• 대한수의학회지
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• 제34권1호
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• pp.127-134
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• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, a delicate relationship between host and parasite, in the present studies golden hamsters were alloted to experiment 1(normal undefinitive host group) and experiment 2(immunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 1,500 embryonated Ascaris suum eggs. The recovery rates, sizes and features of the larvae and immunological responses in the hamsters were chronologically monitored according to somatic migration. In both experiments, the larvae failed to develop into the adults, but the more and larger larvae were observed for a longer period from experiment 2 in comparison with experiment 1. The numbers of the mast cells in the small intestinal mucosa and mesenteric lymph nodes, of the goblet cells in the small intestinal mucosa and of T-cells in the mesenteric lymph nodes, spleens and cardiac blood from experiment 2 were fewer than those from the experiment 1. In general, increasing of these cells followed by expulsion of the worms in the both groups. Profound leukopenia due to lymphopenia was found through trial period in experiment 2. Considering the experimental results, development or expulsion mechanism of somatic migrant larvae may be related to lymphopenia and temporary increasing tendency of the mast cells, the goblet cells and T-cells. In addition, patent infection of A suum in the hamsters was not obviously observed in spite of immunosuppression by prednisolone acetate.

• Parasites, Hosts and Diseases
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• 제61권2호
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• pp.103-126
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• 2023

In the l950s, under the legacy of traditional agriculture, Ascaris lumbricoides, spread epidemically in the war-bitten society of Korea. Consensus on the parasite control was drafted in the Parasite Disease Prevention Act, which passed a parliamentary agreement in 1966, and established safe disposal of feces and mass chemotherapy as control strategies. Biannual stool examinations and treating infected schoolchildren were basic scheme of the control activity through which revenue could be secured for organized business. In the 27 years following 1969, a maximum of 16 million stool examinations had been done every year. Cellophane thick smear enabled the task. The infection declined remarkably in the 1970s when industrialization and green revolution proceeded. A population study of A. lumbricoides in the late 1970s helped us better understand its epidemiology. The data also settled down the understandable protest of teachers against the repeated stool examinations. In the 9 years following 1987, the target population was gradually reduced when the egg positive rate was below 0.1%. An article in the Korean Law, stipulating obligatory stool examinations, was made optional. Although the long-term Korean effort of Ascaris control was a success, the effect of mass chemotherapy was not as succinct in terms of lowering reinfection. In the period of control, Korean agricultural technology changed, and the economy grew and supplied sanitary facilities by which the vicious cycle was disconnected. Reduction of morbidity was a benefit of mass chemotherapy, which is the only control method feasible in economically difficult countries. The most important hurdle of parasite control in the 1960s was poverty of general population and limited financial resources in Korea but the society formed a consensus on the priority of intestinal helminthiasis control during the ordeal period. The national consensus in the 1960s was the critical milestone for Ascaris control in Korea. Under the social agreement, application of timely technical and research advancements in parasitology achieved the success of ascariasis elimination. The successful experience of ascariasis elimination in Korea can be a benchmark for countries where neglected tropical diseases are endemically recycled.

• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.471-476
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• 2016

To know the infection status of helminths in primary schoolchildren of southern parts of Vietnam, we performed an epidemiological study in Krong Pac district, Dak Lak Province, Vietnam. A total of 1,206 stool specimens were collected from ethnic Ede schoolchildren in 4 primary schools in 2015 and examined by the Kato-Katz technique. In addition, stool cultures were done by the Harada-Mori method to obtain hookworm larvae and then to clarify the species of hookworms infected. The results showed that the helminth infection rate was 25.0%, including 2.0% Ascaris lumbricoides, 0.33% Trichuris trichiura, and 22.8% hookworm infections. The average intensity of infection was 102.0 eggs per gram of feces (EPG) for Ascaris, 36.0 EPG for Trichuris, and 218.0 EPG for hookworms. ITS1 gene sequences of the hookworm larvae were identical with those of Necator americanus (100% homology) reported in GenBank. It has been confirmed in this study that the hookworm, N. americanus, is a dominant helminth species infected in primary schoolchildren of a southern part of Vietnam. Public health attention is needed for control of hookworm infections among schoolchildren in surveyed areas of Vietnam.

• Pediatric Infection and Vaccine
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• 제27권1호
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• pp.77-82
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• 2020

한국의 회충 감염률은 1970년대까지 높았으나 성공적인 기생충 관리로 매우 낮은 수준으로 감소하였다. 최근 회충 유행 지역으로부터의 인구 유입 및 해외여행 증가, 수입 농산물의 증가 등으로 인해 발생 가능성이 높아지는 가운데 성인에서 회충감염으로 장폐쇄나 췌담관 질환이 유발된 증례 보고들이 있었다. 저자들은 회충증을 의심할 만한 위험 요인이 없는 2세 남아의 기저귀에서 회충 성충이 발견된 증례를 경험하여 보고한다. 아침에 환아의 어머니가 기저귀를 갈다가 움직이는 충체를 발견하여 내원하였다. 특이 과거력 없이 평소 건강하던 환아로 이상 증상은 없었고 신체 진찰에서 특이 소견은 관찰되지 않았다. 충체는 길이 약 25 cm, 폭 5 mm의 선충으로 머리와 꼬리는 원추상을 보여 회충으로 추정하였고 대변 기생충란 검사에서 Ascaris lumbricoides의 불수정란이 확인되어 회충증으로 진단하였다. 구충제인 알벤다졸 400 mg을 1회 경구 투여 후 추적 관찰하였고 추가적인 회충 발견이나 증상 발생은 없었다. 전체적인 기생충 감염률이 감소하여 관심이 줄어드는 현실에서 회충 감염에 대한 인식을 높일 필요가 있겠다.

• Parasites, Hosts and Diseases
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• 제55권6호
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• pp.659-660
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• 2017

Biliary ascariasis is still the leading cause of surgical complication of ascariasis, though its incidence has been dramatically reduced. Herein, we report a case of biliary ascariasis for the purpose of enhancing awareness of parasitic infections as a possible cause. A 72-year-old male visited the emergency room of Dankook University Hospital on 12 July 2015, complaining of right-upper-quadrant pain. By endoscopic retrograde cholangiopancreatography (ERCP), a tubular filling defect in the right hepatic duct was detected. The defect was endoscopically removed and diagnosed as an adult female of Ascaris lumbricoides worm, of 30 cm length. Upon removal of the worm, the pain subsided, and the patient was discharged without any complication. When treating cases of biliary colic, physicians should not neglect biliary ascariasis as the possible cause.

• Parasites, Hosts and Diseases
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• 제50권1호
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• pp.83-87
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• 2012

To determine the effects of kimchi extracts at different temperatures on larval development, $Ascaris$ $suum$ eggs were mixed with soluble part of 7 different brands of commercially available kimchi and preserved at either $5^{\circ}C$ or $25^{\circ}C$ for up to 60 days. $A.$ $suum$ eggs incubated at $25^{\circ}C$ showed marked differences in larval development between kimchi extract and control group. While all eggs in the control group completed embryonation by day 21, only 30% of the eggs in the kimchi extract group became embryonated by day 36 and about 25% never became larvated even at day 60. At $5^{\circ}C$, however, none of the eggs showed larval development regardless of the incubation period or type of mixture group. To determine the survival rate of $A.$ $suum$ eggs that showed no embryonation after being preserved at $5^{\circ}C$, eggs preserved in kimchi extracts for 14, 28, and 60 at $5^{\circ}C$ were re-incubated at $25^{\circ}C$ for 3 weeks in distilled water. While all eggs in the control group became larvated, eggs in the kimchi extract group showed differences in their embryonation rates by the incubation period; 87.4 % and 41.7% of the eggs became embryonated after being refrigerated for 14 days and 28 days, respectively. When refrigerated for 60 days, however, no eggs mixed in kimchi extract showed larval development. Our results indicate that embryogenesis of $A.$ $suum$ eggs in kimchi extract was affected by duration of refrigeration, and that all eggs stopped larval development completely in kimchi kept at $5^{\circ}C$ for up to 60 days.

• Parasites, Hosts and Diseases
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• 제54권1호
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• pp.103-107
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• 2016

The objective of this study was to evaluate the effects of several different commercial disinfectants on the embryogenic development of Ascaris suum eggs. A 1-ml aliquot of each disinfectant was mixed with approximately 40,000 decorticated or intact A. suum eggs in sterile tubes. After each treatment time (at 0.5, 1, 5, 10, 30, and 60 min), disinfectants were washed away, and egg suspensions were incubated at $25^{\circ}C$ in distilled water for development of larvae inside. At 3 weeks of incubation after exposure, ethanol, methanol, and chlorohexidin treatments did not affect the larval development of A. suum eggs, regardless of their concentration and treatment time. Among disinfectants tested in this study, 3% cresol, 0.2% sodium hypochlorite and 0.02% sodium hypochlorite delayed but not inactivated the embryonation of decorticated eggs at 3 weeks of incubation, because at 6 weeks of incubation, undeveloped eggs completed embryonation regardless of exposure time, except for 10% povidone iodine. When the albumin layer of A. suum eggs remained intact, however, even the 10% povidone iodine solution took at least 5 min to reasonably inactivate most eggs, but never completely kill them with even 60 min of exposure. This study demonstrated that the treatment of A. suum eggs with many commercially available disinfectants does not affect the embryonation. Although some disinfectants may delay or stop the embryonation of A. suum eggs, they can hardly kill them completely.

• 대한수의학회지
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• 제34권3호
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• pp.559-567
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• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, and a delicate relationship between host and parasite, in the present studies, SPF ICR mice were alloted to experiment 1(normal undefinitive host group) and experiment 2(immunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 1,100 embryonated A suum eggs. In normal group, the infection essentially terminates 4 days after inoculation(DAI) with the attainment of middle third-stage in the liver, although few larvae migrate to the lungs where a few advance to late third stage. In immunosuppressive group, significant numbers developed to late third-stage in liver 8 DAI. In general, increasing of the mast cells and the goblet cells in the jejunum mucosa, of T-cells in the spleen and of activity of peritoneal macrophages followed by expulsion of the worms in the both groups. Considering a series of the results, suitabilities for the host of the worm appeared the highest from rabbit, hamster and mouse in that order. In addition, patent infection of A suum in the mice was also not obviously observed in spite of immunosuppression by prednisolone acetate.

• 한국환경보건학회지
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• 제9권2호
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• pp.11-17
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• 1983

The soil-transmitted helminthes, such as ascaris, whipworm, hookworm and trichostrongylus, have been considered as the most prevalent parasitic diseases in a matter of several decades ago in Korea. In facts, the attached eggs and/or larvae to the vegetables have been played a great role on the transmission to human because of raw eating the vegetables without the proper recipe. The aims of this study is to outline the attached helminthes egg in vegetables and to define whether the detection rates on them show a decreasing pattern or not in present. The subjected vegetables were collected from the three markets which are located at Goo-Pa Bal, Soo-Yoo Dong, Cheon-Ho Dong in suburban area, Seoul from April to May 1983. A total of 180 samples including such as 60 Korean cabbages, 60 young radishes and 60 Korean onions were examined. For the detection of helminthes eggs, the both methods of formalin-ether sedimentation and zinc-sulfate floatation were applied. The results were summarized as follows: 1) The detected eggs of ascaris, whipworm, hookworm, trichostrongylus and either filariform larvae or rhabditoidform larvae of hookworm, as well as unknown ones were found in vegetables subjected. 2) Out of 180 subjects, the overall detection rate showed 48 (26.7%). And in case of Korean onion, the rate revealed 22 heads (36.7%) among 60, 17 heads (28.3%) out of 60 Korean cabbages, 9 roots (15.0%) out of 60 young radishes respectively. 3) The ascaris eggs were detected 6 heads (10%) out of 60 Korean cabbages, while the filariform larvae of hookworm appeared in 7 heads (11.7%) among 60 Korean onions. 4) In the results of present study, the detection rates in vegetables were appeared to be the marked decreasing tendency as like 28.3%, 36.7%, 15% compared with 96%, 100%, 88% of previous investigators (Choi et al. 1967)each on Korean cabbage, Korean onion, young radish.

• Parasites, Hosts and Diseases
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• 제52권1호
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• pp.111-115
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• 2014

To evaluate the effects of pesticides to parasite eggs, Ascaris suum eggs were incubated with 5 different pesticides (1:1,500-1:2,000 dilutions of 2% emamectin benzoate, 5% spinetoram, 5% indoxacarb, 1% deltamethrin, and 5% flufenoxuron; all v/v) at $20^{\circ}C$ for 6 weeks, and microscopically evaluated the egg survival and development on a weekly basis. The survival rate of A. suum eggs incubated in normal saline (control eggs) was $90{\pm}3%$ at 6 weeks. However, the survival rates of eggs treated with pesticides were 75-85% at this time, thus significantly lower than the control value. Larval development in control eggs commenced at 3 weeks, and $73{\pm}3%$ of eggs had internal larvae at 6 weeks. Larvae were evident in pesticide-treated eggs at 3-4 weeks, and the proportions of eggs carrying larvae at 6 weeks ($36{\pm}3%-54{\pm}3%$) were significantly lower than that of the control group. Thus, pesticides tested at levels similar to those used in agricultural practices exhibited low-level ovicidal activity and delayed embryogenesis of A. suum eggs, although some differences were evident among the tested pesticides.