If you saw it on USA, it was probably
"I Was A Teenage Zombie." However, maybe not, as that zombie didn't turn others into zombies, he just killed his victims. One of the victims is turned into a zombie, though, in the same manner as the original.
...By dipping him in radioactive waste runoff. You know, I tried that once and it didn't work. The burns on my thingie won't heal, either.