An ancient adversary, resident on this earth long before our evolutionary ancestors arrived, the virus is without conscience or compassion, without mind. It enjoys the advantage of countless numbers and infinite time. it is a being almost too simple to understand and too basic to outwit. We are locked in war with the virus. Each battle kills some of us. the battles have many names: Ebola, Lassa fever, Crimean Congo Hemorrhagic Fever, AIDS...Joseph McCormick and Susan Fisher-Hoch have met them all. And they have fought them all. Level 4 : virus hunters of the CDC is their story. -- From the book jacket.

Includes index.