Tell them you vacation in Africa. They'll never call again.
Actually, I told them, truthfully, that I have viral flareups and may have been having one now.
I reported this to the nurses too and they just shrugged. Unless the specific virus shows up on their little check-list, you are considered “healthy”.
I didn’t know much about these things at the time, but it turns out that I was in the midst of an Acute Epstein Barr outbreak. Whoever got that blood got a full dose. Despite my protests and expressed concerns, the Red Cross nurses classified and sold my, relatively, rare and valuable donation as “baby safe”, since it fetches a much higher price. Oddly, I test neg. for most all other adult human viruses which pose a threat to newborns, thus, I have “baby blood”. I am certain EB would be very dangerous to children.
Gives you a little glimpse into, and a perspective on how national healthcare would be handled by such people with “checklists”.