A review of endemic mycoses after hematopoietic stem cell transplantation

The Known and Unknown "Knowns" of Human Susceptibility to Coccidioidomycosis

Coccidioidomycosis occurs after inhalation of airborne spores of the endemic, dimorphic fungus, Coccidioides. While the majority of individuals resolve the infection without coming to medical attention, the fungus is a major cause of community-acquired pneumonia in the endemic region, and chronic pulmonary and extrapulmonary disease poses significant personal and economic burdens. This review explores the literature surrounding human susceptibility to coccidioidomycosis, including chronic pulmonary and extrapulmonary dissemination. Over the past century of study, themes have emerged surrounding factors impacting human susceptibility to severe disease or dissemination, including immune suppression, genetic susceptibility, sex, pregnancy, and genetic ancestry. Early studies were observational, frequently with small numbers of cases; several of these early studies are highly cited in review papers, becoming part of the coccidioidomycosis "canon". Specific genetic variants, sex, and immune suppression by TNF inhibitors have been validated in later cohort studies, confirming the original hypotheses. By contrast, some risk factors, such as ABO blood group, Filipino ancestry, or lack of erythema nodosum among black individuals, are repeated in the literature despite the lack of supporting studies or biologic plausibility. Using examination of historical reports coupled with recent cohort and epidemiology studies, evidence for commonly reported risk factors is discussed.

Coccidioidomycosis presenting years after returning from travel

After having traveled to California in 2017, a 26-year old Dutch man presented in 2020 with persisting cough and shortness of breath. Radiology showed cystic bronchiectasis with peri-bronchial consolidation in his right upper lobe. Laboratory studies in August 2021 showed an increased total IgE, specific Aspergillus IgE, eosinophilia and positive BAL culture for Coccidioides immitis/posadasii. After 6 weeks of itraconazole treatment for suspected allergic bronchopulmonary aspergillosis, symptoms persisted and respiratory cultures remained positive. The infection was cleared after a 6-month course of fluconazole. (max 75 words).