Assessment of control strategies against Clonorchis sinensis infection based on a multi-group dynamic transmission model

Clonorchiasis is one of the most important food-borne trematodiases affecting millions of people. Strategies were recommended by different organizations and control programmes were implemented but mostly in short-time periods. It’s important to assess the long-term benefits and sustainability of possible control strategies on morbidity control of the disease. We developed a multi-group transmission model to describe the dynamics of C. sinensis transmission among different groups of people with different raw-fish-consumption behaviors, based on which, a full model with interventions was proposed and three common control measures (i.e., preventive chemotherapy, information, education, and communication (IEC) and environmental modification) and their possible combinations were considered. Under a typical setting of C. sinensis transmission, we simulated interventions according to different strategies and with a series of values of intervention parameters. We found that combinations of measures were much beneficial than those singly applied; higher coverages of measures had better effects; and strategies targeted on whole population performed better than that on at-risk population with raw-fish-consumption behaviors. The strategy recommended by the government of Guangdong Province, China shows good and sustainable effects, under which, the infection control (with human prevalence C. sinensis infection under a typical transmission setting, with application of a multi-group dynamic transmission model. The proposed model is easily facilitated with other transmission settings and the simulation outputs provide useful information to support the decision-making of control strategies on clonorchiasis.华支睾吸虫病（Clonorchiasis）是威胁数百万人群健康的重要食源性吸虫病之一。尽管不同机构已推荐相应防控策略并实施了多项防控项目，但多数项目的实施周期较短。评估各类防控策略在该病发病率控制方面的长期效益与可持续性，具有重要的现实意义。本研究构建了多组传播模型，用于刻画不同生食鱼消费行为人群间的华支睾吸虫（Clonorchis sinensis）传播动态；在此基础上，提出了纳入干预措施的完整模型，并考量了三种常见防控手段：预防性化疗、信息-教育-传播（Information, Education and Communication，简称IEC）以及环境改造，及其多种组合方案。在典型的华支睾吸虫传播场景下，我们针对不同防控策略及一系列干预参数取值开展了干预模拟。研究结果表明：联合使用多种防控手段的效果远优于单一手段；干预措施的覆盖率越高，防控效果越好；针对全人群的防控策略，其效果优于仅针对有生食鱼消费行为的高危人群的策略。中国广东省人民政府推荐的防控策略展现出优异且可持续的防控效果，在该策略框架下，典型传播场景中的华支睾吸虫人群感染率可得到有效管控。本研究提出的多组动态传播模型可便捷适配其他传播场景，模拟结果可为华支睾吸虫病防控策略的决策制定提供有力支撑。