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).

Community prevalence study of taeniasis and cysticerosis in Bail, Indonesia.

Taenia solium, a human cestode parasite endemic throughout most of South-east Asia, causes a number of public health and economic problems. The parasite is endemic in Bali due to a mix of cultural and religious practices. Immunoepidemiological investigation of three rural communities revealed a taeniasis prevalence of 0.72% (3/415). One of the three cases was due to Taenia solium, the other two to Taenia saginata. A further nine cases of Taenia infection were identified from patients from villages surrounding the chosen communities, suggesting that prevalence levels may be higher in other areas. Seroprevalence of human cysticercosis by immunoblot was 1.65% (6/363), though all cases were detected within a single community (6/115; prevalence 5.22%). Several other cases of subcutaneous cysticercosis were identified from local clinics, suggesting continued transmission of Taenia solium in the region. Other intestinal helminth parasites identified within the communities were Ascaris lumbricoides (29.9%), Trichuris trichiuria (33.9%) and hookworm (8.2%).

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.

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.