The Relationship Between Epidemiological Factors and the Parasite Load of Sarcocystis in Yezo-Deer ( Cervus nippon yesoensis ) in Hokkaido, Japan.

Several cases of gastrointestinal symptoms including diarrhea and vomiting due to the consumption of -infected venison have been reported in Japan. However, the control of case incidence is difficult, as epidemiological information concerning in venison in Japan is insufficient. We examined the prevalence and parasite load of in 89 samples of Yezo-deer () venison in Hokkaido by quantifying the copy numbers of the 18S rRNA gene of , followed by a statistical analysis that considered the sampling area, age, and sex to clarify the parameters related to the parasite load. The copy numbers per gram of venison in samples ranged from 4.8 to 8.8 log. Wilcoxon rank-sum test, the one-way factorial analysis of variance (ANOVA), Steel-Dwass test, and a two-way factorial ANOVA showed significant differences in the copy numbers among sampling areas, not by age or sex, suggesting that the load of in wild deer depended on the sampling area in Hokkaido. Notably, more than 80% of Hokkaido venison has a higher gene copy number than the meat that caused -food poisoning. This information is expected to contribute to the establishment of hygiene standards for safe venison consumption and the control of gastrointestinal symptom cases due to consumption of -infected venison.