Intestinal and blood parasites of man on Alor Island Southeast Indonesia.

A survey of blood and intestinal parasites in a coastal and a mountainous area of the remote island of Alor, southeastern Indonesia revealed widespread infection with pathogenic intestinal protozoa and helminths, malaria and filaria. Amoebiasis (31.2%), ascariasis (35.3%) and hookworm infections (28.6%) were common, reflecting primitive sanitation and hygiene. Trichuriasis rates (6.8%) were less than expected perhaps due to the prolonged dry season and soil factors in the area. Timor filariasis was found in coastal villagers (10.5%), but not in persons living at an elevation of 500 meters; a low rate of bancroftian filariasis (1.8%) was found in both areas. Malaria, caused by P. vivax, P. falciparum and P. malariae was mesoendemic. Soil-transmitted and vector-borne parasitic infections are an important health problem in the populations examined.

Microfilarial periodicity analysis of the survey data from six localities in Indonesia.

The survey data of microfilarial periodicity of 2 species of filariae Brugia malayi at 4 localities, Mahang and Lampihong in South Kalimantan, Bengkulu in South Sumatra, Palolo in Central Sulwesi, and the species of Brugia timori at 2 localities, Flores and Alor Islands in Nusa Tenggara were analysed by using Aikat and Das's modified statistical method. Nine cases at Mahang and five cases at Lampihong were recognized as same group of non-periodic B. malayi and 1 case at Mahang was considered to be nocturnal subperiodic B. malayi by their parameters estimated by the wave equation, the amplitude (a), the peak hour of microfilaria density (k) the periodicity index (D) and the test of equality for comparison of two series of data. The data of 9 cases from Bengkulu and 11 cases from Palolo were similarly analysed and recognized as the nocturnal periodic type of B. malayi. The data of 5 cases from Flores Island and 5 cases from Alor Island were also recognized as the nocturanal periodic type of B. timori. Thus, in these observations the non periodic strain of Brugia malayi was detected in South Kalimantan. Further studies on the principal vectors and their bionomics should be carried out.

Distribution and prevalence of cases of microfilaraemia in Indonesia.

Blood smear surveys were conducted in principal villages on the major islands of Indonesia to determine the microfilarial rates presently existing in the populations. A total of 163,454 persons were examined and 10.8 percent found positive for microfilariae of Wuchereria bancrofti, Brugia malayi or Brugia timori. The highest prevalence rates were found in Nusatenggara-Maluku-Irian Jaya (15.5%) followed by Sulawesi (13.7%) Kalimantan (10.8%) Sumatera (8.9%) and Jawa and Bali (1.7%). Many areas endemic for filariasis are used for the settlement of transmigrants from non-filarial endemic areas. Control program must therefore be implemented to prevent filarial infections in these new susceptible population groups.

Human filariae in Indonesia.

The distribution of human filariae in Indonesia has not changed significantly since initial reports of the disease were made in 1928. Wuchereria bancrofti and Brugia malayi are widely distributed but the newly described Brugia timori appears to be restricted to the Lesser Sunda Islands. W. bancrofti and B. timori in Indonesia are nocturnally periodic and B. malayi has nocturnally periodic and B. malayi has nocturnally periodic and nocturnally subperiodic strains.

Malayan filariasis in Central Sulawesi (Celebes), Indonesia.

Seven villages in Central Sulawesi were surveyed in September 1971 and finger blood samples from 3,658 persons examined for microfilariae. Periodic, nocturnal Brugia malayi was endemic in all seven villages with microfilarial rates (Mf-rate) of 10-42% (av. 25%). The median microfilarial density (MfD50) averaged 5.4 and varied from 0.8 to 9.4 microfilariae per 20 microliter of blood. Males had higher Mf-rate and MfD50 value than females and in males Mf-rates and MfD50 values increased with age. In the female population, however, neither Mf-rates or MfD50 values varied significantly with age. Clinical manifestations of filariasis were found in 12% of 2,412 persons examined and only 2% had elephantiasis. Clinical signs of disease with the exception of elephantiasis, showed good correlations with Mf-rates but not with MfD50 values. Transmigrants experienced clinical manifestations of filariasis earlier and more often than the indigenous population.

Filariasis in West Kalimantan (Borneo), Indonesia.

A survey was carried out among persons residing in 8 villages in the Province of West Kalimantan, Indonesia to determine the prevalence of filariasis. Finger tip blood smears were obtained at night from over 3,000 people and microfilariae of Brugia malayi were found in 108 (3.5%) and Wuchereria bancrofti in 10 (0.3%). Most B. malayi (96 carriers) was found in Kakap, a village near the coast, 20 km from the provincial capital of Pontianak. Nine of 10 cases of W. bancrofti were located in Pahauman, a village 130 km northeast of the provincial capital. Periodicity studies indicate the strain of B. malayi to be subperiodic. In Kakap 18% of 226 persons examined had a clinical history of filariasis and elephantiasis was seen in 13%. This is the first report of rural bancroftian filariasis in the area. A few Mansonia species of mosquitoes were examined but none were infected with filarial larvae.

Brugia malayi in seven villages in South Kalimantan, Indonesia.

Seven villages in South Kalimantan were visited in 1971 and night peripheral blood smears from 2,764 people examined for microfilariae. Brugia malayi was found endemic in all villages with microfilarial rates of 12--46% (average 25%) and the median microfilarial density (MfD50) of 6 to 15 microfilariae per 20 microliter of blood. The microfilariae showed a typical subperiodic pattern. The disease was more common in males than females and the prevalence increased with age. Clinical manifestations of filariasis were found in 20% of 1,099 persons examined. Mansonia species are considered important vectors and cats important reservoir hosts. In addition to B. malayi, Dirofilaria repens and an unknown microfilaria were found in cats in the area and strains of the B. malayi and D. repens have been established in the laboratory.

Intestinal and blood parasites of man in Bireuen and Takengon, Aceh Province, Sumatra, Indonesia.

A survey for blood and intestinal parasites was carried out in Aceh Province of North Sumatra, Indonesia. A total of 348 stool specimens were obtained from 167 males and 181 females ranging in age from 6 months to 70 years. Over 98% of the population sampled were found infected with at least one intestinal parasite. Ascaris lumbricoides, Trichuris trichiura, hookworm and Entamoeba coli, in that order, were the most common parasites detected. Other intestinal parasites found less frequently were Entamoeba histolytica, Iodamoeba bütschlii, Entamoeba hartmanni, Endolimax nana and Giardia lamblia, Brugia malayi microfilaraemias were detected in 2% of those examined and only in the coastal villages of Cot Ketapang and Rusip Dayah. No malaria was found.

A study of the microfilarial periodicity at Bireuen, the type locality of Brugia malayi.

A field study was conducted in August 1974 at Bireuen, Indonesia, at the type locality of Brugia malayi from where the parasite was first described by Lichtenstein (1927) and Brug (1927), in order to determine the pattern of the microfilarial periodicity. From the results, it has been demonstrated that both the microfilariae of B. malayi as well as those of W. bancrofti in man from Bireuen area are the nocturnally periodic form. The microfilaria rates observed in the present survey were much lower than those recorded by Lichtenstein (1927) some 50 years ago in the same areas.

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.

Parasitology survey in the Palu Valley, central Sulawesi (Celebes), Indonesia.

A survey was undertaken in the Palu Valley, Central Sulasesi to determine whether schisto somiasis japonica was endemic in the area and to determine the prevalences rates of intestinal and blood parasites. Seven villages along the Palu River drainage system with an estimated popualtion of 18,700 were surveyed and 2,433 stools, 3,651 blood smears and 1,167 sera were collected and examined.

Parasitology survey and seroepidemiology of amoebiasis in South Kalimantan (Borneo), Indonesia.

A parasitology surevy was conducted among inhabitants of 7 villages in 3 regencies in South Kalimantan Province, Indonesia. A total of 2,169 stool specimens, 2,756 blood smears and 1,027 serum specimens were obtained, representing samples from approximately 10%, 12% and 5% of the population, respectively. One to 8 different intestinal parasitic infections were detected in 97% of the people. Those parasites most frequently found were Trichuris trichiura (83%), Ascaris lumbricoides (79%), and hookworm (65%), followed by Entamoeba coli (37%), Endolimaxnana (12%), Entamoeba histolytica (12%), Iodamoeba bütschlii (11%), Giardia lamblia (5%), Entamoeba hartmanni (2%), Chilomastix mesnili (2%). Other parasites found were Enterobius vermicularis, Strongyloides stercoralis, Capillaria sp., Echinostoma sp., Hymenolepis diminuta, and Trichomonas hominis. Giardia lamblia was found more often in younger people and Entamoeba coli, Iodamoeba bütschlii and hookworm in the older age group. Ascaris lumbricoides occurred more frequently in females, and hookworm in males. Plasmodium vivax and Plasmodium falciparum were found in the blood smears of 4.4% of the people, mostly in the younger age groups. Seroepidemiological studies on amoebiasis were done by use of the indirect hemagglutination test with antigens prepared from the HK9 strain of Entamoeba histolytica maintained in axenic cultures. The frequency distribution of the reciprocal antibody titers showed a bimodal distribution with 34% of the population demonstrating positive reactions at titers of 1:128 or greater.