Accurate diagnosis of infection with Histoplasma capsulatum var. duboisii

Epidemiological, clinical, diagnostic, and therapeutic features of histoplasmosis: A systematic review

Histoplasmosis is a mycosis due to a dimorphic fungus Histoplasma capsulatum. This study aimed at providing an overview of histoplasmosis epidemiological, clinical, diagnostic, and therapeutic aspects from the last 30 years. This review was carried out using a systematic literature search on histoplasmosis from 1992 to 2021. We describe the clinical features, diagnostic methods and treatment. Empirical searches were conducted via the databases PubMed, Google Scholar and Science Direct. Between 1992 and 2021, 190 manuscripts were published and reported 212 cases of histoplasmosis. These publications included 115 and 97 cases of American and African histoplasmosis respectively. The number of publications increased over the last ten years with a maximum in 2020 (12.34 % of the cases reported). The disseminated forms of histoplasmosis were the most frequently reported cases as compared to the localized forms. This was the case with the American histoplasmosis (75.65 %) as well as with the African histoplasmosis (55.67 %). Itraconazole (31.17 %) and Amphotericin B (26.62 %) were the most used drugs in the management of these cases. American histoplasmosis is distributed worldwide whereas African histoplasmosis is mainly present in intertropical Africa. There is a critical need for setting up a global surveillance system, towards a better understanding of the disease.

Histoplasmosis Caused by Histoplasma capsulatum var. duboisii: A Comprehensive Review of Cases From 1993 to 2019

BACKGROUND

Histoplasmosis caused by Histoplasma capsulatum var. duboisii (Hcd) is a rare, but probably underestimated, endemic infection described in intertropical Africa. Therefore, the epidemiology of the infection remains unclear, and there is no consensus on therapeutic management.

METHODS

Using a comprehensive search on different Internet databases, we collected case reports of Hcd infection published from 1993 to 2019. Epidemiological and clinical charts and therapeutic strategies were analyzed.

RESULTS

We found 94 well-documented cases of Hcd infection, and 30.1% of the patients were under 18 years old. Symptoms occurred in some patients several decades after leaving the endemic area. Cutaneous/subcutaneous lesions, bone infections, and lymphadenopathies, both isolated and combined, were the most frequent presentations. The human immunodeficiency virus (HIV) coinfection rate was at 20.8%, with fever, lymphadenopathies, and an absence of bone infection being the differentiating elements from patients living without HIV. The rate of disseminated forms (60.6% in our review) significantly increased as compared to studies published before 1993, but without correlation with HIV infection. The global mortality rate was at 23.4% by the end of follow-up. The outcome was not correlated with the antifungal drug prescribed, nor with HIV serologic status, but was correlated with the initiation of an antifungal therapy.

CONCLUSIONS

Hcd histoplasmosis is a severe fungal infection for which the precise mode of acquisition remains to be determined. There is a need for affordable and more specific diagnostic tools. Itraconazole and amphotericin B are the best therapeutic alternatives and should be available in all low-income countries of the endemic area.

Literature review and case histories of Histoplasma capsulatum var. duboisii infections in HIV-infected patients

African histoplasmosis during HIV infection is rare.

African histoplasmosis caused by Histoplasma capsulatum var. duboisii is an invasive fungal infection endemic in central and west Africa. Most of its ecology and pathogenesis remain unknown. H. capsulatum var. capsulatum is an AIDS-defining opportunistic infection in HIV-infected patients who are living in or have traveled to histoplasmosis-endemic areas. In contrast, reports concerning African histoplasmosis during HIV infection are rare, although both pathogens coexist in those regions. We report 3 cases of imported African histoplasmosis diagnosed in France in HIV-infected patients and a literature review on similar cases.