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Serological evidence of Toxoplasma gondii in hunted wild boar from Portugal
Veterinary Parasitology 202 (2014) 310–312
Contents lists available at ScienceDirect
Veterinary Parasitology journal homepage: www.elsevier.com/locate/vetpar
Short Communication
Serological evidence of Toxoplasma gondii in hunted wild boar from Portugal Catarina Coelho a,b , Madalena Vieira-Pinto a,c,∗ , Ana Sofia Faria a,d , Hélia Vale-Gonc¸alves a,d,e , Octávia Veloso a,d,e , Maria das Neves Paiva-Cardoso a,c,d , João Rodrigo Mesquita b,f , Ana Patrícia Lopes a,c a CECAV, Centro de Ciˆencia Animal e Veterin´ aria, Universidade de Tr´ as-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal b Escola Superior Agr´ aria de Viseu, Instituto Polit´ecnico de Viseu, Quinta da Alagoa, 3500-606 Viseu, Portugal c Departamento Ciˆencias Veterin´ arias, Universidade de Tr´ as-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801 Vila Real, Portugal d CITAB, Centro de Investigac¸˜ ao e de Tecnologias Agroambientais e Biol´ ogicas. Universidade de Tr´ as-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal e Laborat´ orio de Ecologia Aplicada, CITAB, Centro de Investigac¸˜ ao e de Tecnologias Agroambientais e Biol´ ogicas. Universidade de Tr´ as-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal f CIBIO, Centro de Investigac¸˜ ao em Biodiversidade e Recursos Gen´eticos, 4485-661 Vair˜ ao, Portugal
a r t i c l e
i n f o
Article history: Received 5 February 2014 Received in revised form 7 March 2014 Accepted 8 March 2014
Keywords: Modified agglutination test Serology, Toxoplasma gondii Wild boar
a b s t r a c t Toxoplasmosis is an important parasitic zoonosis with a worldwide distribution, being the parasitic disease with the highest occurrence in Europe. Wild boar has an important role in the epidemiological cycle of Toxoplasma gondii as an intermediate host, that can potentially infect humans when the meat is consumed raw or undercooked. The purpose of this work was to determine the presence of antibodies to T. gondii in serum of hunted wild boar. During the hunting season 2011/2012, sera samples were collected from 97 wild boar and tested for IgG antibodies to T. gondii, using the modified agglutination test. Twenty out of the 97 wild boar (20.6%) were seropositive for T. gondii IgG antibodies. Multivariate logistic regression analysis showed that males and older animals were associated with T. gondii seropositivity. These results show that T. gondii has an important presence in wild boar population from Portugal, suggesting a potential zoonotic risk for humans when wild boar meat or meat products are consumed raw or undercooked. © 2014 Elsevier B.V. All rights reserved.
1. Introduction Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is an important zoonosis with a worldwide
∗ Corresponding author at: Lab. Inspecc¸ão Sanitária-P2, Dept. Ciências Veterinárias, Universidade de Trás-os-Montes e Alto, 5001-801 Vila Real, Portugal. Tel.: +351 259350523. E-mail address: [email protected] (M. Vieira-Pinto). http://dx.doi.org/10.1016/j.vetpar.2014.03.013 0304-4017/© 2014 Elsevier B.V. All rights reserved.
distribution, being the parasitic disease with the highest occurrence in Europe (EFSA, 2011). Cats and other felids are the only known definitive hosts, shedding unsporulated oocysts into the environment (Dubey, 2009). Intermediate hosts are all homoeothermic animals, including humans. Infection may be acquired by ingestion of food or water contaminated with sporulated oocysts, consumption of meat with cysts or by vertical transmission (Dubey, 2010). Foodborne transmission of T. gondii is considered the most important route for human infection in some parts
C. Coelho et al. / Veterinary Parasitology 202 (2014) 310–312
311
Table 1 Multivariate logistic regression analysis of risk factors for seropositivity to Toxoplasma gondii in wild boar according to age group, gender and district (n = 97). Animals (n)
Seropositivity (%) (95% CI)
OR (95% CI)
Age group (months) Juvenile (6–14) Young adult (15–25) Mature adult (≥26)
27 33 37
3.7 (2.0–5.4) 24.2 (20.4–28.1) 29.7 (25.6–33.8)
1.0 11.6 (1.2–111.0) 19.2 (2.0–182.8)
Gender Female Male
66 31
15.2 (11.9–18.4) 32.3 (28.1–36.4)
1.0 4.12 (1.3–13.2)
District Vila real Braganc¸a
46 51
21.7 (18.0–25.4) 19.6 (16.0–23.2)
1.0 1.84 (0.6–5.6)
p Value
p LR 0.003
0.033 0.010 0.014 0.017 0.284 0.290
CI, confidence intervals; OR, odds ratios; LR, likelihood ratio.
of the world and the consumption of raw or undercooked meat or meat products is pointed as the main risk factor for infection (Cook et al., 2000). Although wild boar is the main large game species hunted in Portugal, scarce information is available about T. gondii infection in these animals. Lopes et al. (2011) reported a study on T. gondii infection, in wild birds and mammals from north and central regions of the country, with 8 wild boar sampled and a seropositivity of 100%. The purpose of the present study was to evaluate the occurrence of antibodies anti-T. gondii in hunted wild boar, and risk factors associated with the presence of specific antibodies, contributing to the assessment of this zoonotic hazard and potential implications to public health. 2. Materials and methods
Positive and negative controls were supplied with the kit and included in each testing plate. Serum was diluted at 1:20, 1:400, 1:1600 and 1:6400. A cut-off titer of 20 was chosen to maximize both sensitivity and specificity of the test (Dubey et al., 1995; Lopes et al., 2011). 2.3. Statistical analysis Confidence limits for the proportions were established by exact binomial test with 95% confidence intervals (CI). Multivariate logistic regression models were used to identify risk factors for seropositivity, calculating odds ratios (OR) and their 95% CI (Vicente et al., 2006). Variables with a probability [p] value ≤0.05 were considered significant. All analyses were performed using Epicalc package in the R software (R 2.15.1) (R Development Core Team 2012).
2.1. Sampling 3. Results Samples were collected from 97 wild boar harvested during the hunting season of 2011/2012 in two districts of Portugal (Vila Real and Braganc¸a). Blood was collected with sterile tubes directly from the thoracic cavity upon evisceration. Sera was separated and stored at −20 ◦ C until analysis. For statistical purposes, animal data was collected: sampling district, gender, and age. Animals were categorized into three age groups based on tooth eruption patterns: juvenile (6–14 months), young adult (15–25 months) and mature adult (≥26 months) (Saenz de Buraga et al., 1991).
According to the MAT (≥20), 20 wild boar were positive, resulting in a seropositivity of 20.6% (95% CI: 17.0–24.2). Seventeen animals were positive at the dilution of 1/20, two at the dilution of 1/400 and one at the dilution of 1/1600. Risk factors for T. gondii infection in wild boar from Portugal were aged above 26 months (OR = 19.2; 95% CI: 2.0–182.8, p = 0.010), age between 15 and 25 months (OR = 11.6, 95% CI: 1.2–111.0, p = 0.033) and male gender (OR = 4.12; 95% CI: 1.3–13.2, p = 0.017). Sampling district was not identified as a risk factor (Table 1).
2.2. Modified agglutination test (MAT) 4. Discussion Serum samples were tested for immunoglobulin G (IgG) antibodies against T. gondii, by the modified agglutination test (MAT) using a commercial kit (Toxo-Screen DA® , bioMérieux, Lyon, France), with whole formalin-fixed tachyzoites as antigen. The MAT was chosen because it was previously proven to be the most sensitive and specific test for diagnosis of T. gondii infection in pigs (Sus scrofa domesticus), which are the same specie as wild boar (Dubey, 1997; Dubey et al., 1995; Dubey et al., 1997).
In the present study the presence of antibodies to T. gondii in wild boar was evaluated. From a total of 97 animals, 20 (20.6%) were seropositive. Similar results were found in France (17.6%) (Richomme et al., 2009), Germany (24.4%) (Opsteegh et al., 2011) and Czech Republic (26.2%) (Bártová et al., 2006). In Spain, Gauss et al. (2005) found a higher value of 38.4%. The information about T. gondii infection in wild boar hunted in Portugal is very scarce. The only
312
C. Coelho et al. / Veterinary Parasitology 202 (2014) 310–312
available data found was based on a very small number of analyzed animals (Lopes et al., 2011). The MAT was used in the present work, for the detection of antibodies to T. gondii. Among all the serological tests available, the MAT is considered to be the most reliable to detect antibodies to T. gondii in animals, especially in latently infected animals (Dubey, 2010). The MAT was validated in naturally exposed pigs using isolation of the viable parasite as the standard (Dubey et al., 1995). In the present study, the major risk factor for T. gondii infection in wild boar was age above 15 months. The increase of T gondii seropositivity in the older age groups is consistent with previous studies. Higher T. gondii IgG antibody seropositivity among adults has been reported in wild boar (Ruiz-Fons et al., 2006). This result might be related to a more prolonged time of exposure to the infective forms of the parasite. Besides age, gender was also found to be a risk factor, with males having a probability four times higher of becoming infected. This is not in accordance with previous studies that shown that female wild boars are more likely to be T. gondii seropositive (Jokelainen et al., 2012). Our findings could be explained by the higher home range of males, potentially increasing their exposure to infective stages of T. gondii (Fernández-Llario, 2006). In Portugal there is a strong tradition of consumption of wild boar meat. According to the official data, it is estimated that around 15,400 wild boar are hunted per year in Portugal (Personal communication, AFN 2009). Additionally, this meat is widely used to make uncontrolled homemade sausages, prepared without any heat processing and, therefore, consumed raw, increasing the likelihood to T. gondii becoming a foodborne pathogen for humans. Additionally, infected viscera and carcasses left by hunters, may pose a threat to scavenging susceptible animals. To prevent further infection, incineration or burying of carcasses should be encouraged. This study shows that wild boar from Portugal may represent a potential zoonotic risk of T. gondii for humans if meat or meat products are consumed raw or undercooked. Risk groups like pregnant women and immunocompromised individuals should take special care with the consumption of this meat. Since this parasite cannot be directly detected during meat inspection, implementation of surveillance and monitoring programs in live animals is of extreme importance to mitigate the transmission of this zoonotic parasite and its introduction into the food chain, as it was already recommended by EFSA (2013). Acknowledgments The work was supported by the strategic research Project PEst-OE/AGR/UI0772/2014 financed by the
Foundation for Science and Technology (FCT) and by a PROFAD grant from Polytechnic Institute of Viseu. References Bártová, E., Sedlák, K., Literák, I., 2006. Prevalence of Toxoplasma gondii and Neospora caninum antibodies in wild boars in the Czech Republic. Vet. Parasitol. 142, 150–153. Cook, A.J., Gilbert, R.E., Buffolano, W., Zufferey, J., Petersen, E., Jenun, P.A., Foulon, W., Semprini, A.E., Dunn, D.T., 2000. Sources of Toxoplasma infection in pregnant women: European multicenter case-control study. European Research Network on Congenital Toxoplasmosis. Brit. Med. J. 321, 142–147. Dubey, J.P., 1997. Validation of the specificity of the modified agglutination test for toxoplasmosis in pigs. Vet. Parasitol. 71, 307–310. Dubey, J.P., Andrews, C.D., Thulliez, P., Lind, P., Kwok, O.C., 1997. Longterm humoral antibody responses by various serologic tests in pigs orally inoculated with oocysts of four strains of Toxoplasma gondii. Vet. Parasitol. 68, 41–50. Dubey, J.P., 2009. History of the discovery of the life cycle of Toxoplasma gondii. Int. J. Parasitol. 39, 877–882. Dubey, J.P. (Ed.), 2010. Toxoplasmosis of Animals and Humans. , 2nd ed. CRC Press, Boca Raton, 313 pp. Dubey, J.P., Thulliez, P., Weigel, R.M., Andrews, C.D., Lind, P., Powell, E.C., 1995. Sensitivity and specificity of various serologic tests for detection of Toxoplasma gondii infection in naturally infected sows. Am. J. Vet. Res. 56 (8), 1030–1036. EFSA & ECDC (European Food Safety Authority, European Centre for Disease Prevention and Control), 2011. The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2009. EFSA J. 9 (3), http://dx.doi.org/10.2903/j.efsa.2011.2090, 2090, 378 pp. EFSA (European Food Safety Authority), 2013. Scientific Opinion on the public health hazards to be covered by inspection of meat from farmed game. EFSA J. 11 (6), 3264, 181 pp. Fernández-Llario, P., 2006. Jabalí – Sus scrofa. In: Carrascal, L.M., Salvador, ˜ Museo A. (Eds.), Enciclopedia Virtual de los Vertebrados Espanoles. Nacional de Ciencias Naturales, Madrid. Gauss, C.B.L., Dubey, J.P., Vidal, D., Ruiz, F., Vicente, J., Marco, I., Lavin, S., Gortazar, C., Almería, S., 2005. Seroprevalence of Toxoplasma gondii in wild pigs (Sus scrofa) from Spain. Vet. Parasitol. 131, 151–156. Jokelainen, P., Näreaho, A., Hälli, O., Heinonen, M., Sukura, A., 2012. Farmed wild boars exposed to Toxoplama gondii and Trichinella spp. Vet. Parasitol. 187, 323–327. Lopes, A.P., Sargo, R., Rodrigues, M., Cardoso, L., 2011. High seroprevalence of antibodies to Toxoplasma gondii in wildlife from Portugal. Parasitol. Res. 108, 1163–1169. Opsteegh, M., Swart, A., Fonville, M., Dekkers, L., van der Giessen, J., 2011. Age-related Toxoplasma gondii seroprevalence in Dutch wild boar inconsistent with life long persistence of antibodies. PLoS ONE 6, e16240. Richomme, C., Aubert, D., Gilot-Fromont, E., Ajzenberg, D., Mercier, A., Ducrot, C., Ferté, H., Delorme, D., Villena, I., 2009. Genetic characterization of Toxoplasma gondii from wild boar (Sus scrofa) in France. Vet. Parasitol. 164, 296–300. Ruiz-Fons, F., Vicente, J., Vidal, D., Höfle, U., Villanúa, D., Gauss, C., Segalés, J., Almería, S., Montoro, V., Gortázar, C., 2006. Seroprevalence of six reproductive pathogens in European wild boar (Sus scrofa) from Spain: the effect on wild boar female reproductive performance. Theriogenology 65, 731–743. Saenz de Buraga, M., Calero, A.L., Iraizoz, F.J.P., 1991. Reconocimiento de sexo y edad en especies cinegéticas. Edilesa. Vicente, J., Höfle, U., Garrido, J.M., Fernández-de-Mera, I.G., Juste, R., Barral, M., Gortazar, C., 2006. Wild boar and red deer display high prevalences of tuberculosis-like lesions in Spain. Parasitol. Res. 37, 107–119.
Contents lists available at ScienceDirect
Veterinary Parasitology journal homepage: www.elsevier.com/locate/vetpar
Short Communication
Serological evidence of Toxoplasma gondii in hunted wild boar from Portugal Catarina Coelho a,b , Madalena Vieira-Pinto a,c,∗ , Ana Sofia Faria a,d , Hélia Vale-Gonc¸alves a,d,e , Octávia Veloso a,d,e , Maria das Neves Paiva-Cardoso a,c,d , João Rodrigo Mesquita b,f , Ana Patrícia Lopes a,c a CECAV, Centro de Ciˆencia Animal e Veterin´ aria, Universidade de Tr´ as-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal b Escola Superior Agr´ aria de Viseu, Instituto Polit´ecnico de Viseu, Quinta da Alagoa, 3500-606 Viseu, Portugal c Departamento Ciˆencias Veterin´ arias, Universidade de Tr´ as-os-Montes e Alto Douro, UTAD, Quinta de Prados, 5000-801 Vila Real, Portugal d CITAB, Centro de Investigac¸˜ ao e de Tecnologias Agroambientais e Biol´ ogicas. Universidade de Tr´ as-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal e Laborat´ orio de Ecologia Aplicada, CITAB, Centro de Investigac¸˜ ao e de Tecnologias Agroambientais e Biol´ ogicas. Universidade de Tr´ as-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal f CIBIO, Centro de Investigac¸˜ ao em Biodiversidade e Recursos Gen´eticos, 4485-661 Vair˜ ao, Portugal
a r t i c l e
i n f o
Article history: Received 5 February 2014 Received in revised form 7 March 2014 Accepted 8 March 2014
Keywords: Modified agglutination test Serology, Toxoplasma gondii Wild boar
a b s t r a c t Toxoplasmosis is an important parasitic zoonosis with a worldwide distribution, being the parasitic disease with the highest occurrence in Europe. Wild boar has an important role in the epidemiological cycle of Toxoplasma gondii as an intermediate host, that can potentially infect humans when the meat is consumed raw or undercooked. The purpose of this work was to determine the presence of antibodies to T. gondii in serum of hunted wild boar. During the hunting season 2011/2012, sera samples were collected from 97 wild boar and tested for IgG antibodies to T. gondii, using the modified agglutination test. Twenty out of the 97 wild boar (20.6%) were seropositive for T. gondii IgG antibodies. Multivariate logistic regression analysis showed that males and older animals were associated with T. gondii seropositivity. These results show that T. gondii has an important presence in wild boar population from Portugal, suggesting a potential zoonotic risk for humans when wild boar meat or meat products are consumed raw or undercooked. © 2014 Elsevier B.V. All rights reserved.
1. Introduction Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is an important zoonosis with a worldwide
∗ Corresponding author at: Lab. Inspecc¸ão Sanitária-P2, Dept. Ciências Veterinárias, Universidade de Trás-os-Montes e Alto, 5001-801 Vila Real, Portugal. Tel.: +351 259350523. E-mail address: [email protected] (M. Vieira-Pinto). http://dx.doi.org/10.1016/j.vetpar.2014.03.013 0304-4017/© 2014 Elsevier B.V. All rights reserved.
distribution, being the parasitic disease with the highest occurrence in Europe (EFSA, 2011). Cats and other felids are the only known definitive hosts, shedding unsporulated oocysts into the environment (Dubey, 2009). Intermediate hosts are all homoeothermic animals, including humans. Infection may be acquired by ingestion of food or water contaminated with sporulated oocysts, consumption of meat with cysts or by vertical transmission (Dubey, 2010). Foodborne transmission of T. gondii is considered the most important route for human infection in some parts
C. Coelho et al. / Veterinary Parasitology 202 (2014) 310–312
311
Table 1 Multivariate logistic regression analysis of risk factors for seropositivity to Toxoplasma gondii in wild boar according to age group, gender and district (n = 97). Animals (n)
Seropositivity (%) (95% CI)
OR (95% CI)
Age group (months) Juvenile (6–14) Young adult (15–25) Mature adult (≥26)
27 33 37
3.7 (2.0–5.4) 24.2 (20.4–28.1) 29.7 (25.6–33.8)
1.0 11.6 (1.2–111.0) 19.2 (2.0–182.8)
Gender Female Male
66 31
15.2 (11.9–18.4) 32.3 (28.1–36.4)
1.0 4.12 (1.3–13.2)
District Vila real Braganc¸a
46 51
21.7 (18.0–25.4) 19.6 (16.0–23.2)
1.0 1.84 (0.6–5.6)
p Value
p LR 0.003
0.033 0.010 0.014 0.017 0.284 0.290
CI, confidence intervals; OR, odds ratios; LR, likelihood ratio.
of the world and the consumption of raw or undercooked meat or meat products is pointed as the main risk factor for infection (Cook et al., 2000). Although wild boar is the main large game species hunted in Portugal, scarce information is available about T. gondii infection in these animals. Lopes et al. (2011) reported a study on T. gondii infection, in wild birds and mammals from north and central regions of the country, with 8 wild boar sampled and a seropositivity of 100%. The purpose of the present study was to evaluate the occurrence of antibodies anti-T. gondii in hunted wild boar, and risk factors associated with the presence of specific antibodies, contributing to the assessment of this zoonotic hazard and potential implications to public health. 2. Materials and methods
Positive and negative controls were supplied with the kit and included in each testing plate. Serum was diluted at 1:20, 1:400, 1:1600 and 1:6400. A cut-off titer of 20 was chosen to maximize both sensitivity and specificity of the test (Dubey et al., 1995; Lopes et al., 2011). 2.3. Statistical analysis Confidence limits for the proportions were established by exact binomial test with 95% confidence intervals (CI). Multivariate logistic regression models were used to identify risk factors for seropositivity, calculating odds ratios (OR) and their 95% CI (Vicente et al., 2006). Variables with a probability [p] value ≤0.05 were considered significant. All analyses were performed using Epicalc package in the R software (R 2.15.1) (R Development Core Team 2012).
2.1. Sampling 3. Results Samples were collected from 97 wild boar harvested during the hunting season of 2011/2012 in two districts of Portugal (Vila Real and Braganc¸a). Blood was collected with sterile tubes directly from the thoracic cavity upon evisceration. Sera was separated and stored at −20 ◦ C until analysis. For statistical purposes, animal data was collected: sampling district, gender, and age. Animals were categorized into three age groups based on tooth eruption patterns: juvenile (6–14 months), young adult (15–25 months) and mature adult (≥26 months) (Saenz de Buraga et al., 1991).
According to the MAT (≥20), 20 wild boar were positive, resulting in a seropositivity of 20.6% (95% CI: 17.0–24.2). Seventeen animals were positive at the dilution of 1/20, two at the dilution of 1/400 and one at the dilution of 1/1600. Risk factors for T. gondii infection in wild boar from Portugal were aged above 26 months (OR = 19.2; 95% CI: 2.0–182.8, p = 0.010), age between 15 and 25 months (OR = 11.6, 95% CI: 1.2–111.0, p = 0.033) and male gender (OR = 4.12; 95% CI: 1.3–13.2, p = 0.017). Sampling district was not identified as a risk factor (Table 1).
2.2. Modified agglutination test (MAT) 4. Discussion Serum samples were tested for immunoglobulin G (IgG) antibodies against T. gondii, by the modified agglutination test (MAT) using a commercial kit (Toxo-Screen DA® , bioMérieux, Lyon, France), with whole formalin-fixed tachyzoites as antigen. The MAT was chosen because it was previously proven to be the most sensitive and specific test for diagnosis of T. gondii infection in pigs (Sus scrofa domesticus), which are the same specie as wild boar (Dubey, 1997; Dubey et al., 1995; Dubey et al., 1997).
In the present study the presence of antibodies to T. gondii in wild boar was evaluated. From a total of 97 animals, 20 (20.6%) were seropositive. Similar results were found in France (17.6%) (Richomme et al., 2009), Germany (24.4%) (Opsteegh et al., 2011) and Czech Republic (26.2%) (Bártová et al., 2006). In Spain, Gauss et al. (2005) found a higher value of 38.4%. The information about T. gondii infection in wild boar hunted in Portugal is very scarce. The only
312
C. Coelho et al. / Veterinary Parasitology 202 (2014) 310–312
available data found was based on a very small number of analyzed animals (Lopes et al., 2011). The MAT was used in the present work, for the detection of antibodies to T. gondii. Among all the serological tests available, the MAT is considered to be the most reliable to detect antibodies to T. gondii in animals, especially in latently infected animals (Dubey, 2010). The MAT was validated in naturally exposed pigs using isolation of the viable parasite as the standard (Dubey et al., 1995). In the present study, the major risk factor for T. gondii infection in wild boar was age above 15 months. The increase of T gondii seropositivity in the older age groups is consistent with previous studies. Higher T. gondii IgG antibody seropositivity among adults has been reported in wild boar (Ruiz-Fons et al., 2006). This result might be related to a more prolonged time of exposure to the infective forms of the parasite. Besides age, gender was also found to be a risk factor, with males having a probability four times higher of becoming infected. This is not in accordance with previous studies that shown that female wild boars are more likely to be T. gondii seropositive (Jokelainen et al., 2012). Our findings could be explained by the higher home range of males, potentially increasing their exposure to infective stages of T. gondii (Fernández-Llario, 2006). In Portugal there is a strong tradition of consumption of wild boar meat. According to the official data, it is estimated that around 15,400 wild boar are hunted per year in Portugal (Personal communication, AFN 2009). Additionally, this meat is widely used to make uncontrolled homemade sausages, prepared without any heat processing and, therefore, consumed raw, increasing the likelihood to T. gondii becoming a foodborne pathogen for humans. Additionally, infected viscera and carcasses left by hunters, may pose a threat to scavenging susceptible animals. To prevent further infection, incineration or burying of carcasses should be encouraged. This study shows that wild boar from Portugal may represent a potential zoonotic risk of T. gondii for humans if meat or meat products are consumed raw or undercooked. Risk groups like pregnant women and immunocompromised individuals should take special care with the consumption of this meat. Since this parasite cannot be directly detected during meat inspection, implementation of surveillance and monitoring programs in live animals is of extreme importance to mitigate the transmission of this zoonotic parasite and its introduction into the food chain, as it was already recommended by EFSA (2013). Acknowledgments The work was supported by the strategic research Project PEst-OE/AGR/UI0772/2014 financed by the
Foundation for Science and Technology (FCT) and by a PROFAD grant from Polytechnic Institute of Viseu. References Bártová, E., Sedlák, K., Literák, I., 2006. Prevalence of Toxoplasma gondii and Neospora caninum antibodies in wild boars in the Czech Republic. Vet. Parasitol. 142, 150–153. Cook, A.J., Gilbert, R.E., Buffolano, W., Zufferey, J., Petersen, E., Jenun, P.A., Foulon, W., Semprini, A.E., Dunn, D.T., 2000. Sources of Toxoplasma infection in pregnant women: European multicenter case-control study. European Research Network on Congenital Toxoplasmosis. Brit. Med. J. 321, 142–147. Dubey, J.P., 1997. Validation of the specificity of the modified agglutination test for toxoplasmosis in pigs. Vet. Parasitol. 71, 307–310. Dubey, J.P., Andrews, C.D., Thulliez, P., Lind, P., Kwok, O.C., 1997. Longterm humoral antibody responses by various serologic tests in pigs orally inoculated with oocysts of four strains of Toxoplasma gondii. Vet. Parasitol. 68, 41–50. Dubey, J.P., 2009. History of the discovery of the life cycle of Toxoplasma gondii. Int. J. Parasitol. 39, 877–882. Dubey, J.P. (Ed.), 2010. Toxoplasmosis of Animals and Humans. , 2nd ed. CRC Press, Boca Raton, 313 pp. Dubey, J.P., Thulliez, P., Weigel, R.M., Andrews, C.D., Lind, P., Powell, E.C., 1995. Sensitivity and specificity of various serologic tests for detection of Toxoplasma gondii infection in naturally infected sows. Am. J. Vet. Res. 56 (8), 1030–1036. EFSA & ECDC (European Food Safety Authority, European Centre for Disease Prevention and Control), 2011. The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2009. EFSA J. 9 (3), http://dx.doi.org/10.2903/j.efsa.2011.2090, 2090, 378 pp. EFSA (European Food Safety Authority), 2013. Scientific Opinion on the public health hazards to be covered by inspection of meat from farmed game. EFSA J. 11 (6), 3264, 181 pp. Fernández-Llario, P., 2006. Jabalí – Sus scrofa. In: Carrascal, L.M., Salvador, ˜ Museo A. (Eds.), Enciclopedia Virtual de los Vertebrados Espanoles. Nacional de Ciencias Naturales, Madrid. Gauss, C.B.L., Dubey, J.P., Vidal, D., Ruiz, F., Vicente, J., Marco, I., Lavin, S., Gortazar, C., Almería, S., 2005. Seroprevalence of Toxoplasma gondii in wild pigs (Sus scrofa) from Spain. Vet. Parasitol. 131, 151–156. Jokelainen, P., Näreaho, A., Hälli, O., Heinonen, M., Sukura, A., 2012. Farmed wild boars exposed to Toxoplama gondii and Trichinella spp. Vet. Parasitol. 187, 323–327. Lopes, A.P., Sargo, R., Rodrigues, M., Cardoso, L., 2011. High seroprevalence of antibodies to Toxoplasma gondii in wildlife from Portugal. Parasitol. Res. 108, 1163–1169. Opsteegh, M., Swart, A., Fonville, M., Dekkers, L., van der Giessen, J., 2011. Age-related Toxoplasma gondii seroprevalence in Dutch wild boar inconsistent with life long persistence of antibodies. PLoS ONE 6, e16240. Richomme, C., Aubert, D., Gilot-Fromont, E., Ajzenberg, D., Mercier, A., Ducrot, C., Ferté, H., Delorme, D., Villena, I., 2009. Genetic characterization of Toxoplasma gondii from wild boar (Sus scrofa) in France. Vet. Parasitol. 164, 296–300. Ruiz-Fons, F., Vicente, J., Vidal, D., Höfle, U., Villanúa, D., Gauss, C., Segalés, J., Almería, S., Montoro, V., Gortázar, C., 2006. Seroprevalence of six reproductive pathogens in European wild boar (Sus scrofa) from Spain: the effect on wild boar female reproductive performance. Theriogenology 65, 731–743. Saenz de Buraga, M., Calero, A.L., Iraizoz, F.J.P., 1991. Reconocimiento de sexo y edad en especies cinegéticas. Edilesa. Vicente, J., Höfle, U., Garrido, J.M., Fernández-de-Mera, I.G., Juste, R., Barral, M., Gortazar, C., 2006. Wild boar and red deer display high prevalences of tuberculosis-like lesions in Spain. Parasitol. Res. 37, 107–119.