COVID-19: Transmission from Older Kids / Pooled Sample Test Authorized / Persistent Viral RNA in Blood Donor

By Amy Orciari Herman

Edited by Susan Sadoughi, MD, and André Sofair, MD, MPH

Take a look at some of the latest developments on COVID-19:

Transmission from older children: Children aged 10–19 years might spread SARS-CoV-2 to household members more readily than adults do, suggests a study in Emerging Infectious Diseases. Researchers in South Korea followed nearly 60,000 contacts of 5700 COVID-19 index patients for roughly 10 days. Some 12% of household contacts were infected, versus 2% of non-household contacts. When the index patient was aged 10–19 years, 19% of household contacts were infected. In contrast, when the index patient was aged 30–49, 12% of household members were infected (and when the index patient was aged 0–9 years, just 5% of household contacts were infected). The authors write, "These risks largely reflected transmission in the middle of mitigation and therefore might characterize transmission dynamics during school closure." Of note, they acknowledge that they "could not determine direction of transmission."

Pooled sample test authorized: The FDA on Saturday issued an emergency use authorization for the Quest Diagnostics reverse transcriptase-polymerase chain reaction (RT-PCR) test for SARS-CoV-2 to be used with swab specimens pooled from up to four patients. It's the first SARS-CoV-2 diagnostic test to be approved for use with pooled samples (if the pool tests negative, all patients are considered negative; if it's positive, each individual sample needs to be retested). "This ... is an important step forward in getting more COVID-19 tests to more Americans more quickly while preserving testing supplies," the FDA commissioner said in a news release.

Persistent viral RNA in blood donor: SARS-CoV-2 RNA was detected in blood donated 40 days after the donor's upper respiratory symptoms had resolved, researchers report in the Annals of Internal Medicine. After this finding, the donor had a nasopharyngeal swab specimen tested, and it was negative for SARS-CoV-2. The researchers say the finding "is concerning in light of current guidelines, which do not recommend SARS-CoV-2 screening in the general allogeneic donor population." They note, however, that "the infectivity of SARS-CoV-2 from blood remains unknown and, to date, we are not aware of cases of transfusion-transmitted COVID-19." They conclude, "Out of an abundance of caution ... our institution plans to continue donor screening for SARS-CoV-2 RNA and has extended the deferral period from 28 to 56 days after resolution of symptoms."