Touray Abdoulie O, Mobegi Victor A, Wamunyokoli Fred, Butungi Hellen, Herren Jeremy K
Department of Molecular Biology and Biotechnology, Institute of Basic Sciences, Technology and Innovation, Pan African University (PAUSTI), Nairobi, Kenya.
International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
Wellcome Open Res. 2021 Apr 13;5:259. doi: 10.12688/wellcomeopenres.16299.2. eCollection 2020.
Asymptomatic gametocyte carriers are reservoirs for sustaining transmission in malaria endemic regions. Gametocyte presence in the host peripheral blood is a predictor of capacity to transmit malaria. However, it does not always directly translate to mosquito infectivity. Factors that affect mosquito infectivity include, gametocyte sex-ratio and density, multiplicity of infection (MOI), and host and vector anti-parasite immunity. We assess the prevalence of gametocyte carriage and some of its associated risk factors among asymptomatic schoolchildren in Western Kenya and to further analyse the association between gametocyte density, multiplicity of infection (MOI) and mosquito infection prevalence. parasite infections were detected by RDT (Rapid Diagnostic Test) and microscopy among schoolchildren (5-15 years old). Blood from 37 microscopy positive gametocyte carriers offered to laboratory reared mosquitoes. A total of 3395 fully fed mosquitoes were screened for sporozoites by ELISA. was genotyped using 10 polymorphic microsatellite markers. The association between MOI and gametocyte density and mosquito infection prevalence was investigated. A significantly higher prevalence of infection was found in males 31.54% (764/2422) ( -value < 0.001) compared to females 26.72% (657/2459). The microscopic gametocyte prevalence among the study population was 2% (84/4881). Children aged 5-9 years have a higher prevalence of gametocyte carriage (odds ratios = 2.1 [95% CI = 1.3-3.4], = 0.002) as compared to children aged 10-15 years. After offering gametocyte positive blood to by membrane feeding assay, our results indicated that 68.1% of the variation in mosquito infection prevalence was accounted for by gametocyte density and MOI (R-SQR. = 0.681, < 0.001). We observed a higher risk of gametocyte carriage among the younger children (5-9 years). Gametocyte density and MOI significantly predicted mosquito infection prevalence.
无症状配子体携带者是疟疾流行地区维持传播的传染源。宿主外周血中存在配子体是疟疾传播能力的一个预测指标。然而，它并不总是直接转化为对蚊子的感染性。影响蚊子感染性的因素包括配子体的性别比例和密度、感染复数（MOI）以及宿主和媒介的抗寄生虫免疫力。我们评估了肯尼亚西部无症状学童中配子体携带的流行情况及其一些相关危险因素，并进一步分析配子体密度、感染复数（MOI）与蚊子感染率之间的关联。通过快速诊断检测（RDT）和显微镜检查在学童（5至15岁）中检测寄生虫感染。从37名显微镜检查呈阳性的配子体携带者采集血液，提供给实验室饲养的蚊子。通过酶联免疫吸附测定（ELISA）对总共3395只饱血蚊子进行子孢子筛查。使用10个多态性微卫星标记进行基因分型。研究了感染复数（MOI）与配子体密度和蚊子感染率之间的关联。与女性的26.72%（657/2459）相比，男性的感染率显著更高，为31.54%（764/2422）（P值<0.001）。研究人群中显微镜下配子体的流行率为2%（84/4881）。与10至15岁的儿童相比，5至9岁的儿童配子体携带率更高（优势比=2.1[95%置信区间=1.3 - 3.4]，P = 0.002）。通过膜饲法将配子体阳性血液提供给蚊子后，我们的结果表明，蚊子感染率68.1%的变异是由配子体密度和感染复数（MOI）造成的（R平方=0.681，P<0.001）。我们观察到年龄较小的儿童（5至9岁）中配子体携带风险更高。配子体密度和感染复数（MOI）显著预测了蚊子感染率。
