Transmission

人类疟疾仅由按蚊传播。在南部非洲，这些媒介物种中最重要的是按蚊。阿拉伯树，An.冈比亚、An. funestus，与 An.阿拉伯树具有更广泛的范围和更大的生态和生物可塑性。这些载体的相对分布和丰度因生态和地理原因而异。该提案针对的研究地点不仅反映了疟疾传播生物学和强度的差异，而且还反映了影响这些媒介差异的生态差异。传播生物学在很大程度上受到蚊子行为及其对基于蚊子的控制措施（例如经杀虫剂处理的蚊帐（ITN））的反应的影响。驱虫蚊帐广泛分布于整个南非，是一项巨大的投资。驱蚊蚊帐不仅为蚊子提供了物理屏障，而且众所周知，驱蚊蚊帐可以驱除昆虫，鼓励蚊子以替代宿主为食。然而，在南部非洲的一些地区，尽管已分发和使用驱虫蚊帐，蚊子仍然几乎专门针对人类宿主。来自西非的最新数据表明，在某些地区，通常由使用杀虫剂蚊帐引起的驱避作用失效，具有抗药性的蚊子并没有阻止它们吸食人血。因此，了解生物学、觅食行为、杀虫剂抗药性水平以及群体遗传学和分布对于指导南部非洲地区有效和适当的疟疾干预措施的选择和实施至关重要。目标 1) 描述三个研究地点中疟疾病媒的生物学和昆虫学接种率 (EIR)。 描述南部非洲疟疾病媒种群的群落结构，并进一步描述南部非洲阿拉伯按蚊的摄食和休息行为。目标 2) 调查所有三个野外地点病媒种群的杀虫剂敏感性并确定杀虫剂抗性机制。目标 3) 使用单核苷酸多态性 (SNP) 标记对阿拉伯按蚊种群进行种群遗传分析。

Human malaria is exclusively vectored by anopheline mosquitoes. In southern Africa the most important of these vector species are An. arabiensis, An. gambiae, and An. funestus, with An. arabiensis having a wider range and considerably greater ecological and biological plasticity. The relative distribution and abundance of these vectors vary ecologically and geographically. The study sites targeted in this proposal not only reflect differences in malaria transmission biology and intensity, but also ecological differences that affect these vector differences. Transmission biology is largely affected by mosquito behavior and their response to mosquito-based control measures such as insecticide-treated bed nets (ITNs). ITNs are widely distributed throughout south Africa and represent an enormous investment. ITNs not only provide a physical barrier to mosquitoes, but it is also well known that ITNs repel insects, encouraging mosquitoes to feed on alternative hosts. In some areas of southern Africa, however, mosquitoes have continued to almost exclusively target human hosts, despite the distribution and use of ITNs. Recent data from West Africa have shown that in some areas the repellency, typically induced by ITN use, fails and resistant mosquitoes are not deterred from taking human blood meals. Therefore, understanding the bionomics, foraging behavior, levels of insecticide resistance and population genetics and distribution are integral for guiding selection and implementation of effective and appropriate malaria interventions within the southern African region. Aim 1) Characterize the bionomics and entomological inoculation rates (EIR) of malaria vectors in each of the three study sites. Characterize the community structure of malaria vector populations in southern Africa and further characterize the feeding and resting behavior of Anopheles arabiensis in southern Africa. Aim 2) Survey insecticide susceptibility of vector populations at all three field sites and to determine the mechanisms of insecticide resistance. Aim 3) Conduct population genetic analysis of Anopheles arabiensis populations using single-nucleotide polymorphism (SNP) markers.