Re- Infection Rate of Opisthorchis Viverrini Five Years After Treatment with Praziquantel in High-Risk Area: A Community-Based Study.

BACKGROUND: Opisthorchis viverrini (OV)  is a significant public health problem in Thailand, and  OV reinfection poses a serious risk of cholangiocarcinoma with little evidence of a decrease.  While numerous studies have explored OV reinfection and prevalence, most have been limited to short study period. Therefore, there is a need for long-term investigations to gather sufficient evidence. OBJECTIVES: This study aimed to access the current status of re-infection rates in high- risk areas and to determine associations between factors of and re-infection of OV at 5 years after treatment  with praziquantel. MATERIALS AND METHODS: In total, this study included 457 participants from a cohort study. Each participant was required to answer a questionnaire and undergo stool examination using the formalin ethyl acetate concentration technique. Data were analyzed using descriptive statistics and multiple logistic regression. RESULT: Out of the total 457 participants, 418 (91.5%) successfully completed the questionnaires and underwent stool examinations. Among the participants, 10.8% showed re-infection with OV. Using multivariate analysis, factors significantly associated with reinfection OV included yearly income (OR adj = 2.14, 95%CI = 1.11- 4.12, p-value = 0.022) and past stool examination five years (OR adj = 2.47, 95%CI = 1.13-5.43, p-value = 0.023), respectively. CONCLUSIONS: Subjects who frequently experience OV reinfection should undergo CCA screening by experts while closely monitoring their raw fish consumption behavior. Moreover, it is essential to implement comprehensive programs aimed at promoting behavioral changes and provide preventive education, with a specific focus on high epidemic areas, to discourage the consumption of raw fish.

Anthelmintic activity and pathophysiological effect of anthelmintic drugs against carcinogenic liver fluke, Opisthorchis viverrini.

Human liver fluke, Opisthorchis viverrini poses a significant risk for development of cholangiocarcinoma (CCA) in Thailand, primarily attributed to consumption of undercooked cyprinoid fishes. The current use of anthelmintic drug treatment such as praziquantel (PZQ), as the main therapeutic agent against O. viverrini. There is a need to explore the efficacy of alternative anthelmintic drugs for O. viverrini treatment. This study aimed to assess the efficacy of anthelmintic drugs, which are commonly use in endemic areas of Southeast Asian countries; PZQ, albendazole (AL), niclosamide (NI), and mebendazole (ME) at concentrations of 600, 400, 500, and 500 mg/ml. The study included a negative and positive control group treated with roswell park memorial institute (RPMI) and PZQ. Reactive oxygen species (ROS) levels, indicative of oxidative stress, were quantified using 2',7'-dichlorofluorescein diacetate staining. Morphological changes were observed using scanning electron microscopy. Furthermore, motility assessments were conducted at various time points (0, 5, 30 minutes, 1, 3, 6, 12, and 24 hours), calculating relative motility (RM) and survival index (SI). The results revealed a significant increase of ROS levels with the intensity and corrected total worm fluorescence (CTWF) mostly observed in order of PZQ, followed by NI, ME, and AL, respectively. Morphological damage was presented the tegumental swelling, papillae changes, and disruption of microvilli (Mv), particularly in the group treated with the most effective anthelmintics PZQ, NI, ME, and AL, while negative control group did not exhibit such alterations. Also, the most efficacy for suppressing the motility of adult worms were displayed in PZQ treatment group, followed by NI, ME, and AL, respectively. Overall, first novel findings suggest that apart from NI, ME, and AL demonstrate potential as alternative therapeutic options for O. viverrini infection. Furthermore, animal model is needed to investigate the efficacy of NI, ME, and AL compare with standard treatment.

Modeling the persistence of Opisthorchis viverrini worm burden after mass-drug administration and education campaigns with systematic adherence.

Opisthorchis viverrini is a parasitic liver fluke contracted by consumption of raw fish, which affects over 10 million people in Southeast Asia despite sustained control efforts. Chronic infections are a risk factor for the often fatal bile duct cancer, cholangiocarcinoma. Previous modeling predicted rapid elimination of O. viverrini following yearly mass drug administration (MDA) campaigns. However, field data collected in affected populations shows persistence of infection, including heavy worm burden, after many years of repeated interventions. A plausible explanation for this observation is systematic adherence of individuals in health campaigns, such as MDA and education, with some individuals consistently missing treatment. We developed an agent-based model of O. viverrini which allows us to introduce various heterogeneities including systematic adherence to MDA and education campaigns at the individual level. We validate the agent-based model by comparing it to a previously published population-based model. We estimate the degree of systematic adherence to MDA and education campaigns indirectly, using epidemiological data collected in Lao PDR before and after 5 years of repeated MDA, education and sanitation improvement campaigns. We predict the impact of interventions deployed singly and in combination, with and without the estimated systematic adherence. We show how systematic adherence can substantially increase the time required to achieve reductions in worm burden. However, we predict that yearly MDA campaigns alone can result in a strong reduction of moderate and heavy worm burden, even under systematic adherence. We predict latrines and education campaigns to be particularly important for the reduction in overall prevalence, and therefore, ultimately, elimination. Our findings show how systematic adherence can explain the observed persistence of worm burden; while emphasizing the benefit of interventions for the entire population, even under systematic adherence. At the same time, the results highlight the substantial opportunity to further reduce worm burden if patterns of systematic adherence can be overcome.

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.

Accuracy of a new rapid diagnostic test for urinary antigen detection and assessment of drug treatment in opisthorchiasis.

BACKGROUND: Screening for opisthorchiasis, a parasitic worm infection affecting many millions of people in Southeast Asia, has traditionally relied on faecal egg examination such as the formalin-ethyl acetate concentration technique (FECT) and Kato-Katz method. Although the urinary enzyme-linked immunosorbent assay (ELISA) has been used more recently, we developed a urinary antigen-based rapid diagnostic test (RDT) to simplify diagnosis and as a point-of-care testing (POCT) and field applications for surveillance and control of opisthorchiasis. METHODS: A urinary Opisthorchis viverrini (OV)-RDT was developed using immunochromatographic methodology with a specific monoclonal antibody against OV. The diagnostic performance of the urinary OV-RDT was compared to that of quantitative faecal FECT and urinary antigen ELISA (n = 493). Cross-reactivities of urinary OV-RDT with other helminthiases coexisted with O. viverrini were determined (n = 96). A field trial in the application of urinary OV-RDT was compared with urinary antigen ELISA at baseline screening and assessment of drug treatment outcomes in opisthorchiasis (n = 1629). The McNemar chi-square, Kruskal-Wallis and Cohen's kappa coefficient (κ-value) tests were used for statistical analyses. RESULTS: Urinary OV-RDT had sensitivity of 94.2% and specificity of 93.2%, compared to faecal FECT. Urinary OV-RDT had high diagnostic agreement (Kappa = 0.842-0.874, P < 0.001) and quantitative correlation with urinary antigen ELISA (Kruskal-Wallis tests = 316.2, P < 0.0001) and faecal FECT (Kruskal-Wallis tests = 362.3, P < 0.0001). The positive rates by OV-RDT, ELISA and FECT were 48.9%, 52.5% and 49.3%, respectively. Cross-reactions of urinary OV-RDT with other helminthiases were few (2%). Field trials of urinary OV-RDT yielded comparable prevalence of O. viverrini between urinary OV-RDT (53.2%) and urinary antigen ELISA (54.0%). OV screening showed high diagnostic agreement (kappa > 0.8, P < 0.0001) between urinary OV-RDT and urinary antigen ELISA. The cure rates of opisthorchiasis at 1 month post-praziquantel treatment determined by urinary OV-RDT (86.6%) and urinary antigen ELISA (80.5%) were similar (P > 0.05). CONCLUSIONS: The urinary OV-RDT test has high potential as a new tool for screening and evaluating treatment outcomes in opisthorchiasis. The ease of sample collection and simplicity of urinary OV-RDT may facilitate mass screening, control and elimination of opisthorchiasis, thereby contributing to a reduction in the disease burden in Southeast Asia.

Apoptotic and Anti-metastatic Effects of Atractylodes lancea (Thunb.) DC. in a Hamster Model of Cholangiocarcinoma.

OBJECTIVES: Cholangiocarcinoma (CCA) is a highly aggressive tumor with a greater risk of distant metastasis. The promising anti-CCA activity and safety profile of Atractylodes lancea (AL) have previously been reported in a series of in vitro, in vivo and clinical studies. The present study investigated the effect of AL extract on apoptosis and metastasis signaling pathways in the Opisthorchis viverrini/dimethylnitrosamine (OV/DMN)-induced CCA hamster model. MATERIALS AND METHODS: Hamster liver tissues were obtained from the four groups (n = 5 per group), i.e., (i) 5-FU treated CCA (40 µg/mL); (ii) CCA; (iii) AL-treated CCA (5,000 mg/kg), and (iv) normal hamsters. Total RNA was isolated, and the expression levels of apoptosis-related and metastasis-related genes were determined by qRT-PCR analysis. RESULTS: The expression levels of p16, caspase-3, caspase-8, caspase-9, Apaf-1, p53 and Eef1a1 were downregulated, while that of the remaining genes were upregulated in CCA hamsters compared with normal hamsters. AL treatment increased the expression of p16, caspase-9, caspase-3, Apaf-1, p53 and E-cadherin and decreased the expression of cyclin D1, cdk4, Bax, Akt/PKB, Bcl-2, Mfge-8, Lass4, S100A6, TGF-ß, Smad-2, Smad-3, Smad-4, MMP-9, and N-cadherin. The expression of Eef1a1 was unchanged. CONCLUSION: The anti-CCA activity of AL in OV/DMN-induced CCA hamsters could be due to the induction of cell cycle arrest at the G1 phase and activation of the apoptosis pathway, resulting in cancer cell death. The activation of the apoptosis pathway mainly involved the intrinsic pathway (activation of caspase-3 and caspase-9 through p53 and Mfge-8 modulation and downregulation of anti-apoptotic genes Akt and Bcl-2). In addition, AL could also inhibit the canonical TGF-ß signaling pathway, MMP-9 and N-cadherin to suppress tumor metastasis.

Pharmacokinetics of Ascending Doses of Praziquantel in Adults Infected with Opisthorchis felineus in Western Siberia, Russian Federation.

Opisthorchiasis due to the liver fluke Opisthorchis felineus is highly prevalent in rural regions of Western Siberia, causing severe liver and bile duct maladies. Praziquantel administered as a three-dose regimen is the only drug used to treat O. felineus-infected individuals. A simpler single-dose treatment might serve as an alternative. The aim of this study was to compare the pharmacokinetic (PK) properties of single, ascending doses of praziquantel compared to multiple dosing in patients infected with O. felineus to contribute to updated treatment guidelines. Dried blood spots (DBSs) of 110 adults were collected at 11 time points post-drug administration at single oral doses of 20, 40, and 60 mg/kg, as well as 3× 20 mg/kg (4 h dosing interval). DBS samples were analyzed using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, and PK parameters were obtained for R-, S-, and R-trans-4-OH-praziquantel employing noncompartmental analysis. We observed the highest drug exposure for all analytes when the triple-dose scheme was used; area under the concentration-time curve from 0 to 24 h (AUC0-24) values of 8.04, 27.75, and 36.38 µg/mL·h were obtained, respectively. Maximal plasma concentrations (Cmax) values of 1.72, 4.89, and 2.69 µg/mL were calculated for R-, S-, and R-trans-4-OH-praziquantel, respectively, when patients were given a single 60-mg/kg dose, and they peaked at 1.5 and 2 h for the enantiomers and at 3 h for the metabolite. The herein-generated PK data, together with results that will be obtained from the integrated efficacy study, lay the groundwork for a possibly optimized treatment scheme for O. felineus-infected patients.

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.

Persistent advanced periductal fibrosis is associated with cagA-positive Helicobacter pylori infection in post-praziquantel treatment of opisthorchiasis.

BACKGROUND: Liver fluke infection caused by Opisthorchis viverrini is associated with several hepatobiliary diseases including advanced periductal fibrosis (APF) and cholangiocarcinoma. Recently, we demonstrated a persistent APF in over one-third of opisthorchiasis patients after worm removal by praziquantel (PZQ) treatment. However, the underlying mechanism(s) of this phenomena is unclear. Given a co-infection with Helicobacter pylori (H. pylori) especially cagA-positive strain enhances APF, we hypothesized that H. pylori with CagA virulent factor contributes to persistent APF. MATERIALS AND METHODS: Seventy-five opisthorchiasis patients who underwent ultrasonography and treatment with PZQ were recruited in the 2-year follow-up study. Helicobacter and its cagA in the feces were examined by conventional and qPCR. Correlations between prevalence or bacterial loads of Helicobacter spp., H. pylori, and cagA-positive H. pylori before and after PZQ treatment were analyzed among resolved, slowly resolved, relapsed, and persistent APF groups. RESULTS: Overall, prevalence of Helicobacter spp., H. pylori, and cagA-positive H. pylori declined after PZQ treatment. However, only the prevalence and bacterial loads of cagA-positive H. pylori detected at 2-year post-treatment were significantly lower than those before treatment (p < .05). In addition, both prevalence and bacterial loads of cagA-positive H. pylori were significantly lower in the resolved APF group after PZQ treatment, while there were no significant changes in the slowly resolved, relapsed, and persistent APF groups. Among the APF subgroups, cagA-positive H. pylori prevalence in both relapsed and persistent APF groups were significantly higher than the resolved APF group. CONCLUSION: The results support our hypothesis that H. pylori, especially cagA-positive strain, contributes to the relapsed and persistent APF. A supplementary antibiotic treatment for H. pylori to reduce persistent APF and eventually CCA is warranted.