Simultaneous zika and dengue serotype-4 viral detection and isolation from a donor plasma unit.

During zika and dengue viruse (ZIKV and DENV) outbreaks, the majority of the infected individuals remain clinically asymptomatic. Such asymptomatic individuals may occasionally acquire both arboviruses, donate blood, and contaminate haemoderivatives. The aim of this study was to characterize a ZIKV/DENV-4 coinfection in asymptomatic blood donor who donated blood during a large mixed ZIKV/DENV outbreak in the Säo Paulo State, Brazil. On the basis of post-donation information, one blood donor sample was found positive for ZIKV and DENV RNA. The DENV molecular serotyping was performed by molecular testing. The sample was also titrated on VERO E6 cells in order to define the presence of infectious arboviruses. The real-time PCR testing of the blood donor sample demonstrated very high viral load for both ZIKV and DENV. Further, molecular serotyping of DENV showed that the presence of DENV-4. The viral titration in cell culture indicated a titre of 2.75x10[6] PFU/ml which was concordant with the presence of infectious viruses in the blood donation. This is an interesting report for the simultaneous presence of infectious ZIKV and DENV-4 in asymptomatic blood sample. Special attention must be paid during mixed arboviral outbreaks for the possibility of transfusion-transmission of multiple arboviral agents.