Going MAD is just the beginning of the terror!

The basic plot here is a bunch of residents in a suburban high-rise apartment building are being infected by a strain of parasites that turn them into mindless, sex-crazed fiends out to infect others by the slightest sexual contact.

This was also known in the US as "They Came From Within".  This was David Cronenberg's first feature film in 1975 and was quite controversial at the time.  Check it out before the re-make hits.  I'm not too fond of re-makes, but that's another post.