Schistosoma ovuncatum n. sp. (Digenea: Schistosomatidae) from northwest Thailand and the historical biogeography of Southeast Asian Schistosoma Weinland, 1858.

Schistosoma sinensium Bao, 1958 was first isolated from an unidentified snail in Sichuan Province, PR China. This species was apparently rediscovered in Chiang Mai Province, northwest Thailand (Baidikul et al., 1984); the definitive host was the rat Rattus rattus and the intermediate host was the snail Tricula bollingi. In this paper S. sinensium is rediscovered in Sichuan Province and compared with worms recovered from experimentally infected mice, which had been exposed to cercariae shed by T. bollingi from Chiang Mai. Evidence is presented suggesting that the schistosome collected by Baidikul was not S. sinensium and that a new species is involved. The new species, named Schistosoma ovuncatum (etymology: ovum (egg) + uncatus (hooked)), is described and compared with related taxa. All previous papers on the Thai schistosome have used worms recovered from field-collected rodents only; this is the first account in which the life-cycle has been completed in the laboratory, using cercariae shed by T. bollingi, and the resulting worms described. S. ovuncatum differs from S. sinensium in terms of size and shape of body and egg, number of testes, size of ovary, length of vitellarium, intermediate host and biogeographical distribution. The relationships of the two taxa and their position with respect to the Schistosoma indicum- and S. japonicum-groups are discussed. The implications of the findings for the evolution of human schistosomiasis in the region are also commented upon.

Overview reflection of primary health care in Thailand supported from 1976 to 1996 by Japan-Thailand partnership.

The international health cooperation of Japan for developing countries has been mostly concentrated on matters such as improvement of hygienic environment, prevention of tropical infectious diseases, establishment of hospitals with modern medical instruments and devices, and dispatch of medical experts. PHC (Primary Health Care) activities based on voluntary participation of local inhabitants in developing countries have been largely neglected. In the field of health and medical care, sufficient effect may not be achieved unless the local health activity is based on voluntary participation of the inhabitants. The introduction of advanced modern medical technics may be beneficial to some of the inhabitants, while most of the local inhabitants may not have the chance to receive such benefits, and additionally it is difficult to propagate modern medical care and technics widely to rural areas. In Thailand, PHC activity based on community participation was started in 1985, with the following three main themes: (1) Training of Village Health Volunteers (VHV) and Village Health Communicators (VHC), and development of their activities. (2) Establishment and operation of Health Centers. (3) Establishment and operation of a Drug Cooperative System (DC). Earlier, one of PHC activities developed by Japan, "Thailand Local Health Activity Improvement Project" based on the program of Thailand-Japan Partnership, was initiated in 1976 in rural areas of Chanthaburi Prefecture. From 1982, third country training programs have been carried out by the Japan International Cooperation Agency (JICA). As 10 years have elapsed since the initiation of PHC activity in rural areas in Thailand under the cooperation of the Governments of Thailand and Japan, it seems to be time to reconsider how PHC activity should be developed in future based on a candid evaluation of achievements and results.

Treatment of soil-transmitted nematode infections in children with mebendazole.

Treatment of soil-transmitted nematodes with mebendazole was carried out in 137 children aged 6--15 years in Thailand. There were 100 cases of hookworm infection, 37 of ascariasis, 16 of trichuriasis and 32 of strongyloidiasis. Mebendazole was given at 100 mg twice daily for three consecutive days irrespective of age or weight. The reduction rates as seen by mean egg counts four weeks after treatment were 94.9% for hookworm infection, 100% for ascariasis and 93.9% for trichuriasis; the reduction rates of the mean larval count in 15 cases of strongyloidiasis was 82.1%. No side-effects were observed. Mebendazole was thus confirmed as effective and safe in the treatment of soil-transmitted nematode infections in children in Thailand.