Ignore mild and asymptomatic cases at your peril...

Infected but apparently well people may be key points along the transmission chain - not just in spreading infectious virus, but also in contaminating surfaces.

Or they may have no role in transmission at all.

When you have problems that weren't solved by the easy answers - look harder.

Study. Test. Find out. Communicate.

Knowing the full story of how a virus spreads is hard work. But transmission is not necessarily a simple process. Like everything biological, it may be more complex than we care to acknowledge. Such a complex scenario is shown here. Completely fictitious.
Or maybe not.
Testing can answer questions. Communication can provide answers.Click on image to enlarge.