question: What further evidence is needed to be reassured that persistent or recurrent shedding of SARS-CoV-2 RNA after recovery does not represent the presence of infectious virus?
answer: Prospectively collecting serial respiratory samples and attempting to isolate live virus in tissue culture from multiple persons testing positive by RT-PCR following illness recovery is needed. If repeated attempts to recover replication-competent virus in culture from such serial samples are unsuccessful, that data would be sufficient evidence that infectious virus is absent. Then we would be sure that persons continuing to test positive do not pose an infectious risk to others.