Many animals and people may be exposed to Cryptococcus neoformans without developing infection. The most common predisposition factor for developing cryptococcosis is immune system problems, such as feline immunodeficiency virus (FIV) in cats and acquired immunodeficiency syndrome (AIDS) in humans. Once in the lungs, infection may heal on its own, remain localized, or spread throughout the body. In cats and dogs the infection frequently spreads to the eyes, skin and central nervous system. In humans, pulmonary disease and cryptococcocal meningitis are the most frequent manifestations. Although cryptococcosis infects humans and animals, there are no documented cases of transmission between the species.