FDA科学家---西尼罗河病毒和献血者筛选

FDA Scientists - West Nile Virus and Blood Donor Screening

FDA科学家---西尼罗河病毒和献血者筛选

End of July, the FDA/CBER published a short summary about the scientific work of FDA researchers who were concerned with the genetic background and genetic changes of the mosquito-borne West Nile Virus (WNV). This virus, normally hosted by birds and mosquitos, can be occasionally transmitted by the mosquitos to humans and causes symptoms in 20% of these cases. As many other viruses too, the WNV underlies permanent genetic changes and the study of the FDA scientists highlights the need for continuously tracking and identifying new genetic variants of WNV in order to protect public health from the annual outbreak of this disease, for which there are no specific therapies or vaccines.

在7月底，FDA/CBER公布了一份关于研究蚊子产生的西尼罗河病毒（WNV）基因背景和基因变化的FDA研究员的科学工作简短总结。该病毒一般借宿于鸟和蚊子，可能偶尔会由蚊子传播给人类，导致20%发病率。和许多其它病毒一样，WNV可能会产生永久基因变化，FDA科学家的研究强调需要进行持续跟踪，识别出新的WNV基因变体，以保护公众健康，防止引疾病年度爆发。此病毒目前尚无特定的治疗和疫苗。

It is important, because it is known, that WNV can be transmitted by transfusion of blood and blood components and by organ transplantation. Therefore some guidelines and guidance documents were published since WNV emerged in the United States in 1999 - as examples:

我们已知WNV可以通过输血和血液成分传输及组织移植传染，所以上述问题显得尤其为重要。因此一些指南在WNV于1999年进入美国后相继公布，如：

• FDA Guidance for Industry: Assessing Donor Suitability and Blood and Blood Product Safety in Cases of Known or Suspected West Nile Virus Infection
• FDA FEDERAL REGISTER Medical Devices; Immunology and Microbiology Devices; Classification of the West Nile Virus IgM Capture Elisa Assay
• FDA Draft Guidance for Industry: Use of Nucleic Acid Tests to Reduce the Risk of Transmission of West Nile Virus from Donors of Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps)
  

But if the virus will underlie genetic changes, it is a valid question, whether tests used to diagnose infection and screen blood donors, as well as vaccines and drug therapies may not perform as well against newer genetic variants of WNV.

但是如果病毒会产生基因变化，这就会产生一个是否有效的问题，用于诊断感染和筛选献血者的测试，以及疫苗和药品治疗可能无法对更新的基因变化WNV产生作用。

The scientists tracked now samples obtained from 1999 - 2012 and they detected several codons in the WNV genetic material that had undergone mutations that remained in a variety of virus populations over the years.

科学家现在跟踪的是从1999-2012年所获得的样本，他们发现WNV基因材料的几个遗传密码经过了突变，保持在大量病毒群体中多年。

FDA summarized: "The study’s findings also suggest that these genetically similar variants may be a new strain of WNV emerging in the United States. They also suggest that by studying genetic changes in the virus, scientists can obtain important insights into the virus’s ability to spread, clues for designing anti-WNV vaccines, drug treatments, and reliable tests for screening blood donors for this virus."

FDA总结说，“研究还发现这些基因类似变体可能是在美国产生的一种新WNV病株。他们还说，通过病毒基因变化研究，科学发可以对病毒扩散的能力有重要了解，找到设计抗WNV病毒疫苗、药物治疗和此类病毒对献血者进行可靠的筛选测试的线索。”

For more details, please see the FDA publication: Tracking genetic changes in West Nile Virus that could affect its spread and the ability of blood donor screening tests, future treatments, and vaccines to work effectively or the publication Genetic Variability of West Nile Virus in U.S. Blood Donors from the 2012 Epidemic Season by Andriyan Grinev , Caren Chancey, Evgeniya Volkova,  Germán A?ez,  Daniel A. R. Heisey,  Valerie Winkelman,  Gregory A. Foster,  Phillip Williamson,  Susan L. Stramer, Maria Rios, Published: May 16, 2016

更多信息，参见FDA官网。