Asymptomatic spread of the SARS-CoV-2 virus that causes COVID-19 is a big problem.  And, this problem  does not behave the same as with many other viruses, even the close relative SARS-CoV-1, the virus that caused SARS in 2002-2003.  When SARS struck, health authorities controlled and eventually stopped the epidemic by using symptoms to detect cases.  … Continue reading Risk and the asymptomatic carrier of COVID-19