• Parasites, Hosts and Diseases
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• 제31권1호
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• pp.1-6
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• 1993

현재 인체에는 기새하는 Taenia 조충으로는 돼지고기 유구낭미층(Cysticercus cellulosae)을 먹어서 감염되는 Taenia solium Linnaeus 1785과 쇠고기의 무구낭미층(Cysticercus bovis)을 먹어서 감염되는 Taenia saginata Goeze 1782 두 종이 알려져 있다. 한편 인체에 기생하는 제 3의 Taenia 조충으로 최근 타이완, 한국, 인도내시아, 태국, 필리핀 등 아시아국가를 중심으로 발견되는 Asian Taenia saginata 조충은 돼지나 소의 간 또는 내장에 있는 내장형낭미충을 먹어서 감염되는 것으로 추정된다. 그러나 이러한 생활사상의 구분에도 불구하고 형태하적으로는 본충이 Taenia saginate Groeze 1782와 유사하기 때문에 아직 신종으로 인정되지 않은 상태이다. 이에 연구자들은 Asian Taenia saginata 조충의 형태학적 구분점을 새로이 발견하고 학명으로서 Taenia asiatica sp.n.(한국명:아시아조총)을 제시하고자 한다. 감별적으로는 1.선충의 두절에 있는 액취의 존재, 2. 성충의 수태편절에서 관찰되는 자궁세지의 수, 3.성충의 수태관절에서 관찰되는 미돌기의 존재 및 4.유추의 낭벽표면에서 관찰되는 사마귀양 구조가 광학 및 전자현경적으로 관찰되었다. 이중 '자궁세지'와 '미돌기'는 새로이 관찰하여 기재하는 구조물로서 처음으로 Taeniid의 종감별에 사용하였다.

• Parasites, Hosts and Diseases
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• 제30권1호
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• pp.21-24
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• 1992

Asian Taenia saginata낭미충에 의한 인체감염이 성립된다는 것을 실험적으로 확인하였다. 감염에 사용한 5개의 낭미충은 우리나라 돼지간에 자연감염되었던 것으로 청주 소재 도축장에서 얻은 것이었다. 감염 후 제76일에 활발한 운동성을 가진 수태편절이 자연배출되었다. 2년 후 치료하여 두마리의 성충을 회수하였다. 두절에는 소구가 없었고 수태편절의 자궁측지수는 16∼21개 이었으며 다른 부분은 형태학상으로 무구조충과 유사하였다. 돼지 간을 날로 먹으면 우리나라에서 Asian Taenia saginata에 감염될 수 있다는 것을 실험적으로 증명하였다.

• Parasites, Hosts and Diseases
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• 제30권1호
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• pp.15-20
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• 1992

충북 청주시 소재 도축장에서 6개월령 균격돈 (Yorkshlre, Landrace, Duroc 및 Hampshire의 교잡종)을 조사하여 Asian Taenin saginata 예미충의 간장내 감염률을 조사하였다. 낭미충은 1.01% (256/25,358 마리)의 돼지에서 발견되었으며 낭미충의 상태는 살아있었거나 (0.01%, 3/25,358), 죽은 후 변성되어 있었거나 (0.12%, 30/25,358), 석회화된 (0.88%, 223/25,358) 상태로 검출되었다. 감염된 제지간 중 석회화된 낭미충만 발견되는 경우가 87.1%(223/256)로 대부분이었다. 간장내에서는 우측엽(14.7%), 우중엽(29.9%), 좌중엽(28.2%), 좌측엽 (27.l%)에 고르게 분포하였고, 표면과 실질에도 각각 45.8% 및 54.2%로서 고르게 분포하였다. 남미충의 크기는 생존상태에서 2.07~2.14$\times$1.98~2.01 mm이었고, 불규칙소구(rudimetary hooklets)는 17.0% (8/47)의 낭미충에서 발견되었다. 이상의 결과는 돼지에 자연 감염된 Asian Taenia sagippata 낭미충이 이제까지 무구조충(Taenia saginata)으 로 오인되었던 Asian Taenia saginata의 인체 감염원이 되었을 것으로 생각되었다.

• Parasites, Hosts and Diseases
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• 제38권1호
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• pp.1-7
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• 2000

In certain Asian countries, a third form of human Taenia, also known as the Asian Taenia, has been discovered. This Asian Taenia seems to be an intermediate between Taenia solium and T. saginata since in morphological terms it is similar to T. saginata, yet biologically, as it uses the same intermediate host (pigs) , it is more akin to T. solium. Taenia solium causes human cysticercosis, while T. saginata does not. It is not known whether the Asian taeniid is able to develop to the larval stage in humans or not. The arguments proposed by those authors who consider it unlikely that the Asian Taenia causes human cysticercosis are: (a) its molecular similarities with T. saginata: (b) the absence of cases of human cysticercosis in populations where the Asian adult is highly prevalent; and (c) the unsupporting results derived from an experimental infestation study. These three arguments are debated, although bearing in mind that at present there is still no clear scientific data to support that human cysticercosis can be caused by the Asian Taenia.

• 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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• 제30권4호
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• pp.269-276
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• 1992

• Parasites, Hosts and Diseases
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• 제59권2호
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• pp.179-182
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• 2021

Human infection with Taenia asiatica or a hybrid between Taenia saginata and T. asiatica has not been reported in Cambodia. We detected for the first time a hybrid form between T. saginata and T. asiatica in Preah Vihear Province, Cambodia. An adult tapeworm specimen, i.e., 75 cm long strobila without scolex, was expelled from a 27-year-old man after praziquantel medication and purging. It was morphologically indistinguishable between T. saginata and T. asiatica. Several proglottids were molecularly analyzed to confirm the tapeworm species. The mitochondrial gene encoding cytochrome c oxidase subunit 1 (cox1) and nuclear genes encoding elongation factor-1α (ef1) and ezrin-radixin-moesin (ERM)-like protein (elp) were sequenced, and a single-allele analysis was performed to confirm the haploid genotype. The results revealed that our sample showed a discrepancy between the mitochondrial and 2 nuclear genes. It possessed homozygous sequences typical of T. saginata at cox1 and ef1 loci. However, it was heterozygous at the elp locus, with 1 allele in T. asiatica (elpA) and 1 in T. saginata (elpC), which indicates that it is a hybrid between T. saginata and T. asiatica. The present results confirmed the presence of a hybrid between T. saginata and T. asiatica in Cambodia and strongly suggest the existence of also 'pure' T. asiatica in Cambodia.

• Parasites, Hosts and Diseases
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• 제52권1호
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• pp.79-83
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• 2014

Human taeniases had been not uncommon in the Republic of Korea (=Korea) until the 1980s. The prevalence decreased and a national survey in 2004 revealed no Taenia egg positive cases. However, a subsequent national survey in 2012 showed 0.04% (10 cases) prevalence of Taenia spp. eggs suggesting its resurgence in Korea. We recently encountered 4 cases of Taenia saginata infection who had symptoms of taeniasis that included discharge of proglottids. We obtained several proglottids from each case. Because the morphological features of T. saginata are almost indistinguishable from those of Taenia asiatica, molecular analyses using the PCR-RFLP and DNA sequencing of the cytochrome c oxidase subunit 1 (cox1) were performed to identify the species. The PCR-RFLP patterns of all of the 4 specimens were consistent with T. saginata, and the cox1 gene sequence showed 99.8-100% identity with that of T. saginata reported previously from Korea, Japan, China, and Cambodia. All of the 4 patients had the history of travel abroad but its relation with contracting taeniasis was unclear. Our findings may suggest resurgence of T. saginata infection among people in Korea.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.201-204
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• 2020

Taenia saginata infection has seldom been reported in Cambodia. In this study, we performed a survey of intestinal parasites in 1,156 residents of Preah Vihear and Stung Treng Provinces in 2018. The results revealed that 26 (2.4%) cases were positive for Taenia spp. eggs. In order to obtain the strobilae of the tapeworms, 2 patients in Preah Vihear were treated with praziquantel and purged with magnesium salts. The proglottids expelled after the medication were morphologically and molecularly analyzed to determine the species. The main uterine lateral braches in gravid proglottids were > 15 in number suggesting that they are either T. saginata or Taenia asiatica. The sequences of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and 2 nuclear loci, elongation factor-1 alpha (ef1) and ezrin-radixin-moesin-like protein (elp), were identical to the sequences of T. saginata available in GenBank but distant from Taenia solium, T. asiatica, and T. saginata-T. asiatica hybrid. This is the first report of the presence of T. saginata in the northern part of Cambodia bordering Lao PDR based on a molecular confirmation.

• Parasites, Hosts and Diseases
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• 제55권4호
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• pp.457-460
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• 2017

Previous paleoparasitological studies of Joseon specimens established that the prevalence of Taenia infection was not much different from that of the early 20th century Korean population. As many of taeniases originally diagnosed as Taenia saginata in South Korea were revealed to be actually Taenia asiatica, which share a common intermediate host with T. solium (the pig), Joseon people must have ingested raw pork frequently. However, the current examination of extant Joseon documents revealed that the population ate significant amounts of beef even if the beef ban was enforced; and pork was not consumed as much as we thought. Considering the meat consumption pattern at that time, Joseon people should have been infected by T. saginata more frequently than T. asiatica. This may suggest a low prevalence of T. saginata metacestodes in cattle compared to that of T. asiatica metacestodes in pigs, possibly due to the traditional way of rearing pigs (using human feces). This letter gives us a chance to reconsider the existing preconception about parasitic infections in Korean history though we are still hard to accurately estimate the historical patterns of taeniases at this stage.