In October 2013, Porcine epidemic diarrhea (PED) was confirmed in Japan for the first time in seven years. Since then, the outbreak has spread nationwide, and more than new 100 cases per week were confirmed in April 2014 when the largest number of cases was confirmed. Then, the number of new cases started to decline and, so far, 822 cases in total have been confirmed in 39 prefectures as of 31 October. Under the circumstances, the Ministry of Agriculture, Forestry and Fisheries has been implementing actions to prevent further PEDV spread, for instance, by carrying out thoroughly the control measures based on the interim report on the epidemiological investigation and the comprehensive guidelines on PED control publicized this October.

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A large-scale outbreak of porcine epidemic diarrhea (PED) has been observed in Japan in 2013 after seven years absence. Above 1.2 million pigs have shown typical symptoms such as anorexia, vomiting and watery diarrhea, and approximately 380,000 pigs have died from October 2013 through August 2014. Several virus strains have been successfully isolated from the affected piglets during outbreak of PED. Sequence analyses of the 2013-2014 strains indicated that these were genetically distinct from the strains reported previously in Japan, but were related to the strains recently circulating in the US, Korea and China. It is suggested that PED virus strains detected almost simultaneously in the US, Korea, China and Japan are derived from the common origin. New strains have probably invaded from overseas and rapidly spread throughout Japan since 2013. Further full-genomic analysis of the current field strains in Japan will be required to clarify the global spread and evolutionary dynamics of emerging PEDV strains.

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New Porcine Epidemic Diarrhea (PED) began occurring in Asia in the 2010s. The PED spread to United States, Canada, Mexico, Korea, Taiwan and Japan during 2013 and 2014. PED occurred for the first time in the United States in April, 2013. The United States was a PED-free country until then, and pigs in the United States did not have immunity against it. Therefore infections of the PED virus in the United States caused the deaths of millions of piglets. On the other hand, in Japan, an outbreak of PED occurred in the 1990s, and a live vaccine for PED has been already approved. There were the sporadic occurrences of PED in Japan, but there was no full-blown outbreak, so it seemed that PED was under control in Japan. However, another outbreak of PED occurred in Japan in 2014. In this report, I focus on the background of this outbreak and describe the PED.

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The hearts, diaphragms, hind legs, and back muscles of 64 Japanese sika deer (Cervus nippon centralis) caught in a mountainous area of Hyogo Prefecture, Japan, were examined for Sarcocystis infection by detecting sarcocysts. Sarcocysts were detected in the muscles of 52 (81.3%) individuals, and their prevalence did not differ among 1-5-year-old individuals, although no sarcocysts were detected in deer younger than 1 year old. Sarcocyst prevalence was significantly lower in the back muscles than in the other tissues. The intensity of sarcocyst infection was also significantly higher in the heart than in any other organ examined. This high prevalence of Sarcocystis infection in Japanese sika deer may be attributable to their frequent contact with the feces of the final hosts, including the hunting dogs that accompany hunters culling deer, and stray dogs, wild foxes, and raccoon dogs. The detected sarcocysts were oval to rod-like in shape and the internal section was divided by septa into many compartments. Many crescent-shaped bradyzoites were present in each compartment. The average size of 177 sarcocysts was 698.5×170.2μm. However, the measurements ranged widely, with lengths of 243.0-1,067.4μm and widths of 58.7-351.1μm. The variation of the sizes of the sarcocysts did not correlate with their shape or location of parasitization in the host.

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Four novel polymorphisms were identified in a 2.3-kb region spanning the proximal promoter of the swine Prophet of Pit-1 (PROP1) gene. We conducted association analysis between polymorphisms in the promoter region of the PROP1 gene and reproductive traits in sows. We genotyped 267 Landrace×Large White crossbred sows and conducted the association analysis using 10 reproductive traits for first and second parities. In this population, the C allele of the g. -442 G>C SNP was associated with significantly greater numbers of total pigs born and pigs born alive (PBA) in parity 1, and with higher summed PBA in parity 1 and 2 (P<0.05). These results suggest that the g. -442 G>C SNP in the promoter region of the PROP1 gene affects reproductive traits at early parities in sows.

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This is the report of Avian influenza seminar held in Tokyo University on August 28^th, as 40^th scientific seminar of the Japan Society of Veterinary Epidemiology. Two lectures are included here ; “Controlling Avian Influenza With and Without Vaccination” by Dr Davis Swayne (USDA), and “Event-based and Active Surveillance for Avian Influenza” by Dr Cristobal Zepeda (USDA). Dr Swayne recommended the targeted vaccination program with the combination of appropriate surveillance to watch the immunity level of the targeted population and effectiveness of the vaccine strain to the field strain, in the case when the AI control with vaccination is needed. Dr Zepeda explained the AI surveillance, focusing two types ; Indicator-based, and Event-based surveillance. Event-based surveillance is currently being incorporated in surveillance system as a complement to Indicator-based surveillance. He also mentioned the roll of veterinary epidemiologist in planning and interpretation of surveillance, and application of the outcome to the decision-making.

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HACCP system is very effective system to control food safety hazards during food production and processing. Japan introduced this system since 1995, as voluntary system in the five food categories, those are milk and milk products, processed meat products, soft drinks, canned and retort foods, fish products. However, as it is voluntary system, 80% companies introduced this system, but only 25% of small and less developed food producing companies introduced this system. Therefore, Japanese government revised Japanese Food Sanitation Law, HACCP system is able to selectively introduce HACCP system in all categories of foods, instead of general hygiene management. HACCP system will be mandatory in all kinds of food in next ten years.

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