Mar 30 2020
Q: Is this true that some recovered patients carry the virus?
A: Yes, this is true. The article titled SARS-CoV-2–Positive Sputum and Feces After Conversion of Pharyngeal Samples in Patients With COVID-19 was published today.
Q: If true, how does that effect the use of serum (antibodies) from recovered patients?
A: The virus was isolated from feces and sputum. It does not mean that patient have viremia - virus circulating in blood. The only way to know that is to analyze blood for viremia before collecting serum. I think it is done in the same way as we test blood, plasma used for infusions and organs used for transplantation. At least it should be done, it would be a prudent approach.
Q: Also, is this something unique to SARS-CoV-2 or is it typical with all/most viruses? Is the 3 to 10% normal?
A: No, finding of the virus or bacteria on the skin, in sputum, feces, etc. is not unique at all. This can happen with any infectious agent from much feared antibiotic-resistance staphylococci (MRSA, dubbed superbug) to E.Coli, herpes virus, and so on. In fact, up to 40% of healthy population carry MRSA around their noses and anuses and the current guidance is to leave it alone: no need to treat, unless patient is preparing for surgery or becomes symptomatic.