Characterizing malaria vector competence among natural populations of Anopheles

项目摘要 在非洲许多地区，尽管疟疾控制措施广泛存在，但疟疾负担仍然很重 措施最近关于非洲疟疾感染率上升的报告强调需要确保 目前和今后的干预措施针对这些环境中疟疾传播的主要来源。的 按蚊对允许摄入的疟原虫配子母细胞完全发育至 可传播的子孢子阶段或载体能力仍然知之甚少。在马拉维和其他许多国家， 在非洲南部和东部地区，不吉按蚊和阿拉伯按蚊现在是最常见的 疟疾病媒，可能在病媒能力方面具有重要的变异性，而在控制方面尚未考虑到这一点 和消除努力。 我们的长期目标是更好地了解人类和病媒对传播的贡献 疟疾寄生虫的研究，为非洲负担最重的地区设计有效的病媒控制战略。我们 有独特的机会对主要疟疾传播媒介的能力进行严格评估， 通过我们在马拉维国际疟疾卓越中心正在进行的项目， 研究（ICEMR）。这项拟议中的研究由一位流行病学家领导，他是以下项目的负责人： ICEMR内的传播研究，重点是人类到矢量周期的阶段，以及 领导ICEMR昆虫学核心的昆虫学家。我们已经建立了一个运作良好的昆虫库， 定期从该地区几个高传播环境中收集活的雌性按蚊。在 此外，我们正在建立一个儿童和成人队列，对他们进行随访以识别恶性疟原虫 含有配子体的感染。我们将使用从这些配子体感染的供体中采集的标本， 比较群体饲养的安氏按蚊之间的媒介能力。gambiae基苏穆和野外捕获的安. funestus和An. arabiensis的载体能力，以验证假设，天然的An. funestus和An. Arabiensis不同于 彼此和来自殖民地菌株。我们将进一步评估同雌体之间载体能力的变化 系的相同按蚊物种，以评估载体能力的遗传力。最后提出 比较同一物种内但来自马拉维地理隔离地区的病媒能力。 该提案的预期结果包括对An的媒介能力的估计。阿拉伯和 一个. funestus。确定病媒在物种之间、物种内或基于 可能表明需要研究载体能力的基因组基础。我们的结果将 也影响马拉维和其他高传播国家合理实施病媒控制措施， 设置.

PROJECT SUMMARY The burden of malaria remains high in many regions of Africa, despite widespread availability of malaria control measures. The recent report of increases in malaria infection rates in Africa highlights the need to ensure that current and future interventions target the key sources of malaria transmission in these settings. The susceptibility of an Anopheles mosquito to permit ingested Plasmodium gametocytes to develop fully to the transmissible sporozoite stage, or vector competence, remains poorly understood. In Malawi and many other regions in southern and eastern Africa, Anopheles funestus and Anopheles arabiensis are now the most common malaria vectors and may have important variability in vector competence that has not been considered in control and elimination efforts. Our long-term goal is to better understand the contributions of both humans and vectors to transmission of malaria parasites to design effective vector control strategies for the highest-burden regions of Africa. We have the unique opportunity to conduct a rigorous assessment of the vector competence of the key malaria vectors in Malawi through our on-going projects in the Malawi International Center of Excellence in Malaria Research (ICEMR). The proposed study is being led by an epidemiologist who serves as the project leader for a transmission study within the ICEMR that focuses on the human to vector phases of the cycle, and an entomologist who leads the ICEMR entomology core. We have established a well-functioning insectary and routinely collect live female Anopheles mosquitoes from several high transmission settings in the region. In addition, we are establishing a cohort of children and adults who will be followed to identify P. falciparum infections that contain gametocytes. We will use specimens collected from these gametocyte-infected donors to compare vector competence between colony-reared An. gambiae Kisumu and field-caught An. funestus and An. arabiensis to test the hypotheses that vector competence of natural An. funestus and An. arabiensis differs from each other and from the colony strain. We will further evaluate variation in vector competence among isofemale lines of the same Anopheles species to assess the heritability of vector competence. Finally, we propose comparing vector competence within the same species but from geographically isolated areas of Malawi. The expected outcomes of this proposal include estimates of vector competence for An. arabiensis and An. funestus. Identifying significant differences in vector competence among species, within species or based on region of origin, may indicate the need to investigate a genomic basis for vector competence. Our results will also impact the rational implementation of vector control measures in Malawi and other high transmission settings.