Analysis of variance has been applied as a new tool for precise substantiation of taxometric differences between Eustrongylides spinispiculum n. sp. and close species, as indicated by the polythetic divisive classificatory system. A revised key to the species of genus Eustrongylides Jagerskiod (1909) has been presented.
parasitology-helminth-nematoda ; Eustrongylides spinispiculum

Five cases infected with Rhabditis sp. were detected in a survey to examine the stool specimen from rural primary school children. A large number of the larvae of Rhabditis sp. detected by the direct cellophane thick smear were cultured by the filter paper method. The examination was carried out in April through June 1980 in Tangjeong-Myon, Ahsan-Gun, and in September 1983 in Sandong-Eup, Yeongwol-Gun. The results obtained in this study were as follows: Prevalence: Out of 925 children, 5(0.54 percent) children were found to be positive. The number of the detected larvae was 110/0.1 gm of feces in case 1, 35 in case 2, 130 in case 3, 86 in case 4 and 62 in case 5. Larvae: The larvae were prepared by means of the direct fecal smear and measured by a micrometer equipped in the microscope. Twelve(12) through 15-day old larvae in culture were 197.1 micrometer long in average, and the maximum size of the matured stage larvae was 884.0 x 25.9 micrometer. However, the length variation was ranged as 173.0 to 884.0 micrometer. Adults: The size of clubbed adult female was 1,357 micrometer(1,176-1,419) in length and 80 micrometer(79-82) in width. Length of buccal cavity was 33 micrometer. A long cylindrical esophagus (273 micrometer) of the worms with a valved posterior cardiac bulb and with median bulbar swelling was morphologically indicated. Distance from mouth to vulva was occupied 58 percent of body length. Male worm was 1,006 micrometer (890-1,148) in length and 49 micrometer(48-49) wide. Caudal alae of bursa and spicules (75 micrometer in length) were well developed. Eggs: The oval shaped eggs in the female uterus, when cultured, were 66 x 56 micrometer in size, and the eggs laid by the adult could not be detected. So, reproduction might be through to be ovoviviparity. The five cases were re-examined during the period from the 1st to the 3rd week after stool examinations, but Rhabditis sp. were detected again in 4 cases in 1st week. When they were examined in 3rd week, larvae could not be detected . So, it was thought that the infection of Rhabditis sp. to humans was facultative.
parasitology-helminth-nematoda ; Rhabditis sp. ; case report

Epidemiological studies on the reinfection pattern of Ascaris lumbricoides were undertaken by means of blanket mass chemotherapy and worm collection in a rural village in Korea, during 1977~1980. The study objectives were to determine the age(sex)-specific reinfection rate during 2, 4, 6 and 12 months through repeated mass chemotherapy with pyrantel pamoate, and to observe the familial aggregation tendency of the reinfected cases. The results obtained are as follows: The age(sex)-reinfection curve revealed that the reinfection rate is much higher in younger individuals than in olders in all of 4 kinds of interval chemotherapy groups. The highest reinfection rate and the highest burden of reinfected worms were observed in preschool childen, followed by primary school students. Such fluctuation in the age-specific reinfection rates was more pronounced in males than in females. There was noted a significant tendency of familial aggregation among the reinfected cases. It is suggested that reinfection occurs never randomly but preferably to the members of certain household families. From these reinfection analyses, it is inferred that the principal mode of A. lumbricoides transmission in the surveyed rural area is likely to be of 'dooryard type', in which case childen and certain family members are more preferably reinfected. It is also suggested that the preschool childen should be included in the primary targets of mass control programme.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; epidemiology ; reinfection

The epidemiological relationship between the current prevalence and monthly reinfection rate of Ascaris lumbricoides was observed in rural communities in Korea by measns of blanket mass chemotherapy and worm collection for measurement of the prevalence and reinfection rates. During the period from 1975 to 1980, a total of 4,466 inhabitants in 10 different localities were treated with 10 mg/kg of pyrantel pamoate and 2 days' whole stools were collected from 2,547 inhabitants. The stools were examined for the presence of expelled adult and/or young worms, which represent the prevalence and reinfection rates for past 2 months respectively. After then, the obtained rates were correlated each other applying the time-prevalence curve proposed by Hayashi. It was observed that the prevalence (overall worm positive rate) and worm burden per individual ranged by areas from 13.6 to 72.3% and 1.4-10.2 respectively. The calculated monthly reinfection rates (X) (from young worm positive rates) according to areas were in the range, 2.6~16.2%, and clearly correlated with the current prevalence (Y) under the equation, Y=1-(1-X)(7.2) where 7.2 is time in month. The equation means that after one time mass chemotherapy the period needed to attain equilibrium of prevalence again would be about 7~8 months. And it is inferred that the majority of reinfected worms in human host turn over every 7~8 months.
parasitology-helminth-nematoda ; Ascaris lumbricoides ; epidemiology ; reinfection

An epidemiological study on brugian filariasis was carried out in endemic areas including Cheju Island in Korea, with a brief review of literatures.The results showed that the incidence among residents has remarkably decreased in Cheju Island, which was the main endemic area. Reviewing available informations on the prevalence of filariasis reported in recent years and also judging from the present socio-economic conditions which enable people to practice personal protection against mosquitos, it can be said with confidence that filariasis has almost disappeared from Cheju Island and inland areas. The disease is considered to remain at a low level of endemicity in Hugsan Islands. Certainly mass diethylcarbamazine (DEC) treatment carried out in Cheju Island in the 1960s and 1970s and remarkable economic growth followed by improved living standard and altered life-style of inhabitants could all have combined effects on the disappearance of this mosquito-borne diseae in this island. If the present trends go on, the possibility of resurgence of filariasis in Cheju Island is hardly postulated.
parasitology-helminth-nematoda ; Brugia malayi ; filariasis ; epidemiology

The periodicity of the microfilariae of Brugia malayi was studied in 9 human carriers from Shin-san Ri, Seong-san Myon, Cheju Island. The periodicity pattern was markedly nocturnal and the peaks were observed between 21:30 p.m. and 5:30 a.m. The average peak count was 1:30 a.m. and the percentage of peak count at this time was 95.3. The ratio of minimum of the average peak count percentage to the maximum was 8.3. The periodicity pattern of B.malayi in Cheju Island was compared with that in Inland and no differences were found between two forms. From the above observations, it was concluded that the periodicity of B. malayi in Korea is markedly nocturnal and closely resembles that in the strain of Penang, Malaya.
parasitology-helminth-nematoda-Brugia malayi ; periodicity ; microfilaria

A total of 860 cellotape anal swab specimens from 326 school children of urban area, 243 of rura1 farm village and 291 of rural fishing village was submitted for Enterobius vermicularis egg detection from September through November 1985. Each specimen was collected in the morning. Among the total 860 children's submitting specimens, 316 (36.7 per cent) were positive for E. vermicularis eggs. Of the 326 children in the urban area, E. vermicularis eggs were detected in the 45 (13.8 per cent). This detection rate was lower significantly as compared with 143 (55.6 per cent) of 243 children in the farm village or 136 (46.7 per cent) of 291 children in the fishing village. The egg detection rate in the male children was lower remarkably than that in the female children.
parasitology-helminth-nematoda ; Enterobius vermicularis ; epidemiology

In order to determine the prevalence of Necator americanus, 182 fecal samples were collected from school children in the Taegu vicinity. These sample were subsequently cultured by the Harada-Mori technique. Necator americanus was differentiated from Ancylostoma duodenale using the bases of morphological characteristics of filariform larvae. Necator americanus was not found in the vicinity of Taegu.
parasitology-helminth-nematoda- Necator americanus ; epidemiology

Authors were observing a case of infection with Thelazia callipaeda in Korean girl, on 11th Sep. in 1971. The case was 23 years old Korean girl who visited with the complaints of foreign body sensation and lacrimation in right eye. The worm had slender creamy white which was fixed in 10 percent formaline solution. The worm is 10.5mm in length, 0.5mm in body diameter. The oral end in provided with a chitinoid capsule. Esophagus moderately short, tail blunt, poserior extremity had a distinctly recurved. Spicules dissimilar, left spicule is 0.1mm in length, and right spicule is 0.08 mm in length.
parasitology-helminth-nematoda-Thelazia callipaeda ; case report

To investigate the infection status of Enterobius vermicularis the author tried surveys by scotch-tape anal swap on school-children and household environmental factors considered to have influences on the infection were analyzed by an inquiry method with questionnaire. The survey was carried out in October 1986 and 1988 in urban and suburban areas and the results could summarized as follow: The egg positive rate in anal swab was 16.0 per cent (male 14.5 per cent, female 17.6 per cent) out of 2,156 school-children and higher in female group. The egg positive rate in suburban school-children (17.5 per cent out of 1,305 children of two primary school)was a little higher than that of urban school-children(13.6 per cent out of 851 children of one primary schools). The questionnaire analysis on environmental factors showed some significant relations between the egg positive rate and such factors as the number of brothers and sisters, householder's occupation, and avalibility of childroom or bathroom. The result indicate that, although enterobiasis in school-children has shown decreasing tendency in Korea, it is still considerably high in some urban and suburban areas.
parasitology-helminth-nematoda ; Enterobius vermicularis ; enterobiasis ; epidemiology