Mosquito biting behavior and malaria transmission: interactions between host preferences and local environmental conditions

病媒传播的疾病，特别是疟疾，对热带地区的人口造成重大负担。这些疾病的分布是由环境和社会因素共同决定的，这些因素反过来又影响病媒和宿主的相互作用。病媒传播疾病背后的一个关键因素是病媒自身在其环境中的行为。数学建模在帮助预测疾病传播动态方面起着至关重要的作用，并允许在各种情况下评估控制措施的潜在影响。尽管它具有明显的重要性，但它目前被认为是一个被忽视的研究领域。所有的数学模型在模型内都有反映与现场情况有关的各种情景的因素。通常，这些可以基于假设或从现场收集的实验证据。近年来，节肢动物传播疾病的数学模型得到了发展，并且越来越复杂，导致参数数量增加。尽管复杂模型激增，但许多模型的核心仍然存在一些假设。其中一个假设是宿主可用性如何影响矢量宿主首选项。不同种类的蚊子对宿主的叮咬行为各不相同。例如，冈比亚按蚊（一种主要疟疾病媒）对人类血液的偏好超过了对其他血液来源的偏好。因此，它们对人群中疾病传播的影响是非常显著的。目前，许多疾病模型假设人类被蚊子叮咬的比例与人类宿主的可用性成正比。然而，对昆虫生态学的研究告诉我们，这种情况很少发生。尽管如此，这一假设是许多病媒传播疾病模型的核心，目前仅基于理论数据。宿主物种可获得性的作用，特别是种群中人类的可获得性，对于确定疾病传播和控制规划预测是否能够准确建模至关重要。这对疟疾等疾病尤其重要，因为疟疾的控制和减轻疾病负担主要是通过使用蚊帐、驱蚊剂和其他控制措施，减少可叮咬的人数。重要的是，这可能对预测疾病控制干预措施的有效性产生深远影响，因此在现场环境中确定这种反应至关重要。这个博士学位提供了收集新颖的经验领域数据的机会，使我能够发展分子生物学技能，并学习如何生成数学模型来预测疾病传播和更好地评估疾病控制策略。这项工作不仅可以对疟疾控制战略产生深远影响，而且可以对整个病媒控制工作产生深远影响。此外，基于实验室的工作还将允许收集物种组成、杀虫剂抗性状况、媒介物种重叠以及当地蚊子种群中节肢动物传播疾病流行情况的数据，从而使控制工作更有针对性。

Vector-borne diseases particularly malaria cause a significant burden on human populations in the tropics. Distribution of these diseases is governed by a mix of both environmental and social factors which in turn effect vector and host interactions. A key factor behind the transmission of vector borne diseases is the behavior of the vector its self within its environment. Mathematical modelling plays a crucial role in aiding in predicting disease transmission dynamics and allow the potential impact of control measures to be assessed across various scenarios. Despite its clear importance, it is currently recognised as a neglected area of research. All mathematical models have factors within the model to reflect various scenarios which relate to the field situation. Usually these can be based on assumptions or on experiment evidence collected from the field. Recently mathematical models of arthropod borne disease have developed and increased in complexity resulting in an increased number of parameters. Despite this surge in complex models, at the core of many of these models there are still some assumptions. One of these assumptions is how vector host preference is affected by host availability.Different mosquito species show a variety of host biting behaviours. For example, Anopheles gambiae (a primary malaria vector) has shown an extreme preference for human blood over other blood meal sources. As a result of this, their influence on disease transmission in human populations is highly significant. Currently many disease models assume the proportion of bites humans receive from a mosquito population is directly proportional to the human host availability. However, research into insect ecology shows us that this is rarely the case. Despite this, this assumption is central to many vector-borne disease models and at this time is solely based on theoretical data.The role of host species availability, particularly availability of humans in a population is crucial to determine if disease transmission and control programs predictions are to be accurately modelled. This is particularly important for diseases such as malaria where control and reduction of disease burden operates by reducing the number of individuals available to bite, primarily through use of bed nets, repellents and other control measures. Importantly, this can have a profound effect on how effective a disease control intervention is predicted to be and therefore it is vital to determine this response in a field setting.This PhD has provided the opportunity to collect novel, empirical field data and is allowing me to develop skills in molecular biology as well as learn how to generate mathematical models to predict disease transmission and better assess disease control strategies. This work could not only have a profound effect on malaria control strategies but also on vector control efforts as a whole. In addition, the lab based work will also allow data to be collected of species composition, insecticide resistance status, vector species overlap and prevalence of arthropod borne disease in the local mosquito populations allowing control efforts to be better targeted.