Community control studies on Strongyloides infection in a model island of Okinawa, Japan.

The community control program for Strongyloides infection was conducted by fecal examination and subsequent treatment of the population on a model island (Kume Island) in Okinawa, Japan, for 5 years from 1993 to 1997. More than 1,200 persons, accounting for 17% to 20% of the persons subjected, received fecal examinations each year. The positive rate in 1993 was found to be 9.7% (133/1,374). The positive rate decreased to 6.5% (95/1,468) in 1994, then 4.8% (60/1,245) in 1995, 2.2% (27/1,225) in 1996 and 2.7% (33/1,217) in 1997 through treatment with albendazole or ivermectin on the positive persons detected each year. Among the positive persons detected after operation of the control program, more than 70% were newly detected persons who did not receive an examination in the previous year or were falsely-negative in the previous examination. The low enforcement of procuring fecal examinations, as well as low sensitivity of fecal examination, might have had an effect on the relatively gradual decrease in the prevalence rate, in spite of the high efficacy of the treatment. The results indicate that continuation of the control program for several years is needed to effectively reduce the prevalence of the parasitic infection in the community.

Mercury content in the gallstones and bile of Thai people (Chiang Mai and Bangkok) and Japanese.

Mercury contents in the gallstones and bile of patients living in Thailand (Chiang Mai and Bangkok) and Japan were studied by neutron activation analysis. The correlation between contents in the gallstones and bile, and the amount of mercury in the diet and environment was investigated by comparing the contents in patients living in three different areas. The content in the bile of the Japanese patients was significantly greater than that of the Thai patients. The distribution of mercury contents in the pigment and rare stones of patients living in Bangkok indicated a bipolarity. However, the distribution of the contents in cholesterol, pigment, and rare stones of Japanese patients did not indicate a bipolarity. Bipolarity would indicate the amount of mercury in dietary foods, and the pollution level of mercury. The mercury contents in the gallstones and bile would reflect the amount of mercury in the diet and environment.