofa) hunted in Ukraine
2024, International Journal for Parasitology: Parasites and WildlifeEpidemiology of Trichinella in the Arctic and subarctic: A review
2022, Food and Waterborne ParasitologyCitation Excerpt :Corresponding percentages for T. nativa were 62.5, 74.7, and 90.2, respectively. Antibodies against Trichinella were detected in 11% of 99 and 2% of 197 farmed Finnish wild boars that had been tested negative for muscle larvae in meat inspection (Sukura et al., 2001; Jokelainen et al., 2012). The seropositive wild boars had possibly been exposed to T. nativa, which has low infectivity to swine, including wild boar (Kapel, 2001).
All about Toxoplasma gondii infections in pigs: 2009–2020
2020, Veterinary ParasitologyCitation Excerpt :Most data were from hunted wild swine. The prevalence was generally low in a few samples from farmed boars in China (9.9%, Bai et al., 2017), Denmark (28.0%, Laforet et al., 2019), Finland (33.0%, Jokelainen et al., 2012), Latvia (20.3%, Deksne and Kirjusina, 2013), and Ukraine (6.6%, Galat et al., 2018). These pigs are probably slaughtered for general human consumption.
A systematic review and meta-analysis on the global seroprevalence of Trichinella infection among wild boars
2018, Food ControlCitation Excerpt :We performed subgroup analyses to find source of heterogeneity, but it remained high after subgroup analysis. We assumed that differences in study design or sampling strategy, characteristics of the serological assays used, different positive cut-off values and different sources of animals studied (e.g., Cuttell et al., 2014 studied wild boar from a low risk region and Jokelainen, Näreaho, Hälli, Heinonen, and Sukura (2012) used farmed wild boar in their study) could be reasons for high heterogeneity. Despite the aforementioned limitations, the analysis and interpretation presented here furthers our understanding of the global seroprevalence of Trichinella infection among wild boar.
The global seroprevalence of Toxoplasma gondii among wild boars: A systematic review and meta-analysis
2017, Veterinary ParasitologyCitation Excerpt :Whereas, the seroprevalence of T. gondii decreases in subarctic and arctic areas (higher altitude than 65°), where environment temperature is low and domestic cats are rare, and, when present are mostly kept indoors. In support of this statement, a geographical north-south gradient in seroprevalence of T. gondii was estimated in domestic moose, sheep, farmed wild boars, and lynx in Finland (Jokelainen et al., 2010, 2012, 2013). Moreover, Flegr et al. (2014) showed that prevalence of human toxoplsmosis decreases with an increase in geographical latitude.