Epidemiology of trichinellosis in Asia and the Pacific Rim.

The epidemiology of trichinellosis, species of Trichinella present and the food and eating habits of people affected in Asia and the Pacific Rim are reviewed with emphasis on Japan, China and Thailand. Trichinella seems to be prevalent throughout this region although outbreaks of trichinellosis have not been reported in some areas. Major outbreaks of the disease have been reported primarily in China and Thailand. This is the result of three factors: (1) China and Thailand are highly endemic areas for this parasite; (2) the two countries are well-organized and there is a public health system that enables precise reporting of disease outbreaks and (3) culinary habits provide many opportunities to eat undercooked meats. Trichinella found in Asia and the Pacific Rim includes both encapsulated species (Trichinella spiralis, Trichinella britovi, Trichinella nativa) and noncapsulated species (Trichinella pseudospiralis, Trichinella papuae). T. britovi, isolated in Japan, is a different genotype from the European strain. Therefore, the Japanese strain of T. britovi is designated Trichinella T9. Human trichinellosis caused by T. pseudospiralis has occurred in New Zealand and Thailand. Tasmania has had animal cases of T. pseudospiralis infection and animals with T. papuae infection have been found in Papua New Guinea. Economic losses due to Trichinella infection are not negligible in China, where there have been more than 500 outbreaks of human trichinellosis, affecting more than 20,000 people and causing more than 200 deaths. In Thailand, over the past 27 years, 120 outbreaks were reported involving nearly 6700 patients and 97 deaths. Japan has had fewer outbreaks and some sporadic cases have been attributed to imported infection.