• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.315-318
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• 2009

Quantitative fecal egg counts represented as the number of eggs per gram of feces (EPG) are generally a reliable parameter to estimate the worm burden of intestinal and hepatic parasitoses. Although Haplorchis taichui (Digenea: Heterophyidae) is one of the most common minute human intestinal flukes, little is known about the relationship between EPG and the actual worm burden in patients or the severity of the disease. In the present study, fecal samples were collected from 25 villagers in northern Thailand before and after praziquantel treatment. The EPG values of each participant were determined by the modified cellophane thick smear method, and adult worms were collected from the whole stool after the treatment. Eggs per day per worm (EPDPW) of H. taichui were estimated 82 from egg counts and expelled worms. The EPG was not well correlated with the worm burden, and a reverse correlation was observed between the EPDPW and the worm burden.

• Parasites, Hosts and Diseases
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• 제23권2호
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• pp.241-246
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• 1985

우리나라 8개 농촌지역의 회충 감염율, 감염 량 및 기초산란율(basic reproductive rate)등 역학적 변수의 상관관계를 관찰함으로써 우리나라 회충감염 실태를 분석하였다. 이들 감염율, 감염량 등은 대변검사는 물론 pyrantel pamoate투여후 충체 회수결과에 의해 측정하였으며 그 결과는 다음과 같다. 1. 각 조사지역의 충체양성률(감염율)은 16.5~79.5%의 범위에 있었고 이것은 대변검사에 의한 충란양성률 3.3~66.7%보다 9~18%가 높은 수치이었다. 조사대상 주민의 평균 회충 감염량은 지역에 따라 0.21에서 8.44로 나타났고 개인별 감염량 분포는 'k'치가 0.38~0.54인 부이항분포(negative binomial distribution)를 보였다. 2. 이 조사에서 나타난 충체양성률은 Anderson과 May의 수식 $p=1-(1+M^{*}/k)^{-k}$ (p : 충체양성률, $M^*$ : 평형상태의 평균 감염량)에 의해 구한 이론치와 거의 일치하여 우리나라 농촌지역의 회충감염률과 감염량의 상관관계는 이 수식에 의해 매우 정확히 표현됨을 알 수 있었다. 또 회충 암컷 1마리가 평생 산출하는 무수한 충란중 다음 숙주에 성공적으로 감염되고 성숙되는 암컷의 수를 표시하는 기초산란을(R)은 지역에 따라 1.03에서 2.11까지인 것으로 나타났다. 이상의 결과로 보아 'R'치가 1에 가까운 지역은 역학적으로 재감염의 breakpoin떼 도달하고 있는 것으로 판정되므로 회충 박멸이 매우 희망적이지만 전국적으로 'R'치가 1이하로 될 때까지 우리나라 회충관리사업은 계속되어야 할 것으로 생각된다.

• ETRI Journal
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• 제28권5호
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• pp.692-695
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• 2006

Recently, there has been a constant barrage of worms over the Internet. Besides threatening network security, these worms create an enormous economic burden in terms of loss of productivity not only for the victim hosts, but also for other hosts, as these worms create unnecessary network traffic. Further, measures taken to filter these worms at the router level incur additional network delays because of the extra burden placed on the routers. To develop appropriate tools for thwarting the quick spread of worms, researchers are trying to understand the behavior of worm propagation with the aid of epidemiological models. In this study, we present an optimization model that takes into account infection and treatment costs. Using this model we can determine the level of treatment to be applied for a given rate of infection spread.

• Parasites, Hosts and Diseases
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• 제35권1호
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• pp.47-54
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• 1997

윤충 감염시 증가되는 기생충 특이 IgE 항체는 항기생충 작용을 하는 것으로 알려져 있으나 총 IgE 항체의 90% 이상을 차지하는 비특이성 IgE 항체의 역할에 대해서는 잘 알려져 있지 않다 이 실험에서는 폐흡충 감염 마우스에 anti-lgE 단일크론 항체를 처치한 후 혈청내 IfgE. 비장 B 세포 의 $Fc{\varepsilon}RII/CD23$의 발현 및 충체수를 관찰하여 비특이성 IgE가 숙주의 방어면역에 미치는 역할을 알아보았다. Anti-lgE를 처치한 폐흡충 감염 마우스의 혈청내 총 IgE 항체의 양은 실험 기간 동안 억제되어(($<{\;}1{\;}{\mu\textrm{g}/ml}$) PBS로 처치한 감염군에 비해 유의한 수준(P < 0.05)으로 감소되었다 또 한 Anti-IgE를 처치한 폐흡충 감염 마우스에서의 $Fc{\varepsilon}RII/CD23$ 양성인 비장 B 세포수 및 그 발현도 PBS로 처치한 감염군에 비해 실험 기간 동안 유의한 수준(P < 0.05)으로 감소되었다. 충체 회수율에 있어서도 anti-lgE를 처치한 감염 마우스는 6주에 44%로 PBS로 처치한 감염군(75%)에 비해 유의한 수준(P < 0.05)으로 감소하였다. 이상의 결과를 종합할 때 폐흡충 감염 마우스에서 높게 증가되는 비특이성 IgE는 숙주의 방어면역을 방해하여 오히려 충체를 보호하는 역할을 하는 것으로 생각된다.

• Parasites, Hosts and Diseases
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• 제38권2호
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• pp.51-57
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• 2000

Follow-up studies have been conducted every three years on the endemicity of Gymnophalloides seoi infection in a small coastal village of Chollanam-do (Province), Korea, since it was first known as an endemic area in 1994. Special attention was given to its egg laying capacity in the human host. In fecal examinations, the overall helminth egg and/or cyst positive rate was 78.7% (74/94) in 1997 and 76.6% (82/107) in 2000. Among them G. seoi eggs showed the highest rate; 71.3% (67/94) in 1997 and 72.0% (77/107) in 2000. The average number of eggs per gram of feces (EPG) was 1,015 in 1997, while a reduced rate of 353 was observed in 2000. In 1997, total of 320,677 adult flukes of G. seoi (av. 10,344/person, 94-69,125 in range) were collected from the diarrheic stools of 31 treated patients. The EPG/worm obtained from 21 cases ranged from 0.04 to 0.77 (av. 0.23), suggesting density-dependent constraints on the worm fecundity. The relationship between the worm burden (X) and EPG/worm (Y) can be expressed as $Y=0.42{\cdot}e{\cdot}^{-l.2x}(r=0.49)$. The results showed that G. seoi infection is persistently endemic in this village.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.37-42
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• 2013

Taeniasis is prevalent in all regions of Thailand, except the South. Infections were more frequently found in males than females of any age from 7-83 years. Taenia saginata is the most common species throughout the country. Taenia asiatica was reported only in the province of Kanchanaburi in the Central region. Co-infections, with Taenia solium and T. asiatica or T. solium and T. saginata, were found. Hybridization between T. asiatica and T. saginata is evidence that co-infection is never found between these 2 species. Finding more than 1 worm in a single patient was not entirely rare. Genetic variation was found without correlation to its geographic distribution in T. saginata, whereas no variation was found in T. asiatica.

• Parasites, Hosts and Diseases
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• 제24권2호
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• pp.187-193
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• 1986

Enzyme-linked immunosorbent assay(ELISA) using crude and affinity-purified antigens of adult worms of Paragonimus westermani was performed for infected cat sera with different worm burden, from preinfection to 18th week after infection. Crude antigen was used with supernatant of homogenated worms by freezing-thawing method, and the supernate was centrifuged for 1 hour at 10,000 rpm at $4^{\circ}C$. Affinity-purified antigen(antibody-bound antigen) was prepared from fractions(bound and unbound) of crude antigen by affinity chromatography on CNBr-activated sepharose 4B, and IgG as a ligand was prepared from paragonimiasis cat serum(6 months infected) obtained by ammonium sulfate ($40%{\sim}45%$ saturated) precipitation method. By SDS-PAGE, crude antigen showed 22 polypeptide fractions while purified antigen showed 4 fractions: 36, 400, 34, 700, 27, 600 and 11, 500 in molecular weights. All cats were divided into five groups($G_1-G_5$) by different worm burdens. The mean of recovered worms(${\pm}SD$) and the number of cats in each group are as follows: $G_1$, 2 worms(0) and 4 cats; $G_2$, 4.75 (${\pm}0.66$) and eight; $G_3$, 10.75(${\pm}1.92$) and four; $G_4$, 23.20(${\pm}3.43$) and five; $G_5$, 48(${\pm}12.63$) and five cats. The results were summarized as follows: 1. The antibody levels(OD value) increased by worm burden in $G_1$ to $G_4$ generally. However, individual antibody levels were not exactly related with worm burden in all groups, especially there was a wide difference in $G_4$ and $G_5$. These results suggested that the worm burden in $G_4$ (about $20{\sim}30$ worms) is enough to produce antibody maximum in cats of $2{\sim}3kg$ weight. 2. The antibody levels increased significantly(p<0.05) compared to control sera at the 3rd week in $G_1$ and $G_2$, at the 2nd week in $G_3$, and at the 1st week in $G_4$ and $G_5$. Especially in the 4th week, OD value increased more in $G_1$(p<0.01) and in $G_2$ to $G_5$(p<0.001). In the pattern of antibody levels by ELISA in each group, OD in $G_1$ increased to the 18th week continuously, in $G_2$ OD was maintained same after the 16th week, but in $G_3$ it decreased after the 16th week, and it was maintained same in $G_4$ and $G_5$ after the 14th week. 3. The antibody levels by ELISA with the affinity-purified antigen were higher than those with crude antigen in all groups generally. Especially, the difference of OD values between two antigens was larger from the 4th to the 10th week. In $G_1$ and $G_2$ OD with purified antigen was higher than that with crude one to the 18th week. It was also higher in $G_3$ than that with crude antigen to the 16th week and OD of $G_4$ and $G_5$ were higher before the 14th week than that with crude antigen, however became lower at the 16th week. Consequently, the antibody level in ELISA with affinity-purified antigen was more sensitive at the early weeks after infection and in light infection groups than that with crude antigen.

• 한국임상수의학회지
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• 제30권1호
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• pp.36-40
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• 2013

Caval syndrome은 감염된 다수의 심장사상충이 우심방, 우심실을 포함한 우심계와 대정맥으로 이동하여 삼첨판의 움직임을 물리적으로 방해하고 폐동맥으로 가는 혈류의 장애를 유발하여 생명을 위협하는 질환이다. 이 질환의 치료를 위해 외과적인 사상충의 제거가 필요하다. 본 증례는 modified extraction brushes를 이용한 새로운 방법의 심장사상충 제거 방법에 대한 보고이다. 본 연구에서 새롭게 만들어진 사상충 제거 카테터를 사용하여 caval syndrome에 감염된 두 마리의 개를 성공적으로 치료하였다. 비록 새로운 시술법의 적용이 단지 두 증례에 불과하지만, 본 시술법은 심장 사상충 치료를 위한 외과적 제거방법 중 하나로 선택할 수 있다.

• Parasites, Hosts and Diseases
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• 제50권1호
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• pp.45-51
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• 2012

Fascioliasis is one of the public health problems in the world. Cysteine proteinases (CP) released by $Fasciola$ $gigantica$ play a key role in parasite feeding, migration through host tissues, and in immune evasion. There has been some evidence from several parasite systems that proteinases might have potential as protective antigens against parasitic infections. Cysteine proteinases were purified and tested in vaccine trials of sheep infected with the liver fluke. Multiple doses (2 mg of CP in Freund's adjuvant followed by 3 booster doses 1 mg each at 4 week intervals) were injected intramuscularly into sheep 1 week prior to infect orally with 300 $F.$ $gigantica$ metacercariae. All the sheep were humanely slaughtered 12 weeks after the first immunization. Changes in the worm burden, ova count, and humoral and cellular responses were evaluated. Significant reduction was observed in the worm burden (56.9%), bile egg count (70.7%), and fecel egg count (75.2%). Immunization with CP was also found to be associated with increases of total IgG, $IgG_1$, and $IgG_2$ ($P$<0.05). Data showed that the serum cytokine levels of pro-inflammatory cytokines, IL-12, IFN-${\gamma}$, and TNF-${\alpha}$, revealed significant decreases ($P$<0.05). However, the anti-inflammatory cytokine levels, IL-10, TGF-${\beta}$, and IL-6, showed significant increases ($P$<0.05). In conclusion, it has been found that CP released by $F.$ $gigantica$ are highly important candidates for a vaccine antigen because of their role in the fluke biology and host-parasite relationships.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.629-632
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• 2013

Members of the genus Trichinella are small nematodes that can infect a wide range of animal hosts. However, their infectivity varies depending on the parasite and host species combination. In this study, we examined the susceptibility of 4 species of laboratory rodents, i.e., mice, rats, hamsters, and gerbils to Trichinella papuae, an emerging non-encapsulated Trichinella species. Trichinella spiralis and Trichinella pseudospiralis were also included in this study for comparison. Fifteen animals of each rodent species were infected orally with 100 muscle larvae of each Trichinella species. Intestinal worm burden was determined at day 6 and 10 post-inoculation (PI). The numbers of muscle larvae were examined at day 45 PI. The reproductive capacity index (RCI) of the 3 Trichinella species in different rodent hosts was determined. By day 6 PI, 33.2-69.6% of the inoculated larvae of the 3 Trichinella species became adult worms in the small intestines of the host animals. However, in rats, more than 96% of adult worms of all 3 Trichinella species were expelled from the gut by day 10 PI. In gerbils, only 4.8-18.1% of adult worms were expelled by day 10 PI. In accordance with the intestinal worm burden and the persistence of adults, the RCI was the highest in gerbils with values of $241.5{\pm}41.0$ for T. papuae, $432.6{\pm}48$ for T. pseudospiralis, and $528.6{\pm}20.6$ for T. spiralis. Hamsters ranked second and mice ranked third in susceptibility in terms of the RCI, Rats yielded the lowest parasite RCI for all 3 Trichinella species. Gerbils may be an alternative laboratory animal for isolation and maintenance of Trichinella spp.