[Cystic hydatidosis--its occurrence and prevention in Japan].

The history of cystic hydatidosis (CH) in Japan is reviewed on the basis of case reports and other references during the period from 1881 to 2003. A total of 76 cases were identified as CH patients in Japan of which 47 were reported prior to 1945 and 29 thereafter. The occurrence was divided into 2 stages before and after the Slaughterhouse Act that was brought into force in 1906. The presence of endemic foci of CH was suggested before the Act was introduced in Japan, especially in southwestern prefectures, and the development of cattle breeding and unsanitary small slaughterhouses in the areas were thought to be cause. Japan emphasized cattle as a dietary protein source and also for various military accouterments such as shoes and rucksacks for soldiers. China was a transit port to Japan from Europe and also a big endemic area of CH. Japan had sent a huge number of soldiers and citizens to China in the Japanese-Sino and Japanese-Russian War and a number of cattle, pet dogs and people have also came to Japan from China. After enforcement of the Slaughterhouse Act in 1906, the number of CH cases decreased dramatically, and only 2 cases were reported for the 30 years between 1920 and 1950 in Japan. The situation regarding CH in Japan thus suggested the existence of endemic foci in southwestern prefectures, although direct evidence was lacking because no one had found E. granulosus in dogs of the area. Almost all of the patients recently presenting with CH appear to have been infected in overseas endemic countries. The available information strongly suggest that sanitary control of slaughterhouses is essential for preventing CH in endemic areas. Diagnostic laboratory examinations and appropriate medical intervention are clearly important. An animal quarantine system against echinococcal infestation of pet dogs should also be established urgently in Japan, because hundreds of pet dogs are being imported annually from endemic countries in Europe and Asia.