The efficacy of reduced single doses of mebendazole against Ascaris lumbricoides infection was evaluated by cellophane thick smear and egg counting techinques, in two rural populations from December 1977 to March 1978. Total 191 infected cases were divided into five dose groups; 100 mg single dose, 200 mg single dose, 300 mg single dose, 400 mg and 600 mg in repeated doses. The cure rate of mebendazole in the treatment of Ascaris infection was remarkably high and satisfactory in every dose groups. The egg reduction rates were all over 98 percent in every dose groups. Side effects were observed during the treatment, mainly mild and transient gastrointestinal troubles, and not exacerbated by the increase of doses upto 300 mg in single dose. Above results confirmed that in case of mass chemotherapy of Ascaris infection, 100 mg or 200 mg of single dose treatment is sufficient to achieve the economic and acceptable method of treatment.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; chemotherapy-mebendazole

In order to determine the susceptible age of Enterobius vermicularis to anthelmintics and to observe the chronologic growth of female E. vermicularis in man, experimental infections were done. About 500 eggs were challenged to 19 volunteers. After 4, 8, 16, 20, 24, 28, 32 and 35 days of infection, each case was treated by either mebendazole or pyrantel pamoate. On the 40th day of infection all cases including control were treated again to terminate the expermental infection and to evaluate the effect of previous treatment. Each case collected 3-day stools to harvest the expelled worms. The results could be summarized as follows: The infection rates of females were in range of 0.6-13.1% in control cases. Because the collected worms showed comparable growth and development by day, the worns were concluded to be derived from experimental infection. Cases that were treated with mebendazole on 4, 8 and 16 days after infection expelled 37.5%, 2.5% and 67.5% of the number expelled by a control case on the 40th day. Cases treated thereafter expelled no worms on the 40 days. Cases that were treated with pyrantel pamoates on 4, 8, 16, 24, 28, 32 and 35 days, expelled 90.7%, 25%, 45.3%, 8%, 2.7%, 5% and 29.3% of the number collected from control cases in respect. All the worms collected were females. The total body length increased consistently and comparably from the 20th day of infection. Those collected on the 20th day were 2.5-3.0 mm long with vigina, sac-like structure and strands of ovaries; 24 day-old worms may have short uterus, 28 day-old worms had long uterus without eggs, 32 day-old worms began to produce eggs, 35 day-old worms showed wide variations in egg deposit in uterus, and 40 day-old worms had uterus filled with eggs from vulva to anal levels. From the above results, it was inferred that the life span of female Enterobius vermicularis was longer than 40 days, and the developmental stages of worms younger than 16 days resisted considerably to both mebendazole and pyrantel pamoate.
parasitology-helminth-nematoda ; Enterobius vermicularis ; chemotherapy-mebendazole-pyranel pamoate ; susceptibility ; mebendazole ; pyranel pamoate

To evaluate the efficacy of anthelmintic treatment of Enterobius vermicularis in highly endemic population, total 82 children in two orphanage institutes were divided into 4 groups and treated with placebo, 5 mg/kg of pyrvinium pamoate, 100 mg of mebendazole and 10 mg/kg of pyrantel pamoate respectively. Total 4 anal swabs were taken from each child before treatment and the even distributions of positive rate and consecutive results between groups were considered. Follow-up swabs were taken 8 times up to the 40th day after treatment. After remarkable and significant reduction of positive rates up to 19-27th day after treatment in respective groups, the remarkable egg positive conversions were observed 3-4 weeks after treatment. The positive conversion was the earliest and the most remarkable in pyrantel-treated children and the slowest and the least remarkable in mebendazole-treated cases. Also found was that the figures of negative conversion were different with statistical significance between two categories of cases, consecutively positive and alternately positive cases of pre-treatment swabs. This means that the conventional indices of cure rate in E. vermicularis infection may be variable by the selection of subjected cases. Above results mean that the spectrum of susceptible pinworms according to the developmental stages are different between currently available drugs, and the ability to remove pinworms completely in certain developmental stage are also different between chemotherapeutics. These results suggest the need of interval chemotherapy of Enterobius vermicularis infection in heavily infected cases of in highly endemic population to achieve the complete eradication of whole range of pinworms in intestine.
parasitology-helminth-nematoda ; Enterobius vermicularis ; chemotherapy- mebendazole ; pyrantel pamoate ; enterobiasis

Mebendazole was tested for its efficacy in individual treatment and mass control of Trichuris trichiura infection in Korea. The results were as follows: The efficacy of mebendazole in 430 cases 3 weeks after treatment with mebendazole(100-1,200 mg) was not so satisfactory (15.0-64.0 and 24.6-95.2% in cure and egg reduction rates respectively). But it was observed that the higher the total dose of the drug the better the efficacy. The egg positive rate of the inhabitants in mass control programme by 600 mg mebendazole decreased form 40.0 to 5.6 % during one year, May 1982-May 1983, by repeated blanket mass chemotherapy every 3 months (in conventional regimen), while the decrease was less marked or unrecognizable in 3-month (signle or two divided doses), 6-month, 12-month interval and placebo control groups. From the results, it was concluded that, although mebendazole was not highly effective in individual treatment of T. trichiura infection, it was fairly useful in mass cotrol, by repeated mass chemotherapy every 3 months.
parasitology-helmith-nematoda ; trichuriasis ; Trichuris trichiura ; chemotherapy-mebendazole ; mebendazol

To observe the effect of egg-free state in an institute on the endemicity of Enterobius vermicularis, the theoretical condition was made by repeated chemotherapy. Mebendazole or pyrantel pamoate were administered to all orphans and their staffs concomitantly for four times, each 20-day interval. In two low endemic orphanages, in which mean egg positive rates were 18 % and 39 % respectively, the pinworm infection was controlled up to 6-7 months period. And other two highly endemic orphanages, with 70% and 55% of egg positive rates, were controlled up to 90th day after the first treatment. After then up to 7 months, the reinfection occurred, but the endemicity was brought down to about 20 % of egg positivity.
parasitology-helminth-nematoda ; Enterobius vermicularis-chemotherapy ; enterobiasis ; mebendazole ; pyrantel pamoate

When enterobiasis cases were treated with anthelmintics only for one time, the interval to recurrence was variable by different drugs used. And this phenomenon is supposedly connected with biological or developmental cycle of the worm and the consequent efficacy of the different anthelmintics. This study was undertaken to confirm this fact by studying the expelled worms morphologically to correlate the anthelmintics efficacy and stage of worm development in Enterobius vermicularis. A total of 131 children in 3 orphanages was examined by 4 anal swabs (mean positive rate, 80%). They were randomized into 5 experimental groups. Each group was treated with placebo, mebendazole, pyrantel, pyrvinium , and piperazine (70 mg/kg, single dose) respectively. After treatment, all stool were collected for 3 days to get the expelled Enterobius. A total of 6,165 pinworms was studied under the microscope. The sex was discriminated and the length was individually measured. A number of male pinworms was collected in all groups. Females of 2-11 mm in length were also collected in 5 groups. However, significantly larger number of short females was observed in mebendazole group compared with other groups. Twenty-one days after the first treatment, all children were again treated with mebendazole. Once more stool were examined. A total of 1,853 worms was collected. In mebendazole group, there were no females longer than 8.74 mm in the second treatment. In pyrvinium group, 8.31mm in lenght was the longest for female. However in control, pyrantel and piperazine groups, females of 2-11 mm in length were collected. From above results, one could conclude that the removing ability of mebendazole and pyrvinium was satisfactory for the worms in the early stage of development in Enterobius. Pyrantel and single dose of piperazine showed less effective in worm reduction ability especially on those at the early stages.
parasitology-helminth-nematoda ; Enterobius vermicularis-enterobiasis ; chemotherapy ; mebendazole ; pyrantel ; pyrvinium ; piperazine ; morphology

: A clinical trial of Korean Patent mebendazole was undertaken upon some intestinal helminthic infections in 288 rural Koreans residing in Pochun and Jinyang Gun, from November to December, 1976. They were examined by the cellophane thick smear technique, Stoll's egg counting technique and/or Scotch-tape anal swab before and 3 weeks after the treatment. The administered dose of mebendazole was 600 mg, divided by 100 mg, twice daily for 3 consecutive days disregarding the body weight and the age of the cases. It was confirmed that mebendazole is very effective, broad-spectrum anthelmintic, especially against Ascaris, Ancylostoma, Trichostrongylus and Enterobius infections. Their negative conversion rate and egg reduction rate were respectively; 94.0 and 99.6 per cent in Ascaris, 71.4 and 97.3 per cent in Ancylostoma and 95.0 and 100 per cent in Trichostrongylus. The negative conversion rate in Enterobius was 92.3 per cent. The anthelmintic efficacy against T. trichiura infection was not satisfactory in spite of low worm burden (negative conversion rate, 27.3%, egg reduction rate, 65.5%).
parasitology-helminth-nematoda ; Ascaris lumbricoides ; Ancylostoma duodenale ; Trichostrongylus orientalis ; Trichuris trichiura ; chemotherapy-mebendazole ; Enterobius vermiculariss