Positive Singles is the best, largest, completely anonymous and most trusted online dating site for people with Herpes, HPV, HIV / AIDS and other STDs in the world.We have 60,000 STD dating success stories, 120,000 daily conversations, 15,000 daily active members and 500 daily blog posts. You are not required to submit any information that would make you uncomfortable.To answer your question: it depends on what you mean by legitimate.
My first recommendation would be to try Lavalife's Intimate Encounters section; you sign up with them and then decide which of the three sections you want to be a part of (Dating, Relationships or Intimate Encounters).
You can use different handles in each section under the same account too, so no one will be any wiser if you want to advertise for one thing in one place without ruining your chances for something more should it come up.
After Lavalife, I only know of a few others that are worth mentioning, although I've yet to find one that's truly ideal.
There are over 110 million people living with STDs in the US as well as an estimated 400 million people worldwide. Meet Positive Singles in Reykjavík TODAY and connect with more than one million singles like you now!
(As a Silicon Valley firm, we have been in the online dating business for over 16 years!