236 - Estimating ZIKV seroprevalence in a DENV endemic population: the use of blood donors and multiplex serology to monitor arbovirus outbreaks in the Dutch Caribbean

Abstract: The past few decades mark the emergence and expansion of arboviruses worldwide, including the rapid spread of Zika virus (ZIKV) to and in South America. This led to two ZIKV outbreaks on Aruba and Curacao in 2016 and 2017, of which the actual magnitude and risk of exposure remains unclear. Studying ZIKV seroprevalence against a highly arbovirus endemic background is challenging due to extensive antibody cross-reactivity. Here, we show that by using a multiplex protein microarray containing 11 flavivirus (NS1) proteins, it was possible to disentangle ZIKV exposure from exposure to other flaviviruses, and therefore estimate the ZIKV seroprevalence during and after the Aruba and Curaçao ZIKV outbreaks. On Curaçao, the seroprevalence of ZIKV antibodies was higher than on Aruba, and flavivirus IgG antibody titers increased with age (p-value < 0.05). This study gives insights into the complex antibody background patterns of various flaviviruses over time, and highlights the utility of an existing blood donor program to monitor and respond to future (flavivirus) outbreaks.