Though not endemic in Europe, reports of microfoci of histoplasmosis due to Hcc have been reported in Italy. Hcd is primarily found in Central and West Africa and Madagascar, and histoplasmosis caused by this fungus is often referred to as African histoplasmosis, which is a misnomer because African patients can be infected with both variants. In Africa, the most predominant infective agent is Hcc, which can coexist with Hcd.
It is also endemic in India and Southeast Asia. Histoplasmosis is highly prevalent in areas along the Mississippi and Ohio valleys in the United States and in Central and South America.
However, in immunocompetent persons, it is mostly asymptomatic or spontaneously self-limiting. In these areas, progressive disseminated histoplasmosis (PDH) can occur in 5% to 20% of patients infected with HIV.
Primary infection is extremely common in highly endemic areas based on the prevalence of skin test reactivity, with 23% to 81% and 5% to 50% of the population testing positive in Guatemala and Mexico, respectively. ĭuring highly active antiretroviral therapy (HAART), morbidity and mortality due to histoplasmosis remain a public health problem in low- and middle-income countries (LMICs). Disseminated histoplasmosis was classified as an AIDS-defining infection in 1987. The greatest attributable risk factor for histoplasmosis is the spread of HIV, although immunosuppressive agents used in transplant patients or chronic inflammatory diseases also contribute to its increase. Recently, WHO broadened their list of core neglected tropical diseases (NTDs) to include deep mycoses, of which histoplasmosis is one. Histoplasmosis is not a notifiable disease, thus hard data on the incidence and prevalence, as well as information on its morbidity and mortality, are fragmentary or not available in many endemic areas. The true global burden of histoplasmosis is not well documented despite its endemicity and not addressed previously for Africa. The first case of Hcd was described in West Africa in 1943 by Duncan. Histoplasmosis was first described by Darling in the Canal Zone in Panama in 1906 patients were described as presenting with features suggestive of disseminated TB. Hcc is patchily distributed around the world, whereas Hcd is essentially restricted to Africa. capsulatum leads to histoplasmosis in some people. Treatment requires amphotericin B and itraconazole, both of which are not licensed or available in several parts of Africa. Rapid diagnosis of histoplasmosis in Africa is only currently possible using microscopy antigen testing and PCR are not available in most of Africa. Most cases of Hcd presented as localised lesions in immunocompetent persons however, it was disseminated in AIDS patients. There have been 12 histoplasmin skin test surveys with rates of 0% to 35% positivity. From the Southern African region, 150 cases have been reported, and the majority (119) were caused by H. West Africa had the highest number of recorded cases with 179 the majority (162 cases) were caused by Histoplasma capsulatum var. HIV-infected patients accounted for 38% (178) of the cases. In the last six decades (1952–2017), 470 cases of histoplasmosis have been reported. Pulmonary histoplasmosis may be misdiagnosed as tuberculosis (TB). Histoplasmosis in Africa has markedly increased since the advent of the HIV/AIDS epidemic but is under-recognised.