• Molecules and Cells
• /
• 제23권3호
• /
• pp.379-390
• /
• 2007

We sequenced and characterized the complete mitochondrial genome of the Japanese fish tapeworm D. nihonkaiense. The genome is a circular-DNA molecule of 13607 bp (one nucleotide shorter than that of D. latum mtDNA) containing 12 protein-coding genes (lacking atp8), 22 tRNA genes and two rRNA genes. Gene order and genome content are identical to those of the other cestodes reported thus far, including its congener D. latum. The only exception is Hymenolepis diminuta in which the positions of trnS2 and trnL1 are switched. We tested a PCR-based molecular assay designed to rapidly and accurately differentiate between D. nihonkaiense and D. latum using species-specific primers based on a comparison of their mtDNA sequences. We found the PCR-based system to be very reliable and specific, and suggest that PCR-based identification methods using mtDNA sequences could contribute to the study of the epidemiology and larval ecology of Diphyllobothrium species.

• Parasites, Hosts and Diseases
• /
• 제57권2호
• /
• pp.179-184
• /
• 2019

Sparganosis is a parasitic infestation caused by sparganum, a plerocercoid tapeworm larva of the genus Spirometra. Since the first case of human sparganosis reported in 1908, sparganosis has been a global disease, and is common in China, Japan, and Southeast Asian countries. Consumption of raw snakes, frogs, fish, or drinking contaminated beverages are sources of human infections. Human sparganosis usually manifests in subcutaneous fat in areas such as the abdomen, genitourinary tract, and limbs. Breast sparganosis cases are rare, representing less than 2% of total cases of human infections. Complete surgical extraction of the sparganum is the treatment of choice. Because of the rarity of the disease, clinical suspicion is vital to reach the diagnosis of breast sparganosis. Here we report 2 rare cases of breast sparganosis presenting with a painless breast lump, both treated with surgical excision and sparganum extraction.

• Parasites, Hosts and Diseases
• /
• 제59권2호
• /
• pp.153-157
• /
• 2021

This study reports the first two clinical cases of spirometrosis caused by Spirometra sp. in cats in Korea. In these two cases, the cats vomited, and long proglottids of tapeworm were recovered. The sick cats presented with anorexia and lethargy. However, they unexpectedly showed no diarrhea, which is the main symptom of spirometrosis. Based on a fecal floatation test as well as morphological and molecular analyses, the parasite was diagnosed as Spirometra sp. The 2 cases were treated with praziquantel. This study suggests regular monitoring of health and deworming in companion animals, even when animals are well cared for, with regular preventive medication. Additionally, spirometrosis should be considered in the differential diagnosis in cases of gastrointestinal symptoms in Spirometra endemic areas.

• Parasites, Hosts and Diseases
• /
• 제59권4호
• /
• pp.369-376
• /
• 2021

Several factors presumed to facilitate the transmission of Taenia spp. were reported in Vietnam. We conducted a cross-sectional study taking questionnaires from 1,185 participants, and collecting 1,151 sera and 1,036 stool samples in northern Vietnam. Sera were examined for circulating antigens of Taenia solium cysticerci using ELISA, stools for Taenia eggs by Kato-Katz smear, and copro-antigens by ELISA. Ag-ELISA revealed 4.6% antigen positivity, indicating infection with viable cysticerci. Taenia eggs were detected in 1.5% of participants. Copro-antigens were found in 2.8% of participants. Eating raw meat and/or vegetables was significantly associated with the presence of copro-antigen (OR=8.6, 95% CI: 1.16-63.9, P=0.01). Considering the high taeniasis prevalence and the associated threat, public health attention should be given to treat the tapeworm carriers in the projected areas.

• Parasites, Hosts and Diseases
• /
• 제48권2호
• /
• pp.161-165
• /
• 2010

Echinococcus granulosus, an intestinal tapeworm of dogs and other canids, infects humans in its larval stage and causes human echinococcosis or hydatid disease. In the Republic of Korea, 31 parasite-proven human echinococcosis cases have been reported, most of which were imported from the Middle East. We recently examined a 61-year-old Korean man who had a large cystic mass in his liver. ELISA was negative for tissue parasitic infections, including echinococcosis, cysticercosis, paragonimiasis, and sparganosis. The patient underwent surgery to remove the cyst, and the resected cyst was processed histopathologically for microscopic examinations. In sectioned cyst tissue, necrotizing protoscolices with disintegrated hooklets of E. granulosus were found. In some areas, only freed, fragmented hooklets were detected. The patient had traveled to western and central Europe in 1996, and had no other history of overseas travel. We report our patient as a hepatic echinococcosis case which was probably imported from Europe.

• Parasites, Hosts and Diseases
• /
• 제51권4호
• /
• pp.471-474
• /
• 2013

Diphyllobothrium nihonkaiense has been reported in Korea as Diphyllobothrium latum because of their close morphologic resemblance. We have identified a human case of D. nihonkaiense infection using the mitochondrial cytochrome c oxidase subunit I (cox1) gene sequence analysis. On 18 February 2012, a patient who had consumed raw fish a month earlier visited our outpatient clinic with a long tapeworm parasite excreted in the feces. The body of the segmented worm was 2 m long and divided into the scolex (head) and proglottids. It was morphologically close to D. nihonkaiense and D. latum. The cox1 gene analysis showed 99.4% (340/342 bp) homology with D. nihonkaiense but only 91.8% (314/342 bp) homology with D. latum. The present study suggested that the Diphyllobothrium spp. infection in Korea should be analyzed with specific DNA sequence for an accurate species identification.

• Parasites, Hosts and Diseases
• /
• 제22권1호
• /
• pp.66-71
• /
• 1984

만손열두조충(Spirometra erinacei)의 성충에 의한 인체감염 2예가 투약후 충체를 수집함으로써 확인되었다. 환자는 강원도 산간지방에 거주하는 24세 및 21세 남자로 복통 및 상복부 통증이 있다고 하였으며 대변에서는 크기 $53-59{\times}37-42{\mu}m$의 조충류 충란이 발견되었다. 치료를 위해 atabrine 500mg과 하제를 투여한 바 3~4시간후 설사편으로부터 조충류 편절이 다수 수집되었다. 수집된 충체는 광선형 여관, 융구(vaginal opening)가 음경낭(cirrus sac)으로부터 분리되어 개구된 점, 저정낭(seminal vesicle)이 음경낭내로 포합된 점, 편절의 이음새부위에도 고환이 분포하는 점, 충란이 길고 한쪽 끝이 뾰족한 경향이 있으며 비대칭형인 점 등으로 Spirometra erinacei(Rudolphi, 1819)로 동정하였다. 환자는 모두 뱀을 날로 먹은 경험이 있으며 따라서 뱀이 감염원이었을 것으로 추측된다.

• Parasites, Hosts and Diseases
• /
• 제49권4호
• /
• pp.413-418
• /
• 2011

Human alveolar echinococcosis (AE), a hepatic disorder that resembles liver cancer, is a highly aggressive and lethal zoonotic infection caused by the larval stage of the fox tapeworm, Echinococcus multilocularis. E. multilocularis is widely distributed in the northern hemisphere; the disease-endemic area stretches from north America through Europe to central and east Asia, including northern parts of Japan, but it has not been reported in Korea. Herein, we represent a first case of AE in Korea. A 41-year-old woman was found to have a large liver mass on routine medical examination. The excised mass showed multinodular, necrotic, and spongiform appearance with small irregular pseudocystic spaces. Microscopically, the mass was composed of chronic granulomatous inflammation with extensive coagulation necrosis and parasite-like structure, which was revealed as parasitic vesicles and laminated layer delineated by periodic acid-Schiff (PAS) stain. Clinical and histologic features were consistent with AE. After 8 years, a new liver mass and multiple metastatic pulmonary nodules were found and the recurred mass showed similar histologic features to the initial mass. She had never visited endemic areas of AE, and thus the exact infection route is unclear.

• Parasites, Hosts and Diseases
• /
• 제54권4호
• /
• pp.509-518
• /
• 2016

Parasites are recorded from the red squirrel, Sciurus vulgaris, from Cheongju, the Republic of Korea. A total of 5 road-killed squirrels were thoroughly examined for internal and external parasites from November 2011 to May 2014. Total 4 parasite species, including 1 tapeworm and 3 ectoparasite species were recovered. They were morphologically identified as Catenotaenia dendritica (Cestoda: Catenotaeniidae), Hirstionyssus sciurinus, Leptotrombidium pallidum, and Ceratophyllus (Monopsyllus) indages. Among them, C. dendritica and H. sciurinus are recorded for the first time in the Korean parasite fauna. In addition, the possibility that the red squirrel could act as a reservoir host for a zoonotic disease like tsutsugamushi disease with L. pallidum as its vector has been raised.

• Parasites, Hosts and Diseases
• /
• 제53권6호
• /
• pp.689-697
• /
• 2015

The tapeworm Taenia solium is an important human zoonotic parasite that causes great economic loss and also endangers public health. At present, an effective vaccine that will prevent infection and chemotherapy without any side effect remains to be developed. In this study, codon usage patterns in the T. solium genome were examined through 8,484 protein-coding genes. Neutrality analysis showed that T. solium had a narrow GC distribution, and a significant correlation was observed between GC12 and GC3. Examination of an NC (ENC vs GC3s)-plot showed a few genes on or close to the expected curve, but the majority of points with low-ENC (the effective number of codons) values were detected below the expected curve, suggesting that mutational bias plays a major role in shaping codon usage. The Parity Rule 2 plot (PR2) analysis showed that GC and AT were not used proportionally. We also identified 26 optimal codons in the T. solium genome, all of which ended with either a G or C residue. These optimal codons in the T. solium genome are likely consistent with tRNAs that are highly expressed in the cell, suggesting that mutational and translational selection forces are probably driving factors of codon usage bias in the T. solium genome.