The zapper will kill small bacteria, virus and protozoa very quickly. For the larger parasites, the zapping will make them weaker over time by (most likely and as previsously discussed at Zapper Forum , unfourtunely the posts are gone) reaching the symbiotic bacteria that lives in their guts which their living is dependant upon. Belive it or not, people have reported WORMS elimination, not only at curezone but other places. The trick is to get a really good zapper and also foot plates so that a large area of skin is exposed to the electrification.
I bet Newport or others can report their experience aswell, check the Zapper Forum too.