Hi Brian,
refering to http://www.katadyn.ch/site/ch_en/home/outdoor_products/micropur/micropur_classic Micropur works by silver ions and not by chlorine. By that I canīt imagine a neative influence on latex.
But Micropur forte (!) consists of silver and additional chlorine and so I think that it could be a bad idea of using it in a condom.

greets Molf