In September 2018, classical swine fever (CSF) occurred in a pig farm in Japan for the first time in 26 years. Outbreaks unfortunately still continued at pig farms, and the epidemic has expanded to several prefectures. Furthermore, wild boar involvement has made is difficult to control inhibitory the spread of CSF. Most of the CSF that occurred in Japan in the past showed the acute virulent type, but the current CSF in Japan is the so-called “mild type”, which has already known worldwide. The current CSF that emerged while “diversification of CSF” has begun to be recognized internationally is different from the CSF that Japan had experienced in the past.

Classical swine fever (CSF) reemerged in Gifu prefecture in Japan on September 2018. It is suspected that the initial case was caused to wild boar through pork products contaminated with CSFV brought by foreign tourists. After the first confirmation of the outbreak, 51 cases of CSF in domestic pigs as well as more than two thousands notifications in wild boar have reported in 12 prefectures at the end of December 2019. Taking into account that the notifications have reported continuously in the affected area, there’s a possibility that the disease spreads more widely. It is believed that the current epidemics of CSF has spread through contacts between domestic pigs and wild boar. As the farm biosecurity play an important role in terms of prevention of the disease invasion, questionnaire study was conducted to 232 pig farms in 25 prefectures to understand the current situation of farm biosecurity level and to find the critical factors for disease control.

The results of questionnaire showed that most of farms have implemented adequate vehicle disinfection, and clothing and boot changes in farms and pig pens, however, small farmers tend to neglect these rules. More than 60% of farmers feed “eco-feed” to pigs, and most of these materials didn’t include pig meats. However, it was found that almost all feeds were fed with insufficient heat treatment. In terms of the prevention of wild animal invasion, some of farms set bird net, but only few farmers set wire-mesh fence for wild boar.

The vaccination program against CSF for domestic pigs has begun on October 2019. In addition to the control of wild boar movement, prevention of the disease invasion to the farm is another key factor. The results of present study should be useful to review the current farm biosecurity.

Since the outbreak of African swine fever (ASF) spread into China, Animal Quarantine Service (AQS) in Japan started to test samples taken from pork products confiscated from travelers from China as a result of quarantine inspection to examine the presence of ASF virus. As a result, ASF virus (ASFV) was isolated from two of these samples. As this means the serious increase of the risk of ASF introduction from Asian countries via travelers, AQS have enhanced the level of penal measures against travelers with prohibited pock products by doing such as issuing the Alarming Documents with the list of legal punishments to them. In addition, travelers who have issued the Alarming Documents were listed in the database and when a traveler with repeated violation was identified, the person will be arrested for assembling the case. After the start of these enhancement measures, 7 travelers were arrested for four cases. A list of these cases is published at the AQS homepage. We bereave that these our efforts effectively raise the interest to Japanese AQS regulations among travelers and will reduce the risk of ASF introduction into Japan.

This study aimed to investigate the recent prevalence of intestinal parasites and enteric bacterial pathogen (diarrheagenic Escherichia coli, Salmonella sp., Yersinia sp., Campylobacter sp.) in companion animals in Niigata Prefecture, Japan. From May to December each of 2015 and 2016, fecal samples were collected from 136 dogs and 176 cats in Niigata public animal shelters and were examined parasitologically and bacteriologically in Niigata prefectural institute of public health and environmental sciences. Overall, the prevalence of intestinal parasites in dogs and cats were 3.7% and 42.0%, and of diarrheagenic Escherichia coli were 19.1% and 15.3%, respectively. In dogs, Spirometra erinaceieuropaei (2.9%), Pharyngostomum cordatum (0.7%), and Cytoisospora canis (0.7%) were detected of intestinal parasites. Eae positive E.coli (10.3%), astA positive E.coli (8.1%), Campylobacter sp. (1.5%), eae-astA positive E.coli (0.7%), and eae-astA-bfpA positive E.coli (0.7%) were detected of enteric bacterial pathogen. However, in cats, Toxocara cati was the most prevalent parasite species (31.3%), followed by S.erinaceieuropaei (10.2%), C.felis (6.3%), and Ancylostoma tubaeforme (5.7%). Eae positive E.coli (11.4%), astA positive E.coli (4.5%), eae-bfpA positive E.coli (1.1%), and eae-astA positive E.coli (0.6%) were detected of bacteria. Epidemiologically, it is suggested that parasitic infection is related to the condition of animals, such as captured, bred outdoors, and bred in large-scale. Although some Escherichia coli strains with virulence gene were isolated, these strains were possibly indigenous bacterium in dogs and cats. These data will be useful resources for the dissemination and awareness raising of public health about keeping animals. This study also suggests that research about zoonotic pathogens in shelter animals, sharing the role between shelters and laboratory, as for the former, specimen collection, the latter are examination, will be a useful model for surveillance of zoonotic diseases.

日本の養豚業は2013年に国内に侵入した世界的な豚流行性下痢（PED）の流行により甚大な被害を被った。本研究は，国内最大の養豚地帯である鹿児島県にて発生したPED流行初期における農場レベルでの感染力を定量化するために実施された。

農場内感染状況により農場を以下の5つのコンパートメントに分けたコンパートメントモデルを作成した：感染豚がいない感受性期（S） ; 少なくとも一頭の感染豚がいるが一頭も症状を呈していない暴露期（E） ; 少なくとも一頭の豚が症状を呈しているが，意図的にあるいは意図せずにまだ獣医当局に報告されていない感染性期（In） ; 症状を呈している豚がおり，獣医当局に感染農場として認識されている感染性期（Id） ; 全ての豚がPEDから回復した回復期（R）。

パラメーターは，鹿児島県から提供された流行開始から40日間の実際のデータを基に，日ごとの新発生数と累積清浄化農場数の最尤推定により導出した。潜伏期間は2日間，獣医当局へは発生翌日に通報されるものと仮定した。基本再生産数R₀は次世代行列を用いて計算した。

結果として，感染性期間およびR₀はそれぞれ54.4日と5.39と推定された。まとめとして，流行初期の農場間感染力は非常に高く，これまですでに報告されている共通感染源感染に加えて農場の感染性期間の長期化が本病の迅速な拡大の原因となっていたことが明らかとなった。