**2. Epidemiology**

Histoplasmosis is a disease that affects people all over the world, but it is especially prevalent in North and Central America and South America along the valleys of the Ohio and Mississippi Rivers. It has been identified in Madagascar, West Africa, South Africa, Eastern and Central Africa, and Africa. Additionally, isolated cases from the Mediterranean Basin and Southeast Asia have been documented [2–5]. Uganda, Nigeria, the Democratic Republic of the Congo, and Senegal are the countries where African histoplasmosis disease has been most frequently documented, as Hcd only occurs on the continent of Africa. African histoplasmosis accounted for 61% of the 470 histoplasmosis cases that were documented in Africa from 1952 to 2017 [3]. Central and western Africa accounted for 87% of all cases of histoplasmosis in Africa. Eastern and Southern Africa have recorded fewer occurrences than other continents. The bulk of histoplasmosis cases found in southern Africa are caused by Hcc, whereas Hcd is more common in the west, central Africa, and 4Madagascar [6]. The majority (n = 119) of the 150 cases that were reported from Southern Africa were brought on by *H. capsulatum var. capsulatum* (Hcc), and neither Hcd nor Hcc had any case reports from Northern Africa [6]. It's important to remember that, unlike Hcd, which is only found in Africa, Hcc is more prevalent in North and South America, even if it can also be found in Europe, Asia, and other parts of the world.

The predominance of Hcd in Africa has been confirmed by the 400 cases of African histoplasmosis alone that have been reported from 32 African nations in 2020, either as case reports or as case series [7]. In the Democratic Republic of the Congo and Togo, studies conducted during the previous six and fifteen years, respectively, identified 17 and 36 cases [8, 9].

Surveys of Histoplasma skin sensitivity remain crucial for identifying endemic regions or preclinical histoplasmosis. However, a survey conducted in Nigeria, revealed a 4% Histoplasma skin-positive rate [10]. Histoplasmosis is an unknown public health concern in Africa that is mistakenly diagnosed for tuberculosis, as evidenced by the detection of *H. capsulatum* in 13% of HIV-infected individuals in Cameroonian research [11]. It's vital to avoid undervaluing the diagnosis of

disseminated histoplasmosis (HD) in HIV-infected people due to the endemicity of tuberculosis, the main HIV-defining disease in Africa.

According to various case studies, 2:1 more men than women contract histoplasmosis [8]. Cases have been documented among people between 13 months and 70 years, but all age groups may be affected [12]. Histoplasmosis, particularly classical histoplasmosis, frequently co-occurs with TB and HIV and is expected to be a major health burden in sub-Saharan Africa. However, there appears to be little correlation between HIV and African histoplasmosis [13]. Epizootic histoplasmosis can affect nonhuman primates, including dogs, cats, horses, baboons, and dogs. In Ethiopia, an African nation, equine histoplasmosis has been extensively reported [14]. A recent case of histoplasmosis associated with Hcd in a baboon in America has been related to the import of baboons from Senegal [15]. Still, there is lack of evidence for either human-to-human or animal-to-animal transmission.
