A schistosomiasis pilot control project in Lindu valley, Central Sulawesi, Indonesia.

This pilot control project was an intervention study, consisting of: 1) treating the positive cases with Niridazole; 2) spraying the foci with Niclosamide; 3) improving the water supply system and construction of public latrines. The intervention not only has lowered the human prevalence rate, but has also lowered the transmission of the disease in that area. Niridazole appeared relatively safe and effective, the cure rate after one year was 80%. Spraying the foci with Niclosamide 20-40 mg per litre did not appear very effective. Using this epidemiological data it was estimated that infected persons would become spontaneously negative after 4.75 years, if there was no reinfection.

Control of Schistosoma japonicum infection in Lindu Valley, Central Sulawesi, Indonesia.

In Indonesia, schistosomiasis is presently confined to two endemic areas in Central Sulawesi; Lindu (1,500) and Napu (5,000 inhabitants) valleys. Because of various development schemes now underway, it is feared that the natural balance which existed for many years between the parasite, the snail intermediate hosts and man, will be upset and will place some 70,000 people of the adjoining Palu and Palolo areas at risk. Measures are being taken to control and prevent the spread of the disease. A pilot control programme is planned for two years in the village of Anca in Lindu with a population of 391 and a prevalence rate of 70.5%. Langko village with a population of 464 and a prevalence rate of 53.7% will be utilized as the comparison area. Baseline data on human, malacological and animal reservoir hosts are being collected and control operations are anticipated to commence in July 1975. Measures to be applied to control schistosomiasis in the order of priorities are: (a) agro-engineering or modification of the environment; (b) environmental sanitation through the provision of adequate water supply and construction of latrines; (c) mollusciciding of remaining snail infested areas; (d) chemotherapy, and (e) health education campaign. At the end of the two-year control programme, the following activities will be carried out to determine the degree of intervention achieved; (a) human data: calculation of prevalence rates, incidence rates, and changes in the intensity of infection based on quantitative egg counts; (b) malacological data: changes in the number and extent of snail foci; snail density, and snail infection rates; (c) reservoir hosts: changes in the prevalence rates among domestic and wild animals. Calculation of reclaimed areas and increase in agricultural production will also be assessed together with the overall cost/benefit analysis of the project undertaking.