A prospective, multi-centric study on the prevalence of dengue, zika and chikungunya in asymptomatic blood donors from different geographical regions of Brazil.

Background And Objectives: Arboviruses outbreaks are increasing in their frequency, geographical area and extension. Brazil is one of the most affected countries in the world, due to its tropical weather and favourable mosquito proliferation conditions. During outbreaks, the safety of the blood supply is a concern, in spite of the low number of transfusion-transmitted cases with clinical impact. The aim of this study was to evaluate the use of NAT for Dengue, Zika and Chikungunya RNA in actual screening.

Materials And Methods: Blood donors from services located in 4 Brazilian regions were invited to participate in the study and provide an extra blood sample during the collection period between February 7, 2020, and April 4, 2020. Plasma from 21 341 donations was tested in mini pools of 6 by a duplex NAT for Dengue and Chikungunya, in addition to a Zika single assay. Confirmed viremic samples were submitted to an alternative NAT and serological assays.

Results: There were 33 (0.15%) Dengue RNA+ and 5 (0.02%) Chikungunya RNA+ donations. The South region showed the highest prevalence of Dengue-infected donors (0.29%). These results are in line with the incidence of these arboviruses on the respective geographical regions. Viremic units were discarded and blood services notified.

Conclusion: Screening blood donors for arboviruses during the outbreak season in Brazil reveals a significant number of viremic individuals. Arbovirus NAT testing is feasible and may be incorporated to the current screening policy.