The White Plague by Frank Herbert
Amazon.com Product Description (ISBN 0765317737, Paperback)
What if women were an endangered species?It begins in Ireland, but soon spreads throughout the entire world: a virulent new disease expressly designed to target only women. As fully half of the human race dies off at a frightening pace and life on Earth faces extinction, panicked people and governments struggle to cope with the global crisis. Infected areas are quarantined or burned to the ground. The few surviving women are locked away in hidden reserves, while frantic doctors and scientists race to find a cure. Anarchy and violence consume the planet.
The plague is the work of a solitary individual who calls himself the Madman. As government security forces feverishly hunt for the renegade scientist, he wanders incognito through a world that will never be the same. Society, religion, and morality are all irrevocably transformed by the White Plague.