[Prevalence of intestinal parasites among Thais in Israel].

Stool samples from 93 Thais working in Israel were examined for the presence of parasites. The overall prevalence of infection by 1 or more species was 74%. Opisthorchis viverrini and hookworm were the most prevalent parasites (51.6% and 44.1%, respectively). They were also the parasites most frequently found in mixed infections; about a quarter of the workers were infected with both. Other helminths found in only a few cases were: Fasciolopsis buski (3 cases), Taenia sp. (3), Paragonimus sp. (1), Ascaris lumbricoides (1), Trichuris trichiura (1) and Trichostrongylus sp. (1).

Mass treatment of intestinal parasites among Ethiopian immigrants.

Intestinal parasites are common among the Ethiopian immigrants to Israel and mass treatment is necessary to prevent local transmission. For this purpose, stool samples obtained from the immigrants in absorption centers were examined. Of 5,412 samples obtained, 4,399 (81.3%) were positive: 2,644 (54.2%) for Necator americanus, 2,273 (46.6%) for Schistosoma mansoni, 990 (20.3%) for Ascaris lumbricoides, 1,040 (21.3%) for Hymenolepsis nana, 940 (19.2%) for Trichuris trichiura, 219 (4.5%) for Strongyloides stercoralis, 17 (0.4%) for Fasciola hepatica, 551 (11.3%) for Giardia lamblia, and 499 (9.2%) for Entamoeba histolytica. The cure rate for necatoriasis by treatment with 400 mg of albendazole was 84.4% (better than with other drugs), either alone or in combination (pyrantel with bephenium or pyrantel with praziquantel, or praziquantel with albendazole). Albendazole, 400 mg for 3 days, cured 92% of the cases of S. stercoralis infection. Praziquantel, 40 mg/kg body weight, in a single dose was effective in 89.7% of cases of S. mansoni, and 60% of cases of H. nana, although a 100% cure rate for H. nana was achieved with praziquantel at a dose of 20 mg/kg per day for 2 days. Two persons infected with F. hepatica were cured by 40 mg/kg praziquantel for 7 days. Tinidazole, 2 g in a single dose, cured 100% of persons infected with G. lamblia, while 60% of persons infected with E. histolytica were cured when treated with 2 g tinidazole for 3 days. Mass treatment of all the immigrants with 400 mg albendazole and 40 mg/kg praziquantel concomitantly resulted in a cure rate of 84.4% of all intestinal worms.

Persistent Schistosoma mansoni infection in Yemeni immigrants to Israel.

Following sporadic reports on persistent Schistosoma mansoni (S.m) infections in Israelis of Yemeni origin, we systematically surveyed a group of 129 individuals who immigrated to Israel 38 years ago. Physical examination was uneventful in all members of the study group. A single stool examination revealed S.m eggs in 15 of 129 subjects (12%). Specific anti-S.m. IgE was detected in the sera of 48 individuals (37%). Among the 15 egg-positives, 14 had specific IgE (sensitivity 93.3%), but only 80 of the 114 egg-negatives were also negative for specific IgE (specificity 70%). This specific IgE positivity among egg-negatives in the study group (34/114) and its complete absence from two control groups, one of them comprising Yemenites born in Israel, suggest either an S.m infection with low egg output stemming from a low worm burden or low fecundity of senescent worms, or occult infections. Since the S.m infections could not have been contracted in Israel, our findings point to inordinately persistent infections in the members of our study group, and incidentally also to the diagnostic usefulness of specific IgE testing in such cases.