Interspecies Phylogenetic Analysis of / 生物医学与环境科学（英文）

Objective@#This study aims to investigate the infection of @*Method@#Infection of the definitive human host and intermediate fish host by @*Results@#In 2016-2020, the average population infection rate of Hunan was 1.38%, while in Tongdao County the rate was up to 26.90%, and the highest fish infection rate was detected in Qiyang County (99.44% in the dorsal fin of @*Conclusion@#The systematically study of

Status of common parasitic diseases in Korea in 2019

This study aimed to determine the status of common parasitic disease in Korea in 2019. Twelve parasitic diseases were selected: toxocariasis, anisakiasis, paragonimiasis, sparganosis, cysticercosis, toxoplasmosis, clonorchiasis, enterobiasis, trichuriasis, trichomoniasis, cryptosporidiosis, and malaria. Their biology, epidemiology, pathogenesis, symptoms and signs, diagnosis, treatment, and prognosis were evaluated. Of the parasitic diseases, toxocariasis was the most prevalent according to serological results. Anisakiasis should be considered when acute gastrointestinal symptoms occur with a recent past history of raw seafood ingestion. Paragonimiasis, sparganosis, and cysticercosis can be diagnosed using an enzyme-linked immunosorbent assay; thus, enzyme-linked immunosorbent assay needs to be performed for suspected cases. Toxoplasmosis and cryptosporidiosis are opportunistic infections. The symptoms and signs are aggravated under immunocompromised conditions. Although the egg positivity rate of Clonorchis sinensis is higher than that of other intestinal parasitic diseases, encountering patients with complaints of symptoms caused by clonorchiasis is rare because the worm burden is low. Trichomoniasis is usually managed by gynecologists; therefore, it should be included in the differential diagnoses of vaginal diseases. The annual number of malaria cases has decreased, although it remains at approximately 500 cases per year. Malaria should be suspected when symptoms such as intermittent fever, headache, and splenomegaly are noted especially when the patients reside near demilitarized zones. Although the prevalence and number of reported cases of parasitic diseases have decreased in Korea, we should consider parasitic diseases in the list of differential diagnoses.

Partial Characterization of Two Cathepsin D Family Aspartic Peptidases of Clonorchis sinensis

Cathepsin D (CatD, EC 3.4.23.5) is a member belonging to the subfamily of aspartic endopeptidases, which are classified into the MEROPS clan AA, family A1. Helminth parasites express a large set of different peptidases that play pivotal roles in parasite biology and pathophysiology. However, CatD is less well known than the other classes of peptidases in terms of biochemical properties and biological functions. In this study, we identified 2 novel CatDs (CsCatD1 and CsCatD2) of Clonorchis sinensis and partially characterized their properties. Both CsCatDs represent typical enzymes sharing amino acid residues and motifs that are tightly conserved in the CatD superfamily of proteins. Both CsCatDs showed similar patterns of expression in different developmental stages of C. sinensis, but CsCatD2 was also expressed in metacercariae. CsCatD2 was mainly expressed in the intestines and eggs of C. sinensis. Sera obtained from rats experimentally infected with C. sinensis reacted with recombinant CsCatD2 beginning 2 weeks after infection and the antibody titers were gradually increased by maturation of the parasite. Structural analysis of CsCatD2 revealed a bilobed enzyme structure consisting of 2 antiparallel β-sheet domains packed against each other forming a homodimeric structure. These results suggested a plausible biological role of CsCatD2 in the nutrition and reproduction of parasite and its potential utility as a serodiagnostic antigen in clonorchiasis.

Cytochrome C Oxidase Subunit 1, Internal Transcribed Spacer 1, Nicotinamide Adenine Dinucleotide Hydrogen Dehydrogenase Subunits 2 and 5 of Clonorchis sinensis Ancient DNA Retrieved from Joseon Dynasty Mummy Specimens

We analyzed Clonorchis sinensis ancient DNA (aDNA) acquired from the specimens of the Joseon mummies. The target regions were cytochrome C oxidase subunit 1 (CO1), internal transcribed spacer 1 (ITS1), nicotinamide adenine dinucleotide hydrogen (NADH) dehydrogenase subunits 2 (NAD2) and 5 (NAD5). The sequences of C. sinensis aDNA was completely or almost identical to modern C. sinensis sequences in GenBank. We also found that ITS1, NAD2 and NAD5 could be good markers for molecular diagnosis between C. sinensis and the other trematode parasite species. The current result could improve our knowledge about genetic history of C. sinensis.

Clonorchis sinensis Infection Presenting as Acute Cholangitis and Acute Cholecystitis / 대한췌담도학회지

A 59-year-old woman presented with abdominal pain. Abdominal computerized tomography was suggestive of biliary stones. During endoscopic retrograde cholangiopancreatography, adult worms resembling Clonorchis sinensis (C. sinensis) were drained. Eggs were detected in stool using the formalin-ether concentration method and C. sinensis-specific antibody was detected in the serum. A diagnosis of C. sinensis infection was made. The symptoms of the patient gradually resolved after treatment with anti-parasite medication. The patient lived in a non-endemic region for C. sinensis infection and had no history of intake of raw or undercooked freshwater fishes. South Korea is one of the endemic countries for C. sinensis infection and people can be infected via indirect routes of transmission such as cooking utensils. Therefore, the possibility of C. sinensis infection should be considered in patients presenting with biliary diseases in South Korea. We describe the clinical findings of this case with a review of literature.

Cytokine Production in Cholangiocarcinoma Cells in Response to Clonorchis sinensis Excretory-Secretory Products and Their Putative Protein Components

Clonorchis sinensis is a carcinogenic human liver fluke that promotes hepatic inflammatory environments via direct contact or through their excretory-secretory products (ESPs), subsequently leading to cholangitis, periductal fibrosis, liver cirrhosis, and even cholangiocarcinoma (CCA). This study was conducted to examine the host inflammatory responses to C. sinensis ESPs and their putative protein components selected from C. sinensis expressed sequenced tag (EST) pool databases, including TGF-β receptor interacting protein 1(CsTRIP1), legumain (CsLeg), and growth factor binding protein 2 (CsGrb2). Treatment of CCA cells (HuCCT1) with the ESPs or bacterial recombinant C. sinensis proteins differentially promoted the secretion of proinflammatory cytokines (IL-1β, IL-6, and TNF-α) as well as anti-inflammatory cytokines (IL-10, TGF-β1, and TGF-β2) in a time-dependent manner. In particular, recombinant C. sinensis protein treatment resulted in increase (at maximum) of ~7-fold in TGF-β1, ~30-fold in TGF-β2, and ~3-fold in TNF-α compared with the increase produced by ESPs, indicating that CsTrip1, CsLeg, and CsGrb2 function as strong inducers for secretion of these cytokines in host cells. These results suggest that C. sinensis ESPs contribute to the immunopathological response in host cells, leading to clonorchiasis-associated hepatobiliary abnormalities of greater severity.

Infections with Digenetic Trematode Metacercariae in Freshwater Fishes from Two Visiting Sites of Migratory Birds in Gyeongsangnam-do, Republic of Korea

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from 2 representative visiting sites of migratory birds in Gyeongsangnam-do, the Republic of Korea (Korea). A totaly 220 freshwater fishes (7 species) were collected from Junam-jeosuji (reservoir), and 127 fishes (7 species) were also collected from Woopo-neup (swamp) in June and October 2017. As the control group, total 312 fish (22 spp.) from Yangcheon in Sancheong-gun, Gyeongsangnam-do were also collected in June and October 2017. All fishes collected in 3 sites were examined with the artificial digestion method. In the fishes from Junam-jeosuji, more than 4 species, i.e., Clonorchis sinensis, Echinostoma spp., Diplostomum spp. and Cyathocotyle orientalis, of DTM were detected and their endemicy was very low, 0.70. More than 6 species, i.e., C. sinensis, Echinostoma spp., Metorchis orientalis, Clinostomum complanatum, Diplostomum spp. and C. orientalis, of DTM were found in the fishes from Woopo-neup, and their endemicy was low, 5.16. In the fishes from Yangcheon, more than 8 species, i.e., C. sinensis, Metagonimus spp., Centrocestus armatus, C. complanatum, C. orientalis, M. orientalis, Echinostoma spp., and Diplostomum spp., of DTM were detected, and their endemicity was relatively high, 95.48. The percentages of avian trematode metacercariae (ATM) were 99.6% and 94.7% in fishes from Junam-jeosuji and Woopo-neup whereas it was 74.1% in the control site, Yangcheon. The above findings suggested that migratory birds partly affect in endemicity of DTM in the fish in the 2 visiting sites in Gyeongsangnam-do, Korea.

A Clonorchiasis Case of a Leopard Cat, Prionailurus bengalensis euptilurus, Diagnosed by Ultrasonography and Egg Detection in Republic of Korea

A clonorchiasis case in a captive leopard cat, Prionailurus bengalensis euptilurus, was confirmed by ultrasonographic findings and egg morphologies found in the bile juice sample in the Korea. The leopard cat was introduced from the wild habitat of Gyeongsangnam-do, to Cheongju Zoo in Cheongju-si, Chungcheongbuk-do, Korea in August 2014. Physical examinations were basically performed for quarantine and check-up health. The cat was comparatively good in health except anorexia. The cyst-like bile duct dilation and the increased echogenicity of gall bladder wall and hepatic parenchyma were observed by ultrasonography. Ultrasound-guided needle biopsy was conducted for collecting bile juice and the specimens were observed under light microscope. The numerous small trematode eggs were detected in the bile juice sample of the light microscopy. The eggs were 25–33 (28±3) μm by 18–22 (20±1) μm in size and showed typical characteristics of Clonorchis sinensis egg, i.e., a dominantly developed operculum, shoulder rim and dust-like wrinkles in surface. To treat the liver fluke infection, 20 mg/kg of praziquantel was orally administered only once to the case. Follow-up studies including fecal examinations were conducted during 2 years after treatment. But no more eggs were detected from the case. In the present study, we described the first clonorchiasis case of leopard cat, which was confirmed by ultrasonographic findings and egg morphologies from the bile juice sample in Korea.

Infection Status with Clonorchis sinensis Metacercariae in Fish from Yangcheon (Stream) in Sancheong-gun, Gyeongsangnam-do, Korea

The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yangcheon (a branch of Gyeongho-gang), which is located in Sancheong-gun, Gyeongsangnam-do, the Republic of Korea. Total 2,201 fishes in 26 species were examined by the artificial digestion method through 7 years. CsMc were detected in 1,171 (53.2%) fishes in 21 spp. (80.8%) and their density was 85 per fish infected. Total 532 (99.6%) out of 534 Pungtungia herzi (index fish) examined were infected with 147 CsMc per fish infected. Metacercarial densities in this fish were highest in 2015 (179 CsMc), followed by 2012 (168), 2013 (152), 2016 (145), 2014 (114), and 2017 (89) respectively. In the gobioninid fish group, i.e., P. herzi, Sarcocheilichthys spp., Squalidus spp., Pseudogobio esocinus, Hemibarbus longirostris, and Hemibarbus labeo, 841 (92.7%) fishes were infected with 117 CsMc per fish infected. Total 250 (54.7%) acheilognathinid fish (bitterlings), Acheilognathus spp. and Acanthorhodeus spp. were infected with 5.8 CsMc. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, and Zacco koreanus, 77 (13.7%) out of 563 fish examined were infected with 2.4 CsMc in average. The susceptibility indices of CsMc were 49.09 in the overall positive fish group, 104.15 in the gobioninid group, 3.17 in the acheilognathinid group and 0.35 in the rasborinid fish group respectively. Only 1 CsMc was detected in 3 fish species, Coreoperca herzi, Channa argus, and Lepomis macrochirus, respectively. Conclusively, it was confirmed that CsMc are moderately prevalent in fishes from Yangcheon in Sancheon-gun, Gyeongsangnam-do, Korea.

A Case of Papular Eruption Associated with Clonorchiasis / 대한피부과학회지

No abstract available.

Internal Quality Assurance Status of Stool Examination as Assessed by a Questionnaire in Korean Clinical Laboratories

This study aimed to survey the status of quality control (QC) assurance for stool examinations at clinical laboratories in Korea. We sent a questionnaire related to QC practices in stool examination by electronic mail to Korean clinical laboratories that performed stool examination. Overall, 20 of the 39 laboratories (51.3%) reported performing stool concentration methods, and 28 (71.8%) examined the slides using only saline. A large proportion (74.4%) of respondents did not check the internal QC because of the restriction of appropriate control materials. Only four laboratories (10.3%) checked the reactivity of the dye solution routinely. For appropriate external QC systems, QC slides (43.6%) were preferred, followed by QC materials (30.8%), virtual slides (17.9%), and a combination of the above options (7.7%). The most commonly observed parasites in stool samples at the clinical laboratories were Clonorchis sinensis (75%), followed by Endolimax nana, Enterobius vermicularis, and Entamoeba coli. The present study describes the difficulties in internal QC assessment due to the absence of standardized QC materials and systems. We hope the findings of this report will provide a foundation for a QC assessment program for stool examinations in the near future.

Survey on Intestinal Helminthic Infection Status of Students in Two Counties, Hadong-gun and Goseong-gun, Korea

This study was conducted to investigate the prevalence of intestinal parasites among students from Goseong-gun, Gangwon-do and Hadong-gun, Gyeongsangnam-do as typical low and high endemic counties. From May to July 2017, a total of 2,033 fecal samples were collected at 27 elementary, 10 junior high, and 8 high schools from 2 counties and examined by the Kato-Katz technique for egg-positive surveys (Collection rate: 37.02% [2,033/5,492]). Of the participants examined, 13 (0.64%) were found to harbor eggs of 3 parasitic species, Trichuris trichiura, Clonorchis sinensis and Metagonimus yokogawai. Based on the regional distribution, the egg-positive rate in Goseong-gun was 0% (0/550) and that in Hadong-gun was 0.88% (13/1,483). The positive rates for C. sinensis, M. yokogawai, and T. trichiura in Hadong-gun were 0.20% (3/1,483), 0.61% (9/1,483), and 0.07% (1/1,483), respectively. The present survey showed that the prevalence of parasitic infection among students is currently very low even in remote, previously endemic areas, and the present status of parasitic diseases can be summarized as some transmission of fish/food-borne trematodes. Thus, it is necessary to carefully, continuously monitor the trematode infection status, particularly of C. sinensis and M. yokogawai.

Infections of Soil-Transmitted Helminth in Refugees from North Korea

Soil-transmitted helminthiases (STH) are now no longer public health problems in the Republic of Korea (South Korea), but their status are unavailable in the residents of North Korea (NK) despite the expectation of large scale traffic and future reunification of the Korean Peninsula. A total of 20 female refugees from NK who had been admitted to the Division of Gastroenterology, Dankook University Hospital, were subjected in this study. Among them, 15 refugees were examined by the colonoscopy and 10 ones were examined with the stool examination (formalin-ether sedimentation). Both diagnostic methods were commonly adopted in 5 patients. Eggs of Trichuris trichiura were detected in 7 out of 10 refugees in the stool examination. In the colonoscopy, T. trichiura worms were found in 6 (40.0%) out of 15 refugees. Total 9 (45.0%) peoples were confirmed to be infected with human whipworms. Additionally, 1 case of clonorchiasis was diagnosed in the stool examination and a worm of Ascaris lumbricoides was discovered from a trichuriasis case. These findings suggested that STH is highly prevalent in NO, in which living conditions are not so good in the aspect of general hygiene and medical care.

Infection Status with Clonorchis sinensis Metacercariae in Fish from Tamjin-gang (River) in Jeollanam-do, Republic of Korea

The present study was performed to investigate the infection status with Clonorchis sinensis metacercariae (CsMc) in fishes from 2 sites, the middle and lower reaches, of Tamjin-gang (River) in Jeollanam-do, the Republic of Korea. Total 1,132 fishes in 22 species were collected from the middle reaches in Jangheung-gun for 4 years (2014–2017) and 517 fishes in 17 species were also collected from the lower reaches in Gangjin-gun in 2014 and 2017. They were all individually examined with the artificial digestion method in our laboratory. CsMc were detected in 322 (28.5%) out of 1,132 fishes from Jangheung-gun, and in 161 (31.1%) out of 517 fishes from Gangjin-gun, and their densities were 51 and 57 per fish infected each. In the fish species with CsMc, positive rates were 61.5% in Jangheung-gun and 62.7% in Gangjin-gun. A total of 222 Pungtungia herzi were examined and they were all infected with CsMc. The average intensity was 103 CsMc in the index fish, P. herzi (95 in Jangheung-gun and 121 in Gangjin-gun). In P. herzi bimonthly examined in 2017, the intensity was commonly most higher in March in 2 surveyed sites, however the significant seasonal endemicity was not showed. Conclusively, it was confirmed that CsMc is more or less prevalent in fishes from Tamjin-gang and their endemicity is higher in fish from the lower reaches in Gangjin-gun than the middle reaches in Jangheung-gun in Jeollanam-do, Korea.

Prevalence and Intensity of Clonorchis sinensis Metacercariae in Freshwater Fish from Wicheon Stream in Gunwi-gun, Gyeongsangbuk-do, Korea

The infection status of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from a highly prevalent site, Wicheon (a branch of Nakdong-gang), which is located in Gunwi-gun, Gyeongsangbuk-do, the Republic of Korea. Total 1,162 fish in 32 species were examined by the artificial digestion method through 6 years. CsMc were detected in 720 (67.5%) out of 1,067 fish (26 spp.) and their density was 610 per fish infected. In the susceptible gobioninid fish group, i.e., Pungtungia herzi, Squalidus gracilis majimae, Squalidus japonicus coreanus, Sarcocheilichthys variegatus wakiyae and Pseudorasbora parva, all of 323 fish were infected with an average of 1,310 CsMc. Total 23 (95.8%) gobioninid fish, i.e., Pseudogobio esocinus, Abbottina springeri, Hemibarbus longirostris, Microphysogobio koreensis, and Microphysogobio jeoni, were infected with 127 CsMc in average. In the acheilognathinid fish (bitterlings) group, the prevalence was 77.0%, and the density was 50 CsMc per fish infected. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, Zacco koreanus, and Opsariichthys uncirostris amurensis, 147 (36.5%) out of 403 fish examined were infected with 15 CsMc in average. The susceptibility indices of CsMc were 412 in the overall positive fish group, 1,310 in the gobioninid group-1, 122 in the gobioninid group-2, 38.5 in the acheilognathinid group, and 5.5 in the rasborinid fish group. Conclusively, it was confirmed that CsMc are highly prevalent in fish from Wicheon, and their infection tendency varied according to the subfamily groups in Cyprinidae fish hosts.

Codon Usage Patterns of Tyrosinase Genes in Clonorchis sinensis

Codon usage bias (CUB) is a unique property of genomes and has contributed to the better understanding of the molecular features and the evolution processes of particular gene. In this study, genetic indices associated with CUB, including relative synonymous codon usage and effective numbers of codons, as well as the nucleotide composition, were investigated in the Clonorchis sinensis tyrosinase genes and their platyhelminth orthologs, which play an important role in the eggshell formation. The relative synonymous codon usage patterns substantially differed among tyrosinase genes examined. In a neutrality analysis, the correlation between GC₁₂ and GC₃ was statistically significant, and the regression line had a relatively gradual slope (0.218). NC-plot, i.e., GC₃ vs effective number of codons (ENC), showed that most of the tyrosinase genes were below the expected curve. The codon adaptation index (CAI) values of the platyhelminth tyrosinases had a narrow distribution between 0.685/0.714 and 0.797/0.837, and were negatively correlated with their ENC. Taken together, these results suggested that CUB in the tyrosinase genes seemed to be basically governed by selection pressures rather than mutational bias, although the latter factor provided an additional force in shaping CUB of the C. sinensis and Opisthorchis viverrini genes. It was also apparent that the equilibrium point between selection pressure and mutational bias is much more inclined to selection pressure in highly expressed C. sinensis genes, than in poorly expressed genes.

Intestinal Parasite Infections among Inhabitants in Yanbian Prefecture, Jilin Province, China

To investigate the prevalence of intestinal parasite infections in Yanbian Prefecture, Jilin Province, China, epidemiological surveys were conducted on a collaboration basis between the Korean Centers for Disease Control and Prevention and the Yanbian Center for Disease Control and Prevention. A total of 8,396 (males 3,737 and females 4,659) stool samples were collected from 8 localities and examined with the formalin-ether sedimentation technique, and additionally examined with the cellotape anal swab to detect Enterobius vermicularis eggs. The overall rate of intestinal parasites was 1.57%. The prevalence of Ascaris lumbricoides was the highest (0.80%), followed by Entamoeba spp. (0.23%), heterophyid flukes (0.15%), Clonorchis sinensis (0.08%), Enterobius vermicularis (0.07%), hookworms (0.06%), Trichostrongylus spp. (0.06%), Giardia lamblia (0.04%), Paragonimus spp. (0.02%), Diphyllobothrium spp. (0.02%), Trichuris trichiura (0.02%). The prevalence by sex was similar, 1.58% (n=59) in males and 1.57% (n=73) in females. By the present study, it is partly revealed that the prevalences of intestinal parasite infections are relatively low among the inhabitants of Yanbian Prefecture, Jilin Province, China.

Prevalence of Clonorchis sinensis Metacercariae in Fish from Water Systems of Seomjin-gang (River)

The prevalence of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from the water systems of Seomjin-gang (River), the Republic of Korea. Total 1,604 fish from 7 local sites of Seomjin-gang were examined by artificial digestion methods. The metacercariae of C. sinensis were detected in 102 (39.8%) out of 256 fish (14 species) from the upper reaches of Seomjin-gang, i.e., Osucheon (22.3% in 6 fish species) in Imsil-gun, and Seomjin-gang (63.9% in 9 fish species) in Sunchang-gun, Jeollabuk-do. Their average density was 9.0 per infected fish. They were also found in 132 (48.0%) out of 275 fish (12 spp.) from the middle reaches of Seomjin-gang, i.e., Songdaecheon (58.9% in 4 fish species) in Namwon-si, Jeollabuk-do, and Seomjin-gang (45.2% in 10 fish species) in Gokseong-gun, Jeollanam-do. Their average density was 21.0 per infected fish. CsMc were detected in 77 (56.6%) out of 136 fish (11 species) from the lower reaches of Seomjin-gang, i.e., Seomjin-gang (73.3% in 11 fish species) in Gurye-gun, Jeollanam-do, and Namsancheon (8.6% in 1 fish species) in Hadong-gun, Gyeongsangnam-do. Their average density was 64.9 per infected fish. The metacercariae of Metorchis orientalis were also detected in 6 fish species from 4 sites of Seomjin-gang. Conclusively, it has been confirmed that CsMc are more or less prevalent in fish from some water systems of Seomjin-gang in Korea.

Discovery of Parasite Eggs in Archeological Residence during the 15th Century in Seoul, Korea

During civil engineering construction near Sejong-ro, Jongro-ku, Seoul, cultural sites were found that are thought to have been built in the 15th century. This area was home to many different people as well as the leaders of the Yi dynasty. To gain further insight into the life styles of the inhabitants of the old capital, soil samples were collected from various areas such as toilets, water foundations, and drainage ways. Parasite eggs were examined by microscopy after 5 g soil samples were rehydrated in 0.5% trisodium phosphate solution. A total of 662 parasite eggs from 7 species were found. Species with the highest number of eggs found were Ascaris lumbricoides (n=483), followed by Trichuris trichiura (138), Trichuris vulpis (21), Fasciola hepatica (8), Clonorchis sinensis (6), Paragonimus westermani (4), and Metagonimus yokogawai (2). These findings indirectly indicate the food habits of the people in Yi dynasty.

Ancient Human Parasites in Ethnic Chinese Populations

Whilst archaeological evidence for many aspects of life in ancient China is well studied, there has been much less interest in ancient infectious diseases, such as intestinal parasites in past Chinese populations. Here, we bring together evidence from mummies, ancient latrines, and pelvic soil from burials, dating from the Neolithic Period to the Qing Dynasty, in order to better understand the health of the past inhabitants of China and the diseases endemic in the region. Seven species of intestinal parasite have been identified, namely roundworm, whipworm, Chinese liver fluke, oriental schistosome, pinworm, Taenia sp. tapeworm, and the intestinal fluke Fasciolopsis buski. It was found that in the past, roundworm, whipworm, and Chinese liver fluke appear to have been much more common than the other species. While roundworm and whipworm remained common into the late 20th century, Chinese liver fluke seems to have undergone a marked decline in its prevalence over time. The iconic transport route known as the Silk Road has been shown to have acted as a vector for the transmission of ancient diseases, highlighted by the discovery of Chinese liver fluke in a 2,000 year-old relay station in northwest China, 1,500 km outside its endemic range.