Prevalence of intestinal helminthic infections in Kao District, north Halmahera, Indonesia.

A parasitological survey was conducted on the inhabitants of six villages of Kao District, Halmahera Island, North Maluku, Indonesia, in July 1993. A total of 422 fecal samples were examined by using Kato-Katz thick smear, modified Harada-Mori culture and formalin ether concentration techniques. Seven nematode species, ie Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Ancylostoma duodenale, Strongyloides stercoralis, Enterobius vermicularis and unidentified rhabditoids of free-living nature, were detected. Trematode and cestode infection was not proven. Necator americanus was the predominant species of hookworm. Soil-transmitted nematode infections were highly prevalent. Among the young inhabitants aged less than 15, positive rates of Ascaris, Trichuris and hookworm infections were 32.7, 52.7 and 68.6%, respectively. Among the people aged 15 or more, the positive rate for hookworm (85.9%) was much higher than that for Ascaris and Trichuris (13.5 and 40.5%, respectively). Egg count revealed that more than 90% of inhabitants with Trichuris or hookworm had light infections. The latrines in the surveyed area seemed to have only limited effects on the improvement of the parasitological status because the prevalence of Trichuris infections was much higher in a village where most houses were provided with latrines. These conflicting conditions were considered to have been caused by many factors including the inadequate structure of the latrines.

Intestinal parasitic infections in Campalagian district, south Sulawesi, Indonesia.

Intestinal parasitic infections were surveyed in the inhabitants of 3 coastal and 2 inland villages of Campalagian District, South Sulawesi, Indonesia, in July 1992. A total of 398 fecal samples were examined by using Kato-Katz thick smear, Harada-Mori culture and agar-plate culture techniques. Protozoan cysts were examined by formalin ether concentration technique on 380 fecal samples. Soil-transmitted helminth infections were highly prevalent with the overall positive rates as follows: Ascaris lumbricoides 25.3%, Trichuris trichiura 59.3%, hookworm 68.3% and Strongyloides stercoralis 2.3%. Eight species of protozoan were detected with the overall prevalence as follows: Entamoeba histolytica 10.9%, E. hartmanni 16.3%, E. coli 31.9%, Endolimax nana 12.5%, Iodamoeba buetschlii 5.4%, Giardia lamblia 4.6%, Chilomastix mesnili 0.8% and Blastocystis hominis 18.0%. In the inland villages, prevalence of hookworm infection was higher than Ascaris and Trichuris infections, while in the coastal villages Trichuris infection was predominant. Egg count revealed that the infection level was light in most of the hookworm and Trichuris carriers. Prevalence of lavatories among houses appeared to be inversely proportional to the prevalence of hookworm infection. Meanwhile, the incomplete structure of the lavatories might result in contamination of environment with Ascaris and Trichuris eggs. Harada-Mori culture was the most efficient method in the detection of hookworm infection compared to other techniques. Both Necator americanus and Ancylostoma duodenale were found in all villages, but the former was the predominant species. An adult pinworm was detected by agar-plate culture of feces. Two types of pinworm males, corresponding to Enterobius vermicularis and E. gregorii, were observed.

Enzyme-linked immunosorbent assay for diagnosis of human strongyloidiasis.

Crude antigen (CA) was prepared from Strongyloides stercoralis filariform larvae obtained from in vitro culture of the human feces containing rhabditiform larvae. The lyophilized filariform larvae were ground and ultrasonicated in distilled water then the soluble antigenic preparation was delipidized. The protein content of the crude soluble antigen was 20% of the original dried larvae. The CA was passed through a gel filtration chromatography column and yielded three different protein fractions namely F1, F2 and F3. CA and its fractions were used in the indirect enzyme-linked immunosorbent assay (ELISA) for detecting antibodies to S. stercoralis in serum samples of 5 groups of individuals. These were patients with parasitologically confirmed strongyloidiasis (group 1), patients with mixed S. stercoralis and other parasitic infections (group 2), non-strongyloidiasis patients with other worm infestation(s) (group 3), normal parasite-free Thais (group 4) and normal parasite-free Swedes (group 5). It was found that F2 was the best antigen in the ELISA. The sensitivity, specificity and positive and negative predictive values of the test using F2 as the antigen were 95.0%, 96.4%, 95.0% and 96.4%, respectively.