Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary &Life Sciences, University of Glasgow, Glasgow, Scotland, UK.
Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary &Life Sciences, University of Glasgow, Glasgow, Scotland, UK.
Sci Rep. 2017 Jan 17;7:40520. doi: 10.1038/srep40520.
The efficiency of malaria parasite development within mosquito vectors (sporogony) is a critical determinant of transmission. Sporogony is thought to be controlled by environmental conditions and mosquito/parasite genetic factors, with minimal contribution from mosquito behaviour during the period of parasite development. We tested this assumption by investigating whether successful sporogony of Plasmodium falciparum parasites through to human-infectious transmission stages is influenced by the host species upon which infected mosquitoes feed. Studies were conducted on two major African vector species that generally are found to differ in their innate host preferences: Anopheles arabiensis and An. gambiae sensu stricto. We show that the proportion of vectors developing transmissible infections (sporozoites) was influenced by the source of host blood consumed during sporogony. The direction of this effect was associated with the innate host preference of vectors: higher sporozoite prevalences were generated in the usually human-specialist An. gambiae s.s. feeding on human compared to cow blood, whereas the more zoophilic An. arabiensis had significantly higher prevalences after feeding on cow blood. The potential epidemiological implications of these results are discussed.
疟原虫在蚊媒（孢子增殖）中的发育效率是传播的关键决定因素。孢子增殖被认为受环境条件和蚊/寄生虫遗传因素的控制，而蚊子在寄生虫发育期间的行为对其影响很小。我们通过研究感染蚊子所吸食的宿主种类是否会影响疟原虫寄生虫的成功孢子增殖到人类感染传播阶段来检验这一假设。在两种主要的非洲媒介物种上进行了研究，这些物种通常在先天宿主偏好上存在差异：阿拉伯按蚊和冈比亚按蚊。我们表明，在孢子增殖期间消耗的宿主血液来源会影响可传播感染（孢子）的向量比例。这种影响的方向与媒介的先天宿主偏好有关：通常在人类中专门传播的冈比亚按蚊 s.s. 在吸食人血时产生更高的孢子虫患病率，而更嗜动物的阿拉伯按蚊在吸食牛血后则具有明显更高的患病率。讨论了这些结果的潜在流行病学意义。
