Changing pattern of Clonorchis sinensis infection among school children in the Gumho basin, Kyungpook Province, Korea

A study was required to evaluate the prevalence of clonorchiasis among school children in the 7 differnet schools located near the Gumho basin and to determine the effectiveness of the anticlonorchis campaign conducted in that area. Surveys for Clonorchis sinensis and the worm burden in the same areas were compared for the period 1960-1970. Both surveys concentrated on children in grades 1-3 ranging from 6-11 years old. They were examined using primarily intradermal tests with Clonorchis antigen and followed by stool examinations. Stool examinations consisting of the formalin-ether sedimentation(Ritchie, 1948 ) and the Stoll egg-count techniques were performed in those cases which revealed positive and doubtful intradermal reactions. The overall prevalence rate for clonorchiasis was reduced from 13.4 per cent to 4.1 per cent. There was also a significant reduction in the worm burden, suggesting that no clonorchiasis will be found among chileren in the near future. In connection with this survey, the prevalence rate for intestinal helminths in 1960 was compared with 1970. The rate for Ascaris lumbricoides had decreased, while the rates for Trichuris trichiura and Trichostrongylus species had increased. No fluctuation in the rate of hookworm was observed during the past 10 years. Clearly, the present survey denotes a requirement for a combined procedure of health education and mass survey with intradermal testing. It has been found that these methods not only greatly reduce the prevalence of clonorchiasis but also is followed by the marked reductions of the worm burdens of the children examined.

Treatment of hookworm infection with furfurol

Furfurol(Furfudol), a new anthelmintics, was administered to 7 adults and 21 children (6-12 years old) in total amounts of 15.6 mg(base) for 1 to 3 days. It has proven to be effective against hookworms. The anthelmintic effect against hookworms with a single dose of 15.6 mg of furfurol was similar to that of a single dose of 2.5 gm of bephenium hydroxynaphthoate. However, when a total of 15.6 mg of the base was given to both children and adult, the side reactions were so mild that the drug can be administered for therapeutic regimens in mass treatment. Minor abdominal discomfort was the only common side effect. This is the primary advantage of furfurol as compared with bephenium hydroxynaphthoate. These results have indicated that furfurol is safe in therapeutic dosage and is an effective agent to treat patients infected with hookworms.

Intestinal parasite survey of Kyungpook National University Hospital patients

For seven years from 1962 to 1968, fecal specimens of the patients were examined not only for the discovery of intestinal protozoa and helminths, but also to provie data on the incidence of intestinal parasites among the residents of Kyungpook Province, Korea. The Formalin-ether sedimentation, Lugol solution, and Heidenhain's iron-hematoxylin stained films were prepared for the recovery of intestinal parasites. Of 2,414 samples of feces examined, 35.7 percent were found to be infected with one or more species of protozoa. Among six species of protozoa detected, Entamoeba coli was observed most frequently(15.3%) followed by Entamoeba histolytica (11.9%), and then the Enteromonas hominis least often(1 case). For the survey of helminth, of a total of 5,288 fecal specimens examined, 86.7 percent were positive for one or more species of helminths. Trichocephalus trichiurus revealed the highest infection rate (83.6%), while Trichostrongylus orientalis was next (61.6%), and Ascaris lumbricoides was unexpectedly low(40.9%). The incidence for hookworm and Clonorchis sinensis was 22.4 percent and 29.8 percent respectively. Triple infections were found more frequently than double infections, and mixed infections of six or more species of helminths were observed in 3.8 percent of specimens.

Laboratory findings in symptomless clonorchiasis

The duration of infection, frequency of eating raw fresh water fishes, and a series of liver function tests were studied in a group of 23 Korean symptomless cases with Clonorchis sinensis, and compared with those in a control group of uninfected persons. Of 23 lightly infected cases, 11 cases who had been infected for 10 to 20 years was found the highest in percentage(47.8), and 2 had been infected for over 30 years. The frequency of eating raw fresh water fishes ranged from 2 to 35 times. The range of Stoll egg-counts in 23 cases varied from 600 to 8,600 eggs per gram of feces and the average value was approximately 2,800 eggs. A series of liver function tests examined showed normal value in all cases. These results showed no difference in either infected group and its contol group.