Cryptococcal Infections

Cryptococcus species are commonly found in soil contaminated by bird droppings, decaying wood, and tree hollows. The capsule of Cryptococcus is comprised of the polysaccharides glucuronoxylomannan and glucuronoxylomannogalactan, which are the major factors contributing to virulence.

Infection usually occurs by inhalation of spores^4,5 from the environment. The initial infection is mostly asymptomatic and is self-limited in healthy individuals. The spread of the disease from the initial sites of infection occurs through hematogenous dissemination in immune-suppressed patients. An additional way an infection can develop is by reactivating 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, central nervous system diseases, such as meningoencephalitis, are the most common clinical manifestations. Clinical features of cryptococcal meningitis typically manifest within 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 seldom. Physical examination sometimes reveals focal neurological deficits and elevated diastolic pressure indicative of raised intracranial pressure.