Wuhan Virus As Opportunistic Infection?

There is a PDF out from NYC in regards to Wuhan virus deaths. Note the following:

By this data, if you don't have an underlying condition the chances of dying from Wuhan are extremely thin. As in .5% nd that's if you assume the total cases represents the total number of infected. And it's not.

One has to wonder then whether this virus is an opportunistic infection that is "normally" not able to make someone sick but is able to when conditions allow.