The Parasite Doctor Suzune: Genesis.

The city is infested with mysterious parasites that bore into their human hosts to increase their host's power and sexual desires. A beautiful girl, Suzune Arizono is a vet with a specialty in parasites, and who fights daily to end the plague. Before long, she learns that an evil organization, the Kito Zaibatsu, is behind the explosive growth of this ferocious parasite. She also learns that her long-missing father, Dr. Arizono, is also involved. In order to crush the Kito Zaibatsu's ambition and to see her father again, Suzune takes on the fight without regard to the danger involved.