BACKGROUND: Transmission of SARS-CoV-2 by asymptomatic individuals and by blood transfusion are important issues to understand in order to control the viral spread . In this work, we estimated the current SARS-CoV-2 infection rate in blood donors from Belo Horizonte, Brazil . STUDY
DESIGN AND METHODS: Saliva and blood samples were collected from 4103 blood donors from June 15 to September 30 , 2020 . Saliva samples were tested by real-time RT-PCR for SARS-CoV-2 in mini-pools of four samples . Individual samples were tested for positive or inconclusive pools, and positive donors had their plasma tested .
RESULTS: Twenty-seven (0.66 %) blood donors were positive for SARS-CoV-2 in their saliva, but their plasma was negative, except for one, who presented a high viral load in saliva and nasopharyngeal samples and RNAemia in the plasma close to the limit of detection . Fourteen (56 %) positive blood donors reported mild symptoms related to COVID-19 after donation, but the viral load levels were not statistically different between symptomatic and asymptomatic individuals .
DISCUSSION: Despite the measures taken by Blood Centers to avoid blood donors with SARS-CoV-2 infection, asymptomatic or presymptomatic carriers are able to donate . The risk of the virus transmission by transfusion seems to be negligible since plasma RNAemia was seen at a very low level in only one (3.7 %) of the positive donors, but other studies must be performed to confirm this finding . This article is protected by copyright . All rights reserved.