Abstract:
The World Health Organization identifies a strong surveillance system for malaria and its mosquito vector as an essential pillar of the malaria elimination agenda. Anopheles salivary antibodies are emerging biomarkers of exposure to mosquito bites that potentially overcome sensitivity and logistical constraints of traditional entomological surveys. Using samples collected by a village health volunteer network in 104 villages in Southeast Myanmar during routine surveillance, the present study employs a Bayesian geostatistical modeling framework, incorporating climatic and environmental variables together with Anopheles salivary antigen serology, to generate spatially continuous predictive maps of Anopheles biting exposure. Our maps quantify fine-scale spatial and temporal heterogeneity in Anopheles salivary antibody seroprevalence (ranging from 9 to 99%) that serves as a proxy of exposure to Anopheles bites and advances current static maps of only Anopheles occurrence. We also developed an innovative framework to perform surveillance of malaria transmission. By incorporating antibodies against the vector and the transmissible form of malaria (sporozoite) in a joint Bayesian geostatistical model, we predict several foci of ongoing transmission. In our study, we demonstrate that antibodies specific for Anopheles salivary and sporozoite antigens are a logistically feasible metric with which to quantify and characterize heterogeneity in exposure to vector bites and malaria transmission. These approaches could readily be scaled up into existing village health volunteer surveillance networks to identify foci of residual malaria transmission, which could be targeted with supplementary interventions to accelerate progress toward elimination.
摘要:
世界卫生组织确定了一个强大的疟疾及其蚊媒监测系统,作为消除疟疾议程的重要支柱。唾液按蚊抗体是暴露于蚊虫叮咬的新兴生物标志物,有可能克服传统昆虫学调查的敏感性和后勤限制。在例行监测期间,使用缅甸东南部104个村庄的乡村卫生志愿者网络收集的样本,本研究采用贝叶斯地统计建模框架,将气候和环境变量与按蚊唾液抗原血清学相结合,生成按蚊叮咬暴露的空间连续预测图。我们的地图量化了按蚊唾液抗体血清阳性率(9%至99%)的精细尺度的空间和时间异质性,这些异质性是按蚊叮咬暴露的代表,并提高了当前仅按蚊发生的静态地图。我们还开发了一个创新框架来监测疟疾传播。通过在联合贝叶斯地统计模型中掺入针对媒介和疟疾传播形式(子孢子)的抗体,我们预测了几个持续传播的焦点。在我们的研究中,我们证明了唾液按蚊和子孢子抗原的特异性抗体在逻辑上是可行的指标,可用于量化和表征接触媒介叮咬和疟疾传播的异质性.这些方法可以很容易地扩大到现有的乡村卫生志愿者监测网络中,以确定残留疟疾传播的重点,这可以有针对性的补充干预措施,以加快消除进展。