Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA.
J Clin Microbiol. 2017 Dec 26;56(1). doi: 10.1128/JCM.01115-17. Print 2018 Jan.
Cross-reactivity within flavivirus antibody assays, produced by shared epitopes in the envelope proteins, can complicate the serological diagnosis of Zika virus (ZIKAV) infection. We assessed the utility of the plaque reduction neutralization test (PRNT) to confirm recent ZIKAV infections and rule out misleading positive immunoglobulin M (IgM) results in areas with various levels of past dengue virus (DENV) infection incidence. We reviewed PRNT results of sera collected for diagnosis of ZIKAV infection from 1 January through 31 August 2016 with positive ZIKAV IgM results, and ZIKAV and DENV PRNTs were performed. PRNT result interpretations included ZIKAV, unspecified flavivirus, DENV infection, or negative. For this analysis, ZIKAV IgM was considered false positive for samples interpreted as a DENV infection or negative. In U.S. states, 208 (27%) of 759 IgM-positive results were confirmed to be ZIKAV compared to 11 (21%) of 52 in the U.S. Virgin Islands (USVI), 15 (15%) of 103 in American Samoa, and 13 (11%) of 123 in Puerto Rico. In American Samoa and Puerto Rico, more than 80% of IgM-positive results were unspecified flavivirus infections. The false-positivity rate was 27% in U.S. states, 18% in the USVI, 2% in American Samoa, and 6% in Puerto Rico. In U.S. states, the PRNT provided a virus-specific diagnosis or ruled out infection in the majority of IgM-positive samples. Almost a third of ZIKAV IgM-positive results were not confirmed; therefore, providers and patients must understand that IgM results are preliminary. In territories with historically higher rates of DENV transmission, the PRNT usually could not differentiate between ZIKAV and DENV infections.
在包膜蛋白中共享表位产生的黄病毒抗体检测中发生的交叉反应可能会使寨卡病毒（ZIKAV）感染的血清学诊断变得复杂。我们评估了蚀斑减少中和试验（PRNT）在确认近期 ZIKAV 感染和排除具有不同既往登革热病毒（DENV）感染发生率地区的误导性阳性免疫球蛋白 M（IgM）结果方面的作用。我们回顾了 2016 年 1 月 1 日至 8 月 31 日期间为诊断 ZIKAV 感染而采集的血清的 PRNT 结果，这些血清的 ZIKAV IgM 结果呈阳性，并且进行了 ZIKAV 和 DENV PRNT。PRNT 结果解释包括 ZIKAV、未指定的黄病毒、DENV 感染或阴性。在这项分析中，对于解释为 DENV 感染或阴性的样本，ZIKAV IgM 被认为是假阳性。在美国各州，759 例 IgM 阳性结果中有 208 例（27%）被确认为 ZIKAV，而美属维尔京群岛（USVI）为 11 例（21%），美属萨摩亚为 15 例（15%），波多黎各为 13 例（11%）。在美属萨摩亚和波多黎各，超过 80%的 IgM 阳性结果为未指定的黄病毒感染。美国各州的假阳性率为 27%，美属维尔京群岛为 18%，美属萨摩亚为 2%，波多黎各为 6%。在美国各州，PRNT 对大多数 IgM 阳性样本提供了病毒特异性诊断或排除了感染。将近三分之一的 ZIKAV IgM 阳性结果未得到确认；因此，提供者和患者必须了解 IgM 结果是初步的。在历史上 DENV 传播率较高的地区，PRNT 通常无法区分 ZIKAV 和 DENV 感染。
