Assessing the effect of neglected tropical diseases on Plasmodium falciparum transmission in an area of co-endemicity

评估被忽视的热带病对共同流行地区恶性疟原虫传播的影响

• 批准号: 271597907
• 负责人: Professor Dr. Peter Gottfried Kremsner, since 12/2020
• 金额: --
• 依托单位: Afdeling Medische Microbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/271597907?language=en
• 关键词: Assessing; effect; neglected; tropical; diseases

In areas of coendemicity of malaria and helminthiases, coinfection of Plasmodium falciparum and helminths is frequent. Epidemiological studies have shown an effect of helminths on malaria symptoms in coinfected subjects. We and others have found that rate and level of P. falciparum gametocytaemia is significantly and consistently increased in chronic helminthiases. This may lead to an increase in transmission of the malaria parasite. In an exploratory study, we found that individuals who are infected with Schistosoma haematobium have a significant impairment of their humoral response to Pfs48/45, a major gametocyte antigen capable of blocking the development of P. falciparum in the mosquito gut. This could further increase transmission of malaria parasites to mosquitoes and is of particular concern in settings where malaria elimination campaigns are implemented or P. falciparum resistance containment. To date there is no study that has fully elucidated the effect of helminth on malaria transmission. With the first grant given to our project, we started a longitudinal study to assess the effect of S. haematobium on P. falciparum life cycle and transmission in two endemic settings, which are representative for West and Central Africa. In the first phase, a cohort was followed to investigate the effect of chronic S. haematobium infection on i) the reservoir of asexual and sexual P. falciparum parasites in humans, ii) transmission and development of gametocytes in Anopheles mosquitoes, and iii) probability of transmission of sporozoites to humans. The same set of experiments are currently being done in the same population, where those with S. haematobium infection are treated effectively with repeated doses of praziquantel. With such an approach, a complete picture of the interaction between S. haematobium and P. falciparum in regard to its transmission is possible. Additionally, the project will build urgently needed capacity in transmission studies in African research institutions. The project will be accompanied by an intense training program and will seek to develop careers of early and mid-term African scientists. The first, DFG-funded phase of the project is currently ongoing and data are being collected and analysed. From the preliminary findings, we identified a need to extend the project to complement activities and explore further topics: i) the cellular immunologic profile ii) host-vector interactions in Schistosomiasis, iii) Plasmodium diversity and genotyping in mosquito, and iv) insecticide susceptibility of the malaria vector.

在疟疾和蠕虫病并存的地区，恶性疟原虫和蠕虫的合并感染是常见的。流行病学研究表明，蠕虫对合并感染者的疟疾症状有影响。我们和其他人已经发现恶性疟原虫配子体血症的比率和水平在慢性蠕虫病中显著且持续地增加。这可能导致疟疾寄生虫传播的增加。在一项探索性研究中，我们发现感染埃及血吸虫的个体对Pfs 48/45的体液应答显著受损，Pfs 48/45是一种能够阻断恶性疟原虫在蚊子肠道中发育的主要配子体抗原。这可能会进一步增加疟疾寄生虫向蚊子的传播，在实施疟疾消除运动或遏制恶性疟原虫耐药性的环境中尤其令人担忧。迄今为止，还没有研究充分阐明蠕虫对疟疾传播的影响。随着我们项目的第一笔资助，我们开始了一项纵向研究，以评估S。在西非和中非具有代表性的两个地方性环境中，研究了疟原虫对恶性疟原虫生命周期和传播的影响。在第一阶段，一个队列被跟踪调查的影响，慢性S。血吸虫感染对i）人类中无性和有性恶性疟原虫寄生虫的储库，ii）按蚊中配子体的传播和发育，以及iii）子孢子传播给人类的可能性的影响。同样的一组实验目前正在同一人群中进行，其中那些与S。反复服用吡喹酮可有效治疗埃及血吸虫感染。通过这种方法，可以完整地描述S.在传播方面，它与埃及血吸虫和恶性疟原虫的关系是可能的。此外，该项目将在非洲研究机构建立传播研究方面迫切需要的能力。该项目将伴随着密集的培训计划，并将寻求发展早期和中期非洲科学家的职业生涯。该项目的第一阶段由发展基金供资，目前正在进行数据收集和分析。根据初步结果，我们确定需要扩展该项目，以补充活动并探索进一步的主题：i）细胞免疫学特征ii）血吸虫宿主-媒介相互作用iii）蚊子中的疟原虫多样性和基因分型iv）疟疾媒介的杀虫剂敏感性。