Targeted screening for Taenia solium tapeworms

猪带绦虫的靶向筛查

基本信息

批准号：
8129451
负责人：
Seth E O'Neal
金额：
$ 12.41万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-08-15 至 2013-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8129451
关键词：
Adult Advisory Committees Africa South of the Sahara Age Algorithms Animal Husbandry Annelida Area Asia Brain Central Nervous System Parasitic Infections Cestoda Cestode Infections China Clinical Communities Consumption Control Groups Cyst Cysticercosis Data Decision Making Detection Development Disadvantaged Disease Economics Education Effectiveness Enzyme-Linked Immunosorbent Assay Epilepsy Family suidae Feasibility Studies Feces Food Safety Goals Grant Household Human Human Identifications Infection Infection prevention International Intervention Investigation Larva Latin America Lesion Longevity Low Prevalence Marketing Measures Meat Mentorship Methods Neurocysticercosis Peru Physicians Prevalence Public Health Recording of previous events Relative (related person)Research Research Infrastructure Research Training Resources Rural Screening Result Screening procedure Seizures Seroprevalences Sewage Source Taenia solium Technology Tongue Training Vaccines base cohort cost design effective therapy egg experience group intervention health economics human migration nervous system disorder oxfendazole performance tests population based programs public health relevance reproductive socioeconomics tool transmission process two-arm study

项目摘要

DESCRIPTION (provided by applicant): Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system, and the leading cause of acquired epilepsy in the developing world. It occurs when someone ingests Taenia solium eggs passed in the feces of a pork tapeworm carrier. The eggs grow into larvae which then form cysts throughout the body; cysts in the brain are responsible for 30% of seizures in the developing world. In Latin America, over 400,000 people of all ages and socioeconomic classes have symptomatic NCC. Sustainability of control efforts is limited by migration of human tapeworm carriers, persistent conditions for transmission and the enormous reproductive capacity of tapeworms. Our long-term goals are two-fold; 1) to develop an effective, affordable and sustainable strategy for T. solium control in endemic areas, and 2) to increase population-based research capacity around neurologic disorders in rural regions of Peru. In this R21 grant, we begin with a feasibility study of targeted screening as a control strategy, and by leveraging the resources of an existing consortium to extend research and MPH training, field experience, and mentorship to two physicians in Puno, Peru. Field data show spatial clustering of infected pigs around tapeworm carriers. With the short lifespan of pigs raised for consumption, this suggests that infected pigs may mark the presence of a nearby tapeworm carrier. Our specific aims include: 1) To implement and assess targeted screening for human T. solium tapeworm carriers in household clusters surrounding infected pigs, and 2) To identify the most effective screening tools for tapeworm carriers in the context of targeted screening. We propose an intervention cohort with two study arms. Communities in the intervention group receive ongoing targeted screening for tapeworm carriers in household clusters around infected pigs, using all available screening tools (history of passing worm segments, O&P, coproantigen ELISA, EITB, and PCR). Communities in the control group receive education about the T. solium lifecycle and how to prevent infection. We conduct pig serosurveys in both groups every 5 months, using pig seroprevalence to measure overall transmission, and provide mass tapeworm screening and treatment at study end. Our primary hypothesis is that ongoing targeted screening and treatment of tapeworm carriers will decrease transmission of T. solium infection in an endemic area, measured by serial pig seroprevalence. Our secondary hypothesis is that targeted screening around pigs with cysticercosis will increase detection of T. solium tapeworms compared to generalized screening in endemic areas. We estimate prevalence of infection among household clusters using latent-class analysis of all screening results. Finally, we use decision-making analysis to determine the most effective screening tool for targeted screening, taking into consideration test performance, cost, and relative accessibility. Our results will guide design of a subsequent large-scale T. solium control intervention using the most promising methods identified in this study. PUBLIC HEALTH RELEVANCE: Cysticercosis is an emerging public health problem in much of the developing world, where it is the leading cause of preventable epilepsy. This proposal examines targeted screening for pork tapeworm carriers as a potentially effective, affordable and sustainable control strategy.

描述（由申请人提供）：神经囊尾蚴病（NCC）是中枢神经系统最常见的寄生虫感染，也是发展中国家获得性癫痫的主要原因。当有人摄入猪肉绦虫携带者粪便中的猪带绦虫卵时，就会发生这种情况。卵发育成幼虫，然后在全身形成包囊；发展中国家 30% 的癫痫发作是由脑部囊肿引起的。在拉丁美洲，超过 400,000 名各个年龄段和社会经济阶层的人患有有症状的 NCC。控制工作的可持续性受到人类绦虫携带者的迁移、持续的传播条件以及绦虫巨大的繁殖能力的限制。我们的长期目标有两个： 1) 制定有效、负担得起和可持续的战略，控制猪绦虫流行地区；2) 提高秘鲁农村地区神经系统疾病的人群研究能力。在这笔 R21 拨款中，我们首先对有针对性的筛查作为控制策略进行可行性研究，并利用现有联盟的资源，向秘鲁普诺的两名医生扩展研究和公共卫生硕士培训、现场经验和指导。现场数据显示受感染猪在绦虫携带者周围的空间聚集。由于食用猪的寿命较短，这表明受感染的猪可能标志着附近存在绦虫携带者。我们的具体目标包括：1) 在受感染猪周围的家庭群中实施和评估人类猪带绦虫携带者的针对性筛查，以及 2) 在针对性筛查的背景下确定最有效的绦虫携带者筛查工具。我们提出了一个包含两个研究组的干预队列。干预组的社区使用所有可用的筛查工具（蠕虫节段历史、O&P、粪抗原 ELISA、EITB 和 PCR），对受感染猪周围的家庭群中的绦虫携带者进行持续的有针对性的筛查。对照组的社区接受有关 T. solium 生命周期以及如何预防感染的教育。我们每 5 个月对两组猪进行血清调查，利用猪血清流行率来衡量总体传播情况，并在研究结束时提供大规模绦虫筛查和治疗。我们的主要假设是，持续对绦虫携带者进行有针对性的筛查和治疗将减少流行地区猪绦虫感染的传播（通过连续猪血清阳性率来衡量）。我们的第二个假设是，与流行地区的普遍筛查相比，对患有囊尾蚴病的猪进行针对性筛查将增加猪带绦虫的检出率。我们使用所有筛查结果的潜在类别分析来估计家庭群体中的感染流行率。最后，我们利用决策分析来确定最有效的靶向筛选工具，同时考虑测试性能、成本和相对可及性。我们的结果将指导使用本研究中确定的最有前途的方法进行后续大规模猪绦虫控制干预措施的设计。公共卫生相关性：囊尾蚴病是许多发展中国家的一个新出现的公共卫生问题，是可预防癫痫的主要原因。该提案研究了猪肉绦虫携带者的针对性筛查，作为一种潜在有效、负担得起且可持续的控制策略。