National Schistosomiasis Control Programme Research Articles

Impact of Mass Drug Distribution (MDD) of Praziquantel on Schistosomiasis through Sentinel Site Monitoring in Mali

Background—Mali was one of the first countries in sub-Saharan Africa to initiate a National Schistosomiasis Control Program (NSCP) in 1982. The WHO’s 2021–30 roadmap sets out the criteria for eliminating and controlling schistosomiasis as a public health problem. Our study aimed to assess the impact of annual mass drug distribution (MDD) of praziquantel (PZQ) on the prevalence and intensity in school-aged children (SAC) at NSCP sentinel sites (SSs). Methods—This study took place at twelve SSs in the Kayes and Koulikoro regions. Two-round cross-sectional studies were carried out in December 2014–2015 and in April 2018 after four to five years of annual MDD. Our sample size was 2439 schoolchildren aged 7 to 14 years, i.e., 485 in the first round (2014), 246 in the second round (2015) and 1708 in the third round (2018). Urine filtration and the Kato–Katz method were used for determining Schistosoma haematobium and S. mansoni eggs, respectively. Results—A total of 1708 samples were successfully examined. Of the twelve SSs treated from 2014–2015, one met the criterion for elimination of S. haematobium as a public health problem (prevalence of heavy-intensity infections (PHI) < 1%) (i.e., ≥50 S. haematobium eggs per 10 mL of urine or ≥400 S. mansoni eggs per g of stool) and four met the morbidity control criterion (PHI < 5%), while two sites remained below the morbidity control criterion (PHI > 5%). Five SSs had no heavy-intensity infections. The prevalence of S. mansoni was less than 1%. Conclusion—The impact of MDD of praziquantel in the SSs of the NSCP highlights that it has significantly reduced the PHI of schistosomiasis. However, the high prevalence of schistosomiasis or its increase in some sites requires in-depth studies.

High-quality acceleration of the Chinese national schistosomiasis elimination programme to advance the building of Healthy China

The goal of achieving elimination of schistosomiasis across all endemic counties in China by 2030 was proposed in the Outline of the Healthy China 2030 Plan. On June 16, 2023, the Action Plan to Accelerate the Elimination of Schistosomiasis in China (2023-2030) was jointly issued by National Disease Control and Prevention Administration and other 10 ministries, which deployed the targets and key tasks of the national schistosomiasis elimination programme in China. This article describes the progress of the national schistosomiasis control programme, analyzes the opportunities to eliminate schistosomiasis, and proposes targeted recommendations to tackle the challenges of schistosomiasis elimination, so as to accelerate the process towards schistosomiasis elimination and facilitate the building of a healthy China.

Unraveling trends in schistosomiasis: deep learning insights into national control programs in China.

To achieve the ambitious goal of eliminating schistosome infections, the Chinese government has implemented diverse control strategies. This study explored the progress of the 2 most recent national schistosomiasis control programs in an endemic area along the Yangtze River in China. We obtained village-level parasitological data from cross-sectional surveys combined with environmental data in Anhui Province, China from 1997 to 2015. A convolutional neural network (CNN) based on a hierarchical integro-difference equation (IDE) framework (i.e., CNN-IDE) was used to model spatio-temporal variations in schistosomiasis. Two traditional models were also constructed for comparison with 2 evaluation indicators: the mean-squared prediction error (MSPE) and continuous ranked probability score (CRPS). The CNN-IDE model was the optimal model, with the lowest overall average MSPE of 0.04 and the CRPS of 0.19. From 1997 to 2011, the prevalence exhibited a notable trend: it increased steadily until peaking at 1.6 per 1,000 in 2005, then gradually declined, stabilizing at a lower rate of approximately 0.6 per 1,000 in 2006, and approaching zero by 2011. During this period, noticeable geographic disparities in schistosomiasis prevalence were observed; high-risk areas were initially dispersed, followed by contraction. Predictions for the period 2012 to 2015 demonstrated a consistent and uniform decrease. The proposed CNN-IDE model captured the intricate and evolving dynamics of schistosomiasis prevalence, offering a promising alternative for future risk modeling of the disease. The comprehensive strategy is expected to help diminish schistosomiasis infection, emphasizing the necessity to continue implementing this strategy.

Tracking evaluation on the implementation of Survey of oncomelanid snails (WS/T 563-2017) in Sichuan and Anhui provinces

To evaluate the implementation of Survey of oncomelanid snails (WS/T 563-2017) in schistosomiasis-endemic foci, two schistosomiasis-endemic counties were selected from two provinces of Sichuan and Anhui. Professional staff working in province-, city-, county- and township-level disease control and prevention institutions, parasitic disease control institutions or medical institutions were recruited, and the understanding, use and implementation of Survey of oncomelanid snails (WS/T 563-2017) were investigated using questionnaires and interviews. The awareness, use, proportion of propagation and implementation and correct rate of answering questions pertaining to Survey of oncomelanid snails (WS/T 563-2017) were analyzed. A total of 270 questionnaires were allocated, and 269 were recovered, including 254 valid questionnaires. The overall awareness of Survey of oncomelanid snails (WS/T 563-2017) was 84.64% (215/254), and propagation and implementation of Survey of oncomelanid snails (WS/T 563-2017) was not performed in 23.28% (17/73) of the survey institutions following implementation of Survey of oncomelanid snails (WS/T 563-2017), with meeting training and allocation of propagation materials as the main type of propagation and implementation. Among 254 respondents, 77.16% (196/254) were familiar with the standard, 66.14% (168/254) understood the conditions for use of the standard during snail surveys, and 96.85% (246/254) had the approach for identifying snails. In addition, there were 41.73% (106/254), 50.78% (129/254) and 7.48% (19/254) of respondents that considered the operability of Survey of oncomelanid snails (WS/T 563-2017) was very good, good and general, respectively. The findings demonstrate that the issue and implementation of Survey of oncomelanid snails (WS/T 563-2017) has filled the gap for the standardization of snail control techniques, and which plays an importang guiding role in the national schistosomiasis control program.

The prevalence of urogenital and intestinal schistosomiasis among school age children (6-13 years) in the Okavango Delta in Botswana.

This study sought to investigate prevalence of urogenital and intestinal schistosomiasis among school age children 6-13 years in selected communities in the Okavango Delta. The termination of the Botswana national schistosomiasis control program in 1993 contributed to its neglect. An outbreak of schistosomiasis in 2017 at one of the primary schools in the northeastern part of the country resulted in 42 positive cases, indicating that the disease exists. A total of 1,611 school age children 6-13 years were randomly selected from school registers in 10 primary schools; from which 1603 urine and 1404 stool samples were collected. Macroscopic examination of urine and stool for color, odor, blood; viscosity, consistency, and the presence of worms. Urine filtration and centrifugation methods were used to increase sensitivity of detecting parasite ova. Kato-Katz and Formalin-Ether were used for the examination of stool samples. Data were analyzed using SPSS version 25. Results were expressed as odds ratio (OR) with their 95% CI and statistical significance set at p < 0.05. A total of (n = 1611) school age children 6-13 years participated in the study, mean age 9.7years (SD 2.06), females (54%) and males (46%). Results indicated an overall prevalence of SS. hematobium and S.mansoni at 8.7% and 0.64% respectively. Intensity of SS. hematobium was generally light (97.6%) and heavy intensity (2.4%). Results also revealed a knowledge deficit, about 58% of children had never heard of bilharzia even though they lived in communities where the disease was previously endemic. Learners who had a family member who previously suffered from schistosomiasis had higher knowledge than those who did not. Interestingly, these learners were likely to engage in risky behaviors compared to those with lower knowledge of the disease. An integrated approach that emphasizes health education, mass drug administration, water, sanitation, and hygiene infrastructure should be prioritized for prevention and control of schistosomiasis.

Transmission Risk Predicting for Schistosomiasis in Mainland China by Exploring Ensemble Ecological Niche Modeling

Schistosomiasis caused by Schistosoma japonicum is one of the major neglected tropical diseases worldwide. The snail Oncomelania hupensis is the only intermediate host of S. japonicum, which is recognized as an indicator of the schistosomias occurrence. In order to evaluate the risk of schistosomiasis in China, this work investigate the potential geographical distribution of host snail habitus by developing an ensemble ecological niche model with reference to the suitable environmental factors. The historical records of snail habitus were collected form the national schistosomiasis surveillance program from the year of 2005 to 2014. A total of 25 environmental factors in terms of the climate, geographic, and socioeconomic determinants of snail habitats were collected and geographically coded with reference to the snail data. Based on the correlations among snail habitats and the geographically associated environmental factors, an ensemble ecological niche model was developed by integrating ten standard models, aiming for improving the predictive accuracy. Three indexes are used for model performance evaluation, including receiver operating characteristic curves, kappa statistics, and true skill statistics. The model was used for mapping the risk of schistosomiasis in the middle and lower reaches of the Yangtze River. The results have shown that the predicted risk areas were classified into low risk (4.55%), medium risk (2.01%), and high risk areas (4.40%), accounting for 10.96% of the land area of China. This study demonstrated that the developed ensemble ecological niche models was an effective tool for evaluating the risk of schistosomiasis, particularly for the endemic regions, which were not covered by the national schistosomiasis control program.

Short-, Mid-, and Long-Term Epidemiological and Economic Effects of the World Bank Loan Project on Schistosomiasis Control in the People's Republic of China.

It is widely acknowledged that the 10-year World Bank Loan Project (WBLP) on schistosomiasis control in the People's Republic of China played an important role in raising the public and political profile of schistosomiasis, particularly regarding its prevention, control, and elimination. The WBLP adopted large-scale administration of praziquantel as the main control measure. At the end of the 10-year project in 2001, data from high-, medium-, and low-endemic areas suggested that the infection rates of both humans and domestic animals had fallen to the expected levels. However, major floods in the Yangtze River basin, coupled with reduced funding for schistosomiasis control, resulted in a rebound of the disease in endemic areas. Since 2005, a steady decline in infection rates was observed and it was hypothesized that the experiences and technological advances accumulated during the WBLP played a role. Nonetheless, relatively little is known about the long-term effects of the WBLP on schistosomiasis, particularly management mechanisms, technological innovations, epidemiological changes, and long-term economic impact. To fill these gaps, we systematically searched the literature for articles in English and Chinese on the WBLP on schistosomiasis from 1 January 1992 to 30 July 2022. Relevant studies were analyzed for short-, mid-, and long-term epidemiological and economic effects of the WBLP on schistosomiasis prevention, control, and elimination. Overall, 81 articles met our inclusion criteria, of which 17 were related to management mechanism reform, 20 pertained to technological innovation, and 44 examined epidemiological changes and economic effects. Most papers documented the WBLP as a positive contribution to schistosomiasis prevention and control in the People's Republic of China. Regarding the long-term effects, there was a significant contribution to the national schistosomiasis control and elimination programme in terms of renewed management mechanisms, talent development, and technological innovation. In conclusion, the WBLP contributed to enhanced control of schistosomiasis and shaped the ultimate response towards schistosomiasis elimination in the People's Republic of China. Experiences and lessons learned might guide schistosomiasis control and elimination elsewhere.

Oncomelania hupensis control strategy during the stage moving towards elimination of schistosomiasis in China

Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, and O. hupensis control is an important measure for schistosomiasis control. With the progress of national schistosomiasis control program, the prevalence of schistosomiasis is low in China; however, there are still multiple challenges for O. hupensis breeding and schistosomiasis transmission risk. Considering the target of the national schistosomiasis elimination program and environmental protection in the new era, the introduction of precision identification, precision interventions and precision assessment into O. hupensis control may facilitate the progress towards elimination of schistosomiasis in China.

Sharing the WHO guideline on control and elimination of human schistosomiasis to achieve the goal of schistosomiasis elimination in China

Currently, the national schistosomiasis control program of China is moving from transmission interruption to elimination, and there are multiple challenges during the stage moving towards the progression of schistosomiasis elimination, including a high difficulty in shrinking snail-infested areas, unstable achievements for infectious source control, imperfect surveillance system and a reduction in schistosomiasis control and administration. Based on the core suggestions proposed in the 2022 WHO guideline on control and elimination of human schistosomiasis, recommendations on schistosomiasis surveillance system building, development of novel diagnostics, adjustment of the schistosomiasis control strategy and maintaining and improvements of the schistosomiasis control capability are proposed for the national schistosomiasis control program of China in the new era according to the actual status of schistosomiasis control in China. Formulation of the national schistosomiasis control strategy and goal from One Health perspective, verification of transmission interruption and elimination of schistosomiasis, precision implementation of schistosomiasis control interventions with adaptations to local circumstances, development and application of highly sensitive and specific diagnostics are recommended for elimination of schistosomiasis in China. In addition, the implementation of the 2022 WHO guideline on control and elimination of human schistosomiasis may guide the elimination of schistosomiasis in China.

Analysis of the new WHO guideline to accelerate the progress towards elimination of schistosomiasis in China

On February 2022, WHO released the evidence-based guideline on control and elimination of human schistosomiasis, with aims to guide the elimination of schistosomiasis as a public health problem in disease-endemic countries by 2030 and promote the interruption of schistosomiasis transmission across the world. Based on the One Health concept, six evidence-based recommendations were proposed in this guideline. This article aims to analyze the feasibility of key aspects of this guideline in Chinese national schistosomiasis control program and illustrate the significance to guide the future actions for Chinese national schistosomiasis control program. Currently, the One Health concept has been embodied in the Chinese national schistosomiasis control program. Based on this new WHO guideline, the following recommendations are proposed for the national schistosomiasis control program of China: (1) improving the systematic framework building, facilitating the agreement of the cross-sectoral consensus, and building a high-level leadership group; (2) optimizing the current human and livestock treatments in the national schistosomiasis control program of China; (3) developing highly sensitive and specific diagnostics and the framework for verifying elimination of schistosomiasis; (4) accelerating the progress towards elimination of schistosomiasis and other parasitic diseases through integrating the national control programs for other parasitic diseases.

Contribution to global implementation of WHO guideline on control and elimination of human schistosomiasis by learning successful experiences from the national schistosomiasis control program in China

Schistosomiasis is a parasitic disease that seriously hinders socioeconomic developments and threatens public health security. To achieve the global elimination of schistosomiasis as a public health problem by 2030, WHO released the guideline on control and elimination of human schistosomiasis on February, 2022, with aims to provide evidence-based recommendations for schistosomiasis morbidity control, elimination of schistosomiasis as a public health problem, and ultimate interruption of schistosomiasis transmission in disease-endemic countries. Following concerted efforts for decades, great achievements have been obtained for schistosomiasis control in China where the disease was historically highly prevalent, and the country is moving towards schistosomiasis elimination. This article reviews the successful experiences from the national schistosmiasis control program in China, and summarizes their contributions to the formulation and implementation of the WHO guideline on control and elimination of human schistosomiasis. With the progress of the "Belt and Road" initiative, the world is looking forward to more China's solutions on schistosomiasis control.

The prevalence of liver abnormalities in humans due to Schistosoma japonicum by ultrasonography in China: a meta-analysis

BackgroundSchistosoma japonicum was once one of the most severe parasitic diseases in China. After 70 years of national schistosomiasis control programmes, the prevalence and associated morbidity of the infection have been reduced to a much lower level. However, due to the low sensitivity of the current detection approaches, many minor infections in humans could not be identified and ultimately develop chronic injuries with liver abnormalities, a specific ‘network’ echogenic pattern under ultrasonography. Therefore, as more people take part in physical examinations, we performed this meta-analysis to estimate the overall prevalence of schistosomiasis-associated liver abnormalities in China.MethodsThe publications were searched systematically across five electronic databases. All eligible studies were assessed with quality evaluation forms. Heterogeneity of studies was determined using the I2 and Q tests. A random effects or fixed effects model was employed based on heterogeneity results. The pooled prevalence and its 95% confidence intervals were calculated with the Freeman-Tukey double arcsine transformation. All analyses were conducted using R with the “meta” package. The protocol registration number was CRD42021232982.ResultsA total of 19 relevant articles, including 21 studies, were included. The average score of study quality was 6.4 (total score 7), indicating high quality of all included studies. A total of 268, 247 persons were included, and 43, 917 persons were diagnosed with schistosomiasis liver abnormalities by ultrasonography. High degrees of heterogeneity existed among all studies or within subgroups. The overall pooled prevalence was 18.64% (95% CI: 11.88–26.50%). The estimate significantly increased over time and varied among provinces, with the highest in Shanghai and the lowest in Sichuan. The estimate in people aged 60 years or older was significantly higher than that in people of all ages. No significant difference was seen when based on study areas (urban or rural areas) or gender.ConclusionThe long-term burden of schistosomiasis in China remains large, as nearly one-fifth of the examined persons were diagnosed with schistosomiasis liver abnormalities. The pooled prevalence was associated with regions or age groups. Such may have a high reference value in the exact calculation of the disease burden and can be helpful for policy makers in prioritizing public health.

The status of schistosomiasis japonica control in the Philippines: The need for an integrated approach to address a multidimensional problem

Schistosomiasis japonica remains a public health concern in many areas of the Philippines. Adequate and updated information is essential to enhance policy and service delivery toward control and elimination. Despite the efforts on schistosomiasis control in the Philippines, some challenges remain in these dimensions. An integrated surveillance system is recommended to determine the prevalence of infection in humans, animal reservoirs, and snail intermediate hosts, allowing the identification of high-priority areas for targeted interventions. This will entail the enhancement of laboratory diagnosis capacity through the use of more sensitive techniques, complemented by capacity building of concerned human and animal health professionals. Given the zoonotic nature of schistosomiasis japonica, adopting the One Health approach is essential to influence policies and interventions that may accelerate control and elimination. This can be achieved through the attainment of mass drug administration coverage targets and intensified case finding and management, robust implementation and integration of veterinary public health activities, the conduct of snail control measures, provision of safe water, sanitation, and hygiene services, and health promotion and education into the national schistosomiasis control and elimination program. This review aimed to describe the status of schistosomiasis japonica control in the Philippines in the context of human health, animal health, vector ecology and management, environmental health, and sociocultural dimensions.

Emergency responses to schistosomiasis outbreak during the stage moving towards elimination in China

Currently, the national schistosomiasis control program of China is moving from transmission control and transmission interruption to elimination; however, there is still a threat of schistosomiasis outbreak in area where the transmission of schistosomiasis has not been interrupted, and in areas where transmission interruption and even elimination have been achieved because of the complex factors relating to schistosomiasis transmission, as well as socioeconomic factors and natural environments, which greatly affects the consolidation of schistosomiasis control outcomes and the achievement of the goal of schistosomiasis elimination in the country. Here, we summarized the outbreaks of schistosomiasis in China during the past six decades, evaluated the impact of schistosomiasis outbreak on the national schistosomiasis control program and proposed management of schistosomiasis outbreak and prevention of schistosomiasis resurgence as the key point and difficulty for schistosomiasis control in the current stage. Improving the surveillance-response mechanisms and minimizing the development of schistosomiasis outbreak and the resultant damages and losses are recommended to provide technical supports for elimination of schistosomiasis in China.

Schistosomiasis in the People's Republic of China - down but not out.

Schistosomiasis has been subjected to extensive control efforts in the People's Republic of China (China) which aims to eliminate the disease by 2030. We describe baseline results of a longitudinal cohort study undertaken in the Dongting and Poyang lakes areas of central China designed to determine the prevalence of Schistosoma japonicum in humans, animals (goats and bovines) and Oncomelania snails utilizing molecular diagnostics procedures. Data from the Chinese National Schistosomiasis Control Programme (CNSCP) were compared with the molecular results obtained.Sixteen villages from Hunan and Jiangxi provinces were surveyed; animals were only found in Hunan. The prevalence of schistosomiasis in humans was 1.8% in Jiangxi and 8.0% in Hunan determined by real-time polymerase chain reaction (PCR), while 18.3% of animals were positive by digital droplet PCR. The CNSCP data indicated that all villages harboured S. japonicum-infected individuals, detected serologically by indirect haemagglutination assay (IHA), but very few, if any, of these were subsequently positive by Kato-Katz (KK).Based on the outcome of the IHA and KK results, the CNSCP incorporates targeted human praziquantel chemotherapy but this approach can miss some infections as evidenced by the results reported here. Sensitive molecular diagnostics can play a key role in the elimination of schistosomiasis in China and inform control measures allowing for a more systematic approach to treatment.

Schistosomiasis control in the evolution of China's international discourse power

As a successful example of global public health, Chinese schistosomiasis control technology and experiences have been included in global public health governance. Chinese schistosomiasis control program progresses with China's international discourse power. During the period from the initial stage of the founding of the People's Republic of China to China's Reform and opening-up, the national schistosomiasis control program of China achieved great successes through mobilizing multi-sectorial resources under the policy of Independence and Self-reliance. Following China's Reform and opening-up, all advantageous opportunities were captured to solve problems pertaining to schistosomiasis control in the context of complex international situations. As a consequence, transmission control of schistosomiasis was achieved across China in 2015. Since the Eighteenth National Congress of the Communist Party of China, China has contributed the discourse system with distinct Chinese characteristics to the world, and has actively participated in health cooperation projects between China and other "Belt and Road" countries, which has contributed China's wisdom to global schistosomiasis control program and conveyed China's voice to the world.

Progress of researches on the diagnostic techniques for schistosomiasis

Schistosomiasis is an important zoonotic parasitic disease, and is categorized as a neglected tropical disease by the World Health Organization. Following the concerted efforts for more than 70 years, great achievements have been made in the national schistosomiasis control program in China, and the prevalence, disability and mortality due to schistosomiasis has remarkably dropped. Nevertheless, the frequent identification of imported schistosomiasis and the resulting potential transmission risk in mainland China have been recently paid much attention following the implementation of the "Belt and Road Initiative" and the China-Africa Cooperation Forum. This review describes the advances in the diagnostic tools for schistosomiasis, including pathogenic techniques, immunodiagnostic techniques and nucleic acid assays, in order to consolidate schistosomiasis control achievements and promote the capability for detection of external biological safety risks.

Elimination of schistosomiasis in China: Current status and future prospects.

Elimination of schistosomiasis as a public health problem among all disease-endemic countries in 2030 is an ambitious goal. Recent achievements resulting from mass drug administration (MDA) with praziquantel is promising but may need to be complemented with also other means. Schistosomiasis was highly prevalent in China before the initiation of the national schistosomiasis control program in the mid-1950s, and, at that time, the country bore the world’s highest burden of schistosomiasis. The concerted control efforts, upheld without interruption for more than a half century, have resulted in elimination of the disease as a public health problem in China as of 2015. Here, we describe the current status of schistosomiasis in China, analyze the potential challenges affecting schistosomiasis elimination, and propose the future research needs and priorities for the country, aiming to provide more universal insights into the structures needed for a global schistosomiasis elimination encompassing also other endemic regions.

Prevalence of Urinary Schistosomiasis among Almajiri Children in Silame, Sokoto State, North-western Nigeria

Urinary schistosomiasis is a severe threat to global health with uncountable morbidities in Africa including Nigeria where control interventions focused on children in public and private schools neglecting Almajiri children. This undermined control interventions as those infected contaminate the environments with infective stages of the parasite. The objective of the study was to identify the prevalence of urinary schistosomiasis amongst Almajiri children in Silame, Sokoto State, North-western Nigeria. This was a cross-sectional descriptive study, socio-demographic data was collected in April 2020 on 206 consented Almajiri children in Silame and their urine samples were examined using the sedimentation method. The study showed a prevalence of 35.4% among the Almajiri children in Silame, Sokoto State, North-western Nigeria. The highest prevalence was found among children within the age range 16-20 years (63.6%) while the lowest prevalence was among those in the age range 6-10 years (24.4%). There was a statistically significant difference in the occurrence of urinary schistosomiasis between the age groups (χ2 = 11.637a, df =3, p=0.002). Urinary schistosomiasis was prevalent among Almajiri children in the study area and parasite infection was associated with the participant's socio-demographic factors such as age, level of education, and water contact activities. Hence, the National Schistosomiasis Control Programs should incorporate the Almajiri children in the control interventions

Infestation risk of the intermediate snail host of Schistosoma japonicum in the Yangtze River Basin: improved results by spatial reassessment and a random forest approach

BackgroundOncomelania hupensis is only intermediate snail host of Schistosoma japonicum, and distribution of O. hupensis is an important indicator for the surveillance of schistosomiasis. This study explored the feasibility of a random forest algorithm weighted by spatial distance for risk prediction of schistosomiasis distribution in the Yangtze River Basin in China, with the aim to produce an improved precision reference for the national schistosomiasis control programme by reducing the number of snail survey sites without losing predictive accuracy.MethodsThe snail presence and absence records were collected from Anhui, Hunan, Hubei, Jiangxi and Jiangsu provinces in 2018. A machine learning of random forest algorithm based on a set of environmental and climatic variables was developed to predict the breeding sites of the O. hupensis intermediated snail host of S. japonicum. Different spatial sizes of a hexagonal grid system were compared to estimate the need for required snail sampling sites. The predictive accuracy related to geographic distances between snail sampling sites was estimated by calculating Kappa and the area under the curve (AUC).ResultsThe highest accuracy (AUC = 0.889 and Kappa = 0.618) was achieved at the 5 km distance weight. The five factors with the strongest correlation to O. hupensis infestation probability were: (1) distance to lake (48.9%), (2) distance to river (36.6%), (3) isothermality (29.5%), (4) mean daily difference in temperature (28.1%), and (5) altitude (26.0%). The risk map showed that areas characterized by snail infestation were mainly located along the Yangtze River, with the highest probability in the dividing, slow-flowing river arms in the middle and lower reaches of the Yangtze River in Anhui, followed by areas near the shores of China’s two main lakes, the Dongting Lake in Hunan and Hubei and the Poyang Lake in Jiangxi.ConclusionsApplying the machine learning of random forest algorithm made it feasible to precisely predict snail infestation probability, an approach that could improve the sensitivity of the Chinese schistosome surveillance system. Redesign of the snail surveillance system by spatial bias correction of O. hupensis infestation in the Yangtze River Basin to reduce the number of sites required to investigate from 2369 to 1747.Graphical abstract