Cysticercosis in Indonesia: epidemiological aspects.

Cysticercosis caused by the larval stage, cysticercus or cysticerci, of the pork tapeworm Taenia solium was recognized at first in Bali and in Paniai District, Irian Jaya (Papua), Indonesia in the 1970s. In the 1990s a rapid increase in the number of the cases of epileptic seizures and burns in Jayawijaya district, eastern Papua, was observed. There were a total of 1,120 new cases of burns (7.0%) and 293 new cases of epileptic seizures (1.8%) from 15,939 local people during 1991-1995. Both histopathological examination and mitochondrial DNA analysis of resected cysts from patients and pigs revealed cysticerci of T. solium. Antibody responses highly specific to cysticercosis were revealed in approximately 67% and 65% of persons respectively with epileptic seizures and with subcutaneous nodules. Therefore, most cases of epileptic seizures and burns were considered to be associated with cysticercosis in Papua. Additional serologically data from Bali showed that 13.5% of epileptic seizures (10/74) and 12.6% of asymptomatic individuals (94/746) were supposed having been exposed to T. solium. Histopathological evaluation of 80,000 tissue samples in East Java revealed that nine were cysticercosis. All cases were non-moslems and from two ethnic groups, Chinese and Balinese. Epidemiological data on cysticercosis are not available from other provinces of Indonesia, although cases of cysticercosis are occasionally reported. Therefore, other intensive epidemiological studies are strongly recommended, especially covering the eastern part of Indonesia.

Prevalence of soil-transmitted helminth infections in the rural population of Bali, Indonesia.

The objectives of this cross-sectional study were to identify the prevalence of soil-transmitted helminth infection in the rural population of Bali and its relation to age, gender, and geoclimatic conditions. The subjects of study were derived from four villages of different geoclimatic conditions, namely wet lowland, dry lowland, wet highland and dry highland, by a multistage, stratified random sampling technique, based on age and gender of the target populations. The technique of Kato-Katz thick smear was used to determine presence of worm eggs in stools, and modified Harada Mori fecal culture technique was used to identify the species of hookworm larvae in stools. The data were analysed descriptively as well as statistically using chi2 test. Of 2,394 completely examined and analysed samples, the results showed as follows: The prevalences of Ascaris lumbricoides, Trichuris trichiura, hookworms and Strongyloides stercoralis were 73.7%, 62.6%, 24.5%, 1.6%, respectively. Of 2,082 infected samples, 33.1% were single infections and 66.9% were mixed infections. Among the mixed infections, dualfection was most frequent (47.8%), followed by single infection (33.1%), triplefection (18.3%), and quadrifection (0.8%). A combination of A. lumbricoides and T. trichiura was predominant in dualfection, while in triplefection a combination of A. lumbricoides, T. trichiura, and hookworms was most frequently identified. The prevalence in males was not statistically different, except for hookworms where it was higher in males than in females. The differences of prevalence of infection according to age groups for A. lumbricoides, T. trichiura and hookworms proved to be highly significant, but not with Strongyloides stercoralis. The prevalence of hookworm infection increased steadily with age to reach its maximum (37.7%) in adulthood (> 18 years), while A. lumbricoides and T. trichiura reached the highest prevalence level in elementary school age (77.3% and 70.7% respectively). The highest prevalence of S. stercoralis infection was found also in elementary school age, but it was not statistically significant. In wet highland the prevalence of infection of A. lumbricoides was 87.6%, T. trichiura 82.4%, hookworms 44.5%, and S. stercoralis 3.3%; these were significantly higher compared to the prevalence of infection in other areas (wet lowland, dry highland, dry lowland).

Detection by immunoblot assay of antibodies to Taenia solium cysticerci in sera from residents of rural communities and from epileptic patients in Bali, Indonesia.

Several studies from Bali have indicated the presence of Taenia solium. Relatively little has been reported, however, implicating human exposure to this parasite on Bali based upon the prevalence of anti-T. solium antibodies in asymptomatic and epileptic individuals. This study was conducted to determine by immunoblot assay and ELISA the frequency of anti-cysticercus antibodies in two groups of Balinese. Among 746 residents of four ecologic zones, 94 (13%) were positive by immunoblot. Of 74 epileptic patients from throughout the island, 10 (14%) were positive by immunoblot and 8 (11%) by ELISA; however, only 4 (22%) of the 18 sera positive in either test were positive in both assays. The previously defined high specificity and sensitivity of immunoblot indicates that T. solium cysticercosis is well established in Bali and that a significant amount of epilepsy may be due to neurocysticercosis.

Hookworm infection and iron stores: a survey in a rural community in Bali, Indonesia.

A study of the rural population of the village of Belumbang, Province of Bali, Indonesia, has been conducted to assess the relationship between intensity of hookworm infection (hookworm egg count) and iron stores, hemoglobin level or hematocrit. There was a significant negative correlation between serum ferritin level and hookworm egg count. However no correlation was found between hookworm egg count and hemoglobin level or hematocrit. In a separate analysis the above correlation could be shown in male hosts but not in female hosts. It is concluded that hookworm infection, even in light infection, can interfere with iron stores, but in female hosts this effect might be masked by other factors.

Serosurvey of some major zoonotic infections in children and teenagers in Bali, Indonesia.

One hundred and ninety serum samples, mainly from children and teenagers, from northeast Bali were tested for the presence of antibodies against five zoonotic agents: Brucella abortus, Coxiella burnetii, Toxoplasma gondii, Toxocara canis and Trichinella spiralis. All children were negative for brucellosis and Q fever. A high prevalence rate was found for toxocariasis (63.2%) and trichinosis (19.5%). Antibody prevalence against T. gondii was found to be rather low (3.1%). To our knowledge, this is the first evidence of toxoplasmosis, toxocariasis and trichinosis infection in humans on Bali. Eating habits and poor hygiene may explain the frequency of parasitic infestations in the children and teenagers in Bali.

Some epidemiological aspects of hookworm infection among the rural population of Bali, Indonesia.

Stool examination using direct smear method, Kato-Katz thick smear technique and modified Harada Mori test tube cultivation method were done on 2,331 people among the rural population of Bali. The serum ferritin was examined by ELISA technique and hemoglobin concentration by cyanmethemoglobin technique. Overall prevalence of hookworm infection was 24.02% with heterogeneity in local prevalences. The highest prevalence was found in wet highland area (46.3%), followed by wet lowland (27.7%), dry highland (14.2%) and dry lowland (10.9%). The majority of hookworm infection cases were associated with Ascaris and Trichuris infections. Most of the hookworm infections (73.3%) were light/very light in intensity with a mean EPG of 619. The prevalence and intensity of infection were increasing with age, and the age-prevalence and age-intensity curves were slightly convex. There was no significant difference of prevalence or intensity of infection between males and females. The condition and humidity of soil found to be an important determinant for prevalence of hook-worm infection. The frequency distribution of the intensity of hookworm infection showed an over-dispersed distribution pattern with 10% of people harboring more than 63% of parasite burden as measured by EPG. The prevalence of anemia was higher, but not statistically significant, in hookworm infected persons compared with people without infection. But this study failed to show a significant correlation between intensity of infection with hemoglobin level. There was a significant correlation between serum ferritin level with intensity of infection.