indeed, the false positives are a huge problem. That HPV is pretty prevalent from what I've read, herpes too.
Again these assumptions are based on the testing by the inaccurate antibody tests. A positive antibody test DOES NOT mean someone is infected with that microbe. So there is no way to really know what the prevalence is. A lot of this is also hyped to push drug sales such as scaring people in to taking the Guardisil (HPV) vaccine.