Diseases Studied

Invasive aspergillosis (IA) is an infection caused by molds from the genus Aspergillus. These infections are rare but present in people whose immune systems are weakened by certain medical interventions such as chemotherapy for cancer, bone marrow transplantation, solid organ transplantation, or because someone is born with an underlying disease of their immune system. Invasive aspergillosis can be local to one organ or location (e.g., lungs or sinuses) but can disseminate to any other part of the body. If left untreated these infections are fatal.

Non-Aspergillus mold diseases are caused by a wide variety of molds that are not from the Aspergillus genus. The most frequent non-Aspergillus mold diseases fit in the categories of mucormycosis and fusariosis. Mucormycoses are caused by molds from a variety of genera (e.g., Rhizopus, Mucor). These fungi typically live in the environment—in the soil, on plants, and on decaying material like fallen trees. Humans are constantly exposed to these fungi in the form of fungal spores we breathe in every day. Similar to invasive aspergillosis, infection from non-Aspergillus molds are rare but typically present in individuals with compromised immune systems. Non-Aspergillus molds also typically start in one location such as the lungs and can disseminate to any other part of the body. The potential for dissemination may be even greater than the risk for dissemination in patients with Aspergillus. These infections are fatal if left untreated and even when treated still have a high mortality rate.

While Candida species are the most common cause of invasive fungal diseases, there are many other rare non-Candida yeast that can cause serious infections. Among non‐Candida yeast, Cryptococcus is the most common fungal pathogen that causes community‐acquired invasive fungal disease. This pathogen is particularly concerning because of its intrinsic resistance to echinocandins, a commonly utilized class of antifungal agents. Cryptococcosis initially affects the lungs or sinuses, but can disseminate to other parts of the body, including but not limited to the central nervous system and skin. In recent years there has been an increasing recognition of emergence of rare yeast genera such as Trichosporon and Rhodotorula causing invasive fungal diseases. These pathogens are of major concern because of their potential to have resistance to one or more antifungal agents. While patients that are considered immune competent can get non-Candida yeast infections, they are still more common in immunocompromised patients such as those receiving chemotherapy for cancer, underdoing bone marrow transplantation or solid organ transplantation, or those with an underlying primary immune deficiency. These infections can start as a primary blood infection, lung infection or skin infection and then disseminate to other organs. Occasionally, they will reactivate after initial effective treatment.

Dimorphic fungal diseases are defined as infections caused by fungi that exist in two forms: as yeast in warmer temperatures (such as in the human body) and as mold forms in cooler temperatures (such as in laboratory cultures). These infections can have a regional distribution and thus they are often referred to as endemic mycoses. Importantly, the at risk regions of these pathogens is growing, likely related to changes in climate. Common examples include histoplasmosis, coccidiomycosis, and blastomycosis, which can present in pulmonary, cutaneous, or disseminated forms. These pathogens are typically inhaled in their mold state in nature. For immunocompetent individuals these infections can be asymptomatic or self-resolving. Rarely, they cause severe disease in otherwise healthy people. In immunocompromised patients, they can cause significant illness including dissemination from lungs to the central nervous system.

1. Eichenberger EM, Mendoza MA, Baddley JW. Non-Aspergillus molds. JHLT Open. 2025;10:100382. doi:10.1016/j.jhlto.2025.100382
2. Spiliopoulou A, Lekkou A, Vrioni G, Leonidou L, Cogliati M, Christofidou M, Marangos M, Kolonitsiou F, Paliogianni F. Fungemia due to rare non-Candida yeasts between 2018 and 2021 in a Greek tertiary care university hospital. J Mycol Med. 2023 Aug;33(3):101386. doi: 10.1016/j.mycmed.2023.101386. Epub 2023 Apr 4. PMID: 37031651.
3. Lin SY, Lu PL, Tan BH, Chakrabarti A, Wu UI, Yang JH, Patel AK, Li RY, Watcharananan SP, Liu Z, Chindamporn A, Tan AL, Sun PL, Hsu LY, Chen YC; Asia Fungal Working Group (AFWG). The epidemiology of non-Candida yeast isolated from blood: The Asia Surveillance Study. Mycoses. 2019 Feb;62(2):112-120. doi: 10.1111/myc.12852. Epub 2018 Oct 17. PMID: 30230062; PMCID: PMC7379604.
4. Mazi PB, Sahrmann JM, Olsen MA, Coler-Reilly A, Rauseo AM, Pullen M, Zuniga-Moya JC, Powderly WG, Spec A. The Geographic Distribution of Dimorphic Mycoses in the United States for the Modern Era. Clin Infect Dis. 2023 Apr 3;76(7):1295-1301. doi: 10.1093/cid/ciac882. PMID: 36366776; PMCID: PMC10319749.