I don't know the answer, but I suspect this is actually multiple questions: - How many diseases do we learn to distinguish (i.e. from other diseases) every yea

I don't know the answer, but I suspect this is actually multiple questions: - How many diseases do we learn to distinguish (i.e. from other diseases) every year as our biological laboratory technology improves. You can imagine that once upon a time, there were multiple strains of coronaviruses in humans, but we had no way to tell them apart (the strains look the same to whatever scale of study is available), which we can now tell apart. - How many diseases do we discover as we apply modern medical technology to an ever-wider portion of the global human population (again, that are already in humans but which are "discovered" in that year)? - How many new diseases develop for humans every year? For example, we have no evidence that any of the current strains of Covid-19 were present in humans prior to late 2019.