Spatial analysis of cholangiocarcinoma in relation to diabetes mellitus and Opisthorchis viverrini infection in Northeast Thailand.

Cholangiocarcinoma (CCA) exhibits a heightened incidence in regions with a high prevalence of Opisthorchis viverrini infection, with previous studies suggesting an association with diabetes mellitus (DM). Our study aimed to investigate the spatial distribution of CCA in relation to O. viverrini infection and DM within high-risk populations in Northeast Thailand. Participants from 20 provinces underwent CCA screening through the Cholangiocarcinoma Screening and Care Program between 2013 and 2019. Health questionnaires collected data on O. viverrini infection and DM, while ultrasonography confirmed CCA diagnoses through histopathology. Multiple zero-inflated Poisson regression, accounting for covariates like age and gender, assessed associations of O. viverrini infection and DM with CCA. Bayesian spatial analysis methods explored spatial relationships. Among 263,588 participants, O. viverrini infection, DM, and CCA prevalence were 32.37%, 8.22%, and 0.36%, respectively. The raw standardized morbidity ratios for CCA was notably elevated in the Northeast's lower and upper regions. Coexistence of O. viverrini infection and DM correlated with CCA, particularly in males and those aged over 60 years, with a distribution along the Chi, Mun, and Songkhram Rivers. Our findings emphasize the association of the spatial distribution of O. viverrini infection and DM with high-risk CCA areas in Northeast Thailand. Thus, prioritizing CCA screening in regions with elevated O. viverrini infection and DM prevalence is recommended.

Albumin levels in malaria patients: a systematic review and meta-analysis of their association with disease severity.

Albumin, a key protein in human blood plasma, has been linked to various health conditions. However, its association with malaria, particularly in assessing disease severity, remains inadequately understood. This comprehensive systematic review and meta-analysis aimed to elucidate the relationship between albumin levels and malaria severity. A comprehensive literature search was conducted across multiple databases, including Embase, Scopus, PubMed, MEDLINE, Ovid, and Google Scholar, to identify studies examining albumin levels in malaria patients. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Data were pooled using a random-effects model, and heterogeneity was assessed using I2 statistics. Subgroup and meta-regression analyses were performed based on publication year, study location, and Plasmodium species. A total of 37 studies were included in this review. The thematic synthesis indicated that albumin levels in malaria patients varied significantly based on geographical location. A meta-analysis of 28 studies found that albumin levels were significantly lower in malaria patients compared with non-malarial controls (P < 0.001, standardized mean differences [SMD] = -2.23, 95% CI - 3.25 to - 1.20, I2: 98%, random effects model, 28 studies). Additionally, subgroup analysis revealed variations in albumin levels based on geographical location and Plasmodium species. Regarding the association with disease severity, thematic synthesis showed that severe malaria cases generally had decreased albumin levels across various regions. However, one Brazilian study reported higher albumin levels in severe cases. A separate meta-analysis of five studies found significantly lower albumin levels in patients experiencing severe malaria relative to those with less severe forms of the disease (P < 0.001, SMD = -0.66, 95% CI - 1.07 to - 0.25), I2: 73%, random effects model, 5 studies). This study underscores the clinical significance of albumin as a potential biomarker for Plasmodium infection and the severity of malaria. The findings suggest that albumin level monitoring could be crucial in managing malaria patients, especially in assessing disease severity and tailoring treatment approaches. Additional studies are required to investigate the underlying mechanisms driving these associations and validate the clinical utility of albumin levels in malaria patient management.

Spatio-Temporal Analysis of Cholangiocarcinoma in a High Prevalence Area of Northeastern Thailand: A 10-Year Large Scale Screening Program.

BACKGROUND: Cholangiocarcinoma (CCA) is experiencing a global increase, particularly in Northeast Thailand, which has the highest global incidence rates. However, there is a paucity of studies on CCA screening, especially in high-risk populations. This study aimed to investigate the distribution and spatial patterns of CCA in Northeast Thailand over a ten-year screening period. METHODS: The study included CCA patients from the Cholangiocarcinoma Screening and Care Program (CASCAP) between 2013 and 2022, which encompasses 20 provinces and 282 districts in Northeast of Thailand. CCA data were based on pathological diagnosis to determine the distribution and spatial patterns. RESULTS: Of the 2,515 CCA patients, approximately two-thirds were males (63.98%), and the majority were aged over 55 years (72.72%), with a mean age of 61.12 ± 9.13 years. The highest percentage of CCA cases occurred in 2014 at 19.01% of all patients, followed by 2018 at 15.23%. The overall CCA incidence rate in Northeast Thailand over ten years was 32 per 100,000 population. Hotspot statistical analysis identified high-scoring geographic clusters in the upper and middle regions, showing a tendency to expand from hotspot areas into nearby areas. CONCLUSION: The distribution of CCA in Northeast Thailand has continued to rise over the past decade, particularly in the upper and middle regions. Targeted screening in high-risk areas and increased awareness of CCA risks are crucial to mitigate its impact.

Evaluating the Prognostic Factors and Survival Rates of Endometrial Cancer Patients in a Tertiary Referral Hospital in Northeast Thailand.

OBJECTIVES: This study aims to determine the 5-year and 10-year overall survival rates, mortality incidence, median survival time, and factors influencing the survival of endometrial cancer (EC) patients' post-diagnosis at the largest hospital in northeast Thailand. We particularly focus on the impact of access to health insurance schemes. METHODS: We conducted a retrospective analysis of data from EC patients admitted to Srinagarind Hospital between 2010 and 2019. Overall survival was estimated using the Kaplan-Meier method. Multivariate Cox regression analysis identified factors associated with survival, with results expressed as adjusted hazard ratios (AHR) and 95% confidence intervals (CI). RESULTS: Among the 673 patients, the 5-year overall survival rate stood at 76.43% (95% CI: 72.72-79.70), and the 10-year rate at 67.86% (95% CI: 62.98-72.25). Notably, advanced age (≥60 years), stage III and IV cancer, and non-endometrioid histopathology were found to significantly increase post-diagnosis mortality risk (AHR = 2.39, 3.13, 4.62; 95% CI: 1.03-5.53, 2.07-4.74, 2.66-8.04; p-value <0.05, <0.001, <0.001). Surprisingly, we observed no significant correlation between health insurance schemes and mortality risk, suggesting that different insurance programs did not significantly affect EC patient survival in this study. CONCLUSION: health insurance schemes had no significant impact on endometrial cancer patient outcomes in Thailand, likely due to comprehensive coverage. Treatment modalities, notably surgery, showed no statistically significant differences, possibly due to early diagnosis. High-risk groups may benefit from adjuvant therapy. Early surgical intervention is crucial, with its association with disease stage emphasized. These findings inform cancer care decisions and healthcare policy development.
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Association of Cholangiocarcinoma among People with Periductal Fibrosis.

BACKGROUND: Cholangiocarcinoma (CCA) is a highly fatal tumor, and the most favorable chance for long-term survival lies in curative resection. Periductal fibrosis (PDF), a precancerous condition associated with chronic inflammation of the bile ducts, can serve as a screening marker for CCA using hepatobiliary ultrasonography (US). However, limited studies have explored the relationship between PDF and CCA. This study aimed to investigate the association between PDF and CCA in a population at risk in Northeast Thailand. METHODS: The study included participants enrolled in the Cholangiocarcinoma Screening and Care Program (CASCAP) between 2013 and 2021 who underwent US. Histological evaluations were conducted following the standard protocol of the tertiary hospital at Khon Kaen University, Thailand. PDF was defined as the presence of fibrosis in the peripheral (PDF1), segmental (PDF2), or main bile duct (PDF3), diagnosed by well-trained general practitioners or radiologists. The association between PDF and CCA was assessed using multiple logistic regression, calculating adjusted odds ratios (AORs) and 95% confidence intervals (CIs). RESULTS: Out of 751,061 participants, the overall prevalence of PDF was 115,267 (15.35%), with an overall CCA rate of 0.11%. The rates of CCA were 0.1%, 0.15%, and 0.27% in participants with PDF1, PDF2, and PDF3, respectively. After adjusting for gender, age at enrollment, education levels, history of O. viverrini infection, smoking, and alcohol consumption, the AORs for CCA were 0.94 (95% CI: 0.74 - 1.20), 1.4 (95% CI: 1.03 - 1.91), and 2.52 (95% CI: 1.38 - 4.58) for participants with PDF1, PDF2, and PDF3, respectively. CONCLUSION: Our findings demonstrate a significant association between fibrosis of the segmental and main bile ducts (PDF2 and PDF3) and CCA, with the strongest association observed in participants with PDF3. Hepatobiliary US screening could serve as a valuable tool for early detection of CCA, enabling timely curative treatment.

Influence of misconceptions and inappropriate eating behaviors on Opisthorchis viverrini infection among at-risk populations undergoing cholangiocarcinoma screening in Northeastern Thailand.

Raw or undercooked freshwater fish consumption contributes to persistent Opisthorchis viverrini infection in Northeast Thailand. This study aims to assess the relationship between misconceptions, unhealthy eating habits, and O. viverrini infection. Data were obtained from the Cholangiocarcinoma Screening and Care Program in Northeast Thailand from 2019 to 2021. Participants were screened for O. viverrini annually over the following 2 years using the Kato-Katz technique. Misconceptions and unhealthy eating habits were assessed through questionnaires. The relationship between these factors and O. viverrini infection was evaluated using adjusted risk ratios (ARRs) and 95% confidence intervals (CIs) from generalized estimating equations under binomial regression framework. Of 5375 participants screened for O. viverrini over 3 years, infection rates were 21.53%, 10.7%, and 4.6% each year, respectively. Out of those, 636 participants responded to questions regarding misconceptions. Results showed that participants who believed in the efficacy of putting lime or red ants in Koi pla (raw fish salad) or eating Koi pla with white whiskey to kill parasites, and early-stage cholangiocarcinoma can be cured, were 41% (ARR, 1.41; 95% CI, 1.03-1.94) and 57% (ARR, 1.57; 95% CI, 1.06-2.33), respectively, more likely to be infected with O. viverrini. Our study confirms that belief in using lime or red ants in Koi pla or eating Koi pla with white whiskey to make it cooked, or early-stage cholangiocarcinoma can be cured, increases O. viverrini infection risk in high-risk populations. Changing health beliefs and eating habits is necessary to reduce O. viverrini infection and its risk to cholangiocarcinoma.

Digital Innovations (Isan Cohort).

Innovations in digital procedures are discussed and highlighted in this chapter providing a comprehensive background and an overview of the Cholangiocarcinoma Screening and Care Program (CASCAP), and the innovative data base known as the Isan cohort, including the O. viverrini - CCA module, tele-radiology, databases for pathology, surgery, palliative care, and a randomized controlled trial database.

Survival after Diagnosis of Cervical Cancer Patients at a Tertiary Referral Hospital in Northeast Thailand.

BACKGROUND: Cervical cancer (CC) is the third most common cancer in women globally, including Thailand, where the incidence rate was 16.2 cases per 100,000 individuals in 2018. Survival rates for patients with this condition have not improved over recent years. This study evaluated the survival rate and median survival time after diagnosis among CC patients, and investigated factors associated with survival in Northeast Thailand. METHODS: This study included CC patients admitted to the gynecological ward at Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand from 2010 to 2019. Survival rates and median survival time since the date of diagnosis and 95% confidence intervals (CIs) were calculated. Multiple cox regression was performed to investigate factors associated with survival which were quantified by adjusted hazard ratios (AHR) and their 95% CIs. RESULTS: Of 2,027 CC patients, the overall mortality incidence rate was 12.44 per 100 person-years (95% CI: 11.7 - 13.22), median survival time was 4.82 years (95% CI: 3.92 - 5.72), and 10-year survival rate was 43.16% (95% CI: 40.71 - 45.59). The highest 10-year survival rate was 87.85% (95% CI: 82.23 - 91.78) found among those with stage I CC, followed by those who received surgical treatment, which was 81.22% (95% CI: 74.47 - 86.35). Factors that were associated with decreased survival included age ≥60 years (AHR = 1.25; 95% CI: 1.07 - 1.46), health insurance with the Universal Health Coverage Scheme (UCS) (AHR = 6.26; 95% CI: 5.13 - 7.64), malignant neoplasms histopathology (AHR = 1.36; 95% CI: 1.07 - 1.74), and treatment with supportive care (AHR = 7.48; 95% CI: 5.22 - 10.71). CONCLUSION: Among patients diagnosed with CC, those with stage I had the highest 10-year survival rate. CC patients with older age, UCS, malignant neoplasms histopathology, and received supportive care showed the highest survival association.

Associations between ultrasound screening findings and cholangiocarcinoma diagnosis in an at-risk population.

The rate of cholangiocarcinoma (CCA) is increasing every year, especially in northeastern Thailand. Screening for CCA using ultrasonography (US) is the fastest technique to identify patients in early stage of CCA development. Currently, few studies have examined patterns of hepatobiliary abnormalities identified using US, which can be indicative of CCA. We aim to evaluate the rate of CCA and its relations to history of US findings. Our study included participants who underwent US and pathological diagnosis of CCA from the Cholangiocarcinoma Screening and Care Program, Northeast Thailand between 2013 and 2020. Data on histological findings were based on the standard protocol of the tertiary hospital at Khon Kaen University. CCA data is categorized into two groups (yes/no) to find the relationship with history of US findings. The adjusted odds ratio (AOR) and their 95% confidence intervals (CI) were used to evaluate the relationship obtained by multiple logistic regression. Of 1880 subjects who underwent US and a pathological diagnosis of CCA, the overall rate of CCA was 35.74%. CCA rate among those with liver mass (LM) was 54.85% and with dilated bile duct (DBD) was 62.01%. The relationship between DBD and CCA was highly significant (AOR = 3.46; 95% CI 2.74-4.36) followed by LM (AOR = 2.28; 95% CI 1.81-2.86) P value < 0.001. Our study reveals that US findings history have a strong association with CCA, especially in people diagnosed with DBD and LM. Therefore, these abnormalities can be indicators for suspected CCA diagnosis through US.

Association between the Number of Repeated Praziquantel Treatments and Kidney Parenchymal Change in Northeast Thailand.

BACKGROUND: In Northeast Thailand, Praziquantel (PZQ) is used to treat infection with the Opisthorchis viverrnini (OV). OV has highly prevalence in this area due to the traditional consumption of uncooked cyprinid fish. The nephrotoxic effects of PZQ metabolite excretion through the kidney have not been assessed yet. This study investigated the relationship between number of Praziquantel treatments and kidney parenchymal change. METHODS: A study was carried out on participants from the Cholangiocarcinoma Screening and Care Program (CASCAP) between 2013 - 2018. The frequency of PZQ use was reported using a standardized questionnaire. Kidney parenchymal change (KPC) was defined as having a kidney abnormality based on ultrasonography diagnosed by well-trained general practitioners. Adjusted odds ratios (ORs) measured associations between PZQ frequency and KPC controlling for the effects of other extraneous factors using multiple logistic regression. RESULTS: A total of 490,969 subjects with mean age of 55.2 (SD = 9.15) years were enrolled among them 62.1% were female. Prevalence of KPC was 1.2% while prevalence of KPC were 1.2%, 1.3%, 1.4%, and 1.5% for participants with one, two, three, and more than 3 PZQ treatment occasions respectively. Those dose-response relationship was statistically significant based on chi-square test for trend (p-value <0.001). After controlling for possible confounders, compared to non-treatment, subjects with more than 3 treatment occasions were 25% more likely to have a KPC positive result (OR = 1.25; 95% CI: 1.02 - 1.52; p-value = 0.028). CONCLUSION: The number of repeated PZQ treatments is statistically significantly related to KPC. This relationship could be included in health messaging for those who continue eating uncooked fish with an understanding that the OV infection can easily be cured by PZQ without any other health concerns. For positive OV cases, however, the known efficacy of PZQ could over-ride the small magnitude of the adverse effect.

Association of comorbidity between Opisthorchis viverrini infection and diabetes mellitus in the development of cholangiocarcinoma among a high-risk population, northeastern Thailand.

BACKGROUND: Cholangiocarcinoma (CCA) is a category of lethal hepatobiliary malignancies. Previous studies have found that Opisthorchis viverrini infection and diabetes mellitus (DM) are closely correlated with CCA. However, few studies have discussed the association of CCA with a combination of both O. viverrini infection and DM. This study aimed to assess the correlation of CCA with various combinations of O. viverrini infection and DM among a high-risk population in northeastern Thailand. METHODOLOGY: This study included participants from 20 provinces in northeastern Thailand who had been screened for CCA in the Cholangiocarcinoma Screening and Care Program (CASCAP) between 2013 and 2019. Histories of O. viverrini infection and DM diagnosis were obtained using a health questionnaire. CCA screening used ultrasonography with a definitive diagnosis based on histopathology. Multilevel mixed-effects logistic regression was performed to quantify the association, which is presented as adjusted odds ratios (aOR) and their 95% confidence intervals (CI). PRINCIPAL FINDINGS: Overall, 263,776 participants were included, of whom 32.4% were infected with O. viverrini, 8.2% were diagnosed with DM, and 2.9% had a history of both O. viverrini infection and DM. The overall rate of CCA was 0.36%. Of those infected with O. viverrini, 0.47% had CCA; among those with DM, 0.59% had CCA and among those infected with O. viverrini and had DM, 0.73% had CCA. Compared with participants who were not infected with O. viverrini and were non-DM, the aOR for those infected with O. viverrini and with DM was 2.36 (95% CI: 1.74-3.21; p-value <0.001). CONCLUSIONS: The combination of O. viverrini infection and DM was highly associated with CCA, and these two conditions had a combined effect on this association that was greater than that of either alone. These findings suggest that CCA screening should have a strong focus on people with a combination of O. viverrini infection and DM.

Opisthorchis viverrini and Strongyloides stercoralis mono- and co-infections: Bayesian geostatistical analysis in an endemic area, Thailand.

Parasitic infections caused by Opisthorchis viverrini and Strongyloides stercoralis remain a major public health threat in the Greater Mekong Sub-region. An understanding of climate and other environmental influences on the geographical distribution and emergence of parasitic diseases is a crucial step to guide targeted control and prevention programs. A parasitological survey was conducted from 2008 to 2013 and included 12,554 individuals (age between 20 and 60 years) from 142 villages in five districts in Khon Kaen Province, Thailand. Geographical information systems, remote sensing technologies and a Bayesian geostatistical framework were used to develop models for O. viverrini and S. stercoralis mono- and co-infections in areas where both parasites are known to co-occur. The results indicate that male sex, increased age, altitude, precipitation, and land surface temperature have influenced the infection rate and geographical distribution of mono- and co-infections of O. viverrini and S. stercoralis in this area. Males were 6.69 times (95% CrI: 5.26-8.58) more likely to have O. viverrini - S. stercoralis co-infection. We observed that O. viverrini and S. stercoralis mono-infections display distinct spatial pattern, while co-infection is predicted in the center and southeast of the study area. The observed spatial clustering of O. viverrini and S. stercoralis provides valuable information for the spatial targeting of prevention interventions in this area.

Survival after surgery among patients with cholangiocarcinoma in Northeast Thailand according to anatomical and morphological classification.

BACKGROUND: Cholangiocarcinoma (CCA) has been categorized based on tumor location as intrahepatic (ICCA), perihilar (PCCA) or distal (DCCA), and based on the morphology of the tumor of the bile duct as mass forming (MF), periductal infiltrating (PI) or intraductal (ID). To date, there is limited evidence available regarding the survival of CCA among these different anatomical and morphological classifications. This study aimed to evaluate the survival rate and median survival time after curative surgery among CCA patients according to their anatomical and morphological classifications, and to determine the association between these classifications and survival. METHODS: This study included CCA patients who underwent curative surgery from the Cholangiocarcinoma Screening and Care Program (CASCAP), Northeast Thailand. The anatomical and morphological classifications were based on pathological findings after surgery. Survival rates of CCA and median survival time since the date of CCA surgery and 95% confidence intervals (CI) were calculated. Multiple cox regression was performed to evaluate factors associated with survival which were quantified by hazard ratios (HR) and their 95% CIs. RESULTS: Of the 746 CCA patients, 514 had died at the completion of the study which constituted 15,643.6 person-months of data recordings. The incidence rate was 3.3 per 100 patients per month (95% CI: 3.0-3.6), with median survival time of 17.8 months (95% CI: 15.4-20.2), and 5-year survival rate of 24.6% (95% CI: 20.7-28.6). The longest median survival time was 21.8 months (95% CI: 16.3-27.3) while the highest 5-year survival rate of 34.8% (95% CI: 23.8-46.0) occurred in the DCCA group. A combination of anatomical and morphological classifications, PCCA+ID, was associated with the longest median survival time of 40.5 months (95% CI: 17.9-63.0) and the highest 5-year survival rate of 42.6% (95% CI: 25.4-58.9). The ICCA+MF combination was associated with survival (adjusted HR: 1.45; 95% CI: 1.01-2.09; P = 0.013) compared to ICCA+ID patients. CONCLUSIONS: Among patients receiving surgical treatment, those with PCCA+ID had the highest 5-year survival rate, which was higher than in groups classified by only anatomical characteristics. Additionally, the patients with ICCA+MF tended to have unfavorable surgical outcomes. Showed the highest survival association. Therefore, further investigations into CCA imaging should focus on patients with a combination of anatomical and morphological classifications.

Spatial analysis of hepatobiliary abnormalities in a population at high-risk of cholangiocarcinoma in Thailand.

Cholangiocarcinoma (CCA) is a serious health challenge with low survival prognosis. The liver fluke, Opisthorchis viverrini, plays a role in the aetiology of CCA, through hepatobiliary abnormalities: liver mass (LM), bile duct dilation, and periductal fibrosis (PDF). A population-based CCA screening program, the Cholangiocarcinoma Screening and Care Program, operates in Northeast Thailand. Hepatobiliary abnormalities were identified through ultrasonography. A multivariate zero-inflated, Poisson regression model measured associations between hepatobiliary abnormalities and covariates including age, sex, distance to water resource, and history of O. viverrini infection. Geographic distribution was described using Bayesian spatial analysis methods. Hepatobiliary abnormality prevalence was 38.7%; highest in males aged > 60 years (39.8%). PDF was most prevalent (20.1% of males). The Standardized Morbidity Ratio (SMR) for hepatobiliary abnormalities was highest in the lower and upper parts of the Northeast region. Hepatobiliary abnormalities specifically associated with CCA were also more common in males and those aged over 60 years and distributed along the Chi, Mun, and Songkram Rivers. Our findings demonstrated a high risk of hepatobiliary disorders in Northeast Thailand, likely associated with infection caused by O. viverrini. Screening for CCA and improvement of healthcare facilities to provide better treatment for CCA patients should be prioritized in these high-risk areas.

A comparison of the proportion of early stage cholangiocarcinoma found in an ultrasound-screening program compared to walk-in patients.

BACKGROUND: Patients with cholangiocarcinoma (CCA) usually have no specific symptoms until an advance stage of the disease and curative treatment is not possible. Patients with early stage, operable disease can be found using ultrasonography (US). A US-screening program was implemented in Thailand where CCA incidence is the highest worldwide. Here we evaluate the effectiveness of the program by comparing the proportion of individuals with early stage CCA in the screening group with that of the walk-in group presenting at hospitals with clinical symptoms. METHODS: All patients had a pathological diagnosis of CCA. The difference in the proportions and the 95% confidence interval (CI) were obtained using binomial regression. RESULTS: Of the 762 histologically proven CCA cases, 161 were from the screening group and 601 from the walk-in group. The proportion of early stage CCA (stages 0 to II) diagnosed was 84.5% in the screening and 21.6% in the walk-in groups. After adjustment age, gender, and liver fluke infection, there was a significantly higher proportion (P < 0.001) and higher chance (P < 0.001) of having early stage CCA in the screening group than in the walk-in group. CONCLUSIONS: US-screening is an effective tool for detecting early stage, operable CCA in high incidence areas.

Bayesian spatial analysis of cholangiocarcinoma in Northeast Thailand.

Cholangiocarcinoma (CCA) is a malignant neoplasm of the biliary tract. Thailand reports the highest incidence of CCA in the world. The aim of this study was to map the distribution of CCA and identify spatial disease clusters in Northeast Thailand. Individual-level data of patients with histopathologically confirmed CCA, aggregated at the sub-district level, were obtained from the Cholangiocarcinoma Screening and Care Program (CASCAP) between February 2013 and December 2017. For analysis a multivariate Zero-inflated, Poisson (ZIP) regression model was developed. This model incorporated a conditional autoregressive (CAR) prior structure, with posterior parameters estimated using Bayesian Markov chain Monte Carlo (MCMC) simulation with Gibbs sampling. Covariates included in the models were age, sex, normalized vegetation index (NDVI), and distance to water body. There was a total of 1,299 cases out of 358,981 participants. CCA incidence increased 2.94 fold (95% credible interval [CrI] 2.62-3.31) in patients >60 years as compared to ≤60 years. Males were 2.53 fold (95% CrI: 2.24-2.85) more likely to have CCA when compared to females. CCA decreased with a 1 unit increase of NDVI (Relative Risk =0.06; 95% CrI: 0.01-0.63). When posterior means were mapped spatial clustering was evident after accounting for the model covariates. Age, sex and environmental variables were associated with an increase in the incidence of CCA. When these covariates were included in models the maps of the posterior means of the spatially structured random effects demonstrated evidence of spatial clustering.

Correction to: Repeated praziquantel treatment and Opisthorchis viverrini infection: a population-based cross-sectional study in northeast Thailand.

In the original publication of this article [1], there is an error in the section of 'Ethics approval and consent to participate' at the end of the article, the correct Ethics reference number should be HE551404 rather than HE591067.

Repeated praziquantel treatment and Opisthorchis viverrini infection: a population-based cross-sectional study in northeast Thailand.

BACKGROUND: Opisthorchis viverrini infection is highly prevalent in northeast Thailand. This liver fluke is classified as a carcinogen due to its causal links with cholangiocarcinoma (CCA) development. Although treatment with praziquantel (PZQ) effectively cures O. viverrini infection, the prevalence remains high due to the traditional consumption of raw fish. Therefore, re-infection is common in the endemic community, leading to severe hepato-biliary morbidities including the fatal CCA. In this study, we evaluate the association between the frequency of previous PZQ treatment and current O. viverrini infections among Thai adults living in the endemic area of northeast Thailand. METHODS: This study includes all participants who were screened for O. viverrini infection in the Cholangiocarcinoma Screening and Care Program (CASCAP), northeast Thailand. History of PZQ treatment was recorded using a health questionnaire. O. viverrini infections were diagnosed using urine antigen detection. Associations between PZQ and O. viverrini were determined by adjusted odds ratio (aOR) and 95% confidence interval (CI) using multiple logistic regression. RESULTS: Among participants, 27.7% had previously been treated once with PZQ, 8.2% twice, 2.8% three times, and 3.5% more than three times. Current O. viverrini prevalence was 17% (n = 524). Compared with participants who never used PZQ, the aOR for infection among those who used the drug once was 1.09 (95% CI: 0.88-1.37), twice was 1.19 (95% CI: 0.85-1.68), three times was 1.28 (95% CI: 0.74-2.21), and more than three times was 1.86 (95% CI: 1.18-2.93; P = 0.007). CONCLUSIONS: The population with a frequent history of PZQ use and still continued raw fish consumption showed high levels of repeated reinfection with O. viverrini. They were infected, treated and re-infected repeatedly. These findings suggest that certain participants continue raw fish consumption even after previous infection. This is a particular problem in highly endemic areas for O. viverrini and increases the risk of CCA.

Association between periductal fibrosis and bile duct dilatation among a population at high risk of cholangiocarcinoma: a cross-sectional study of cholangiocarcinoma screening in Northeast Thailand.

OBJECTIVES: To assess associations between periductal fibrosis (PDF) and bile duct dilatation (BDD) in ultrasonography (US) screening of population at risk of cholangiocarcinoma (CCA) due to residence in an endemic area for Opisthorchis viverrini. CCA survival rates are low, and early identification of risk factors is essential. BDD is one symptom that can identify patients at risk of CCA. Detection of PDF by US can also identify at-risk patients, at an earlier stage of CCA development. Identification of association between PDF and BDD will inform screening practices for CCA risk, by increasing the viability of PDF screening for CCA risk. SETTING: Nine tertiary care hospitals in Northeast Thailand. DESIGN: Cross-sectional study. PARTICIPANTS: Study subjects in the Cholangiocarcinoma Screening and Care Program (CASCAP) in Northeast Thailand. CASCAP inclusion criteria are all residents of Northeast Thailand aged ≥40 years. Participants are recruited through CCA screening centres and through primary healthcare units. So far, 394 026 have been enrolled. METHODS: PDF and BDD were identified through US. PDF was categorised into three groups, PDF1, 2 and 3, depending on their high echo locality in the peripheral, segmental and main bile duct, respectively. Associations between PDF and BDD were determined by adjusted OR and 95% CI using multiple logistic regression. RESULTS: BDD was found in 6.6% of PDF3, 1.7% of PDF2 and 1.4% of PDF1 cases. Among PDF cases, especially in PDF3, BDD was found in men more than in women (8.9% and 4.6%, respectively). Compared with non-PDF, the association between PDF3 and BDD was highly significant (adjusted OR=5.74, 95% CI 4.57 to 7.21, p<0.001). CONCLUSIONS: Our findings reveal that there is a relationship between PDF and BDD, which is associated with CCA. Therefore, PDF can also be an indicator for suspected CCA diagnosis through US.

Ecological Niche Model based on Maximum Entropy for mapping distribution of Bithynia siamensis goniomphalos, first intermediate host snail of Opisthorchis viverrini in Thailand.

The snail Bithynia siamensis goniomphalos acts as first intermediate host of the liver fluke, Opisthorchis viverrini, which causes opisthorchiasis in humans. In this study, we used a geographic information system (GIS), remote sensing (RS) and software using the maximum entropy (MaxEnt) algorithm to predict the distribution of B. s. goniomphalos in Thailand on the basis of environmental and climatic factors. The MaxEnt model for B. s. goniomphalos was excellent, with average test AUC values of 0.89. The predicted distribution of B. s. goniomphalos was affected by altitude, land cover, normalized difference vegetation index (NDVI), precipitation in the driest month (BIO 14), land surface temperature (LST) and soil pH. The areas suitable for B. s. goniomphalos were mostly in Northeast Thailand and some northern parts of the country. The presence of B. s. goniomphalos decreases with increasing altitude and increasing NDVI value. Bithynia s. goniomphalos is most likely to occur in paddy fields and cropland. Opisthorchiasis prevalence was directly proportional to the likelihood of snail occurrence as predicted by the model. This is the first time this ecological niche model has been used to predict Bithynia snail distribution and hence to provide a basis for future work of opisthorchiasis prevention in opisthorchiasis-endemic countries.