Social and behavioral aspects of filariasis transmission in Kumpeh, Jambi, Indonesia.

Studies on the social and behavioral aspects of filariasis transmission were conducted in the transmigration area of Kumpeh, in the province of Jambi, Sumatra, Indonesia. Three methods were used in the study namely, interview, participation observation and focus group discussion. A total of 266 respondents (136 males and 130 females) were interviewed. The results of the study showed the most of the transmigrants were not familiar with the word "filariasis". They were more used to the name of "penyakit kaki gajah" or "elephant's leg" disease or "untut". The word "untut" is similar to what people of Selangor, Malaysia call this disease. The community attitude towards control efforts against filariasis was positive, as evidenced by their readiness in being bled and their readiness to help change the environment which serves as mosquito breeding places. Usually the transmigrants live in the "ladang" or dry farming area for 3-4 months to protect their crops from damages by pests. This habit was rather negative, because in their "ladangs" they exposed themselves to high risk of mosquito bites and thus to filariasis infection.

The effect of praziquantel treatment on liver and spleen size of children with schistosomiasis in Napu Valley, central Sulawesi.

Forty-six school children with japonicum schistosomiasis living in a village at Napu Valley, Indonesia were treated with praziquantel at a dosage of 70 mg/kg in two divided doses in a day. The number of children with palpable liver dropped significantly from 95.6% before treatment to 58.7% after treatment. The size of the liver was reduced in the majority of cases with a virtual disappearance of cases with very large liver (10 cm). Post-treatment increase of the liver size was observed in all 8 cases with small pre-treatment livers (0.5-1 cm). In contrast to the changes of the size of the liver after treatment, the number of children with palpable spleens before and after treatment was not significantly altered.

The impact of schistosomiasis mass treatment on hepato-splenomegaly in Napu Valley, Central Sulawesi, Indonesia.

The impact of mass treatment with praziquantel on 241 individuals, 131 males and 110 females in Napu Valley, Indonesia was studied. The pre-treatment overall stool positive cases ranged from 43% to 79%, the highest in the 20-29 age group. Post-treatment follow-up study showed that the cases dropped to 2.5%. Significant reduction was seen in liver rate from 68% to 51% and in the age groups 0-9, 10-19, there was a significant decrease in liver enlargement after treatment, but not significant differences were seen in spleen rate in all age groups. This might be due to the early stage of Schistosoma infection in younger age groups where complete resolution of fibrosis might occur.

Ecology of schistosomiasis in Indonesia with certain aspects of control.

Intensive studies on schistosomiasis in Indonesia were carried out since 1971. During this period studies on epidemiology of the disease, ecology of the intermediate host and pilot control trials were conducted. In 1975 a schistosomiasis pilot control measures in two endemic villages of Lindu Valley to develop rational and effective methods for schistosomiasis control under local conditions was initiated. The results showed some improvements of sanitation, snail habitats, decreased infection rates among the human population as well as among the rats and the snails. The increase in travel and better transportation, and development of transmigration programmes in recent years in the endemic areas cause some concern, and prevention of the spread of the disease was discussed.

A study of malayan filariasis in Lubuk Mumpo and Datar Lebar villages in Lais Regency, North Bengkulu, Sumatera, Indonesia.

Filariasis surveys at Lubuk Mumpo and Datar Lebar, Bengkulu, Sumatera, showed microfilarial rates of 23.9% and 30% respectively. Periodicity studies showed the parasite to be nocturnally periodic B. malayi with a periodicity index of 82.17. However, unlike the Malaysian form of periodic B. malayi, 44-100% of the microfilariae in thick blood smears were sheathed. Mansonia annulata, M. bonneae, M. dives, M. uniformis and Anopheles nigerrimus are probably involved in the transmission of the disease. B. malayi infections were seen in 7.1% of domestic cats and 20% of Macaca fascicularis examined. In addition Edesonfilaria malayensis is reported for the first time in Indonesia, 60% of 5 M. fascicularis being infected.

Studies on Malayan filariasis in Bengkulu (Sumatera), Indonesia with special reference to vector confirmation.

In an endemic focus of Brugia malayi in Bengkulu, Indonesia the microfilariae rate was 25%. The microfilariae showed nocturnal periodicity. Domestic cats in the same area were found to harbour B. pahangi, with a microfilariae rate of 23%. In the study area, the most prevalent man-biting Mansonia mosquitoes were Mn.bonneae (41%), followed by Mn.annulata (27%), Mn.uniformis (25%) and Mn.dives (7%). More Mansonia mosquitoes were collected outdoors than indoors between 1800-2200 hours. Natural infections with infective larvae of Brugia spp. were found in Mn.bonneae, Mn.dives, Mn.uniformis, Mn.annulata, and An.nigerrimus. Experimental infection studies revealed that Mn.annulata, Mn.bonneae, Mn.uniformis, An.nigerrimus and An.peditaeniatus permit the development of infective larvae. Under experimental condition, the vectorial competence is high in Mn.bonneae, intermediate in Mn.uniformis and low in An.hyrcanus group. It is concluded that the principal vectors of periodic B.malayi in the study area in Bengkulu are four Mansonia species (Mn.annulata, Mn.bonneae, Mn.uniformis and Mn.dives), and that the potential vectors include two Anopheles species (An.nigerrimus and An.peditaeniatus). This is the first record of Mn.bonneae being a vector of periodic B.malayi in Indonesia.

Intestinal and blood parasites in the Torro Valley, Central Sulawesi, Indonesia.

Approximately 300 blood and fecal specimens were examined in a parasitologic survey of indigenous inhabitants of the small isolated Torro Valley in the mountains of Central Sulawesi. Schistosoma japonicum was not found although the parasite is endemic in the neighboring Lindu and Napu valleys. Hookworm infection (71%) was the most common helminthiasis. The prevalences of ascariasis (3%) and trichuriasis (2%) are low for Indonesia in general but similar to those found in nearby mountainous areas of Sulawesi. Intestinal protozoa endemic to the area are: Entamoeba histolytica (8%). E. coli (23%). Endolimax nana (9%), Iodamoeba butschii (9%) and Giardia lamblia (14%). Plasmodium vivax infections were found in 4% and P. falciparum in 2% of persons examined. Brugia malayi microfilaremia was found with a prevalence of 25%. The high rate of splenic (54%) and hepatic (22%) enlargement found on examination of 206 persons of all ages is considered to be a result of combined effects of endemic malaria and hereditary ovalocytosis.

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.

Human parasitoses in Bali, Indonesia.

A survey of intestinal and blood parasites of man was conducted on the island of Bali, Indonesia in 1974. A total of 270 stool specimens from three villages were examined. Both Ascaris lumbricoides and Trichuris trichiura were found in more than 90% of those examined, and hookworm eggs in 59%. Other intestinal helminth and protozoan parasites found were: Enterobius vermicularis, Entamoeba histolytica, Entamoeba coli, Endolimax nana, and Iodamoeba bütschlii. Taeniid proglottids, Hymenolepis diminuta and dicrocoeliid-like trematode eggs were each found once. No microfilariae were found in 284 blood smears examined, however, in the village of Kusamba, Plasmodium vivax (3 cases) and Plasmodium falciparum (2 cases) were diagnosed.

Susceptibility to DDT, malathion, fenitrothion and dieldrin of three flea species in the boyolali plague endemic area, Central Java, Indonesia.

Insecticide susceptibility tests with 4% DDT, 0.5% and 5.0% malathion, 1% fenitrothion, and 0.2% dieldrin impregnated papers were carried out with fleas spp. from the Boyolali plague zone. The field flea (Stivalius cognatus) which was highly susceptible to malathion before, has now been found to be resistant to the insecticide, but was found susceptible to the other three insecticides. The oriental rat flea (X. cheopis) which found previously highly resistant to DDT, was now found to be less resistant, and susceptible to other insecticides tested. From preliminary tests with DDT to another field flea (Neopsylla sondiacus), it was found to be susceptible to the insecticide.

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.

Some aspects on the ecology and biology of Oncomelania hupensis lindoensis.

Schistosomiasis is known to be endemic in the lake Lindu area since 1937 (Brug & Tesch, 1937). Investigations carried out later between 1940 and 1942 (Bone et al., 1942) failed to find molluscan intermediate host. It was not until April 1971 that the first specimen of Oncomelania was found (Carney et al., 1972). In August of the same year the first focus was discovered at Paku (Hadidjaja et al., 1974). Further investigations revealed 50 more foci in the lowlands surrounding the lake. A survey of the habitat in the Napu Valley revealed 15 more Oncomelania colonies (Crney et al., in prep.). The morphology studied by Davis and Carney (1973) showed that this snail has a close resemblence to O. h. chiui and O. h. quadrasi. It was given the subspecies name Oncomelania hupensis lindoensis. Snail cultures maintained according to Davis' method (1971) were done in the laboratory of the Department of Parasitology, Faculty of Medicine, University of Indonesia. Diatoms and algae were given as food. Biology of the snails concerning the temperature, hymidity, mortality rate of the snail or survival rate and also the living and egg laying habits of the snails were described.

Distribution of Oncomelania hupensis in the Napu Valley of Central Sulawesi, Indonesia.

Fifteen colonies of Oncomelania hupensis were found near trails transecting the North Lore District, Napu Valley, Central Sulawesi. Habitats were in abandoned rice fields, uncultivated grazing areas for livestock, roadside ditches and, in one case, an actively worked rice field. Marsh grasses, Ischaemum barbatum and Laersia hexandra, were the most common plants in oncomelanid habitats. Other mollusks found in association with O. hupensis were Radix sp., Melanoides sp., Gyraulus sp., Idiopoma sp., Thiara sp., Opeas sp. and Indopyrgus sp. in that order of frequency. Schistosoma japonicum cercariae, as determined by mouse exposures, were shed from snails collected at four foci. In Sulawesi, O. hupensis and S. japonicum were found in high mountain valleys near, or above, 1,000 meters in elevation. Oncomelania hupensis, however, were not found in what appeared to be suitable habitats at lower elevations in the same drainage systems.