Nature https://doi.org/10.1038/s41586-020-2196-x (2020)

Virological assessment of SARS-CoV-2 identifies evidence for active viral replication in the throat.

Credit: Iryna Veklich / Moment / Getty

COVID-19 is an acute respiratory-tract infection caused by a coronavirus related to that which caused severe acute respiratory syndrome (SARS). Both use a virus receptor predominantly expressed in the lung, and this aspect is thought to have limited the contagion of SARS.

A research group in Germany has analyzed viral RNA production, isolated active virus and followed the seroconversion of nine people with COVID-19 who were known to have contracted the infection from an index case. The individuals presented diverse symptoms including those of a mild upper-respiratory-tract infection. Infectious virus was isolated from throat- and lung derived-samples but not from stool, blood or urine samples; viral clearance did not occur directly after seroconversion. The data suggest active viral replication in the throat as well as the lungs, thus providing direct implications for infection containment.