Cryptococcus species are commonly found in soil contaminated by bird droppings and in decaying wood and tree hollows. The capsule of the fungus is comprised of the polysaccharides glucuronoxylomannan and glucuronoxylomannogalactan, which are the major factors contributing to the virulence of these pathogens.
Infection usually occurs by inhalation of spores from the environment. The initial infection is mostly asymptomatic and is self-limited in healthy individuals. Spread of the disease from initial sites of infection occurs through hematogenous dissemination in patients who are immune suppressed. An additional way by which infection can develop is through reactivation of the organism at the initial site of infection after several years when the patient becomes immunocompromised.
C. neoformans and C. gatti both spread through inhalation and cause a similar spectrum of illness. Although infection most often occurs by inhalation of cryptococci, diseases of the central nervous system, such as meningoencephalitis, are the most common clinical manifestations. Clinical features of cryptococcal meningitis typically manifest within a period of 1-2 weeks and include fever, malaise, headache, neck stiffness, photophobia, nausea, and vomiting. The disease may rarely progress to coma and death. Symptoms such as a cough, dyspnea, and skin rash have been reported to occur rarely. Physical examination sometimes reveals focal neurological deficits and elevated diastolic pressure indicative of raised intracranial pressure.
