Eating habits of east Asian people and transmission of taeniasis.

In order to understand the role of raw meat and viscera eating habits in the transmission of taeniasis in Asian countries, 1502 infected aborigines in ten mountainous districts/towns of six counties in Taiwan, 58 infected persons in two villages on Cheju Island, Korea, and 97 cases in Ambarita District on Samosir Island, North Sumatra, Indonesia were studied during the field surveys. All infected Taiwan aborigines had the habit of eating raw meat and viscera of wild and/or domestic animals. Among these aborigines, 73% ate wild boar, 66% flying squirrel, 65% wild goat, 56% muntjac, 49% wild rats, 46% monkey, 38% hare, 20% civet-cats, 18% weasel, 17% pheasant, 14% squirrel, 4% grouse, 1% deer, 1% snake, less than 1% bamboo partridge, less than 1% frog, less than 1% bear, less than 1% dog, and less than 1% fox. Of the 58 infected persons with Taenia on Cheju Island, Korea, 72% ate raw meat and/or viscera of pig and cattle, 19% raw pork only, and 9% raw beef only. Among 12 infected persons infected with T. saginata-like tapeworms, 7 had eaten raw pork, 2 raw beef and pork and 3 raw pork. Almost all of the 97 cases of taeniasis on Samosir Island of North Sumatra, Indonesia, had eaten only undercooked pork. Eleven of 15 cases were found to be infected with T. saginata-like tapeworms. Eating habits observed suggest an unusual way of transmission of Taenia in East Asia.

Taeniasis in Indonesia with special reference to Samosir Island, north Sumatra.

In Indonesia, taeniasis is endemic on the islands of Bali, Irian Jaya and Sumatra. The Balinese eat pork or beef raw in a dish called "lawar". Natives of Irian Jaya also have a custom of preparing and consuming raw pork. On Samosir Island in North Sumatra, undercooked pork is consumed in traditional ceremonies. In Bali, the local people defecate into cages (called "teba") of domestic animals. In Irian Jaya, pigs are allowed to feed on human feces inside houses at night. The natives of Samosir Island defecate in their gardens and their feces are easily consumed by freely roaming pigs. Since 1972, studies have been carried out on the epidemiology of taeniasis in North Sumatra. The Taenia sp. found on Samosir Island is morphologically identical to Taenia saginata. However, the local people seldom or never consume beef because it is very expensive, while pork is commonly consumed. The species and the natural intermediate hosts of Taenia sp. on Samosir Island are still under investigation.

Experimental infection of Indonesia Taenia (Samosir strain) in domestic animals.

Three 58-day old Small-Ear-Miniature (SEM) pigs, six 36-day old Landrace-Small-Ear-Miniature (L-SEM) pigs, and two 5-day old Holstein calves were each fed 3000 or 30,000 Indonesia Taenia (Samosir strain) eggs and sacrificed 27-195 days after inoculation. A total of 4922 cysticerci were recovered only from the livers of the three SEM pigs (1977 cysticerci) and six L-SEM pigs (2945 cysticerci). The infection rate in pigs was 100%. Cysticerci recovery rates of SEM and L-SEM pigs were 22.0% and 1.6%, respectively. Calves were not susceptible to Indonesia Taenia. More cysticerci were found in the liver parenchyma (L-SEM, 66.4%; SEM, 76.2%) than on the liver surface (L-SEM, 33.6%; SEM, 23.8%) of the infected animals. Most (99.86%) of the cysticerci recovered from the livers of L-SEM pigs were degenerated or calcified but 77.9% of those in the livers of SEM pigs were mature and only 22.1% were degenerated or calcified. Measurements of length, width, diameters of protoscolex, rostellum, and sucker and hooklet pattern indicated that Indonesia Taenia is very similar to Taiwan Taenia and very different from Taenia saginata and Taenia solium. The present findings indicate that Indonesia Taenia and Taiwan Taenia may be the same new species.

First case of human Thelaziasis in Indonesia.

The thread-like worms removed from the right eye of a 10 month-old boy in North Sumatra were shown to be female Thelazia callipaeda, by the shape of the buccal capsule and the position of the vulva. This is the first report of human infection of Thelazia callipaeda in Indonesia.