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In the United States, negligible rates of zoonotic sarcocystosis occur in feral swine that, by contrast, frequently harbour infections with Sarcocystis miescheriana, a related parasite contracted from canids

  • R. CALERO-BERNAL (a1), S. K. VERMA (a1), S. OLIVEIRA (a1), Y. YANG (a1), B. M. ROSENTHAL (a1) and J. P. DUBEY (a1)...

Transmission of pathogens between domestic and wild life animals plays an important role in epidemiology. Feral pig populations are increasing and expanding in the USA, and may constitute a risk to non-biosecure domestic pig facilities by serving as reservoirs for pathogens. We surveyed, for Sarcocystis infection, the myocardium of 1006 feral pigs (Sus scrofa) trapped or hunted in 29 states during the Comprehensive Feral Swine Disease Surveillance Program of the USDA's Animal and Plant Health Inspection Service, Wildlife Services unit during 2012–2014. Sarcocysts were detected in histological sections of 25% (251/1006) of myocardium with an average parasitic load/intensity of infection of 3·03 sarcocysts/section (1·5×0·7 cm), and higher prevalence of myocarditis in severe infections. Microscopic examination of pepsin digests of 147 hearts revealed a higher prevalence of Sarcocystis bradyzoites (49%, 72/147) than when diagnosed by histology. A fragment of Sarcocystis 18S rRNA was amplified and digested with a restriction endonuclease, revealing a pattern consistent with Sarcocystis miescheriana in all 44 selected samples. Sequencing 31 of these 44 isolates confirmed their correspondence to S. miescheriana. Thus, S. miescheriana infection, but not the zoonotic parasite Sarcocystis suihominis, appears to be prevalent and widespread in feral pigs in the USA.

Corresponding author
* Corresponding author. United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, Maryland 20705-2350, USA. E-mail:
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† Both the authors equally contributed to this work.
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Avapal, R. S., Sharma, J. K. and Juyal, P. D. (2003). Prevalence of Sarcocystis species infection in slaughtered pigs. Journal of Veterinary Parasitology 17, 151153.
Avapal, R. S., Sharma, J. K. and Juyal, P. D. (2004). Pathological changes in Sarcocystis infection in domestic pigs (Sus scrofa). Veterinary Journal 168, 358361.
Barrows, P. L., Smith, H. M. Jr., Prestwood, A. K. and Brown, J. (1981). Prevalence and distribution of Sarcocystis sp among wild swine of southeastern United States. Journal of the American Veterinary Medicine Association 179, 11171118.
Barrows, P. L., Prestwood, A. K., Adams, D. D. and Dykstra, M. J. (1982 a). Development of Sarcocystis suicanis Erber, 1977 in the pig. Journal of Parasitology 68, 674680.
Barrows, P. L., Prestwood, A. K. and Green, C. E. (1982b). Experimental Sarcocystis suicanis infections: disease in growing pigs. American Journal of Veterinary Research 43, 14091412.
Boch, J., Hennings, R. and Erber, M. (1980). Die wirtschaftliche Bedeutung der Sarkosporidiose (Sarcocystis suicanis) in der Schweinemast. Auswertung eines Feldversuches. Berliner und Münchener Tierärztliche Wochenschrift 93, 420423.
Caspari, K., Grimm, F., Kühn, N., Caspari, N. C. and Basso, W. (2011). First report of naturally acquired clinical sarcocystosis in a pig breeding stock. Veterinary Parasitology 177, 175178.
Coombs, D. W. and Springer, M. D. (1974). Parasites of feral pig × European wild boar hybrids in Southern Texas. Journal of Wildlife Diseases 10, 36441.
Dahlgren, S. and Gjerde, B. (2007). Genetic characterisation of six Sarcocystis species from reindeer (Rangifer tarandus tarandus) in Norway based on the small subunit rRNA gene. Veterinary Parasitology 146, 204213.
Dubey, J. P. (1979). Frequency of Sarcocystis in pigs in Ohio and attempted transmission to cats and dogs. American Journal of Veterinary Research 40, 867868.
Dubey, J. P. (2010). Toxoplasmosis of Animals and Humans, 2nd Edn. CRC Press, Boca Raton, FL, USA.
Dubey, J. P. and Powell, E. C. (1994). Prevalence of Sarcocystis in sows from Iowa. Veterinary Parasitology 52, 151155.
Dubey, J. P., Speer, C. A. and Fayer, R. (1989). Sarcocystosis of Animals and Man. CRC Press. Boca Raton, FL, USA.
Freyre, A., Chifflet, L. and Méndez, J. (1992). Sarcosporidian infection in pigs in Uruguay. Veterinary Parasitology 41, 167171.
Hill, D. E., Dubey, J. P., Baroch, J. A., Swafford, S. R., Fournet, V. F., Hawkins-Cooper, D., Pyburn, D. G., Schmit, B. B., Gamble, H. R., Pedersen, K., Ferreira, L. R., Verma, S. K., Ying, Y., Kwok, O. C. H., Feidasf, H. and Theodoropoulos, G. (2014). Surveillance of feral swine for Trichinella spp. and Toxoplasma gondii in the USA and host-related factors associated with infection. Veterinary Parasitology in press,
Hinaidy, H. K. and Supperer, R. (1979). Sarkosporidienbefall des schweines in Österreih. Wiener Tierärztliche Monatsschrift 66, 281285.
Heydorn, A. O. (1977). Beiträge zum Lebenszyklus der Sarkosporidien. IX. Entwicklungszyklus von Sarcocystis suihominis n. sp. Berliner und Münchener Tierärztliche Wochenschrift 90, 218224.
Holmdahl, O. J. M., Mattsson, J. G., Uggla, A. and Johansson, K. E. (1994). The phylogeny of Neospora caninum and Toxoplasma gondii based on ribosomal RNA sequences. FEMS Microbiology Letters 119, 187192.
Hvizdošová, N. and Goldová, M. (2009). Monitoring of occurrence of sarcocystosis in hoofed game in Eastern Slovakia. Folia Veterinaria 53, 57.
Kia, E. B., Mirhendi, H., Rezaeian, M., Zahabiun, F. and Sharbatkhori, M. (2011). First molecular identification of Sarcocystis miescheriana (Protozoa, Apicomplexa) from wild boar (Sus scrofa) in Iran. Experimental Parasitology 127, 724726.
Li, J. H., Lin, Z., Du, J. F. and Qin, Y. X. (2007). Experimental infection of Sarcocystis suihominis in pig and human volunteer in Guangxi. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 25, 466468.
Matschke, G. H. (1967). Aging European wild hogs by dentition. Journal of Wildlife Management 31, 109113.
Moré, G., Pantchev, A., Skuballa, J., Langenmayer, M. C., Maksimov, P., Conraths, F. J., Venturini, M. C. and Schares, G. (2014). Sarcocystis sinensis is the most prevalent thick-walled Sarcocystis species in beef on sale for consumers in Germany. Parasitology Research 113, 22232230.
Ohino, A., Shinzato, T., Sueyoshi, T., Tominaga, M., Arakaki, M., Shiroma, S., Ohshiro, K., Saitou, M. and Itagaki, M. (1993). Prevalence of Sarcocystis infection in slaughter pigs in Okinawa prefecture. Journal of the Japan Veterinary Medical Association (Nippon Juishikai Zasshi) 46, 979982.
Piekarski, G., Heydorn, A. O., Aryeetey, M. E., Hartlapp, J. H. and Kimmig, P. (1978). Klinische, parasitologische und serologische Untersuchungen zur Sarkosporidiose (Sarcocystis suihominis) des Menschen. Immunität und Infektion 6, 153159.
Prestwood, A. K., Cahoon, R. W. and McDaniel, H. T. (1980). Sarcocystis infections in Georgia swine. American Journal of Veterinary Research 41, 18791881.
Reiner, G., Eckert, J., Peischl, T., Bochert, S., Jäkel, T., Mackenstedt, U., Joachim, A., Daugschies, A. and Geldermann, H. (2002). Variation in clinical and parasitological traits in Pietrain and Meishan pigs infected with Sarcocystis miescheriana . Veterinary Parasitology 106, 99113.
Saito, M., Shibata, Y., Ohno, A., Kubo, M., Shimura, K. and Itagaki, H. (1998). Sarcocystis suihominis detected for the first time from pigs in Japan. Journal of Veterinary Medical Science 60, 307309.
Saleque, A. and Bhatia, B. B. (1991). Prevalence of Sarcocystis in domestic pigs in India. Veterinary Parasitology 40, 151153.
Taylor, M. A., Boes, J., Boireau, P., Boué, F., Claes, M., Cook, A. J. C., Dorny, P., Enemark, H., van der Giessen, J., Hunt, K. R., Howell, M., Kirjušina, M., Nöckler, K., Pozio, E., Rossi, P., Snow, L., Theodoropoulos, G., Vallée, I., Vieira-Pinto, M. M. and Zimmer, I. A. (2010). Development of harmonised schemes for the monitoring and reporting of Sarcocystis in animals and foodstuffs in the European Union. Supporting publications. EFSA-Q-2009-01074.
Yan, W., Qian, W., Li, X., Wang, T., Ding, K. and Huang, T. (2013). Morphological and molecular characterization of Sarcocystis miescheriana from pigs in the central region of China. Parasitology Research 112, 975980.
Yang, Z. Q., Zuo, Y. X., Yao, Y. G., Chen, X. W., Yang, G. C. and Zhang, Y. P. (2001). Analysis of the 18S rRNA genes of Sarcocystis species suggests that the morphologically similar organisms from cattle and water buffalo should be considered the same species. Molecular and Biochemical Parasitology 115, 283288.
Yang, Z. Q., Li, Q. Q., Zuo, Y. X., Chen, X. W., Chen, Y. J., Nie, L., Wei, C. G., Zen, J. S., Attwood, S. W., Zhang, X. Z. and Zhang, Y. P. (2002). Characterization of Sarcocystis species in domestic animals using a PCR-RFLP analysis of variation in the 18S rRNA gene: a cost-effective and simple technique for routine species identification. Experimental Parasitology 102, 212217.
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