Liver Flukes: Clonorchis and Opisthorchis.

Clonorchis sinensis, Opisthorchis viverrini and O. felineus are liver flukes of human and animal pathogens occurring across much of Europe and Asia. Nevertheless, they are often underestimated compared to other, better known neglected diseases in spite of the fact that many millions of people are infected and hundreds of millions are at risk. This is possibly because of the chronic nature of the infection and disease and that it takes several decades prior to a life-threatening pathology to develop. Several studies in the past decade have provided more information on the molecular biology of the liver flukes which clearly lead to better understanding of parasite biology, systematics and population genetics. Clonorchiasis and opisthorchiasis are characterized by a chronic infection that induces hepatobiliary inflammation, especially periductal fibrosis, which can be detected by ultrasonography. These chronic inflammations eventually lead to cholangiocarcinoma (CCA), a usually fatal bile duct cancer that develops in some infected individuals. In Thailand alone, opisthorchiasis-associated CCA kills up to 20,000 people every year and is therefore of substantial public health importance. Its socioeconomic impacts on impoverished families and communities are considerable. To reduce hepatobiliary morbidity and CCA, the primary intervention measures focus on control and elimination of the liver fluke. Accurate diagnosis of liver fluke infections in both human and other mammalian, snail and fish intermediate hosts is important for achieving these goals. While the short-term goal of liver fluke control can be achieved by praziquantel chemotherapy, a comprehensive health education package targeting school children is believed to be more beneficial for a long-term goal/solution. It is recommended that transdisciplinary research or multisectoral control approach including one health and/or eco health intervention strategy should be applied to combat the liver flukes and hence contribute to reduction of CCA in endemic areas.

Efficacy assessment of miltefosine and curcumin against Clonorchis sinensis infection.

Praziquantel (PZQ) is currently the only approved drug for treating clonorchiasis, but its poor efficacy against Clonorchis sinensis larvae has highlighted the need to develop newer drugs. In this study, to address this challenge, we investigated the anti-parasitic efficacy of miltefosine (MLT), curcumin (CUR), and PZQ against C. sinensis metacercariae (CsMC), newly excysted juvenile worms (CsNEJs), and adults. Larvicidal effects of MLT and CUR surpassed those elicited by PZQ in vitro. These two drugs exerted their effect against both CsMC and CsNEJs in a dose- and time-dependent manner. To confirm the effect of these drugs in vivo, Syrian golden hamsters were orally infected with 100 CsMC and subsequently treated with MLT, CUR, or PZQ at 1 and 4 weeks post-infection (wpi). MLT and CUR reduced the worm recoveries at 1 and 4 wpi, indicating that these drugs were efficacious against both larvae and adult C. sinensis. PZQ was only efficacious against adult worms. Interestingly, both MLT and CUR showed lower levels of C. sinensis-specific IgG responses than the infection control group, implying that worm burden and bile IgG responses could be correlated. These results indicate that MLT and CUR are efficacious against both larval and adult stages of C. sinensis, thereby highlighting their potential for further development as alternative therapeutic options for clonorchiasis.

Clonorchiasis and opisthorchiasis: epidemiology, transmission, clinical features, morbidity, diagnosis, treatment, and control.

Clonorchis sinensis, Opisthorchis viverrini, and Opisthorchis felineus are important liver flukes that cause a considerable public health burden in eastern Asia, southeastern Asia, and eastern Europe, respectively. The life cycles are complex, involving humans, animal reservoirs, and two kinds of intermediate hosts. An interplay of biological, cultural, ecological, economic, and social factors drives transmission. Chronic infections are associated with liver and biliary complications, most importantly cholangiocarcinoma. With regard to diagnosis, stool microscopy is widely used in epidemiologic surveys and for individual diagnosis. Immunologic techniques are employed for screening purposes, and molecular techniques facilitate species differentiation in reference laboratories. The mainstay of control is preventive chemotherapy with praziquantel, usually combined with behavioral change through information, education and communication, and environmental control. Tribendimidine, a drug registered in the People's Republic of China for soil-transmitted helminth infections, shows potential against both C. sinensis and O. viverrini and, hence, warrants further clinical development. Novel control approaches include fish vaccine and biological control. Considerable advances have been made using multi-omics which may trigger the development of new interventions. Pressing research needs include mapping the current distribution, disentangling the transmission, accurately estimating the disease burden, and developing new diagnostic and treatment tools, which would aid to optimize control and elimination measures.

Structure-based virtual screening and molecular dynamics of potential inhibitors targeting sodium-bile acid co-transporter of carcinogenic liver fluke Clonorchis sinensis.

BACKGROUND: Clonorchis sinensis requires bile acid transporters as this fluke inhabits bile juice-filled biliary ducts, which provide an extreme environment. Clonorchis sinensis sodium-bile acid co-transporter (CsSBAT) is indispensable for the fluke's survival in the final host, as it circulates taurocholate and prevents bile toxicity in the fluke; hence, it is recognized as a useful drug target. METHODOLOGY AND PRINCIPAL FINDINGS: In the present study, using structure-based virtual screening approach, we presented inhibitor candidates targeting a bile acid-binding pocket of CsSBAT. CsSBAT models were built using tertiary structure modeling based on a bile acid transporter template (PDB ID: 3zuy and 4n7x) and were applied into AutoDock Vina for competitive docking simulation. First, potential compounds were identified from PubChem (holding more than 100,000 compounds) by applying three criteria: i) interacting more favorably with CsSBAT than with a human homolog, ii) intimate interaction to the inward- and outward-facing conformational states, iii) binding with CsSBAT preferably to natural bile acids. Second, two compounds were identified following the Lipinski's rule of five. Third, other two compounds of molecular weight higher than 500 Da (Mr > 500 Da) were presumed to efficiently block the transporter via a feasible rational screening strategy. Of these candidates, compound 9806452 exhibited the least hepatotoxicity that may enhance drug-likeness properties. CONCLUSIONS: It is proposed that compound 9806452 act as a potential inhibitor toward CsSBAT and further studies are warranted for drug development process against clonorchiasis.

Efficacy of drugs against clonorchiasis and opisthorchiasis: a systematic review and network meta-analysis.

BACKGROUND: Clonorchis sinensis, Opisthorchis viverrini, and Opisthorchis felineus are the three most important human liver fluke species in the Opisthorchiidae family, infecting approximately 25 million people worldwide. Drug treatment is needed to control morbidity and is also useful in lowering transmission. Several drugs used in various regimens are available to treat these infections, but their comparative efficacy is uncertain. We aimed to compare the efficacy in terms of cure rate and egg reduction rate of currently registered drugs against human liver fluke infection. METHODS: We conducted a systematic review using readily available electronic databases (MEDLINE, Embase, Cochrane Central Register of Controlled Trials, KoreaMed, China National Knowledge Infrastructure, and Wanfang Data) without language restrictions from inception until June 29, 2021. Clinical trials with pairwise comparison of drugs (praziquantel, albendazole, mebendazole, tribendimidine, or combinations of these drugs) against C sinensis, O viverrini, and O felineus were eligible, including trials comparing these drugs or their combinations with placebo. We compared efficacy in terms of cure rate by network meta-analysis. We conducted mixed binomial regression analyses for each species to derive predicted median cure rates for each drug regimen. The models included treatment and infection intensity as fixed factors, year of publication as covariate, and random effects of the different studies assumed to be normally distributed. We also assessed the quality of the included studies. This study was registered with PROSPERO (CRD42018109232). FINDINGS: Overall, 26 trials from 25 studies were included, of which 18 involved C sinensis, seven studied O viverrini, and one focused on O felineus. These trials included a total of 3340 participants. The two long-term treatment courses against C sinensis infection using 400 mg of albendazole (400 mg twice a day for 5 days and 400 mg twice a day for 7 days) resulted in cure rates of 100%, while two other multiple-dose regimens of albendazole resulted in high predicted cure rates: 300 mg twice a day for 5 days (93·9% [95% CI 49·6-99·6]) and 400 mg twice a day for 3 days (91·0% [50·9-99·0]). The WHO-recommended praziquantel regimen (25 mg/kg three times a day for 2 days) also showed a high predicted cure rate (98·5% [85·4-99·9]) in C sinensis infection, and predicted cure rates were above 90% for several other multiple-dose praziquantel regimens, including 20 mg/kg three times a day for 3 days (97·6% [74·7-99·8]), 14 mg/kg three times a day for 5 days (93·9% [44·8-99·7]), and 20 mg/kg twice a day for 3 days (91·0% [50·9-99·0]). In O viverrini infection, the regimen of 50 mg/kg and 25 mg/kg of praziquantel given in a single day showed the highest predicted cure rate (93·8% [85·7-97·5]), while a single dose of 50 mg/kg praziquantel also resulted in a high predicted cure rate (92·1% [64·9-98·6]). The single dose of 400 mg tribendimidine showed a high predicted cure rate of 89·8% (77·5-95·8). A low quality of evidence was demonstrated in most studies, especially those published before 2000. Selection bias due to poor random sequence generation and allocation concealment was high, and performance and detection biases were frequently unreported. INTERPRETATION: Praziquantel shows high efficacy against clonorchiasis and opisthorchiasis. Tribendimidine might serve as a treatment alternative and warrants further investigation. Although albendazole is efficacious when long treatment schedules (5 days or 7 days) are applied, limited size of studies and high risk of bias affect the interpretation of results. More high-quality studies are needed to promote the establishment of treatment guidelines for human liver fluke infection. FUNDING: Fourth Round of Three-Year Public Health Action Plan (2015-2017; Shanghai, China) and Swiss National Science Foundation.

Cost-effectiveness evaluation of different control strategies for Clonorchis sinensis infection in a high endemic area of China: A modelling study.

Clonorchiasis is an important food-borne parasitic disease caused by Clonorchis sinensis infection. The evaluation of long-term cost-effectiveness of control strategies is important for disease control and prevention. The present study aimed to assess the cost-effectiveness of the three recommended strategies (i.e., WHO, Chinese and Guangdong strategies) and different combinations of commonly used measures (i.e., preventive chemotherapy, information, education, and communication (IEC) and environmental improvement) on clonorchiasis. The study area, Fusha town in Guangdong Province, was a typical high endemic area in China. The analysis was based on a multi-group transmission model of C. sinensis infection. We set the intervention duration for 10 years and post-intervention period for 50 years. The corresponding costs and DALYs were estimated. Strategies with incremental cost-effectiveness ratios (ICERs) less than 1/5 of the willingness-to-pay threshold were identified as highly cost-effective strategies. The optimal control strategy was obtained using the next best comparator method. The ICERs of Guangdong strategy were $172 (95% CI: $143-$230) US for praziquantel and $106 (95% CI: $85-$143) US for albendazole, suggesting the highest cost-effectiveness among the three recommended strategies. For praziquantel, 470 sets of control strategies were identified as highly cost-effective strategies for achieving infection control (prevalence<5%). The optimal strategy consisted of chemotherapy targeted on at-risk population, IEC and environmental improvement, with coverages all being 100%, and with the ICER of $202 (95% CI: $168-$271) US. The results for transmission control (prevalence<1%) and albendazole were obtained with the same procedures. The findings may help to develop control policies for C. sinensis infection in high endemic areas. Moreover, the method adopted is applicable for assessment of optimal strategies in other endemic areas.

Localization of Praziquantel Production and Clonorchiasis Control Program in Korea, 1970s~1980s.

The Korean parasite control program is regarded as one of the most successful examples of health care movement in Korea. This 'Parasite Eradication Program' which was conducted from 1969 to 1995, involved testing and treating of 300 million people. In cooperation with Japan, parasitologists and activists who participated in the parasite control program formed a common system called the 'Mass Testing, Mass Treatment.' This study focuses on the localization process of Praziquantel, Clonorchiasis treatment production and its application in Clonorchiasis control program. Parasitologists rapidly introduced newly developed Praziquantel, and Korean chemists quickly reverse engineered the compound to evade patent issues. This allowed for the mass production of Praziquantel at a lower price, which in turn enabled a nationwide Clonorchiasis control program. At the same time, low price and stable supply opened the private market for Praziquantel. However, acceptance and understanding of the Praziquantel differed significantly among the stakeholders. For the government, it was a means for policy propaganda, and for the health agencies, it was a means for mass scale control program, while for the public, it was a means for maintaining conventional eating habits without risk of infection. This study reveals how the material end of a disease control policy is accepted and interpreted by different actors.

High-quality reference genome for Clonorchis sinensis.

The Chinese liver fluke, Clonorchis sinensis, causes the disease clonorchiasis, affecting ~35 million people in regions of China, Vietnam, Korea and the Russian Far East. Chronic clonorchiasis causes cholangitis and can induce a malignant cancer, called cholangiocarcinoma, in the biliary system. Control in endemic regions is challenging, and often relies largely on chemotherapy with one anthelmintic, called praziquantel. Routine treatment carries a significant risk of inducing resistance to this anthelmintic in the fluke, such that the discovery of new interventions is considered important. It is hoped that the use of molecular technologies will assist this endeavour by enabling the identification of drug or vaccine targets involved in crucial biological processes and/or pathways in the parasite. Although draft genomes of C. sinensis have been published, their assemblies are fragmented. In the present study, we tackle this genome fragmentation issue by utilising, in an integrated way, advanced (second- and third-generation) DNA sequencing and informatic approaches to build a high-quality reference genome for C. sinensis, with chromosome-level contiguity and curated gene models. This substantially-enhanced genome provides a resource that could accelerate fundamental and applied molecular investigations of C. sinensis, clonorchiasis and/or cholangiocarcinoma, and assist in the discovery of new interventions against what is a highly significant, but neglected disease-complex.

Impact of Wortmannilactone F and G31P on Clonorchis Sinensis-infected mice.

Clonorchis sinensis could induce inflammation, epithelial hyperplasia and fibrosis in the intrahepatic bile duct as a food-borne parasite, which was associated with the development of cholangiocarcinoma (CCA). Praziquantel was the most effective drug on treatment of this kind of parasite. However, new drugs with minimal toxicity to the host were urgently needed due to the side effects of Praziquantel and its CCA risk. In this study, helminth mitochondria respiratory chain blocker Wortmannilatone F (WF) and IL-8 analogue CXCL8 (3-72) K11R/G31P were used to treat BALB/C mice infected by Clonorchis sinensis. We investigated the gross and histopathological morphology of the liver, inflammation-associated cytokine IL-6, lipid peroxidation-related proteins cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), collagen fiber accumulation and fibroblast-specific protein 1 (FSP1), malignant markers proliferating cell nuclear antigen (PCNA) and cytokeratin 19 (CK19), as well as the disinfection effect on these parasites in vitro. WF inhibited and killed the worms dramatically, and the combination of WF with G31P improved the condition of the hepatobiliary duct tissue greatly. These outcomes indicated that the combination of WF and G31P was a potential therapeutic method to treat the Clonorchis sinensis infection.

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.

A co-infection case report of Taenia saginata in a patient with subclinical clonorchiasis confirmed by the combination of diagnostic tools.

BACKGROUND: Clonorchiasis is the common parasitic infection in the general population of the Republic of Korea, however, taeniasis is scarcely reported recently. Here, we describe a case of co-infection with the cestode T. saginata in a patient with subclinical clonorchiasis diagnosed by a combination of diagnostic tools in Korea. CASE PRESENTATION: A 56-year-old man visited the hospital having passed proglottids in his stool for the past two months and brought a stool sample with segments to our hospital. He had no abdominal symptoms, such as nausea, vomiting, abdominal pain, diarrhea, or constipation. He used to consume raw beef and fish frequently. We could not find evidence of gravid proglottids which contain fully developed uteri filled with ova or branched uterine structures, within the submitted sample. To identify the tapeworm species, we carried out molecular analyses on the proglottids. The cox1 and ef1a sequences had a 100% match with those of T. saginata and differed from the sequences of the other Taenia species. Upon examination of stool samples fixed by formalin-ether concentration method, no Taenia species ova were observed in 10 slides. Instead, C. sinensis ova were observed, despite the level of IgG specific to C. sinensis being within the normal range. The patient was treated with praziquantel (25 mg/kg, three times a day) for 3 days, and subsequently C. sinensis ova were not found in his stool. CONCLUSION: Our case indicates that a combination of morphological, serological, and molecular diagnostic tools should be used for the accurate diagnosis of subclinical parasitic infections.

Clonorchiasis sinensis detected by laparoscopic exploration of biliary tracts in two patients with obstructive jaundice.

BACKGROUND: Hepatic clonorchiasis is one of the most prevalent food-borne parasitic diseases worldwide. Clonorchis sinensis, the pathogen, is the major parasitic trigger contributing to cholangitis, cholelithiasis, and even cholangiocarcinoma. Unfortunately, unspecific clinical manifestations of patients with hepatic clonorchiasis tend to mislead clinicians to neglect or misdiagnose them, following ignorance of appropriate therapy. Our case report may shed light on definite diagnosis of clonorchiasis with concomitant cholelithiasis, methodology for surgical drainage of the parasites, and postoperative anthelmintic therapy. CASE PRESENTATION: Two patients with habit of eating infected raw or undercooked freshwater fish were hospitalized due to right upper quadrant pain and jaundice. Magnetic resonance cholangiopancreatography (MRCP)/computed tomography (CT) detection indicated cholangiolithiasis and cholangiolithiasis with concurrent cholecystolithiasis, respectively. Fecal examinations were both negative for adult worms or eggs of parasites. However, adults of Clonrochis sinensis were detected within hepatobiliary tracts during laparoscopic cholecystectomy. Postoperative drainage and anthelmintic therapy contributed to complete recovery with good prognosis. CONCLUSIONS: Clonorchiasis provokes cholangiolithiasis and cholecystolithiasis. Standardized treatments for these gallstone patients with concomitant clonorchiasis include surgical removal of the calculus, postoperative T tubule drainage and anthelmintic therapy. Serological test or polymerase chain reaction (PCR)-based approaches might be helpful for diagnosis of clonorchiasis when no eggs are found by stool microscopy. Public health promotion on ceasing to eat raw freshwater fish is essential for prevention and control of clonorchiasis.

[Analysis of current drug treatment against clonorchiasis in China].

OBJECTIVE: To analyze the current drug treatment against clonorchiasis in China, in order to promote the standardization of drug treatment and national deworming for clonorchiasis. METHODS: All the 10 provinces were enrolled, which reported clonorchiasis in the work report for important helminthiasis in 2016. Then, 20 counties were selected from these 10 provinces. The data on drug treatment including both mass chemotherapy and individual treatment against clonorchiasis were collected and compared. RESULTS: All the 10 provinces had no guideline for mass chemotherapy, while only 3 had that for individual treatment against clonorchiasis. Out of 20 counties, only 1 implemented mass chemotherapy. Among these 20 counties, 13 applied praziquantel in individual treatment, while other 7 employed albendazole. In the 12 counties with clear protocol for praziquantel, the total dosage for a man of 60 kg ranged from 3.6 to 18.0 g, the days and times for administration ranged from 1 to 6 and from 3 to 18, respectively. In the 4 counties with clear protocol for albendazole, the total dosage for a man of 60 kg ranged from 0.8 to 8.4 g, the days and times for administration ranged from 2 to 7 and from 2 to 14, respectively. CONCLUSIONS: Nowadays, the guideline on mass chemotherapy for clonorchiasis is inadequate in China. Although individual treatment is applied in many areas, the protocols vary in drugs, dosage, and days and times for treatment. Thus, the national guideline of mass chemotherapy for clonorchiasis should be established, while the protocols for individual treatment should be standardized.

An Integrated Control Strategy Takes Clonorchis sinensis Under Control in an Endemic Area in South China.

Clonorchis sinensis is an important foodborne zoonosis worldwide and prevalent in China for more than 2000 years. According to the experience of controlling Schistosoma japonica, China started to establish the integrated control strategy for C. sinensis in endemic areas. Lou village, the largest village in Shenzhen city in South China was taken as a pilot site. This longitudinal study assessed the infection status of C. sinensis among people and intermediate hosts from 2006 to 2014 in Lou village. After a continuous intervention with the integrated control strategy, the prevalence of C. sinensis decreased significantly to 2.01% in 2014. The infection intensity also reduced significantly with eggs per gram varying from 45.6 ± 3.4 in 2010 to 21.7 ± 1.6 in 2012. There is also a statistically significant decrease of the prevalence of C. sinensis metacercariae in fish hosts from 16.51% in 2008 before the intervention to 5.33% in 2014. All the old-styled toilets were replaced by sanitary ones with a harmless processing design in 2014. No viable parasite eggs were detected in stool samples from the reconstructed toilets. Health education played an important role in changing the eating habits among the local residents, with a significant decrease in the prevalence of eating raw fish from 91.99% in 2008 to 59.87% in 2014. The evaluation suggested that the integrated strategy we have performed in Lou village is effective in controlling the C. sinensis infection and maintaining the infection rate at a lower level, which can be promoted in other endemic areas.

Current status and perspectives of Clonorchis sinensis and clonorchiasis: epidemiology, pathogenesis, omics, prevention and control.

Clonorchiasis, caused by Clonorchis sinensis (C. sinensis), is an important food-borne parasitic disease and one of the most common zoonoses. Currently, it is estimated that more than 200 million people are at risk of C. sinensis infection, and over 15 million are infected worldwide. C. sinensis infection is closely related to cholangiocarcinoma (CCA), fibrosis and other human hepatobiliary diseases; thus, clonorchiasis is a serious public health problem in endemic areas. This article reviews the current knowledge regarding the epidemiology, disease burden and treatment of clonorchiasis as well as summarizes the techniques for detecting C. sinensis infection in humans and intermediate hosts and vaccine development against clonorchiasis. Newer data regarding the pathogenesis of clonorchiasis and the genome, transcriptome and secretome of C. sinensis are collected, thus providing perspectives for future studies. These advances in research will aid the development of innovative strategies for the prevention and control of clonorchiasis.

Painless Jaundice Caused by Clonorchis sinensis Infection: A Case Report.

A man with only yellowing of the skin and eye sclera was diagnosed with clonorchiasis, which rarely manifested jaundice as the initial symptom. However, because of a lack of evidence for a diagnostic gold standard, the time until definitive diagnosis was more than a week. The diagnostic process relied on inquiring about the patient's history, including the place of residence, dietary habits, and symptoms, as well as on serological findings, an imaging examination, and pathological findings. MRCP and CT results showed mild dilatation of intrahepatic ducts and increased periductal echogenicity. The eggs were ultimately found in stool by water sedimentation method after the negative report through direct smear. DNA sequencing of PCR production of the eggs demonstrated 98-100% homology with ITS2 of Clonorchis sinensis. After anti-parasite medical treatment, the patient's symptoms were gradually relieved. Throughout the diagnostic procedure, besides routine examinations, the sedimentation method or concentration method could be used as a sensitive way for both light and heavy C. sinensis infection in the definite diagnosis.

Clonorchis sinensis Co-infection Could Affect the Disease State and Treatment Response of HBV Patients.

BACKGROUND: Clonorchis sinensis (C. sinensis) is considered to be an important parasitic zoonosis because it infects approximately 35 million people, while approximately 15 million were distributed in China. Hepatitis B virus (HBV) infection is a major public health issue. Two types of pathogens have the potential to cause human liver disease and eventually hepatocellular carcinoma. Concurrent infection with HBV and C. sinensis is often observed in some areas where C. sinensis is endemic. However, whether C. sinensis could impact HBV infection or vice versa remains unknown. PRINCIPAL FINDINGS: Co-infection with C. sinensis and HBV develops predominantly in males. Co-infected C. sinensis and HBV patients presented weaker liver function and higher HBV DNA titers. Combination treatment with antiviral and anti-C. sinensis drugs in co-infected patients could contribute to a reduction in viral load and help with liver function recovery. Excretory-secretory products (ESPs) may, in some ways, increase HBV viral replication in vitro. A mixture of ESP and HBV positive sera could induce peripheral blood mononuclear cells (PBMCs) to produce higher level of Th2 cytokines including IL-4, IL-6 and IL-10 compared to HBV alone, it seems that due to presence of ESP, the cytokine production shift towards Th2. C. sinensis/HBV co-infected patients showed higher serum IL-6 and IL-10 levels and lower serum IFN-γ levels. CONCLUSIONS/SIGNIFICANCE: Patients with concomitant C. sinensis and HBV infection presented weaker liver function and higher HBV DNA copies. In co-infected patients, the efficacy of anti-viral treatment was better in patients who were prescribed with entecavir and praziquantel than entecavir alone. One possible reason for the weaker response to antiviral therapies in co-infected patients was the shift in cytokine production from Th1 to Th2 that may inhibit viral clearance. C. sinensis/HBV co-infection could exacerbate the imbalance of Th1/Th2 cytokine.

The role of evolutionary biology in research and control of liver flukes in Southeast Asia.

Stimulated largely by the availability of new technology, biomedical research at the molecular-level and chemical-based control approaches arguably dominate the field of infectious diseases. Along with this, the proximate view of disease etiology predominates to the exclusion of the ultimate, evolutionary biology-based, causation perspective. Yet, historically and up to today, research in evolutionary biology has provided much of the foundation for understanding the mechanisms underlying disease transmission dynamics, virulence, and the design of effective integrated control strategies. Here we review the state of knowledge regarding the biology of Asian liver Fluke-host relationship, parasitology, phylodynamics, drug-based interventions and liver Fluke-related cancer etiology from an evolutionary biology perspective. We consider how evolutionary principles, mechanisms and research methods could help refine our understanding of clinical disease associated with infection by Liver Flukes as well as their transmission dynamics. We identify a series of questions for an evolutionary biology research agenda for the liver Fluke that should contribute to an increased understanding of liver Fluke-associated diseases. Finally, we describe an integrative evolutionary medicine approach to liver Fluke prevention and control highlighting the need to better contextualize interventions within a broader human health and sustainable development framework.

Current status of Clonorchis sinensis and clonorchiasis in China.

The oriental liver fluke, Clonorchis sinensis, a pathogen causing clonorchiasis, is of major socio-economic importance in East Asia, including China, Korea and Vietnam. This parasite is now recognized as a biocarcinogen strongly linked to cholangiocarcinoma in humans. Here, we describe the status of clonorchiasis in China, where it has been estimated that more than 15 million patients are affected. This paper also summarizes the major advances in the field of clonorchiasis research during last decade, including diagnosis techniques, pathogenesis and genome/transcriptome/proteome studies in the last years. We strongly hope that our work can stimulate the governments of the countries or regions where clonorchiasis is endemic to pay more attention to this disease and establish related guidelines to prevent and control it.