Newton001 Sero-surveillance to estimate the burden of Plasmodium vivax and P. falciparum infection in Latin America

消除疟疾要求各项活动除治疗疟疾患者外，还应侧重于减少社区内寄生虫的携带。然而，随着疟疾传播水平的下降，使用常规方法（显微镜检查、快速诊断测试）识别可能携带寄生虫的个体变得更加困难，因为这些感染中有许多是低密度和无症状的。因此，有必要采取创新和负担得起的办法来查明可能的寄生虫携带者及其居住地区。一种方法是血清学监测。疟疾感染会在人类宿主的血清中留下抗体“足迹”，这种抗体“足迹”会比感染本身持续更长时间。检测这些抗体是衡量人群感染暴露水平的另一种敏感和特异的方法。最近，LSHTM的研究人员重新使用这种方式使用抗体，作为一种相当准确地估计疟疾负担的方法。抗体措施已被证明与疟疾负担的其他传统估计（昆虫学，寄生虫学和临床）相关。研究还表明，通过评估抗体反应和个人年龄，有可能重现接触疟疾的历史。这一方面允许对特定地区疟疾控制干预措施的效果进行回顾性审查。这项工作主要在非洲恶性疟原虫占主导地位的环境中进行，但最近对巴西帕拉州样本的分析表明，该方法适用于这种环境。因此，该项目的目的是通过收集拉丁美洲目前关于血清流行病学和抗体动态的证据，并通过新的抗体目标和分析方法来扩展这项工作，该项目的预期成果是促进更好地了解拉丁美洲目前的血清监测证据，并确定未来研究中需要解决的研究问题。这些研究将进一步加强参与机构之间的合作，以制定可靠的血清监测方法，估计该区域特定物种的疟疾负担，确定控制方法的目标，并最终促进在该区域消除疟疾。这项建议具体涉及需要迅速和可靠的工具和战略来衡量疟疾负担，我们认为，它将提供大量信息来指导拉丁美洲的决策者。

Malaria elimination requires that activities focus on reducing parasite carriage within communities in addition to treating those sick with the disease. However, as malaria transmission levels decrease, it becomes harder to identify individuals who might be carrying parasites using conventional methods (microscopy, rapid diagnostic tests), as many of these infections will be of low density and asymptomatic. Therefore, there is a need for innovative and affordable approaches to identify likely parasite carriers and the areas where they reside. One approach is serological surveillance. A malaria infection will leave an antibody 'footprint' in the serum of the human host that will last longer than the infection itself. Detection of these antibodies is an additional sensitive and specific approach to measure a population's level of exposure to infection. Using antibodies in this way has recently been revitalised by researchers at LSHTM as a method to estimate malaria burden with considerable accuracy.Antibody measures have been shown to correlate with other conventional estimates of malaria burden (entomological, parasitological and clinical). It has also been shown that by evaluating the antibody responses and age of individuals it is possible to recreate the history of exposure to malaria. This facet allows a retrospective examination of the effect of malaria control interventions in a given locality. This work has primarily been conducted in African settings where Plasmodium falciparum is predominant, however a more recent analysis of samples from Para state, Brazil showed the approach was applicable in this setting. Therefore, the aim of this project is to extend this work by assembling the current evidence on sero-epidemiology and antibody dynamics in Latin America and extending this with novel antibody targets and analytical approaches.The expected results of this project are to promote better understanding of the current landscape of sero-surveillance evidence in Latin America and to identify research needs to be addressed in future studies. These studies will be formulated to further strengthen collaboration between participating institutions in developing reliable sero-surveillance methods to estimate species-specific malaria burden in the region, target control methods and ultimately contribute to malaria elimination in the region. This proposal specifically addresses the need for rapid and reliable tools and strategies to measure malaria burden and we believe it will provide considerable information to guide policy makers in Latin America.