When an antipinworm drug was evaluated in human being, the results are still variable according to authors. Among the various factors involved in these variable results, the selection of subjects must be one of them. In the past, in evaluating a drug, the subjects were simply anal swab positive cases in a population. By that kind of selection method, especially in low endemic population, anal swab positives spontaneously turned to egg negatives at random. Moreover, the time, frequency of negative conversion cannot be predicted. By the results, the cure rates obtained from such ill-defined subjects are variable according to the subjected population. Another problem is that evaluation should represent the efficacy in heavily infected cases. To reinforce and overcome such shortcomings, the evaluator shoud select the cases wha are infected with whole developmental stages of worm. And the evaluator should have a method selecting such ideal cases only with anal swabs. To find out such method the results of anal swabs of long-term follow-up without any antipinworm treatment were reevaluated. In 41 children from 6 orphanages of different endemicity, swabs were taken for 8 or 21 times during 36 or 91 days. The positive rate of follow-up swabs was compared with that of already obtained in 4 preliminary swabs. And we collected other data on the combination of 4 anal swab results in different endemicity. The results are as follows: The positive rate of follow-up swabs was significantly different by the consecutiveness of egg positivity in preliminary swabs as well as the endemicity of subjected population. The consecutively positive cases in higher endemicity over 60% showed the highest, and the least variable positive rate in follow-up swabs. The observed frequency of consecutively positive/consecutively negative combination was always higher than the expected one obtained by binomial distribution equation. This indicates that individual hygiene and previous infection are important factors in determining the actual occurrence of subsequent reinfection. Summarizing these results, the subjects for drug evaluation should be those of consecutively positive cases in population over 60% endemicity. These subjects have the lowest chance of spontaneous negative conversion at random period of follow-up swabs. Eligible cases for such criteria would be sufficiently secured in highly endemic population.
parasitology-helminth-nematoda ; Enterobius vermicularis-chemotherapy ; enterobiasis ; epidemiology ; diagnosis

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

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

The significance of Scotch-tape anal swab technique was evaluated in three communities of Korea, one in orphanage institute and two in rural populations, from November to December, 1975. Based on the epidemiological concept that the prevalence rate of Enterobius vermicularis infection in a community as "the proportion in the population who harboured E. vermicularis at certain point of time", the present authors treated the whole surveyed population with pyrantel pamoate disregard to the results of Scotch-tape anal swab and collected pinworms expelled in stool specimens during 2 consecutive days after the chemotherapy. Although the present authors could not collect the younger adult worms less than 3.54 mm in length after chemotherapy, the positive rates of pinworm collection in three surveyed communities were 80.6%, 92.5% and 91.4% respectively whereas the positive rates of single Scotch-tape anal swab were 52.4%, 53.6% and 57.1% respectively. These results denote that results of single anal swab do not represent the prevalence rate of Enterobius infection in a community. The results of successive two anal swabs and estimation of positivity in a population using Neyman's "Best asymptotically normal estimate" revealed 62.9% in the third trial group of this study and probability of finding eggs in single slide was 0.869. Comparing with the pinworm collection rate after the chemotherapy in this group the estimated positive rate was by far lower than that of pinworm collection(89.3%). The positive results of single anal swab did not correspond to the pinworm collection in average 9.1% of anal swab positive cases and the negative results did not correspond to pinworm collection in 81.3% of anal swab negative cases, when the data from three surveyed communities were amalgamated. These results must come from the principle of anal swab that detect the terminated parasitism. With rare exceptions, the anal swab negative cases harbour relatively fewer number of Enterobius than those of positive cases. And the mean number of E. vermicularis collected from anal swab negative cases was 9.1 whereas the number in anal swab positive cases was 31.5. By analyzing the data on the relationship between bathing interval and anal swab positive conversion, it was assumed that the positive rate of anal swab in a community represent the rate of appearance of gravid female Enterobius vermicularis through anus during approximately past two days prior to examination.
parasitology-helminth-nematoda ; Enterobius vermicularis ; chemotherapy ; pyrantel pamoate ; diagnosis

To relate the results of repeatedly undertaken anal swabs to worm burden of Enterobius vermicularis in a highly endemic community, 193 rural schoolchildren, divided into 4 groups, were examined daily by Scotch-tape anal swab method, 1, 2, 3 and 4 times respectively. All of the schoolchildren were treated with pyrantel pamoate 10 mg/kg body weight exactly after the last anal swab in each group disregard the results. And all of the expelled E. vermicularis were collected and counted. It was found that 68.8% of total anal swabs were positive and the collection rate of E. vermicularis was 90.7% with average worm burden, 17.0, in surveyed children. From the analyses of the obtained data, following three inferences were derived. The consecutive postive findings of anal swabs could not reduce the possibilities of detecting light worm burden cases when the anal swabs were undertaken daily up to 4 times. The possibilities of detecting the heavy infection cases were found in consecutively positive categories of anal swab and the presence of negative result(s) of anal swab during the consecutive examinations did denote the reduced possibilities of detection heavy infection. The consecutive negative findings in anal swab have tendenicies reducing the possibilities of detecting heavy worm burden cases. Above results were highly suggestive that the processes of infection loss in E. vermicularis were taken place continuously, allowing daily small allotments of discharge of fully gravid worms in heavy infection cases and massive discharge in a very short period of time is practically rare event.
parasitology-helminth-nematoda-Enterobius vermicularis ; pyrantel pamoate-chemotherapy ; enterobiasis ; worm burdern ; pyrantel pamoate

Present trial was carried out to evaluate the anthelmintic efficacy of oxantel/pyrantel tablets against intestinal nematode infections, and to determine the efficacy of oxantel tablels against Trichuris infection. A total of 34 subjects with the mixed infections were treated with oxantel/pyrantel tablets (100 mg/tablet each) in a single dose of 15 mg/kg body weight, and another group of 22 Trichuris infected cases received oxantel pamoate tablets (125 mg/tablet) in a single dose of 15 mg/kg. All stool examinations were done before the treatment and 3 weeks after the treatment. The cellophane thick smear (Kato's technique) and Stoll's dilution egg counting method were employed. The results of the trial were summarized as follows: The cure rates (egg negative conversion rates) and egg reduction rates for oxantel/pyrantel tablets were 85.3 percent and 97 percent in trichuriasis, 100 percent each in ascariasis and ancylostomiasis. The oxantel tablet treated group demonstrated a cure rate of 90.9 percent and an egg reduction rate of 96.3 percent in the treatment of Trichuris. There were no detectable objective and subjective side effects in this trial. Both oxantel/pyrantel and oxantel pamoate tablets were readily accepted and well tolerated.
parasitology-helminth-nematoda ; Enterobius vermicularis ; Ancylostoma duodenale ; Trichuris trichiura ; chemotherapy-oxantel/pyrante ; oxantel pamoate

A total of 56 subjects with multiple nematode infections with T. trichiura, Ascaris, hookworms and Enterobius were treated with oxantel and pyrantel pamoate mixture in a paratable suspension(50 mg of each per ml). A single dose of 10 mg per kg body weight in each cured 100 per cent of 54 subjects with Ascaris, 97.1 per cent of 35 subjects with hookworms, 77.8 per cent of 36 with Enterobius and 73.2 per cent of 56 subjects with T. trichiura infestation. The mean egg per gram stool reduction rate in T. trichiura infection was 91.9%. Of the 31 subjects infected with Ancylostoma doudenale 96.8% were cured with a single dose and 4 infected with Necator americanus showed a 100% cure rate with a similar daily dose on 3 consecutive days. Side effects were few and mild. There was no clinical or laboratory evidence of drug toxicity. These findings show a single dose of oxantel and pyrantel pamoate mixture to be a highly effective and acceptable treatment for multiple infections with these nematodes.
parasitology-helminth-nematoda ; Trichuris trichiura ; Ascaris lumbricoides ; hookworm ; Enterobius vermicularis ; chemotherapy-oxantel pamoate-pyrantel pamoate

Effectiveness of flubendazole, a newly introduced as an anthelmintic in Korea, was evaluated in 28 ascariasis, 28 whipworm infections and 17 pinworm infections in primary school children. All patients were orally given by flubendazole of 500 mg once. Stools for roundworm and whipworm and anal swabs for pinworm infections were examined both before and 25 days after treatment. After flubendazole treatment, all ascariasis and pinworm infected cases were cured. On the other hand, in whipworm infections, the cure rate was 82.1 percent (23 cured of 28 infected), and the egg reduction rate was 67.1 percent, respectively. Headache (one case), dizziness (2 cases) and abdominal pain (3 cases) were noticed as untoward effects, but they were mild and disappeared within 24 hours. These results demonstrate the excellent effectiveness of flubendazole in treating these helminth infections.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; Trichocephalus trichiurus ; Enterobius vermicularis ; chemotherapy ; flubendazole

This study was undertaken to observe the fluctuation pattern of E.P.G. (eggs per gram of feces) according to the number of infected worms and developmental status of Ascaris lumbricoides. The cases were selected from 2,109 inhabitants of Hwasung Gun, Kyunggi Do, Korea, who had received pyrantel treatment in dose of 10 mg/kg during April 1977-May 1980 and who were cooperative enough to collect whole-day stool specimens for 2 days. Among them, 602 cases who had been infected with 1-5 worms were subjected to analysis. Egg examination was undertaken by means of cellophane thick smear technique and the amount of produced eggs was checked by Stoll's egg counting technique. The Ascaris worms were collected from stool specimens, counted in number in each case, and each worm was measured by length. The results could be summarized as follows: According to the increase of worm burden per case from l to 5, the egg detection rate increased from 33.4 percent to 95.7 percent. And the same pattern was observed when the only burden was considered. There were ample variations in the individual E.P.G. counts even among the cases with same burden, although the mean E.P.G. counts among the cases were quite proportionately increased from 842 to 3,467 according to the number of female worms, 1-4. However, from the distribution pattern of the number of each grade of E.P.G. count, it was revealed that the lower the number of females the more cases were with low grade of E.P.G. It was observed that the eggs could be detected after the female worm grew longer than 12.6 cm and the amount of eggs increased until the worm became about 25.0 cm, where a plateau was made in E.P.G. 1,300-1,400, and decreased significantly after 27.5 cm. And yet, wide variations in E.P.G. counts were noted even among the worms of similar growth. Accordingly, the E.P.G. value had better be used as a useful index to estimate the intensity of Ascaris infection and to compare the intensity between two communities, rather than be used to estimate the individual worm burden.
parasitology-helminth-nematoda ; Enterobius vermicularis-enterobiasis ; chemotherapy ; pyrantel pamoate ; biology ; morphology

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