The Parasite Doctor Suzune (2004)

Blurb:
In a city so over-indulgent and careless, reveling in food and sex and completely unaware of the epidemic of parasites, it’s no wonder so many people are infected. Dr. Suzune Arizono isn’t exactly a normal doctor. For one, she’s actually a veterinarian- but her specialty is parasites, and when those parasites make a habit of nesting inside human genitalia and overriding their senses with lust, her job is bound to get more than a little messy!

As the spunky and beautiful heroine of this sexy sci-fi mystery, Suzune searches for infected victims to stop the parasites from driving their hosts literally crazy with lust. However, despite her desire to help people, her reasons aren’t completely selfless. The parasites are Suzune’s only link to her missing father, but will following these wet and slimy clues really lead her to his whereabouts, or is this voluptuous vet in over her head?

Source: www.anisearch.com/manga/13491