Cholecystolithiasis is associated with Clonorchis sinensis infection

Effectiveness of health education in improving knowledge, attitude and practice related to foodborne zoonotic trematodes in Vietnam, with a particular focus on Clonorchis sinensis

OBJECTIVE

Foodborne zoonotic trematodes (FZT), which infect the liver, lungs and intestines of humans, are an emerging public health concern in tropical countries including Vietnam. In northern Vietnam, Clonorchis sinensis is recognised as the most important species of the FZT. Up to now, small-scale studies conducted in the country have indicated that health education could improve participants' knowledge and practices related to clonorchiasis, however strong evidence is still lacking. We conducted an intervention trial between 2020 and 2021 in four communes in Yen Bai and Thanh Hoa province, aiming to evaluate the impact of an extended educational package on knowledge, attitude and practices related to clonorchiasis, as well as on knowledge on the large liver fluke and minute intestinal flukes.

METHODS

To this end, baseline and post-intervention questionnaires were conducted. Generalised estimating equations models were run to analyse the impact of the intervention on knowledge, attitudes and practices over time in the intervention versus control group. Finally, 172 people in the intervention group and 162 in the control group were included for analysis.

RESULTS

Results demonstrated that the intervention significantly improved clonorchiasis knowledge, attitudes and practices, with higher odds for a correct knowledge response (odds ratio (OR) = 2.80, 95% confidence interval (CI) = 1.84-4.27, p-value < 0.001), increased average mean attitude score (mean = 0.363, 95%CI = 0.182-0.544, p-value < 0.001), and a reduced odds of consuming raw fish (OR = 0.15, 95%CI = 0.06-0.40, p = 0.002) in the intervention group compared to the control group post-intervention versus baseline. Additionally, participants in the intervention group exhibited enhanced basic knowledge of the large liver fluke and minute intestinal flukes post-intervention.

CONCLUSIONS

These findings demonstrate the potential of health education programs in preventing clonorchiasis in endemic areas, emphasising the importance of continued health education as a critical component of integrated control programs 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.

Features of Metabolite Changes in Disease Evolution in Cholecystolithiasis

BACKGROUND

Cholecystolithiasis is defined as a disease caused by complex and changeable factors. Advanced age, female sex, and a hypercaloric diet rich in carbohydrates and poor in fiber, together with obesity and genetic factors, are the main factors that may predispose people to choledocholithiasis. However, serum biomarkers for the rapid diagnosis of choledocholithiasis remain unclear.

AIMS

This study was designed to explore the pathogenesis of cholecystolithiasis and identify the possible metabolic and lipidomic biomarkers for the diagnosis of the disease.

METHODS

Using UHPLC-MS/MS and GC-MS, we detected the serum of 28 cholecystolithiasis patients and 19 controls. Statistical analysis of multiple variables included Principal Component Analysis (PCA). Visualization of differential metabolites was performed using volcano plots. The screened differential metabolites were further analyzed using clustering heatmaps. The quality of the model was assessed using random forests.

RESULTS

In this study, dramatically altered lipid homeostasis was detected in cholecystolithiasis group. In addition, the levels of short-chain fatty acids and amino acids were noticeably changed in patients with cholecystolithiasis. They detected higher levels of FFA.18.1, FFA.20.1, LPC16.0, and LPC20.1, but lower levels of 1-Methyl-L-histidine and 4-Hydroxyproline. In addition, glycine and L-Tyrosine were higher in choledocholithiasis group. Analyses of metabolic serum in affected patients have the potential to develop an integrated metabolite-based biomarker model that can facilitate the early diagnosis and treatment of the disease.

CONCLUSION

Our results highlight the value of integrating lipid, amino acid, and short-chain fatty acid to explore the pathophysiology of cholecystolithiasis disease, and consequently, improve clinical decision-making.

Prevalence of Platynosomum spp infection and its association with biliary lithiasis and secondary bacterial infections in free-ranging marmosets (Callithrix spp) of the Brazilian Atlantic Forest

Platynosomosis is a parasitic disease caused by a trematode of the genus Platynosomum, a bile duct and gallbladder fluke that has been described in captive neotropical primates (New World primates; NWPs) and causes high morbidity and variable mortality. Although it is a major concern for ex-situ conservation of these animals, there are only a few studies of platynosomosis in free-ranging NWPs. Therefore, the aim of this study was to characterize platynosomosis in a free-ranging population of marmosets (Callithrix spp) from the Brazilian Atlantic Forest, focusing on the epidemiological and pathological aspects of the disease. A total of 1,001 marmosets were evaluated and on the basis of clinicoepidemiological data, histopathology, histochemistry and immunohistochemistry, we concluded that Platynosomum spp infection has a prevalence of 8.9% (confidence interval: 7.3-10.8%) in free-ranging marmosets, with a higher frequency in the Metropolitan Region of Rio de Janeiro. Infection was associated with fibrosing and proliferative cholangiohepatitis associated with biliary lithiasis (3.0% of cases) and secondary bacterial infections (14.6% of cases).

A systematic study on 33 gallbladder stones resembling adult Clonorchis sinensis worms

Limited studies provide direct evidence of Clonorchis sinensis adults in the early stage of gallbladder stone formation. Our current research systematically studied 33 gallbladder stones resembling adult worms and shed light on the definite connection of C. sinensis infection with concomitant cholelithiasis. A total of 33 gallbladder stones resembling adult C. sinensis worms were systematically analysed. Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray energy spectrometry were used to analyse the composition and microstructure. Meanwhile, a histopathological examination of the stone was carried out. The 33 gallbladder stones resembling adult C. sinensis worms included nine calcium carbonate (CaCO₃) stones, 12 bilirubinate stones and 12 mixed stones. Clonorchis sinensis eggs were found in 30 cases, including all CaCO₃ and mixed stones. Parasite tissues were detected in 12 cases, which were mainly CaCO₃ stones or bilirubinate-CaCO₃ mixed stones. The outer layer of stones was wrapped with 12.88% calcium salt, as revealed by X-ray energy spectrometry, while surprisingly, many C. sinensis eggs were found in the inner part of these stones. Based on our current findings, we concluded that calcification and packaging occurred after C. sinensis adult entrance into the gallbladder, subsequently leading to the early formation of CaCO₃ or bilirubinate-CaCO₃ mixed gallbladder stones. This discovery highlights definite evidence for C. sinensis infection causing gallbladder stones.

Children education for sustainable control of liver fluke infections

Significant disease burden is caused by infections with human liver flukes, including Clonorchis sinensis, Opisthorchis viverrini and O. felineus. Epidemiology is characterized by high burden in the male than the female, and in the elder than the younger. Chemotherapy is the mainstream for morbidity control, but it could not prevent re-infection. Meanwhile, behavioral change on the dietary habit of ingesting raw freshwater fish is challenging. In this opinion, we argue why it is important to educate children for sustainable control of liver fluke infections. Then, the design, development and key messages of an educational cartoon for preventing liver fluke infections is introduced. Technical focuses are emphasized based on a pilot using the education cartoon for preventing clonorchiasis in China. Finally, how to further develop and verify this education strategy is discussed.

Association between the Dietary Inflammatory Index with gallstone disease: finding from Dena PERSIAN cohort

OBJECTIVE

The Dietary Inflammatory Index (DII) is a documented nutritional tool for assessing diet-induced inflammation that has been linked to various diseases/outcomes. The association between DII and gallstone disease (GSD) is yet to be explored. The objective of this study was to examine the association between DII and GSD.

DESIGN

This cross-sectional study was conducted using the baseline phase data of the Dena PERSIAN cohort. The analysed data included demographic information, lifestyle variables, body mass index, diabetes and fatty liver history, and laboratory test results. The 113-item Food Frequency Questionnaire was used to estimate the dietary intake of participants and quantify the inflammatory potential of the individual's diet. DII score was analysed as a continuous and quartiles variables. Univariable and multivariate logistic regressions were used to investigate the relationship between GSD and DII scores .

RESULTS

Out of 3626 individuals entering the study, 173 (4.77%) had GSD. The median DII was -0.08 (IQR=0.18). In the unadjusted model, the odds of having GSD were significantly higher in the first and second quartiles of DII (anti-inflammatory diet) than in higher quartiles (proinflammatory diet). In the adjusted model, the odds of having GSD in the third and fourth quartiles of DII scores compared with the first quartile were OR=0.59 (95% CI 0.36 to 0.95) and OR 0.51 (95% CI 0.30 to 0.84), respectively.

CONCLUSION

The results of this study suggest that a proinflammatory diet is associated with a reduced chance of GSD. However, longitudinal studies are needed to examine the causal association.

Epidemiology and determinants of Clonorchis sinensis infection: A community-based study in southeastern China

Clonorchiasis is caused by the ingestion of raw freshwater fish and causes high burden in East Asia. The epidemiological profiles and determinants of C. sinensis infection, knowledge, practice and attitude related to clonorchiasis were demonstrated in Hengxian county, Guangxi, China. The overall prevalence of C. sinensis was 60.3%, which was higher in male than in female and in elder population compared to children. The percentage knowing local transmission, transmission route and harm of C. sinensis was 20.9%, 31.4% and 32.5%. A percentage of 60.4% reported ingestion of raw freshwater fish, while 70.1% persons would like to accept treatment if infected with C. sinensis. Of the individuals ingesting raw freshwater fish, 82.0% did at home and 81.3% drunk alcohol when ingesting raw freshwater fish. Sixty-two percent showed the persistence on ingestion of raw freshwater fish in future. The ingestion of raw freshwater fish varied by seasons, with a proportion of 57.8% in spring, 48.3% in summer, 60.2% in autumn and 92.2% in winter. In multivariable regression models, age groups, history with C. sinensis treatment, and frequency on ingesting raw freshwater fish were related to C. sinensis infection, while gender, educational level, history with C. sinensis infection, and knowing local transmission were related to the practice of ingesting raw freshwater fish. Gender, history with C. sinensis treatment, frequency on ingesting raw freshwater fish, duration of ingesting raw freshwater fish and drinking alcohol when ingesting raw freshwater fish were associated to the attitude to the ingestion of raw freshwater fish in future. Great efforts are needed to combat clonorchiasis, in which the heterogeneity of population in knowledge, practice, attitude and infection needs to be considered. Men are of crucial importance in term of the morbidity control through chemotherapy. Meanwhile, massive education is expected to implement, which needs to promote the change of ingesting raw freshwater fish for sustainable control of clonorchiasis.

Unexpected discovery of Clonorchis sinensis by common bile duct exploration

Coexisting choledocholithiasis and Clonorchis sinensis infection are relatively rare. We report a 39‐year‐old patient with choledocholithiasis who inadvertently found Clonorchis sinensis during common bile duct exploration. Our experience suggests that if preoperative imaging reveals nonspecific changes associated with choledocholithiasis, the possibility of biliary parasite infection should be suspected.

Cost yield of different treatment strategies against Clonorchis sinensis infection

BACKGROUND

Clonorchiasis is attributed to the ingestion of raw freshwater fish harboring Clonorchis sinensis. Morbidity control is targeted through the administration of antihelminthics. This study modelled the cost yield indicated by effectiveness and utility of different treatment strategies against clonorchiasis.

METHODS

About 1000 participants were enrolled from each of 14 counties selected from four provincial-level administrative divisions namely Guangxi, Guangdong, Heilongjiang and Jilin in 2017. Fecal examination was adopted to detect C. sinensis infection, while behavior of ingesting raw freshwater fish was enquired. Counties were grouped into four categories based on prevalence, namely low prevalence group (< 1%), moderate prevalence group (1-9.9%), high prevalence group (10-19.9%) and very high prevalence group (≥ 20%), while population were divided into three subgroups, namely children aged below 14 years old, adult female and adult male both aged over 14 years old. The average of cost effectiveness indicated by the cost to treat single infected cases with C. sinensis and of cost utility indicated by the cost to avoid per disability-adjusted life years (DALYs) caused by C. sinensis infection was calculated. Comparisons were performed between three treatment schedules, namely individual treatment, massive and selective chemotherapy, in which different endemic levels and populations were considered.

RESULTS

In selective chemotherapy strategy, the cost to treat single infected case in very high prevalence group was USD 10.6 in adult male, USD 11.6 in adult female, and USD 13.2 in children. The cost increased followed the decrease of endemic level. In massive chemotherapy strategy, the cost per infected case in very high prevalence group was USD 14.0 in adult male, USD 17.1 in adult female, USD 45.8 in children, which were also increased when the endemic level decreased. In individual treatment strategy, the cost was USD 12.2 in adult male, USD 15.0 in adult female and USD 41.5 in children in very high prevalence group; USD 19.2 in adult male, USD 34.0 in adult female, and USD 90.1 in children in high prevalence group; USD 30.4 in adult male, USD 50.5 in adult female and over USD 100 in children in moderate prevalence group; and over USD 400 in any population in low prevalence group. As to cost utility, the differences by treatment strategies, populations and endemic levels were similar to those in cost effectiveness.

CONCLUSIONS

Both cost effectiveness and cost utility indicators are highly impacted by the prevalence and population, as well as the treatment schedules. Adults especially men in the areas with a prevalence over 10% should be prioritized, in which selective chemotherapy was best and massive chemotherapy was also cost effective. In moderate endemic areas, the yield is not ideal, but selective chemotherapy for adult male may also be adopted. In low endemic areas, all strategies were high costly and new strategies need to be developed.

Spatial epidemiologic analysis of the liver cancer and gallbladder cancer incidence and its determinants in South Korea

BACKGROUND

There have been reports on regional variation in prevalence of hepatitis B and C, and Clonorchis sinensis (C. sinensis) infection, which indicates potential of spatial variation in liver cancer and gallbladder cancer incidence in Korea. Therefore, we aimed to assess the regional variation of liver and gallbladder cancer incidence and its determinants based on the regional distribution of risk factors, including hepatitis B infection in Korea.

METHODS

This study used an ecological study design and district-level cancer incidence statistics generated by the National Cancer Center. Spatial clusters of liver and gallbladder cancer incidence were detected based on spatial scan statistics using SaTScan™ software. We set the size of maximum spatial scanning window of 25 and 35% of the population at risk for analyses of liver and gallbladder cancer, respectively. Significance level of 0.05 was used to reject the null hypothesis of no cluster. We fitted the Besag-York-Mollie model using integrated nested Laplace approximations to assess factors that influence the regional variation in cancer incidence.

RESULTS

Spatial clusters with high liver cancer incidence rates were detected in the southwestern and southeastern regions of Korea. High gallbladder cancer incidence rates are clustered in the southeastern region. Regional liver cancer incidence can be accounted for the prevalence of high household income (coefficient, - 0.10; 95% credible interval [CI], - 0.18 to - 0.02), marital status (coefficient, - 0.14; 95% CI, - 0.25 to - 0.03), the incidence of hepatitis B (coefficient, 0.87; 95% CI, 0.29 to 1.44), and liver cancer screening (coefficient, 0.06; 95% CI, 0.00 to 0.12), while gallbladder cancer incidence was related to the prevalence of high household income (coefficient, - 0.03; 95% CI, - 0.05 to 0.00) and living close to a river with a high prevalence of liver fluke infection (coefficient, 0.55; 95% CI, 0.14 to 0.96).

CONCLUSIONS

This study demonstrated geographic variation in liver and gallbladder cancer incidence, which can be explained by determinants such as hepatitis B, income, marital status, and living near a river.

The Overactivation of NADPH Oxidase during Clonorchis sinensis Infection and the Exposure to N-Nitroso Compounds Promote Periductal Fibrosis

Clonorchis sinensis, a high-risk pathogenic human liver fluke, provokes various hepatobiliary complications, including epithelial hyperplasia, inflammation, periductal fibrosis, and even cholangiocarcinogenesis via direct contact with worms and their excretory-secretory products (ESPs). These pathological changes are strongly associated with persistent increases in free radical accumulation, leading to oxidative stress-mediated lesions. The present study investigated C. sinensis infection- and/or carcinogen N-nitrosodimethylamine (NDMA)-associated fibrosis in cell culture and animal models. The treatment of human cholangiocytes (H69 cells) with ESPs or/and NDMA increased reactive oxidative species (ROS) generation via the activation of NADPH oxidase (NOX), resulting in augmented expression of fibrosis-related proteins. These increased expressions were markedly attenuated by preincubation with a NOX inhibitor (diphenyleneiodonium chloride) or an antioxidant (N-acetylcysteine), indicating the involvement of excessive NOX-dependent ROS formation in periductal fibrosis. The immunoreactive NOX subunits, p47^phox and p67^phox, were observed in the livers of mice infected with C. sinensis and both infection plus NDMA, concomitant with collagen deposition and immunoreactive fibronectin elevation. Staining intensities are proportional to lesion severity and infection duration or/and NDMA administration. Thus, excessive ROS formation via NOX overactivation is a detrimental factor for fibrogenesis during liver fluke infection and exposure to N-nitroso compounds.

The dynamics of select cellular responses and cytokine expression profiles in mice infected with juvenile Clonorchis sinensis

Clonorchiasis is a zoonotic disease that can result in chronic infection in humans. The causative agent, Clonorchis sinensis (C. sinensis), is believed to primarily induce a Th2 immune response in infected mice. However, few studies have profiled host immune responses to C. sinensis infection during the juvenile phase. In the present study, the dynamics of select cellular responses and cytokine expression profiles during juvenile C. sinensis infection were investigated. The flow cytometry results showed that the CD4+ T cells percentage was significantly decreased between 12 days post-infection (dpi) and 24 dpi in the peripheral blood, and the CD8+ T cells percentage was significantly elevated after 3 dpi. The ratio of CD4+/CD8+ T cells was also significantly decreased after 3 dpi. Furthermore, we observed that the proportion of CD14+ monocyte-macrophages in the peripheral blood was significantly increased between 1 dpi and 12 dpi and peaked at 6 dpi. The percentage of classically activated macrophages (M1) and alternatively activated macrophages (M2) in the liver was significantly increased between 18 dpi and 30 dpi. qRT-PCR results showed that the expression levels of iNOS in the liver were significantly elevated after 3 dpi, and Arg-1 expression was significantly increased beginning at 12 dpi. ELISA results showed that the serum levels of the Th1 cytokines IFN-γ and IL-2 peaked at 6 dpi and decreased thereafter. Furthermore, the Th2 cytokines IL-4 and IL-13 began to be expressed and peaked at 24 dpi and 30 dpi, respectively. In addition, the levels of the Treg cytokines IL-10 and TGF-β₁ were significantly increased beginning at 6 dpi until 30 dpi. In the liver homogenate, the expression of IFN-γ, IL-2, and IL-4 mainly occurred before 6 dpi. IL-13 expression was significantly increased at 30 dpi. IL-10 and TGF-β₁ levels were significantly increased at 12 dpi and 24 dpi, and expression peaked at 24 dpi and 30 dpi, respectively. This study provides a fundamental characterization for the future analysis of host-parasite interactions and immune responses in hosts infected with juvenile C. sinensis.

Epidemiology and determinants of clonorchiasis in school children in southeastern China

Clonorchiasis is an important food-borne parasitic disease in China because of the popularity in ingesting raw freshwater fish. To explore the epidemiology and determinants of clonorchiasis in children, a cross-sectional survey was implemented in two middle schools in Qiyang county, Hunan province, in southeastern China. Questionnaire survey and fecal examination were implemented. Questionnaires were fed back by 627 students, while stool samples were collected from 557 students, out of which 545 ones also provided questionnaire information. The percentage of students ingesting raw freshwater fish was 40.5% (254/627), while the prevalence with Clonorchis sinensis infection was 18.9% (105/557). Such factors contributed significantly to the students' practice in eating raw freshwater fish including boys, fathers' eating raw freshwater fish, mothers' eating raw freshwater fish, and preparation of raw freshwater fish at home, with an adjusted odds ratio of 1.9 (95% confidence intervals (95% CI): 1.3-2.8), 3.9 (95% CI: 2.3-6.5), 3.0 (95% CI: 1.8-4.8) and 2.8 (95% CI: 1.8-4.5), correspondingly. Ingestion of raw freshwater fish, fathers' eating raw freshwater fish and preparation of raw freshwater fish at home were risk factors of C. sinensis infection in students, and the adjusted odds ratio was 3.2 (95% CI: 1.9-5.5), 2.1 (95% CI: 1.1-3.9) and 1.8 (95% CI: 1.0-3.2), respectively. Thus, clonorchiasis was endemic in the surveyed schools due to the ingestion of raw freshwater fish, which is influenced by family environment. Education should be implemented in schools to promote behavioral change of eating raw freshwater fish.

Severe hepatobiliary morbidity is associated with Clonorchis sinensis infection: The evidence from a cross-sectional community study

Clonorchis sinensis infection is highly prevalent in Asia. Diverse hepatobiliary morbidity has been documented for C. sinensis infection. This study aimed to assess the association between C. sinensis infection and hepatobiliary morbidity, taking into consideration of the control, confounders and infection intensity. A cross-sectional community survey was implemented in Hengxian county, southeastern China. Helminth infections were detected by fecal examination. Physical examination and abdominal ultrasonography were then conducted. After excluding confounding effects from gender, age and alcohol drinking, quantitative association between C. sinensis infection and hepatobiliary morbidity was assessed, and the effect from infection intensity was also evaluated, through adjusted odds ratio (aOR) and 95% confidence intervals (95% CI). 696 villagers older than 10 years were enrolled. The prevalence and infection intensity of C. sinensis were higher in male, elder people and the individuals consuming alcohol. Light C. sinensis infection was associated with the increase of diarrhoea (aOR: 2.2, 95% CI: 1.1–4.5). C. sinensis infection was associated with the increase of fatty liver (aOR: 2.7, 95% CI: 1.4–5.2), and the effect was similar in different infection intensities. Moderate C. sinensis infection was associated with the increase of gallbladder stone (aOR: 3.0, 95% CI: 1.1–8.6), while moderate and heavy infections with the increase of intrahepatic bile duct dilatation (aOR: 2.2, 95% CI: 1.0–4.9 and aOR: 4.3, 95% CI: 1.9–9.9, respectively). C. sinensis infection had an effect on the development of periductal fibrosis (aOR: 3.2, 95% CI: 2.1–4.9), which showed increasing trend by infection intensity. The length and width of gallbladder in those with C. sinensis infection were enlarged, especially in those over 30 years old. C. sinensis infection is significantly associated with hepatobiliary morbidity. The occurrence of some morbidity was strongly related to the infection intensity. Awareness on harm of clonorchiasis should be raised both for policy-makers and villagers to adopt effective interventions.

Clonorchiasis is caused by ingestion of raw freshwater fish, which carries the larvae of Clonorchis sinensis. In this study, we aimed to assess the damages associated with clonorchiasis. A cross-sectional field survey was carried out in Hengxian county, southeastern China. Stool samples were collected and examined for helminth infections. Then, physical examination and abdominal ultrasonography were conducted. In total, 696 villagers older than 10 years were included. The prevalence and infection intensity of C. sinensis were higher in male, elder people and those drinking alcohol. Excluding the impact from gender, age and alcohol drinking, it was demonstrated that light C. sinensis infection was associated with the increase of diarrhoea, moderate infection with gallbladder stone, and moderate and heavy infections with intrahepatic bile duct dilatation. C. sinensis infection was relevant to the increase of fatty liver, and the effect was similar in different infection intensities. C. sinensis infection was associated with the development of periductal fibrosis and the effect increased by infection intensity. The length and width of gallbladder in individuals with C. sinensis infection were enlarged, especially in those over 30 years old. Thus, our study demonstrates that C. sinensis infection is associated with severe hepatobiliary morbidity, and the effect is strongly related to infection intensity for some morbidity. Concerted efforts should be exerted to tackle the morbidity in clonorchiasis endemic areas.

An investigation of Human Clonorchiasis prevalence in an Endemic County in Guangxi Zhuang Autonomous Region, China, 2016

To effectively promote the implementation of interventions, the identification of high-risk groups and the characteristics of Clonorchis sinensis infection in endemic regions are needed. In a clonorchiasis-endemic area, local residents were randomly enrolled for helminth egg examination in June 2016. The prevalence in subpopulations as well as the knowledge, attitudes, and behaviours and the factors influencing clonorchiasis in egg-positive populations were analysed. A total of 2282 local residents participated in the survey; the C. sinensis prevalence was 48.6% (1109 persons). A higher prevalence was found in males (62.6%) than in females (29.7%). People older than 30 years had the highest prevalence (52.7%-57.6%). Among the 888 persons who were infected with C. sinensis and participated the questionnaire investigation, 19.0% (169/888) knew that it could cause cancer. In addition, 60.6% of people reported that they intended to keep eating raw fish despite knowing the risk of infection. The two primary reasons for continuing to eat raw fish were the disease being regarded as not serious (38.3%) and the belief that anti-parasite medications are effective (39.6%). A total of 94.4% (797/844) of responders reported eating raw fish more frequently in the home than outside of the home. Our study revealed a notably high C. sinensis prevalence in the study area. Awareness of clonorchiasis disease severity should be increased among high-risk individuals and families in highly endemic areas.

Effectiveness of health education in improving knowledge, practice and belief related to clonorchiasis in children

Clonorchiasis is caused by the ingestion of raw freshwater fish containing Clonorchis sinensis larvae. Health education is crucial in sustainable control of clonorchiasis but extremely challenging when dealing with adults. To investigate if education in children would be a beneficial long-term approach, a cluster-controlled trial was implemented in two primary schools between 2017 and 2019 in Binyang county, Guangxi, China. A baseline survey was conducted in both schools, and then comprehensive education activities were implemented in the interventional one. Six and 12 months later, all pupils were subjected to a survey to assess the potential change of knowledge, practice and belief related to clonorchiasis. Finally, 247 pupils in interventional school and 151 ones in control were eligible for analysis. In the interventional school, the percentage of pupils with knowledge on transmission route, early symptoms, complications and carcinogenicity increased from 15.0% to 78.5% (p < 0.001), from 6.5% to 36.8% (p < 0.001), from 4.0% to 93.9% (p < 0.001) and from 4.5% to 49.4% (p < 0.001) after 12 months. In this school, 16 pupils (6.5%) had eaten raw freshwater fish during the year immediately before the baseline survey, a number that decreased to 3 (1.2%) (p = 0.002) 12 months later. The percentage of students had the belief on the ability not to eat raw freshwater fish in the future was 70.9% at the baseline and 97.2% 12 months later (p < 0.001). Although knowledge related to clonorchiasis also increased in the control school, the absolute percentage of changes was lower; in particular, practice and belief had not changed.

Rapid screening of Clonorchis sinensis infection: Performance of a method based on raw-freshwater fish-eating practice

Clonorchis sinensis infection is caused by ingestion of raw freshwater fish containing the infective larvae of Clonorchis sinensis. It is highly endemic in East Asia, especially in China. Selective chemotherapy of people who report habitual eating of raw freshwater fish is a control measure. As the performance of this screening technique has not yet been fully evaluated in China, a cross-sectional study was conducted, covering 17 counties in four major clonorchiasis-endemic provinces. About 1 000 participants were enrolled from each county. Fecal samples were collected and examined for helminth eggs and each person enrolled was asked about their practice with respect to eating raw freshwater fish. In total, 16 230 participants from 16 counties were finally included. The overall prevalence of C. sinensis infection was 10.8%, ranging from 0 to 53.7% in the 16 counties, while the percentage of inhabitants eating raw freshwater fish was 26.5%, ranging from 0 to 79.1%. The overall sensitivity and specificity of screening for C. sinensis infection in this approach was 82.3% and 80.3%, respectively, yielding a Youden's index of 0.6. The overall positive and negative likelihood ratios were 4.2 and 0.2, respectively, while the overall positive and negative predictive values were 33.5% and 97.4%, respectively. Furthermore, the sensitivity was higher with regard to high-intensity infections compared to light infections.

Familial assimilation in transmission of raw-freshwater fish-eating practice leading to clonorchiasis

Clonorchiasis is caused by raw-freshwater fish-eating practice and causes high burden in Asia. Transmission mechanism of this behavior hasn't been illuminated, which hinders the adoption of sustainable control activities. A cross-sectional survey was implemented in students from four endemic provinces in China. Data with 23,222 students aged 9-18 and their parents were eligible. Familial clustering of raw-eating practice, impact of parents' practice on children, interaction of spouses' practice was analyzed. Raw-eating practice met β-binomial distribution (χ2 = 0.8, p>0.05). Clustering coefficient increased by students' age (R2 = 0.82, p<0.001) and was higher in those families with boys compared to girls (t = 4.1, p<0.01). The proportion of students with raw-eating practice increased yearly by 8.9% in girls and 10.5% in boys. Compared to those without parents' raw-eating practice, adjusted odds ratio of students' raw-eating practice was 10.5 (95% confidential intervals (95% CI): 9.4-11.7) in those with fathers' practice, 33.6 (95% CI: 26.3-42.9) in those with mothers' practice and 47.1 (95% CI: 42.0-52.8) in those with both parents' practice. There existed interaction between spouses' practice (χ2 = 6713.1, p<0.001) and the impact from husband on his wife was higher than that from wife on her husband. Familial assimilation characterizes the transmission of raw-freshwater fish-eating practice, consisted of vertical intergenerational assimilation from parents to their children and horizontal martial assimilation between spouses. A sustainable strategy against clonorchiasis should interrupt the transmission of raw-freshwater fish-eating practice. Additionally, further studies are expected to explore more information, e.g. the frequency in raw-eating practice and type of raw freshwater fish, infection status of C. sinensis in participants, as well as direct collection of parents' eating information from themselves.

Clonorchiasis in Patients with Biliary and Pancreatic Diseases: Diagnosis and Risk Factors

Background

Many epidemiological studies have investigated the risk factors for clonorchiasis, but endoscopic findings of this disease in endoscopic retrograde cholangiopancreatography (ERCP) have not been well characterized. In this study, we evaluated clonorchiasis in ERCP in patients with biliary and pancreatic diseases.

Methods

This was a retrospective two-center study in hospitalized patients who received ERCP between January 2012 and October 2018. All patients were divided into clonorchiasis and nonclonorchiasis groups. Data were analyzed using univariate analysis and multivariate analyses.

Results

A total of 1119 patients were included, and clonorchiasis was diagnosed in 19.2% patients. Detection of Clonorchis sinensis eggs in bile samples was higher than that in fecal samples (85.9% vs. 58.7%; P = 0.001). In multivariate analysis, male patients (95% confidence interval (CI): 1.945-4.249, P = 0.001). In multivariate analysis, male patients (95% confidence interval (CI): 1.945-4.249, P = 0.001). In multivariate analysis, male patients (95% confidence interval (CI): 1.945-4.249, P = 0.001). In multivariate analysis, male patients (95% confidence interval (CI): 1.945-4.249, P = 0.001). In multivariate analysis, male patients (95% confidence interval (CI): 1.945-4.249, P = 0.001). In multivariate analysis, male patients (95% confidence interval (CI): 1.945-4.249.

Conclusions

The detection of C. sinensis eggs was significantly higher in bile than in fecal samples; thus, bile samples represent a preferable sample for the diagnosis of clonorchiasis in patients with biliary obstruction. We found that male, age ≤ 60 years old, and CBD diameter < 12 mm were independent risk factors for clonorchiasis, while papilla fistula was a protective factor.C. sinensis eggs was significantly higher in bile than in fecal samples; thus, bile samples represent a preferable sample for the diagnosis of clonorchiasis in patients with biliary obstruction. We found that male, age ≤ 60 years old, and CBD diameter < 12 mm were independent risk factors for clonorchiasis, while papilla fistula was a protective factor.

From awareness to action: NIPD's engagement in the control of food-borne clonorchiasis

Clonorchiasis is caused by ingestion of raw freshwater fish containing infective larvae of Clonorchis sinensis. China harbours the largest number of people with C. sinensis infection. During the past three decades, the National Institute of Parasitic Diseases, affiliated to the Chinese Center for Disease Control and Prevention (NIPD) conducted many studies to facilitate the control on clonorchiasis. Three national surveys have shown the updated epidemiology of clonorchiasis in China. Recently, a national surveillance system has also been established, which will enable the production of high-resolution map. The evaluation of the disease burden has enhanced the awareness on clonorchiasis. Diverse diagnosis techniques including rapid screening by questionnaire, serological tests, faecal examination and a molecular method have been developed or evaluated. The NIPD also participated in the early evaluation of praziquantel against clonorchiasis, which enhanced its application in China. Also, the NIPD has verified the efficacy of tribendimidine against clonorchiasis. A new sustainable strategy is also being explored. However, more research is expected to further facilitate control of clonorchiasis in China, as well as international cooperation in fighting human liver fluke infections in Asia.

Association between eosinophil count and cholelithiasis among a population with Clonorchis sinensis infection in Foshan City, China

The association between eosinophil count and cholelithiasis among people with Clonorchis sinensis infection is still uncertain. We conducted a cross-sectional study to investigate the associations among Clonorchis sinensis infection, eosinophil count and cholelithiasis. The study included 4628 participants from January to December 2018. The levels of eosinophil count were divided into four groups according to the quartiles of eosinophil count. Spearman's rank correlation was performed to assess the association between eosinophil counts and Clonorchis sinensis egg counts. Multiple regression analysis was performed to evaluate the relationships among C. sinensis infection, eosinophil count and cholelithiasis after adjusting for three models. The prevalence of C. sinensis infection was 38.72% (1792/4628), and the prevalence of cholelithiasis was 6.03% (279/4628). The infection rate of C. sinensis was higher in the cholelithiasis group than in the non-cholelithiasis group (63.08% vs. 37.16%, P < 0.001). Significant differences were found among various eosinophil count quartiles for C. sinensis infection, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GT), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA) and non-alcoholic fatty liver disease (NAFLD) (all P < 0.001). A significant positive correlation was found between eosinophil count and log-transformed C. sinensis egg count (r = 0.9477, P < 0.001). Multiple logistic regression analysis revealed that light and moderate intensities of C. sinensis infection were associated with cholelithiasis (P < 0.01 and P < 0.001, respectively), and C. sinensis infection with eosinophil count ranging from 0.05 to 0.5 × 109/l were associated with cholelithiasis (P < 0.05). In conclusion, our findings suggest that the light and moderate infections of C. sinensis with eosinophil count ranging from 0.05 to 0.5 × 109/l may be associated with a higher risk of cholelithiasis.

Improving diagnostic performance of the Kato-Katz method for Clonorchis sinensis infection through multiple samples

BACKGROUND

Clonorchiasis is caused by eating of raw or undercooked freshwater fish containing the larvae of Clonorchis sinensis; the Kato-Katz method is widely applied in diagnosis. The improvement of repeated Kato-Katz smears from multiple stool samples has been well illuminated in many helminths other than C. sinensis.

METHODS

A cross-sectional investigation was implemented to capture the epidemiology and risk factors of clonorchiasis among middle school students in Qiyang county, China. Students with complete data of six Kato-Katz thick smears from two stool samples were included in this analysis. Data on the habits of eating raw freshwater fish were also collected and compared.

RESULTS

Altogether, 397 students had complete information of six smears, out of which 394 reported the information on eating habits. According to the 'gold' standard by six smears, 77 students (19.4%) were detected with C. sinensis. However, only 45 (11.3%) were detected using a single smear, with an underestimation of 41.6% compared to the 'gold' standard. However, the geometric mean of eggs per gram of feces in detected cases was 126.4 in a single smear, overestimated by 105.2% compared to 61.6 by the 'gold' standard. The linear relationship between prevalence and infection intensity of detected cases based on different smears was significantly negative. The habits of eating raw freshwater fish in the false negative cases was similar to those in the detected cases, but these two groups had significantly higher levels for habits of eating raw freshwater fish than negative individuals.

CONCLUSIONS

In low endemicity situations, underestimation of C. sinensis infection could not be avoided based on a limited number of Kato-Katz smears. Thus, repeated smears from at least two stool samples should be considered when an individual eats raw freshwater fish, drug efficacy is evaluated or elimination of C. sinensis is verified. Additionally, when logistics are insufficient for multiple samples to be taken for diagnosis for survey and surveillance in the areas or populations of low endemicity, prevalence accuracy needs to be corrected.

Association of circulating inflammation proteins and gallstone disease

BACKGROUND AND AIM

Inflammation plays a role in the development of both gallstones and gallbladder cancer; however, few studies have investigated the association of circulating inflammation proteins with risk of gallstones.

METHODS

This study measured 13 cytokines (including 10 interleukins [ILs]) that have been associated with cancer in serum samples collected from 150 gallstone patients and 149 population-based controls from Shanghai, China, in 1997-2001. This study estimated the associations of each cytokine, categorized into quartiles and coded as a trend, with risk of gallstones using logistic regression models adjusted for potential confounders.

RESULTS

Higher levels of IL-6, IL-10, IL-12 (p70), and IL-13 were associated with increased risk of gallstones (i.e. P_trend  < 0.003, Bonferroni corrected), with odds ratios (ORs) that ranged from OR_{highest quartile [Q4] versus lowest quartile [Q1]}  = 3.2 (95% confidence interval: 1.4, 7.5) for IL-13 to OR_{Q4 versus Q1}  = 5.7 (95% confidence interval: 2.5, 13.5) for IL-12 (p70). In a regression model including all four ILs, only IL-12 retained statistical significance (P < 0.05).

CONCLUSION

This study found four circulating ILs that were associated with gallstones. Future studies are needed to validate the findings and evaluate the common pathway or mechanism in the development of gallbladder diseases associated with these cytokine signatures.

Secreted phospholipase A2 of Clonorchis sinensis activates hepatic stellate cells through a pathway involving JNK signalling

BACKGROUND

Secreted phospholipase A2 (sPLA2) is a protein secreted by Clonorchis sinensis and is a component of excretory and secretory products (CsESPs). Phospholipase A2 is well known for its role in liver fibrosis and inhibition of tumour cells. The JNK signalling pathway is involved in hepatic stellate cells (HSCs) activation. Blocking JNK activity with SP600125 inhibits HSCs activation. In a previous study, the protein CssPLA2 was expressed in insoluble inclusion bodies. Therefore, it's necessary to express CssPLA2 in water-soluble form and determine whether the enzymatic activity of CssPLA2 or cell signalling pathways is involved in liver fibrosis caused by clonorchiasis.

METHODS

Balb/C mice were given an abdominal injection of MBP-CssPLA2. Liver sections with HE and Masson staining were observed to detect accumulation of collagen. Western blot of mouse liver was done to detect the activation of JNK signalling pathway. In vitro, HSCs were incubated with MBP-CssPLA2 to detect the activation of HSCs as well as the activation of JNK signalling pathway. The mutant of MBP-CssPLA2 without enzymatic activity was constructed and was also incubated with HSCs to check whether activation of the HSCs was related to the enzymatic activity of MBP-CssPLA2.

RESULTS

The recombinant protein MBP-CssPLA2 was expressed soluble and of good enzymatic activity. A mutant of CssPLA2, without enzymatic activity, was also constructed. In vivo liver sections of Balb/C mice that were given an abdominal injection of 50 μg/ml MBP-CssPLA2 showed an obvious accumulation of collagen and a clear band of P-JNK1 could be seen by western blot of the liver tissue. In vitro, MBP-CssPLA2, as well as the mutant, was incubated with HSCs and it was proved that activation of HSCs was related to activation of the JNK signalling pathway instead of the enzymatic activity of MBP-CssPLA2.

CONCLUSIONS

Activation of HSCs by CssPLA2 is related to the activation of the JNK signalling pathway instead of the enzymatic activity of CssPLA2. This finding could provide a promising treatment strategy to interrupt the process of liver fibrosis caused by clonorchiasis.

A comparative study of mud-like and coralliform calcium carbonate gallbladder stones

To gain insight to underlying mechanism of the formation of calcium carbonate (CaCO₃ ) gallbladder stones, we did comparative study of stones with mud appearance and those with coralliform appearance. A total of 93 gallbladder stones with mud appearance and 50 stones with coralliform appearance were analyzed. The appearance, color, texture, and the detection of Clonorchis sinensis eggs by microscopic examination were compared between the two groups. Then, the material compositions of stones were analyzed using Fourier Transform Infrared spectroscopy and the spectrogram characteristics were compared. Moreover, microstructure characteristics of the two kinds of stones were observed and compared with Scanning Electron Microscopy. Mud-like gallbladder stones were mainly earthy yellow or brown with brittle or soft texture, while coralliform stones were mainly black with extremely hard texture, the differences between the two groups was significant (p < .05). The analytic results of FTIR spectroscopy showed that 95.7% (89/93) of the mud-like gallbladder stones were CaCO₃ stones, and mainly aragonite; while all of the coralliform stones were CaCO₃ stones, and mainly calcite (p < .05). Meanwhile, microscopic examination indicated that the detection rate of Clonorchis sinensis eggs in mud-like CaCO₃ stones was lower than that in coralliform CaCO₃ stones (p < .05), and that in aragonite CaCO₃ stones was lower than that in calcite CaCO₃ stones(p < .05). Mud-like CaCO₃ stones mainly happened to patients with cystic duct obstruction. Clonorchis sinensis infection was mainly associated with coralliform (calcite) CaCO₃ stones. Cystic duct obstruction was mainly associated with mud-like (aragonite) CaCO₃ stones.

Increased hepatic Th2 and Treg subsets are associated with biliary fibrosis in different strains of mice caused by Clonorchis sinensis

Previous studies showed that CD4⁺T cells responses might be involved in the process of biliary fibrosis. However, the underlying mechanism resulting in biliary fibrosis caused by Clonorchis sinensis remains not yet fully elucidated. The objectives of the present study were to investigate the different profiles of hepatic CD4⁺T cell subsets (Th1, Th2, Th17 and Treg cells) and their possible roles in the biliary fibrosis of different strains of mice (C57BL/6, BALB/c and FVB mice) induced by C. sinensis infection. C57BL/6, BALB/c and FVB mice were orally gavaged with 45 metacercariae. All mice were sacrificed on 28 days post infection in deep anesthesia conditions. The leukocytes in the liver were separated to examine CD4⁺T cell subsets by flow cytometry and the left lobe of liver was used to observe pathological changes, collagen depositions and the concentrations of hydroxyproline. The most serious cystic and fibrotic changes appeared in FVB infected mice indicated by gross observation, Masson’s trichrome staining and hydroxyproline content detection. In contrast to C57BL/6 infected mice, diffuse nodules and more intensive fibrosis were observed in the BALB/c infected mice. No differences of the hepatic Th1 subset and Th17 subset were found among the three strains, but the hepatic Th2 and Treg cells and their relative cytokines were dramatically increased in the BALB/c and FVB infected groups compared with the C57BL/6 infected group (P<0.01). Importantly, increased Th2 subset and Treg subset all positively correlated with hydroxyproline contents (P<0.01). This result for the first time implied that the increased hepatic Th2 and Treg cell subsets were likely to play potential roles in the formation of biliary fibrosis in C. sinensis-infected mice.

Clonorchis sinensis, an oriental liver fluke, as a human biological agent of cholangiocarcinoma: a brief review

Parasitic diseases remain an unarguable public health problem worldwide. Liver fluke Clonorchis sinensis is a high risk pathogenic parasitic helminth which is endemic predominantly in Asian countries, including Korea, China, Taiwan, Vietnam, and the far eastern parts of Russia, and is still actively transmitted. According to the earlier 8^th National Survey on the Prevalence of Intestinal Parasitic Infections in 2012, C. sinensis was revealed as the parasite with highest prevalence of 1.86% in general population among all parasite species surveyed in Korea. This fluke is now classified under one of the definite Group 1 human biological agents (carcinogens) by International Agency of Research on Cancer (IARC) along with two other parasites, Opisthorchis viverrini and Schistosoma haematobium. C. sinensis infestation is mainly linked to liver and biliary disorders, especially cholangiocarcinoma (CCA). For the purposes of this mini-review, we will only focus on C. sinensis and review pathogenesis and carcinogenesis of clonorchiasis, disease condition by C. sinensis infestation, and association between C. sinensis infestation and CCA. In this presentation, we briefly consider the current scientific status for progression of CCA by heavy C. sinensis infestation from the food-borne trematode and development of CCA.

Four Major Factors Contributing to Intrahepatic Stones

Intrahepatic stone is prevalent in Asian countries; though the incidence declines in recent years, the number of patients is still in a large quantity. Because of multiple complications, high recurrence rates, serious systemic damage, and a lack of extremely effective procedure for the management, it is more important to find out the etiology and pathogenesis of intrahepatic stones to prevent the disease from happening and developing rather than curing. A number of factors contribute to the development of the disease, such as cholestasis, infection, and anatomic abnormity of bile duct and bile metabolic defect. The four factors and possible pathogenesis will be discussed in detail in the review.

Clonorchiasis

On Aug 21, 1875, James McConnell published in The Lancet his findings from a post-mortem examination of a 20-year-old Chinese man--undertaken at the Medical College Hospital in Calcutta, India--in whom he found Clonorchis sinensis in the bile ducts. Now, exactly 140 years later, we have a sound understanding of the lifecycle of this liver fluke, including key clinical, diagnostic, and epidemiological features. Developments in the so-called -omics sciences have not only advanced our knowledge of the biology and pathology of the parasite, but also led to the discovery of new diagnostic, drug, and vaccine targets. C sinensis infection is primarily related to liver and biliary disorders, especially cholangiocarcinoma. Clonorchiasis mainly occurs in east Asia, as a result of the region's social-ecological systems and deeply rooted cultural habit of consuming raw freshwater fish. The Kato-Katz technique, applied on fresh stool samples, is the most widely used diagnostic approach. Praziquantel is the treatment of choice and has been considered for preventive chemotherapy. Tribendimidine showed good safety and therapeutic profiles in phase 2 trials and warrants further investigation. Still today, the precise distribution, the exact number of infected people, subtle morbidities and pathogenesis, and the global burden of clonorchiasis are unknown. Integrated control strategies, consisting of preventive chemotherapy; information, education, and communication; environmental management; and capacity building through intersectoral collaboration should be advocated.

Integrated control programmes for schistosomiasis and other helminth infections in P.R. China

The prevalence of human schistosomiasis and soil-transmitted helminthiasis (STH) has decreased significantly in the People's Republic of China (P.R. China), particularly after 2005 when the national control programmes were reinforced by forming of integrated control strategies. Furthermore, social-economic development also contributed to the decrease of schistosome and soil-transmitted helminth infections. The prevalence of the zoonotic helminthiasis, including clonorchiasis and echinococcosis, on the other hand, is either underestimated or has in fact increased due to changes in social and environmental factors. In comparison with the control strategies in force and their effects on those four kinds of helminthiasis, the challenges and control priorities for the potential transfer from control to elimination of each disease is reviewed, to provide evidence for policy-makers to act upon.

Clonorcis sinensis eggs are associated with calcium carbonate gallbladder stones

Calcium carbonate gallbladder stones were easily neglected because they were previously reported as a rare stone type in adults. The aim of this study was to investigate the relationship between calcium carbonate stones and Clonorchis sinensis infection. A total of 598 gallbladder stones were studied. The stone types were identified by FTIR spectroscopy. The C. sinensis eggs and DNA were detected by microscopic examination and real-time fluorescent PCR respectively. And then, some egg-positive stones were randomly selected for further SEM examination. Corresponding clinical characteristics of patients with different types of stones were also statistically analyzed. The detection rate of C. sinensis eggs in calcium carbonate stone, pigment stone, mixed stone and cholesterol stone types, as well as other stone types was 60%, 44%, 36%, 6% and 30%, respectively, which was highest in calcium carbonate stone yet lowest in cholesterol stone. A total of 182 stones were egg-positive, 67 (37%) of which were calcium carbonate stones. The C. sinensis eggs were found adherent to calcium carbonate crystals by both light microscopy and scanning electron microscopy. Patients with calcium carbonate stones were mainly male between the ages of 30 and 60, the CO2 combining power of patients with calcium carbonate stones were higher than those with cholesterol stones. Calcium carbonate gallbladder stones are not rare, the formation of which may be associated with C. sinensis infection.

Acute cholecystitis associated with Clonorchis sinensis infection

Clonorchis sinensis is one of the most common causes of trematodiasis that is caused by the ingestion of raw fish contaminated with infective cysts. The adult flukes are predominantly present in the intrahepatic bile ducts, but occasionally they may be found in the pancreatic duct and extrahepatic bile ducts. The clinical manifestations depend on the number of flukes, the period of infestation, and complications such as pericholangitic abscess, cholangitis, bile duct stones, and cholangiocarcinoma. However, primary acute cholecystitis associated with C. sinensis infection is extremely rare. Herein, we report on a case of primary acute cholecystitis associated with C. sinensis infection.

Relationship between morphological changes and survival status of Clonorchis sinensis eggs and gallstone formation

AIM: To explore the relationship between Clonorchis sinensis (C. sinensis) infection and gallstone formation by observing the morphology and survival status of C. sinensis eggs in gallbladder bile, biliary sludge and gallstones from gallstone patients with C. sinensis infection.

METHODS: Twenty gallstone patients with C. sinensis infection were enrolled in this study. Their gallbladder bile, biliary sludge and gallbladder stones were collected to observe the morphology of C. sinensis eggs using optical microscopy and scanning electron microscopy (SEM). Von Kossa staining and X-ray energy dispersive spectroscopy were used to analyze the calcium content on the surface of eggs and the substance surrounding them. Trypan blue staining was used for evaluating the survival rate of eggs.

RESULTS: In gallbladder bile, 88.3% of C. sinensis eggs had typical morphology, while 56.7% of eggs in biliary sludge and 91.5% in stones were deformed (including changes in shape and size, egg cover loss, invisible internal miracidia and adhesion bilirubin on the surface or in their surroundings). Under SEM, egg shell showed an uneven texture shape, and its surface and surroundings were adhered with mucus-like substances in varying degrees. The calcium content of egg surface and surroundings gradually increased from the bile, biliary sludge to stones. The survival rates of eggs in bile, biliary sludge and stones were 86.6%, 42.1% and 11.5%, respectively.

CONCLUSION: In patients infected with C. sinensis, C. sinensis eggs can remain in the gallbladder by their uneven texture-like egg shell and mucus-like substance from the biliary tract. Eggs can be further deformed, degenerated, and even calcified to nucleation, resulting in the formation of biliary sludge and participating in gallstone formation.

The systematic classification of gallbladder stones

Background

To develop a method for systematic classification of gallbladder stones, analyze the clinical characteristics of each type of stone and provide a theoretical basis for the study of the formation mechanism of different types of gallbladder stones.

Methodology

A total of 807 consecutive patients with gallbladder stones were enrolled and their gallstones were studied. The material composition of gallbladder stones was analyzed using Fourier Transform Infrared spectroscopy and the distribution and microstructure of material components was observed with Scanning Electron Microscopy. The composition and distribution of elements were analyzed by an X-ray energy spectrometer. Gallbladder stones were classified accordingly, and then, gender, age, medical history and BMI of patients with each type of stone were analyzed.

Principal Findings

Gallbladder stones were classified into 8 types and more than ten subtypes, including cholesterol stones (297), pigment stones (217), calcium carbonate stones (139), phosphate stones (12), calcium stearate stones (9), protein stones (3), cystine stones (1) and mixed stones (129). Mixed stones were those stones with two or more than two kinds of material components and the content of each component was similar. A total of 11 subtypes of mixed stones were found in this study. Patients with cholesterol stones were mainly female between the ages of 30 and 50, with higher BMI and shorter medical history than patients with pigment stones (P<0.05), however, patients with pigment, calcium carbonate, phosphate stones were mainly male between the ages of 40 and 60.

Conclusion

The systematic classification of gallbladder stones indicates that different types of stones have different characteristics in terms of the microstructure, elemental composition and distribution, providing an important basis for the mechanistic study of gallbladder stones.

Microscopic examination of gallbladder stones improves rate of detection of Clonorchis sinensis infection

To improve the rate of detection of Clonorchis sinensis infection, we compared different specimens from patients with cholecystolithiasis. Feces, gallbladder bile, and gallbladder stones collected from 179 consecutive patients with cholecystolithiasis underwent microscopic examination, and according to the results, 30 egg-positive and 30 egg-negative fecal, gallbladder bile, and gallbladder stone specimens, respectively, underwent real-time fluorescent PCR. The detection rates of eggs in feces, bile, and gallbladder stones were 30.7%, 44.7%, and 69.8%, respectively, and the differences were statistically significant (P<0.01). The PCR results confirmed that the eggs in the specimens were C. sinensis eggs. Eggs in the feces were "fresh" and in the gallbladder stones were "old." Microscopic examination of gallbladder stones may improve the detection rates of C. sinensis infection, which is important for developing individualized treatments to prevent the recurrence of gallbladder stones and to prevent the occurrence of severe liver damage and cholangiocarcinoma.

Identification and biochemical characterization of adenylate kinase 1 from Clonorchis sinensis

Adenylate kinase 1 is responsible for the conversion of AMP into ADP involved in purine metabolism. In the present study, adenylate kinase 1 gene (CsADK1) was isolated from an adult cDNA library of Clonorchis sinensis, and the recombinant protein was expressed in Escherichia coli. Bioinformatics analysis implied that the putative protein contained 197 amino acids, and some residues in conservative binding sites of CsADK1 were substituted. The structure modeling analysis showed that CsADK1 was composed of a core domain, an NMP-binding domain, and a LID domain, which was just a small loop. It demonstrated that CsADK1 was a short isoform of ADKs. Moreover, CsADK1 was identified as an excretory/secretory product by western blot analysis. Real-time quantitative PCR showed that expression level of CsADK1 at the stage of excysted metacercaria was higher than those of adult worm (18.8-folds, P<0.01), metacercariae (1.5-folds, P<0.01), and eggs (5.6-folds, P<0.01). In addition, histochemistry analysis showed that CsADK1 was extensively distributed in metacercariae and in the vitellaria and eggs of adult worms. The Km and Vmax value for substrate ADP were 2.2 mM and 0.9 mM/min, respectively. The optimal temperature and pH value were 37 °C and from 7.5 to 8.0, respectively. The enzyme activity was highly dependent on Mg2+, and the optimal concentration of Mg2+ was 2 mM. However, the enzyme activity was slightly activated by Ca2+, and Mn2+ has no effect on activity. For monovalent ions, activity was highly activated by K+ and NH4+, but slightly by Li+. Taken together, CsADK1 was a metal ion-dependent enzyme involved in purine metabolism, which was important for development and reproduction, and might be a potential candidate for drug target for clonorchiasis.

A microstructural study of gallbladder stones using scanning electron microscopy

OBJECTIVE

The objective of this study was to describe the microstructure of different types of gallbladder stones to better understand the basis of gallbladder stone formation.

METHODS

Gallbladder stones from 387 patients with cholecystolithiasis were first analyzed by Fourier transform Infrared spectroscopy to identify the type of the gallbladder stone, and they were then examined using scanning electron microscopy to define their microstructure.

RESULTS

Cholesterol stones were mainly composed of plate-like or lamellar cholesterol crystals stacked tightly in a radial, cord-like, or irregular staggered arrangement. A small number of bilirubinate particles were seen occasionally. Pigment stones were mainly composed of loosely arranged bilirubinate particles with different shapes (sphere-like, clumping-like, or amorphous). Calcium carbonate stones were composed of calcium carbonate crystals having many shapes (bulbiform, ellipsoid, fagot-shaped, fusiform, hawthorn-shaped, cuboid, button-shaped, lamellar, broken firewood-shaped, rod-shaped, acicular, or crushed sugar cane-shaped). Bulbiform shaped crystals were the most common. Phosphate stones were mainly composed of different sized echin-sphere-like or rough bulbiform crystals. Bilirubinate particles were always adherent. Calcium stearate stones usually had a network structure with adherent bilirubinate particles. Protein stones usually had a honeycomb or chrysanthemum petal-like structure. Cystine stones were composed of hexagonal cystine crystals, some of which had prominent edges. Mixed stones presented different shapes according to their mixed components.

CONCLUSION

Different types of gallbladder stones had characteristic shapes and elements. This study provides an objective basis for further research regarding gallbladder stone formation.