What frequency are your cells? Anywhere near the frequency of algae? Nope.
Also the amount of energy run thru your body is so negligible, you can't even feel it, because you, compared to the parasites are HUGE. If you went in a human sized zapper, like doorway sized, maybe, but that little bit does no harm.
After using one for 14 years, I think I would have noticed. I've gotten little electrial burns from one of the cheap ones (with the pennies) and some from my zapper with a fungus specific frequency, but that's not the zapper's fault. It was just too small a connection.
Please stop believing (or trying to make others believe) zappers are dangerous. You're at much more risk with your hair dryer; it could fall into water and electrocute you, eh?