No, I'd say "communicable" makes more sense from where I'm sitting. From what I understand, a contagion is a communicable condition that spreads rapidly, whereas a low-contagious yet communicable condition is usually more intimate/personal. Like, say, a STD or something. (that said I'd seen R18 TS succubus stories where it is more of a rapidly spreading contagion, like Village of Nightmare)
Also you can say you are whoever you'd like, but on the internet that weight doesn't mean much since anyone can claim to be anything. I'm president of the galaxy, btw. I control the rainbow colored robot unicorns currently watching you from orbit.