Over the years when I did research on the dark arts vampirism was one of them. They pray to their own god of darkness and they also are into drinking each others blood. I signed their guest book and I told them about God's 1st Commandment but the dark priest replied back to me and said they are doing nothing wrong in their rituals.
I replied back to him and said if they drink other peoples blood they stand a chance of becoming H.I.V. positive it doesn't just have to the blood it can also cause hepatis. They are tested and are negative!
I replied one more time and said H.I.V. can lay dormant until it's ready to surface that could take years but it could happen.