I am currently reading a book called Peeps by Scott Westerfeld. Cal is a 19 year old with a parasite that makes him a "Peep" or vampire. He is only a carrier of the parasite, but all of his old girlfriends are infected. Cal has to track down all of them before they create more peeps. Cal has overactive hormones, and has to control his thoughts at all times. Cal has to overcome his hormones. He also has to overcome his feelings towards his old girlfriends when he hunts them down. This reminds me of Twilight series. Bella, Edward and his family have to prevent other vampires from creating more vampires.