Whole-Blood Testing for Diagnosis of Acute Zika Virus Infections in Routine Diagnostic Setting

Jolanda J.C. Voermans; Suzan D. Pas; Anne van der Linden; Corine GeurtsvanKessel; Marion Koopmans; Annemiek van der Eijk; Chantal B.E.M. Reusken


Emerging Infectious Diseases. 2019;25(7):1394-1396. 

In This Article

Abstract and Introduction


We evaluated the benefit of whole blood versus plasma to detect acute Zika virus infections. Comparison of Zika virus quantitative reverse transcription PCR results in single timepoint whole blood–plasma pairs from 227 patients with suspected Zika virus infection resulted in confirmation of 8 additional patients with Zika virus infection.


Since its emergence in South and Central America in 2015/2016, Zika virus (genus Flavivirus) has become a major public health concern. Zika virus infections are linked to congenital malformations in neonates from mothers infected during pregnancy and to neurologic disorders in adults.[1] Thus, the stakes for an accurate diagnosis are high when congenital Zika syndrome might be involved, such as in diagnosis in pregnant women and their partners, because Zika virus infections can be sexually transmitted.[1] Diagnostics are based on Zika virus RNA detection, detection of Zika virus–specific antibodies, or both. However, a definitive diagnosis based on serology only is hampered by the existence of a high degree of cross-reactivity between Zika virus and other flaviviruses and their vaccines. In addition, populations with a high background of other flavivirus infections, such as dengue virus, might lack high-titer Zika virus–specific antibody production (also known as original antigenic sin).[2,3] Reverse transcription PCR (RT-PCR) is the most reliable method for confirming Zika virus infections. Viremia in pregnant women can be prolonged, up to 70 days, but more commonly the window of detection for Zika virus RNA in serum or plasma is much shorter (3–14 days after onset of symptoms). The window of detection can be considerably longer for urine and semen, but these specimens are not routinely collected.[4–7]

Various studies have suggested that flavivirus genomic RNA might be detectable for longer periods in whole blood than in plasma, thereby expanding the timeframe for viral genome detection to up to 120 days after onset of symptoms.[4,5,8–11] Therefore, molecular detection of Zika virus RNA in whole blood instead of plasma might improve Zika virus case confirmation.[12,13] In a prospective study, we systematically evaluated the benefit of whole blood versus plasma as the sample of choice to detect acute Zika virus infections in a routine diagnostic setting.