User:Phwikiproj/Cryptococcosis/Skallasj4863 Peer Review

Epidemiology
Cryptococcus species are often found in the soil environment or in bird droppings.

Cryptococcosis is usually associated with immunosuppressed patients, such as AIDs, corticosteroid use, diabetes and organ transplant patients. In 2014, amongst people who had low CD4+ cell count, the annual incidence rate was estimated to be 278,000 cases. Of those, 223,100 resulted in cryptococcosis meningitis. About 73% of cryptococcosis meningitis cases occurred in Sub-Saharan Africa. More than 180,000 fatalities are attributed to cryptococcosis meningitis, 135,000 of which occur in sub-Saharan Africa. Case fatality of cryptococcal meningitis varies widely depending on what country the infection occurs in. In low-income countries, the case fatality from cryptococcal meningitis is 70%. This differs from middle income countries with a case fatality rate of cryptococcal meningitis of 40%. And lastly, in wealthy countries, the case fatality is 20%. Cryptococcosis is the second most common cause of death for patients with AIDs, behind tuberculosis. In sub-Saharan Africa approximately 1/3 of HIV patients will develop cryptococcosis.

Cryptococcus is found in two species, Cryptococcus neoformans and Cryptococcus gattii. C. gattii was previously thought to only be found in tropical climates and in immunocompetent persons, but recent findings of C. gattii in regions such as Canada and Western areas of North America have challenged this initial presumption of the geographic patterns.

Cryptococcosis in the United States
In the United States there are between 2-7 cases of cryptococcosis per 1,000 per year. Since 1990, the incidence of AIDs associated cryptococcosis has decreased by 90% due to the proliferation of antiretroviral therapy. The estimated prevalence of cryptococcosis cases amongst HIV patients in the U.S. is currently 2.8%. Though immunocompetent patients are still susceptible to infections by Cryptococcus gattii. Though cryptococcosis in immunocompetent people is rare, it has been demonstrated that cryptococcosis is more common than previously thought. Upwards of 20% of cases of cryptococcosis occurs in those who are diagnosed as immunocompetent. Over 50% of cryptococcosis infections in North America and Australia are caused by C. gattii. Though C. gattii was originally thought to be restricted to subtropical and tropical regions it has become more prevalent worldwide. C. gattii has been found in over 90 people in the United States, most of these cases originating in Washington or Oregon.

In sub-Saharan Africa
Globally, the majority of cryptococcal meningitis cases are reported in Sub-Saharan Africa. In a significant portion of Sub-Saharan Africa, Cryptococcus has become the prevailing cause of meningitis in adults. Cryptococcal meningitis is a primary contributor to mortality among individuals with HIV/AIDS in sub-Saharan Africa. Approximately 160,000 cases of Cryptococcal meningitis are reported in West Africa, resulting in 130,000 deaths in Sub-Saharan Africa per year??. Cryptococcus is responsible for 15% of AIDS-related fatalities. The source of Cryptococcus species in West Africa is primarily linked to pigeon feces. Most patients acquire the infection through the exposure of complex Cryptococcal species originating from various environmental sources. Analysis of Cryptococcal isolates from environmental sources shows minimal genetic diversity. Clinical isolates exhibit significant genetic variations, similar to those found in environmental isolates. A 2020 study identifies that combined short-term mortality (death within two weeks) exceeds 50% for cryptococcal meningitis, with no recorded instances of long-term mortality (death within 10 weeks) in the Western part of Africa.