Hookworm infection remains a major public health concern in the Lao People’s Democratic Republic (Lao PDR), where it is endemic nationwide and particularly prevalent in remote communities. However, information regarding species-specific identification is limited. This study aimed to determine the prevalence of hookworm infection and identify the infecting species among humans, dogs, and cats in both northern and southern regions of the Lao PDR. A cross-sectional study was conducted between May and July 2023 in Luangprabang Province (northern Lao PDR) and Champasak Province (southern Lao PDR). All residents aged 18 years and older who were present during the survey period and met the inclusion criteria were enrolled. In addition, dogs and cats owned by enrolled participants and/or their household members were included. Hookworm infection was detected by identifying eggs in preserved stool samples using the formalin-ethyl acetate concentration technique (FECT). Species identification was performed using polymerase chain reaction (PCR) targeting the internal transcribed spacer (ITS) region to amplify Necator americanus (485 bp) and Ancylostoma spp. (380 bp), followed by sequencing analysis of stool samples preserved in 70

Opisthorchis viverrini (OV) is a liver fluke endemic to the Lower Mekong Basin. Infections often begin in childhood and are causally linked to cholangiocarcinoma, an often-fatal bile duct cancer. Anthelmintic treatment is the primary control strategy, but infection can recur. Therefore, additional strategies are needed. This study assessed the impact of “The Magic Glasses Opisthorchiasis” (MGO), a cartoon-based intervention, on schoolchildren’s OV-related knowledge, attitudes and practices (KAP). A cluster (school)-randomised controlled trial was conducted in Cambodia, Laos and Thailand. Clusters were randomised into either school health education only or with MGO. OV KAP was measured using a standardised questionnaire. FGDs and interviews were also conducted in intervention schools with schoolchildren, parents, and teachers. Cambodia intervention knowledge and attitude scores improved by 19.2 (p < 0.001) and 25.3 (p < 0.001) percentage points, respectively, relative to the control. Laos intervention knowledge and attitude scores improved by 19.0 (p < 0.001) and 14.2 (p < 0.001) percentage points. However, Thailand’s intervention knowledge and attitude scores declined by 23.3 (p < 0.001) and 15.8 percentage points (p < 0.001). There were no improvements in behaviour scores in any country, but parents and schoolchildren in Cambodia and Laos reported improved fish preparation practices, suggesting positive spillover effects from MGO. The findings support MGO as an effective tool for school-based health education.

BackgroundDespite the widespread implementation of water, sanitation and hygiene (WASH) program over the last two decades, Lao People's Democratic Republic (Lao PDR) remains highly endemic for intestinal helminth infections. We assessed the intestinal helminth infections burden and the link with WASH levels in an area with WASH interventions.MethodA cross-sectional study was conducted across 81 villages in Khammouane province, Lao PDR, where WASH interventions were implemented. Villages and 30 participants (aged 18-87 years) per village were randomly selected. Demographics, individual and household data, including WASH-related factors were collected. Stool samples were examined for intestinal helminth infections using formalin-ethyl acetate concentration technique (FECT). Logistic regression analysis was performed to identify risks associated with intestinal helminth infections.ResultsA total of 1530 participants were included. Multi-helminth species infection was very common, e.g., 30.1% had a double infection. Opisthorchis viverrini was most prevalent (56.9%), followed by hookworm (54.7%), minute intestinal flukes (22.7%), and Trichostrongylus spp. (10.7%). Overall, 56.1% and 44.4% had access to safely management water services and sanitation facilities, respectively, and 17.7% practiced open defecation. Improved WASH levels were not associated with reduced intestinal helminth infections. District of residence, age, gender and raw food consumption predicted helminth infections. E.g., O. viverrini infection was associated with residency in Mahaxai district (Mahaxai, aOR = 14.0; 95% CI = 9.5-20.6; p < 0.001 and Bulapha, aOR = 3.0; 95% CI = 2.0-4.4; p < 0.001).ConclusionOur findings indicate a high intestinal helminth infections burden in this province, with several risk factors such as location, age, gender and consumption of raw food predicting helminth infection. Improved WASH levels are not associated with reduces prevalence of intestinal helminth infection in this cross-sectional study.

Intestinal helminth infection in children remains a significant public health concern. In Lao People's Democratic Republic various water (Lao PDR), sanitation and hygiene (WASH) interventions were implemented. This study aims to assess the infection burden of intestinal helminths in children and adolescents and explore association with different WASH levels in Khammouane province. A cross-sectional study was conducted in 81 villages across three districts with prior WASH interventions in Khammouane province. Stool samples were collected from households members aged 5 - 17 years. Data was collected from parents/caregivers regarding demography, and potential risk factors. Intestinal helminth infections were detected using formalin-ethyl acetate concentration technique (FECT). Random effect logistic regression identified factors associated with infections. Among 512 participants, 12.5% had multiple intestinal helminth species infections. Opisthorchis viverrini was the most prevalent infection (35.4%), followed by hookworm (30.3%) and minute intestinal flukes (11.3%). District of residence, sex and wealth index measurement were significantly associated with intestinal helminth infection, e.g. O. viverrini was significantly associated with living in Boualapha (OR = 5.9, 95% CI = 2.2 - 20.9) or Mahaxai district (OR = 12.8, 95%CI =4.9 - 44.1). WASH levels were not statistically significant predictors of helminth infections. Children and adolescents in Khammouane province, Lao PDR, have a high burden of intestinal helminth infection, particularly O. viverrini and hookworm. Socio-demographics factors (district, sex and wealth measurement) were the most important predictors of helminth infections. Comprehensive control programs, including species-specific strategies such as safe food handling and proper cooking, are essential to reduce infection risk in this vulnerable population.

Strongyloidiasis is caused by a parasitic worm, primarily Strongyloides stercoralis. In rural settings of Côte d’Ivoire, parasitological surveys have revealed that the prevalence of S. stercoralis infection can reach up to 50

Background:Hypertension (HT) is a major risk factor for adult morbidity and mortality in low- and middle-income countries and little is known regarding the distribution of HT risk and treatment access within urban areas. Patients and methods:We used data from the Vientiane Multi-Generational Birth Cohort in urban Lao PDR to assess the prevalence of loss and retention across five stages of HT care for 40+ year old adults: i) prevalence of hypertension, ii) hypertensives who ever had their BP measured by a health care professional, iii) hypertensives ever diagnosed with HT by a professional, iv) patients currently treated with HT medication, and v) patients with currently controlled BP. We estimated associations between sociodemographic and lifestyle predictors and the proportion of participants who reached each care cascade step using mutually adjusted Poisson regression modeling. Results:Among the 3196 participants aged 40 to 99 years, the overall prevalence of HT was 16.3%, with higher rates for women, people over 60 years, peripheral district residents, low educated, widowed, and obese. Among people with HT, 90.2% ever had their BP measured by a health care professional, 69.3% ever received a HT diagnosis, 60.9% HT were currently on (drug) treatment, and 39.5% had currently controlled BP. The largest cascade of care losses occurred at the diagnosis and control stages with better outcomes for women. While central districts showed higher rates of diagnosis, control levels were lower than in peripheral districts, but there these differences appeared to be explained by adjusting for sociodemographic and lifestyle factors. Conclusion:While HT prevalence in Lao PDR is lower than reported for other LMICs, more than 16% over the age of 40 years suffer from HT, and 60% of these cases are currently not controlled. Major policy efforts are needed to support this population and to prevent HT-driven excess mortality.

Hepatitis A and E viruses (HAV and HEV) are transmitted through the faecal-oral route: via contaminated food, water, and contact with infected people and/or animals for HEV. Due to limited data from Lao People's Democratic Republic (Lao PDR), we assessed HAV and HEV seroprevalence in the Lao general population. A cross-sectional study collected 2412 serum samples and demographic information from participants (5-93 years) across five provinces. Anti-HAV (IgM and IgG) and anti-HEV antibodies (IgG) were detected by enzyme-linked immunosorbent assay (Dia.Pro). The overall seroprevalence of anti-HAV was 84.3% and anti-HEV was 57.9%. Seropositivity was associated with occupation, location, increasing age, ethnicity (only for anti-HAV) and sex (only for anti-HEV). The age at which 50% of the population was seropositive differed from 12 years (Oudomxay) to 26 years (Savannakhet and Vientiane) for anti-HAV and from 22 years (Savannakhet) to 49 years (Vientiane) for anti-HEV. The prevalence of double seropositivity was high overall (53.4%), particularly in Savannakhet and Champasack. These significant differences according to location and socio-demographics may be the result of variation of exposure to the viruses, such as through water, sanitation and hygiene-related risks, occupational exposure and animal contact. Further studies are warranted to identify the most important risks for transmission in Lao PDR in order to develop targeted public health interventions.

Strongyloides stercoralis infection is a neglected tropical disease with a global distribution. Serodiagnosis is a sensitive method, but improving its performance and simplifying into a point-of-care test (POCT) are needed. This study aimed to improve the diagnostic performance of serological tests using partially purified Strongyloides ratti antigen in an enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic test (ICT). Crude S. ratti antigen was purified by an IgG affinity column to partition the antigen into flow-through, washing fraction (WF), and elution fractions. Optimized ELISA and ICT using crude and antigen fractions were used to analyze sera from three groups of subjects. Group 1 comprised subjects with proven strongyloidiasis, Group 2 were subjects with other parasitic infections, and Group 3 were negative parasitic infections. The diagnostic performance and Kappa agreement of the serological tests were analyzed and compared, using larvae detection as the reference test (fecal examination). The results showed that the WF was the most efficient antigen in terms of sensitivity and specificity, as determined by the ELISA and ICT. Kappa’s agreement between fecal examination and WF-ELISA was moderate (Kappa = 0.52), and WF-ICT was almost perfect (Kappa = 0.94). The WF antigen reduced cross-reactivity to other parasitic infections, that is, Opisthorchis viverrini, Taenia spp., and hookworms, compared to crude S. ratti antigen when assessed by ELISA and ICT. We concluded that the WF of purified S. ratti improved the ELISA and ICT diagnostic performance, and the latter assay format could be used as a POCT for screening and controlling strongyloidiasis.IMPORTANCEThis study aimed to improve the serological diagnosis of strongyloidiasis, a disease caused by infection with the intestinal nematode Strongyloides stercoralis, by evaluating the impact of Strongyloides ratti antigen purification using an IgG affinity column for detecting parasite-specific IgG in serum via enzyme-linked immunosorbent assay (ELISA) and immunochromatographic test (ICT) formats. Compared to crude S. ratti antigen, the washing fraction (WF) of the purified antigen demonstrated significantly improved sensitivity and specificity in both ELISA and ICT, achieving strong diagnostic concordance with the gold-standard fecal examination. Furthermore, the WF antigen fraction exhibited reduced cross-reactivity with coinfections caused by the liver fluke (Opisthorchis viverrini), tapeworms (Taenia spp.), and hookworms. These findings underscore antigen purification as a promising strategy to enhance the accuracy of strongyloidiasis serodiagnosis.

Opisthorchis viverrini is a water-based disease-causing parasite whose public health implications are relevant in Southeast Asia. Untreated or chronic infections often lead to severe hepatobiliary morbidity including cholangiocarcinoma, a lethal bile duct cancer. The liver fluke O. viverrini can be contracted by consumption of raw fish, after which it settles in the small biliary ducts. The life cycle involves, besides freshwater snails in which asexual reproduction takes place, freshwater cyprinid fish as intermediate hosts. Piscivorous mammals, including humans, dogs and cats, are definitive hosts. Here, we propose a spatially explicit model for the transmission dynamics in realistic freshwater environments. Our model generalises existing local-scale models by assimilating novel spreading mechanisms in space and time. Our study emphasises that spatial connectivity is key to shaping patterns of disease spread. Fish distribution and mobility through river corridors affect disease transmission routes. Our study provides baseline information on the role of connected freshwater bodies and their suitability for intermediate and final hosts. The distributions of fish catch and fish market supplies are also considered because they affect the spatiotemporal spread of opisthorchiasis. Adding a spatial component to transmission models fundamentally changes the description of epidemiological dynamics and the related scenarios of disease propagation through an improved description of the ecology of hosts, parasites and their transmission cycles. This work provides a more realistic description of the environment where infection cycles develop and spread than previous modelling attempts did, thus allowing a better characterisation of transmission routes and enabling a proper design of containment measures.

ABSTRACT There have been several Water, Sanitation, and Hygiene (WASH) interventions in Lao People's Democratic Republic (Lao PDR). We aimed to determine the relationship of exposure to two faecal‐orally transmitted pathogens, hepatitis A virus (HAV) and hepatitis E virus (HEV), with WASH levels and other factors. A cross‐sectional study conducted in three districts in Khammouane Province enrolled 2300 participants aged 5 to 87 years by random sampling. Anti‐HAV and anti‐HEV antibodies were detected by enzyme‐linked immunosorbent assay. The relationship between serology (outcome), WASH and other variables was determined by bivariate and multivariable analysis. Overall, 12.0% of participants had surface water as a water source, 22.0% practiced open defecation and 66.9% had basic hygiene facilities. Anti‐HAV IgG seropositivity was 63.2% and 57.5% were anti‐HEV seropositive. The mean age at which 50% of the population were positive for anti‐HAV and anti‐HEV was 24 and 27 years old, respectively. Anti‐HAV seroprevalence was lower in those with improved sanitation than those practicing open defecation (OR = 0.6, 95%CI = 0.4–0.8, p = 0.001) and higher in adults consuming undercooked meat (OR = 1.5, 95%CI = 1.1–2.0, p = 0.01). It also varied by district, ethnicity, education and age. Anti‐HEV seroprevalence was lower in those with improved water source than those using surface water (OR = 0.6, 95%CI = 0.4–0.8, p = 0.002) and higher in adults consuming raw meat (OR = 1.3, 95%CI = 1.0–1.7, p = 0.04). Anti‐HEV seroprevalence varied by district, sex, education, and age. Khammouane province has low levels of WASH leading to high transmission of HAV and HEV. Reducing the practice of open defecation and other risk practices such as undercooked meat consumption may reduce transmission as well as consideration of HAV vaccine introduction for younger ages.

BackgroundOpisthorchis viverrini (OV) is a major public health concern in the Lower Mekong Basin. This study aimed to synthesize all field-based empirical research examining risk factors and control strategies for OV in the Lower Mekong Basin (LMB).MethodsWe performed a systematic review of published literature (1990-2024) on field-based OV studies that examined risk factors and control strategies in LMB. The literature search included two databases: PubMed and Scopus. We included field-based studies that analysed or reported on OV risk factors or control strategies using quantitative or mixed methods and were written in English. We excluded secondary research articles, laboratory-based research, qualitative only research and studies conducted outside LMB. All prospective studies underwent quality assessment using the Newcastle-Ottawa Scale or the Cochrane Risk of Bias tool II prior to final inclusion.ResultsWe identified 807 citations from PubMed and Scopus. From those, 56 studies were included in the review and three additional studies were identified from citation searches of included studies in the review. Studies were extracted and analysed by research focus. Among the included studies, 45 were conducted in Thailand, 11 in Laos, two in Vietnam, and one in Cambodia. Factors associated with OV infection were explored in 51 studies, and 11 studies reported on control strategies. General education was found to be an important protective factor for OV infection. Consumption of raw or undercooked fish was the most reported risk factor. Anthelmintic treatment was the primary control strategy across studies.ConclusionThis review summarises risk factors and control strategies reported in LMB since 1990. We found that sociodemographic, environmental, and economic factors were important predictors of OV infection. Given the multitude of risk factors for infection identified in this study and the complex lifecycle of OV, we recommend a One Health approach, that recognises the interconnectedness of human, animal and environmental health, for future health promotion and control strategies.Trial registrationPROSPERO registration ID: CRD42022357080.

Schistosomiasis mekongi is endemic in a restricted area in Northern Cambodia and the Southern Lao People's Democratic Republic. Severe hepatobiliary morbidity is associated with chronic untreated S. mekongi infection. Since the 1980s extensive control efforts have been employed in endemic areas, resulting in substantial reduction of infection rates and disease burden. We report on a patient with a fatal course of clinically-assessed chronic schistosomiasis. This report underscores that patients with severe chronic Mekong schistosomiasis may still exist and may need treatment support.

BACKGROUND:Achieving adequate mass drug administration (MDA) coverage for lymphatic filariasis is challenging. We sought to improve stakeholder engagement in MDA planning and increase subsequent MDA coverage through a series of microplanning workshops. METHODOLOGY:Prior to the 2018 MDA, Haiti's Ministry of Public Health and Population (MSPP) and partners conducted 10 stakeholder microplanning workshops in metropolitan Port-au-Prince. The objectives of the workshops were to identify and address gaps in geographic coverage of supervision areas (SAs); review past MDA performance and propose strategies to improve access to MDA; and review roles and responsibilities of MDA personnel through increased stakeholder engagement. Retrospective pre-testing was employed to assess the effectiveness of the workshops. Participants used a 5-point scale to rank their understanding of past performance, SA boundaries, roles and responsibilities, and their perceived engagement by MSPP. Participants simultaneously ranked their previous year's attitudes and their attitudes about MDA following the 2-day microplanning workshop. Changes in pre- and post-scores were analyzed using Wilcoxon signed-rank tests. PRINCIPAL FINDINGS:A total of 356 stakeholders across five communes participated in the workshops. Participants conducted various planning activities, including revising SA boundaries to ensure full geographic reach of MDA, proposing or validating social mobilization strategies, and proposing other MDA improvements. Compared with previous year rankings, the workshops increased participant understanding of past performance by 1.34 points (standard deviation [SD] = 1.05, p <0.001); SA boundaries by 1.14 points (SD = 1.30; p <0.001); their roles and responsibilities by 0.71 points (SD = 0.95, p <0.001); and sense of engagement by 1.03 points (SD = 1.08, p <0.001). Additionally, compared with 2017, drug coverage increased in all five communes during the 2018 MDA. CONCLUSIONS/SIGNIFICANCE:Participatory stakeholder workshops during MDA planning can increase self-reported engagement of key personnel and may improve staff performance and contribute to achievement of drug coverage targets. Microplanning success was supported by MDA results, with all communes achieving preset MDA coverage targets.

BackgroundHelminths are a major global health issue, impacting health, educational, and socioeconomic outcomes. Infections, often starting in childhood, are linked to anemia, malnutrition, cognitive deficit, and in chronic cases of Opisthorchis viverrini (OV), cholangiocarcinoma. The main control strategy for helminth infection is mass drug administration; however, this does not prevent reinfection. As such, prevention strategies are needed. The “Magic Glasses” is a school-based cartoon health education package that has demonstrated success in improving knowledge, attitudes, and practices (KAP) surrounding soil-transmitted helminths (STH) in China and the Philippines. This study is designed to assess the acceptability and impact of the 2 new versions of the Magic Glasses targeting STH and OV designed for the Lower Mekong audience in Cambodia, Lao People’s Democratic Republic (PDR), and Thailand. ObjectiveThe objective of this study is to evaluate the acceptability of the “Magic Glasses Lower Mekong” and “Magic Glasses Opisthorchiasis” education packages among schoolchildren in the Lower Mekong Basin, and the impact of these education packages on students’ KAP surrounding STH and OV, respectively. MethodsSchoolchildren will be recruited into a cluster randomized controlled trial with intervention and control arms in rural schools in Cambodia, Lao PDR, and Thailand. Schoolchildren’s initial acceptability of the intervention will be evaluated using an adapted questionnaire. Sustained acceptability will be assessed at 9-month follow-up through focus group discussions with students and interviews with teachers. Impact will be evaluated by KAP questionnaires on STH and OV. KAP questionnaires will be administered to children at baseline and at follow-up. Indirect impact on parents' KAP of OV and STH will be assessed through focus group discussions at follow-up. ResultsThe trial is in progress in Lao PDR and Thailand and is expected to commence in Cambodia in January 2024. The results of the study are expected to be available 18 months from the start of recruitment. We hypothesize that participants enrolled in the intervention arm of the study will have higher KAP scores for STH and OV, compared with the participants in the control arm at follow-up. We expect that students will have initial and sustained acceptability of these intervention packages. ConclusionsThis trial will examine the acceptability of the “Magic Glasses Opisthorchiasis” and “Magic Glasses Lower Mekong” interventions and provide evidence on the effectiveness of the “Magic Glasses” on KAP related to OV and STH among schoolchildren in the Lower Mekong Basin. Study results will provide insight on acceptability and impact indicators and inform a scaling up protocol for the “Magic Glasses” education packages in Cambodia, Lao PDR, and Thailand. Trial RegistrationAustralian New Zealand Clinical Trials Registry ACTRN12623000271606; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385315&isReview=true International Registered Report Identifier (IRRID)DERR1-10.2196/55290

Opisthorchis viverrini (OV) and soil-transmitted helminths (STH) are two of the most common helminths contributing to the Neglected Tropical Disease (NTDs) burden in the Lower Mekong Basin. Although mass drug administration is the cornerstone of control programs to reduce morbidity caused by these infections, this approach has limitations in preventing re-infections. Elimination requires additional measures such as reservoir host treatment, improved hygiene and health education to reinforce MDA's impact. This study aims to examine the impact of a scalable multi-component One Health Helminth Elimination program in the Lower Mekong Basin (HELM) that combines human praziquantel (PZQ) and albendazole (ALB) treatment with a program that includes the “Magic Glasses” and the “Lawa Model” interventions with health promotion at their core. This study will employ a cluster randomized controlled trial (cRCT) in 18 rural communities (with sub-district or villages as cluster units) across Cambodia, Laos and Thailand. The control arm will receive one round of PZQ/ALB treatment, while in the intervention arm, multi-component HELM program will be implemented, which includes PZQ/ALB treatment together with the Magic Glasses and Lawa Model interventions. OV and STH infections levels will be evaluated in individuals aged 5–75 years at baseline and will be repeated at follow-up (12 months after the HELM intervention), using modified formalin ethyl-acetate concentration technique and quantitative PCR. The primary outcome of the study will be cumulative incidence of human OV and STH infections. Outcomes between the study arms will be compared using generalized linear mixed models, accounting for clustering. Evidence from this trial will quantify the impact of a multi-component One Health control strategy in interrupting Ov and STH infections in the Lower Mekong Basin. Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12622000353796. Prospectively registered 28 February 2022.

BackgroundChildren in Lao People’s Democratic Republic (Lao PDR) receive suboptimal nutrition because of low breastfeeding rates, undermining their developmental potential. While major public health campaigns have attempted to increase breastfeeding rates, they have been largely unsuccessful. One explanation for these unsuccessful interventions is the economic and financial constraints faced by mothers. A potential solution for alleviating these pressures is providing social transfers to support breastfeeding; defined as a cash or in-kind transfer. Capitalizing on key strategies used in previous social transfer programs, we will assess the effectiveness of social transfer intervention for increasing exclusive breastfeeding rates in Vientiane, Lao PDR. ObjectiveThis study aims to conduct a randomized controlled trial (RCT) designed to assess whether social transfers can increase exclusive breastfeeding rates in Vientiane Capital, Lao PDR. MethodsA prospective, parallel cluster-RCT was conducted among 300 mothers who recently gave birth and initiated breastfeeding. Enrolling 100 participants for each intervention arm provided us with 80% power to detect an increase in exclusive breastfeeding from the anticipated 21% in the control arm to 40% in either of the 2 intervention arms. Mother-infant dyads were enrolled at approximately 1 month post partum. Follow-up visits will occur at 6 months, 1 year, 2 years, and 3 years post partum; with the ambition to extend the follow-up period. Mother-infant dyads were enrolled between August 2022 and April 2023 with follow-up until 3 years post partum (2026). A local study team comprised of 2 nurses and 2 laboratory technicians is responsible for enrollment and follow-up of participants. Participants were randomly assigned to one of three groups during the baseline, 1-month visit: (1) control group, no social transfer; (2) intervention group 1, an unconditional social transfer at 6 months post partum; and (3) intervention group 2, a social transfer at 6 months post partum conditional upon mothers exclusively breastfeeding. All groups received educational materials supporting mothers to exclusively breastfeed. The primary end point will be exclusive breastfeeding at 6 months post partum. Secondary end points will include exclusive and complementary breastfeeding duration, childhood wasting and stunting, child growth, maternal and infant stress, predictors of early breastfeeding cessation, intestinal inflammation, anemia, maternal weight loss, maternal blood pressure, maternal anxiety, and GRIT personality score. Questionnaires and physical examinations were used to collect information. ResultsAs of November 2023, the study has enrolled 300 participants. Study participation is ongoing until December 2026 at minimum. Over the study lifetime, 93% have completed all visits. ConclusionsWe see potential for a long-term program that may be implemented in other low- or lower-middle-income countries with only minor modifications. The RCT will be used as a basis for observational studies and to investigate the impact of human milk on child fecal microbiota and growth. Trial RegistrationClinicalTrials.gov NCT05665049; https://clinicaltrials.gov/study/NCT05665049 International Registered Report Identifier (IRRID)DERR1-10.2196/54768

IntroductionCholangiocarcinoma (CCA) is a major contributor to hepatobiliary mortality in the Lao People's Democratic Republic (Lao PDR). Infection with the carcinogenic trematode Opisthorchis viverrini (OV), acquired through consumption of insufficiently-cooked river fish, is a known risk factor for the development of CCA. Together with OV, other risk factors contribute to the pathogenesis of CCA. We conducted this study to identify the burden of CCA and identify risk factors in high-risk communities in Lao PDR.MethodA cross-sectional study was performed in Champasack and Savannakhet provinces, southern Lao PDR, where OV infection is highly endemic. We assessed hepatobiliary morbidity with abdominal ultrasound (US). In addition, multiple risk factors known or suspected to be associated with CCA were assessed such as OV infection (examined by Kato-Katz technique for stool examination), lifestyle risks (e.g. smoking and alcohol consumption by face-to-face questionnaire), co-morbidity (e.g. diabetes mellitus) and hepatitis B infection status, both serologically tested.ResultsIn 3,400 participants, the overall prevalence of suspected CCA was 7.2% (95% confidence interval [95% CI] 5.4-9.6). The suspected CCA prevalence increased with age, and was higher in men at all ages. Almost all participants (88.3%) were infected with OV. In the multivariate regression analysis, suspected CCA was positively associated with OV infection (adjusted odds ratio [aOR] 3.4, 95% CI 1.7-6.5), and a history of cholecystectomy (aOR 2.7, 95% CI 1.5-4.9).ConclusionOur CCA screening in high OV prevalence rural areas of Lao PDR uncovers a high public health burden, primarily driven by elevated OV infection rates. Urgent interventions are needed to curb OV infection in these communities. Age and gender disparities in suspected CCA prevalence highlight the need for targeted efforts. Beyond OV, notable factors like a history of cholecystectomy offer valuable insights for preventive strategies. This research enhances our understanding of hepatobiliary morbidity and informs public health initiatives in Lao PDR.

BACKGROUND:Steatotic liver disease (SLD) prevalence is rising worldwide, linked to insulin resistance and obesity. SLD prevalence can surpass 10% even among those with normal weight. In Lao People's Democratic Republic (Lao PDR), where Opisthorchis viverrini (OV) trematode infection and type 2 diabetes mellitus (T2DM) are common, infection related liver morbidity such as cholangiocarcinoma (CCA) is high, but data on SLD prevalence is lacking. The objective of this study was to estimate the prevalence and explore determinants of SLD in rural southern Lao PDR for lean and non-lean populations. METHOD:A cross-sectional community-based study assessed SLD prevalence using abdominal ultrasonography (US). Factors investigated for association with SLD were identified by interview, serological tests (Hepatitis B surface antigen (HBsAg); lipids and HbA1c), anthropometrical measurements, and parasitological assessments (OV infection). Uni- and multivariable logistic regression analyses with SLD as endpoint were conducted separately for lean (body mass index (BMI) <23.0 kg/m2) and non-lean (BMI ≥ 23.0 kg/m2) participants. RESULT:2,826 participants were included. SLD prevalence was 27.1% (95% confidence interval (95% CI) 24.0%-30.4%), higher among non-lean (39.8%) than lean individuals (17.4%). Lean individuals with OV infection had a statistically significant association with lower odds of SLD (adjusted odds ratio (aOR) 0.49, 95% CI 0.33 - 0.73). T2DM showed a significant positive association with SLD in both lean (aOR 3.58, 95% CI 2.28 - 5.63) and non-lean individuals (aOR 3.31, 95% CI 2.31 - 4.74) while dyslipidemia was significantly associated only in the non-lean group (aOR 1.83, 95% CI 1.09 - 3.07). Females participants exhibited elevated odds of SLD in both lean (aOR 1.43, 95% CI 1.02 - 2.01) and non-lean SLD (aOR 1.50, 95% CI 1.12 - 2.01). CONCLUSION:SLD prevalence is notably high among Laotian adults in rural areas, particularly in females and in non-lean individuals. Lean individuals with OV infection exhibited lower SLD prevalence. SLD was more prevalent in individuals with T2DM, independent of BMI. SLD adds to the burden of infection-related liver morbidity in Lao PDR.

Background Helminth infections, includingOpisthorchis viverrini, hookworm, andTrichuris trichiura, are prevalent in Khong district, Champasack province, southern Lao People’s Democratic Republic (PDR). Schistosomiasis caused bySchistosoma mekongi is of public health concern on the islands of the Khong district. This study aimed to assess the impact of an Eco-Health/One-Health approach in combination with mass drug administration (MDA) to reduce these helminth infections.Methods We conducted a community intervention using a stepped-wedge trial approach on two endemic islands (Donsom and Donkhone) of the Khong district, Champasack province, Lao PDR, between April 2012 and March 2013. In each study village, 30–40 households were randomly selected. All members of selected households, who were at home during the study period were invited to participate in the study. A baseline study was conducted to assess helminth infections, knowledge attitudes and practices towardSchistosoma mekongi infection, behavior of open defecation and availability of latrine at home. After the baseline (T0), the Eco-Health/One-Health approach was implemented on Donsom (intervention) and Donkhone island (control). An assessment was conducted in 2014 (T1), one year after the completion of intervention implementation, to assess the short-term impact of the Eco-Health/One-Health approach on helminth infections and compare intervention and control islands. Later in 2015, the Eco-Health/One-Health approach was implemented on control island (Donkhone). After the implementation of intervention, the parasitological assessments were conducted annually in humans in 2015 (T2), in 2016 (T3) and in 2017 (T4), and in dogs in 2017 (T4) to evaluate the long-term impact of the intervention on helminth infections. Frequency was used to describe the prevalence of helminth infections. Logistic regression was applied to associate the KAP (knowledge, attitudes, and practices and open defecation behavior) and the reduction of helminth infections between intervention and control islands. The reduction in prevalence pre- and post-intervention was associated using a McNemar test. A two-independent samplet-test was applied to compare the mean eggs per gram (EPG) of helminth infections between control and intervention islands. A paired t-test test was used to compare the mean EPG of stool samples before (baseline) and after (follow-up) interventions for the two islands separately. AP-value lower than 0.05 was considered statistically significant.Results Eco-Health/One-Health approach appears to be associated with reduction in prevalence ofS. mekongi by 9.0% [odds ratio (OR) = 0.49,P = 0.003] compared to the use of mass drug administration alone (control island). Additionally, this intervention package significantly reducedO. viverrini infection by 20.3% (OR = 1.92,P < 0.001) and hookworm by 17.9% (OR = 0.71,P = 0.045), respectively. Annual parasitological assessments between 2012 and 2017 showed that the Eco-Health/One-Health approach, coupled with MDA, steadily reduced the prevalence ofS. mekongi on the intervention island from 29.1% to 1.8% and on the control island from 28.4% to 3.1%, respectively.Conclusions The study findings suggest that the Eco-Health/One-Health approach appears to be associated with a significant reduction in prevalence ofS. mekongi and helminth co-infections, particularly hookworm andT. trichiura. Therefore, implementing the Eco-Health/One-Health approach in schistosomiasis-endemic areas could accelerate the achievement of national goals for transmission interruption by 2025 and elimination by 2030.

BackgroundRapid global population growth and urbanization have led to an increase in urban populations in low- and middle-income countries. Although these urban areas have generally better health outcomes than lower-income rural areas, many environmental, social, and health challenges remain. Vientiane, the capital of Lao People’s Democratic Republic (Lao PDR), has approximately 1.5 of the 7.5 million Laotian population (2022) and provides a unique opportunity to examine health outcomes among socioeconomically diverse populations in the rapidly urbanizing context of the country. ObjectiveThe aim of the Vientiane multigenerational birth cohort (VITERBI) project is to (1) establish a multigenerational birth cohort in Vientiane capital, Lao PDR, which is representative of the local population, (2) serve as the basis for additional observational (ie, cross-sectional) and intervention studies that promote population health in Vientiane province, and (3) investigate the social, epidemiological, and medical problems of public health importance to Lao PDR. MethodsVITERBI is a prospective multigenerational birth cohort. The study population is structured around children born between July 1, 2022, and June 30, 2023, who reside in Chanthabuly, Sikhottabong, Sangthong, or Mayparkngum districts of Vientiane. Whenever possible, children and their mothers are enrolled during pregnancy; nonreported pregnancies are enrolled after birth. The cohort plans to enroll 3000 pregnant women and their children and the infants’ fathers, grandparents, and great-grandparents for a total study population of approximately 13,000 individuals. Participants will be followed throughout the life course with a range of data collected, including demographics, behavior, diet, physical activity, physiology, neurodevelopment, health history, quality of life, environmental exposures, depression, anxiety, stress, resilience, household characteristics, obstetric history, birth outcomes, and various living and dementia scales for older adults. Biomarkers collected include height, weight, blood pressure, and hemoglobin levels. Currently, no statistical analyses are planned. ResultsAs of April 2024, this study has enrolled 3500 pregnant women and 4579 family members. Study participation is ongoing until May 2025 at minimum, with the goal to extend follow-up until 2050. ConclusionsThe study cohort will be used as a basis for further observational (cross-sectional, longitudinal) and intervention studies. It also serves as a tool to investigate social, epidemiological, and medical problems of public health importance to Lao PDR, which will contribute to broader understanding of regional and international contexts. International Registered Report Identifier (IRRID)DERR1-10.2196/59545