Serological prevalence of viral hemorrhagic fevers in Equatorial Africa

描述（由申请人提供）：病毒性出血热（VHF）描述了一组不同的通常致命的疾病，伴有严重出血。所有已知的甚高频都是由脂质包膜病毒的四个不同家族的病毒引起的，包括丝状病毒（埃博拉病毒和马尔堡病毒）、沙粒病毒（如拉沙病毒）、布尼亚病毒和黄病毒。通过对从刚果民主共和国（DRC）一名出血热患者的血清样本中提取的核酸进行深度测序，首次发现了横纹肌病毒-刚果病毒（BASV）。在患病之前，上述患者是来自同一村庄的两名青少年的护理人员，这两名青少年死于具有类似症状（包括出血）的严重疾病。基于水疱性口炎病毒（VSV）的假型系统使我们能够检测血清样本中是否存在抗体，这些抗体可以中和携带BASV糖蛋白（BASV- g）的假病毒。从疾病恢复近3年后的初始患者获得的血清样本显示出对BASV-G假型特异性的强中和活性。令人惊讶的是，该患者的一名无症状密切接触者的BASV- g中和抗体检测呈阳性，滴度甚至更高，而该村的其他卫生保健工作者没有显示出暴露于BASV的迹象。对50份献血者的血清进行检测，发现1人对BASV-G具有中等中和活性。估计人类暴露于BASV水平的一个关键步骤将是筛选来自该地区和周边国家的大量血清样本，以确定是否存在BASV抗体。伪中和法适用于大样本量的高通量处理。然而，它将专门检测针对病毒糖蛋白的抗体，从而干扰靶细胞的感染。因此，我们通过其他病毒蛋白（如M和n）的额外检测确认了阳性结果。我们计划筛查来自7个国家的8000多份血清，寻找BASV感染的血清学证据，并观察另外三种VHF（埃博拉病毒、马尔堡病毒和拉沙病毒）以及另一种非洲横纹肌病毒Kotonkan（据信感染人类，但不被认为是VHF）的基础血清阳性率。

DESCRIPTION (provided by applicant): Viral hemorrhagic fevers (VHF) describe a diverse group of often-fatal illnesses accompanied by severe bleeding. All known VHF are caused by viruses from four distinct families of lipid- enveloped viruses, including the filoviruses (ebolavius and marburgvirus), arenaviruses (e.g. Lassa virus), bunyaviruses, and flaviviruses. The rhabdovirus Bas-Congo virus (BASV) was first identified by deep sequencing of nucleic acids extracted from a serum sample obtained from a patient with hemorrhagic fever in the Democratic Republic of Congo (DRC). Prior to falling ill, the mentioned patient was a caregiver for two adolescents from the same village who succumbed to a severe disease with similar symptoms, including hemorrhage. A vesicular stomatitis virus (VSV)-based pseudotype system enables us to test serum samples for the presence of antibodies that neutralize pseudoviruses bearing the BASV glycoprotein (BASV-G). A serum sample obtained from the initial patient almost 3 years after recovering from the disease revealed strong neutralization activity specific for BASV-G pseudotypes. Surprisingly, an asymptomatic close contact of the patient tested positive for BASV-G neutralizing antibodies with even higher titers, whereas other health care workers from the village did not show signs of exposure to BASV. Testing of 50 sera from blood donors identified one individual with moderate neutralizing activity specific to BASV-G. A key step in estimating the level of human exposure to BASV will be the screening of large numbers of serum samples from the area and surrounding countries for the presence of antibodies to BASV. The pseudotype neutralization assay is suitable for high-throughput processing of large sample numbers. However, it will exclusively detect antibodies targeting the viral glycoprotein, thereby interfering with infection of target cells. Consequentially, we confirm positivity with additional assays for other viral proteins, such as M and N. We plan to screen over 8000 sera from a total of seven countries for serological evidence of BASV infection, as well as looking at the basal seroprevalence of three additional VHFs - ebolavirus, marburgvirus and Lassa virus, as well as an additional African rhabdovirus, Kotonkan that is believed to infect humans, but is not thought to be a VHF.