Lack of serological and molecular evidences of Zika virus circulation in non-human primates in three states from Brazil

BACKGROUND Zika virus (ZIKV) was discovered in 1947 with the virus isolation from Rhesus monkey (Macaca mulatta) in Uganda forest, Africa. Old World Primates are involved in a sylvatic cycle of maintenance of this arbovirus, however a limited knowledge about the role of New World primates in ZIKV transmission cycles has been established. OBJECTIVE This work aimed to investigate the presence of enzootic circulation of ZIKV in New World Primates from three Brazilian states: São Paulo, Paraíba, and Paraná. METHODS We analyzed 100 non-human primate samples collected in 2018 and 2020 from free-ranging and captive environments from São Paulo (six municipalities belonging to Sorocaba region), Paraíba (João Pessoa municipality), and Paraná (Foz do Iguaçu municipality) using reverse transcriptase quantitative polymerase reaction (RT-qPCR) assays, indirect enzyme-linked immunosorbent assay (ELISA), and plaque reduction neutralization test (PRNT). FINDINGS All samples (n = 141) tested negative for the presence of ZIKV genome from tissue and blood samples. In addition, all sera (n = 58) from Foz do Iguaçu’ non-human primates (NHPs) were negative in serological assays. MAIN CONCLUSION No evidence of ZIKV circulation (molecular and serological) was found in neotropical primates. In addition, the absence of antibodies against ZIKV suggests the absence of previous viral exposure of NHPs from Foz do Iguaçu-PR.

### 背景
寨卡病毒（ZIKV）于1947年首次从非洲乌干达森林的恒河猴（Macaca mulatta）体内分离获得。旧世界灵长类参与了该虫媒病毒的丛林维持循环，但目前学界对于新世界灵长类在寨卡病毒传播循环中所发挥的作用，相关认知仍较为有限。
### 研究目的
本研究旨在调查巴西圣保罗州、帕拉伊巴州及巴拉那州三地新世界灵长类中寨卡病毒的兽间传播循环存在情况。
### 研究方法
本研究采用逆转录定量聚合酶链反应（RT-qPCR）、间接酶联免疫吸附试验（ELISA）及空斑减少中和试验（PRNT）三种检测方法，对2018年及2020年采集的100份非人灵长类（NHPs）样本进行分析。样本的采集环境涵盖野外自由活动及圈养两种场景，具体采集地包括：圣保罗州索罗卡巴地区下辖的6个市、帕拉伊巴州若昂佩索阿市，以及巴拉那州伊瓜苏港市。
### 研究结果
所有141份组织及血液样本的寨卡病毒基因组检测均呈阴性。此外，采自伊瓜苏港的58份非人灵长类血清样本的血清学检测结果也全部为阴性。
### 主要结论
未在新热带灵长类中发现寨卡病毒传播循环的相关证据（涵盖分子及血清学两个层面）。另外，伊瓜苏港地区的非人灵长类体内未检出寨卡病毒抗体，提示该种群此前未接触过寨卡病毒。