In most cases, samples from blood donors do not need to be tested for SARS-CoV-2, with current blood donor screening guidelines safe to continue following, the National Institutes of Health said June 1.
That's because under the current guidelines, which do not require donor samples to be tested for the virus, there is little chance — about 1 in 100,000 — of a transfusion recipient receiving blood with trace amounts of the virus, according to a study led by NIH researchers and published May 27 in Transfusion. Of the thousands of blood samples tested as part of the study, three came back positive with very low virus concentrations.
"Other studies have shown that in rare cases where a blood sample tested positive, transmission by blood transfusion has not occurred," said Sonia Bakkour, PhD, part of the research team that analyzed the blood. "Therefore, it appears safe to receive blood as a transfusion recipient and to keep donating blood, without fear of transmitting COVID-19 as long as current screenings are used," added Dr. Bakkour, who is also a scientist at UC San Francisco's department of laboratory medicine, and a scientist at the Vitalant Research Institute.
Current blood donor screening guidelines require donors be screened for physical COVID-19 symptoms and for infections that occurred within 14 days, but do not require blood samples to be tested for SARS-CoV-2. Blood from donors with recent infections, or who contract infections soon after donating, cannot be used.