No molecular or serological evidence of Zikavirus infection among healthy blood donors living in or travelling to regions where Aedes albopictus circulates.

Previous studies have shown that Zika virus can infect and be transmitted by A. albopictus. The World Health organization (WHO) has raised concerns of autochthonous transmission of the virus in regions where the vector is endemic. The aim of this pilot study was to assess the occurrence of Zika virus (ZIKV) in western Austria (Tyrol) especially after a history of travel to A. albopictus endemic regions. The study participants were healthy blood donors at randomly selected donation sites in the west Austrian region Tyrol. Rest blood (plasma) samples were tested for the presence of ZIKV nucleic acid and antibodies against the virus. Mean age of the study participants was 44.6 (SD = 12.9) and 58.8% were men. Eighty percent reported to have received vaccine against TBEV, whereas only 4.9 and 0.9% had received YFV and JEV vaccines. Three out of 1001 (0.03%) participants tested positive solely for ZIKV IgM antibody but not for other flaviviruses. Only one individual had ZIKV IgG antibody. All four donors were negative in the neutralization (confirmation) assay. No viral RNA was detected in any of the samples. The null finding of our study refutes WHO's initial fear of global expansion of ZIKV infection including its occurrence in Europe. There appears to be no urgent need to introduce universal screening of donated blood for ZIKV in central Europe at least until the next warm season. Further, Euroimmun anti-Zika ELISA proved to be a highly suitable and reliable test system in populations with high prevalence of TBEV infection and/or immunization.