Distribution is worldwide in soil. The prevalence of cryptococcosis has been increasing over the past 20 years for many reasons, including the increase meningitis guidelines 2016 pdf incidence of AIDS and the expanded use of immunosuppressive drugs. Often there is also silent dissemination throughout the brain when meningitis is present. Cryptococcosis is often fatal, even if treated.
As of 2009 there were globally approximately 958,000 annual cases and 625,000 deaths within three months after infection. This may be due to rare exposure and high pathogenicity, or to unrecognised isolated defects in immunity, specific for this organism. Dependent on the infectious syndrome, symptoms include fever, fatigue, dry cough, headache, blurred vision, and confusion. Symptom onset is often subacute, progressively worsened over several weeks. Blood cultures may be positive in heavy infections.
Unusual morphological forms are rarely seen. A new cryptococcal antigen LFA was FDA approved in July 2011. Cryptococcosis of lung in patient with AIDS. AIDS before the onset of symptomatic meningitis. Cryptococcal antigen screen and preemptive treatment with fluconazole is cost saving to the healthcare system by avoiding cryptococcal meningitis. What is effective preemptive treatment is unknown, with the current recommendations on dose and duration based on expert opinion.
Treatment options in persons without HIV-infection have not been well studied. 8 weeks used with secondary prophylaxis with fluconazole thereafter. The decision on when to start treatment for HIV appears to be very different than other opportunistic infections. A Cochrane review also supports the delayed starting of treatment until crytococcosis starts improving with antifungal treatment. Several weeks or even months into appropriate treatment, there can be deterioration with worsening meningitis symptoms and progression or development of new neurological symptoms.
CSF culture is sterile, and there is no increase in CSF cryptococcal antigen titre. The increasing inflammation can cause brain injury or be fatal. The mechanism behind IRIS in cryptococcal meningitis is primarily immunologic. With reversal of immunosuppression, there is paradoxical increased inflammation as the recovering immune system recognises the fungus.
In severe IRIS cases, treatment with systemic corticosteroids has been utilized – although evidence-based data are lacking. Cryptococcosis is also seen in cats and occasionally dogs. It is the most common deep fungal disease in cats, usually leading to chronic infection of the nose and sinuses, and skin ulcers. Cats may develop a bump over the bridge of the nose from local tissue inflammation.
Cryptococcosis is most common in dogs and cats but cattle, sheep, goats, horses, wild animals, and birds can also be infected. Soil, fowl manure, and pigeon droppings are among the sources of infection. University of Maryland Medical Center. Tripathi K, Mor V, Bairwa NK, Del Poeta M, Mohanty BK. Hydroxyurea treatment inhibits proliferation of Cryptococcus neoformans in mice.