Kwan Nigel C L, Ogawa Hidehito, Yamada Akio, Sugiura Katsuaki
Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Kamikawa Livestock Hygiene Service Center, 4-15 Asahikawa, Kamikawa-shicho, Hokkaido 071-8154, Japan.
Prev Vet Med. 2016 Jun 1;128:112-23. doi: 10.1016/j.prevetmed.2016.04.015. Epub 2016 Apr 26.
Japan has been free from rabies since 1958 and various preventive measures are in place protecting the country from the introduction of the disease. Historical reviews indicate that the illegal landing of dogs from Russian fishing boats in the ports of Hokkaido occurred frequently especially in the early 2000s and this could potentially be a source of introduction of rabies into Japan. The method of scenario tree modelling was used and the following entry and exposure pathway was considered the most likely route of rabies entry: a rabies-infected dog arriving on a Russian fishing boat lands in a port of Hokkaido in Japan, it becomes infectious, contacts and infects a susceptible domestic animal (companion dog, stray dog or wildlife). Input parameter values were based on surveys of Russian fishermen, expert opinion and scientific data from the literature. At present (2006-2015), the probability of the introduction of rabies as a result of one Russian fishing boat arriving at a port of Hokkaido is 8.33×10(-10) (90% Prediction Interval (PI): 7.15×10(-11)-5.34×10(-9)), while this probability would have been 7.70×10(-9) (90% PI: 6.40×10(-10)-4.81×10(-8)) in the past (1998-2005). Under the current situation (average annual number of boat arrivals is 1106), rabies would enter Japan every 1,084,849 (90% PI: 169,215-20,188,348) years, while the disease would have been introduced every 18,309 (90% PI: 2929-220,048) years in the past (average annual number of boat arrivals is 7092). The risk of rabies introduction has decreased 59 fold due to both the effective control of the issue of illegal landing of dogs and the decline in the number of Russian boat arrivals. Control efforts include education of Russian fishermen, establishment of warning signs, daily patrols and regular port surveillance of potential dog landing activity. Furthermore, scenario analysis revealed that the policy of mandatory domestic dog vaccination does not contribute effectively to Japan's rabies prevention system under rabies-free situation. Although the current risk of rabies introduction is minimal, control measures against the illegal landing of dogs must be maintained. Further risk management measures, such as the removal of wildlife from the port area and regular monitoring of the rabies situation in Russia (particularly the easternmost regions), can be established to strengthen the current rabies prevention system in Hokkaido.
自1958年以来，日本一直没有狂犬病，并且实施了各种预防措施以保护该国免受该疾病的传入。历史回顾表明，俄罗斯渔船的狗非法在北海道港口登陆的情况频繁发生，尤其是在21世纪初，这有可能成为狂犬病传入日本的一个源头。采用了情景树建模方法，以下传入和暴露途径被认为是狂犬病传入的最可能途径：一只感染狂犬病的狗乘坐俄罗斯渔船抵达日本北海道的一个港口，它变得具有传染性，接触并感染一只易感的家畜（伴侣犬、流浪狗或野生动物）。输入参数值基于对俄罗斯渔民的调查、专家意见以及文献中的科学数据。目前（2006 - 2015年），一艘俄罗斯渔船抵达北海道一个港口导致狂犬病传入的概率为8.33×10⁻¹⁰（90%预测区间（PI）：7.15×10⁻¹¹ - 5.34×10⁻⁹），而在过去（1998 - 2005年）这个概率为7.70×10⁻⁹（90% PI：6.40×10⁻¹⁰ - 4.81×10⁻⁸）。在当前情况下（每年平均船只抵达数量为1106艘），狂犬病每1,084,849年（90% PI：169,215 - 20,188,348年）会传入日本一次，而在过去（每年平均船只抵达数量为7092艘），该疾病每18,309年（90% PI：2929 - 220,048年）会传入一次。由于对狗非法登陆问题的有效控制以及俄罗斯船只抵达数量的减少，狂犬病传入的风险降低了59倍。控制措施包括对俄罗斯渔民进行教育、设置警示标志、每日巡逻以及对潜在的狗登陆活动进行定期港口监测。此外，情景分析表明，在无狂犬病的情况下，强制对家犬进行疫苗接种的政策对日本的狂犬病预防系统没有有效贡献。尽管目前狂犬病传入的风险极小，但必须维持针对狗非法登陆的控制措施。可以制定进一步的风险管理措施，例如将野生动物从港口区域清除以及定期监测俄罗斯（特别是最东部地区）的狂犬病情况，以加强北海道目前的狂犬病预防系统。
