A recently published study in Clinical infectious diseases assessed deaths from fungal infections during the 2019 coronavirus disease (COVID-19) pandemic in the United States (US).
Yeasts, molds, dimorphs, and yeast-like fungi are common fungal pathogens. Clinically, fungal infections result in superficial lesions as well as life-threatening conditions. Serious infections typically affect immunocompromised individuals such as cancer patients, organ or stem cell transplant recipients, users of immunosuppressive drugs, etc.
To date, more than a million people have died from COVID-19 in the United States. In addition, COVID-19 could increase the risk of severe fungal infection due to COVID-19-associated immune dysfunction, lung damage and therapies, thereby compromising the host’s immune system against pathogenic fungi. There is evidence that severe fungal infection in COVID-19 patients could lead to poor clinical outcomes.
About the study
The present study analyzed data from the US National Vital Statistics System (NVSS) to examine demographic information, fungal disease burden and trends over time. They used preliminary 2021 mortality data and final 2018–2020 mortality data from NVSS. Deaths related to fungal infections were identified and coded according to the International Classification of Diseases, Tenth Revision (ICD-10) codes. Deaths related to COVID-19 were coded similarly.
The number, percentage, and age-adjusted rates of fungal deaths from January 2018 to December 2021 were analyzed by fungal pathogen, year, and COVID-19 association (whether COVID-19 was a contributing factor). The monthly number of deaths from fungi during the COVID-19 pandemic was examined by examining whether COVID-19 contributed to mortality; simultaneous monthly COVID-19 deaths were also analyzed.
Fungal die-off data between January 2020 and December 2021 was stratified by the COVID-19 Association; Age-adjusted death rates were analyzed by US Census race/ethnicity, sex, fungal pathogen, and city of residence.
Between 2018 and 2021, 22,700 deaths from fungal infections/pathogens have occurred. The number of deaths from fungi per 100,000 people for 2018 and 2019 was similar at 4746 and 4833 deaths, respectively, and the age-adjusted rate was 1.2 in both years. However, it rose to 5922 in 2020 with a death rate of 1.5. Likewise, in 2021 about 7199 (fungal) deaths were observed with a rate of 1.8.
COVID-19-associated deaths in 2020 and 2021 accounted for 21.9% of the 13,121 fungal deaths during that period. COVID-19 represented the most common underlying cause of death (90.5%) among COVID-19-associated fungal deaths, accounting for 0.3% of COVID-19 deaths in 2020-21. Candida and aspergillus were the most common fungal pathogens, accounting for 24.4% and 16.4% of the total number of fungal deaths in 2020-21.
Nevertheless, the pathogen remained unspecific in more than 35% of all fungal deaths in the same period. In particular, COVID-19-associated fungal deaths were predominantly due to the following causes Candida and aspergillus Infections relative to non-COVID-19 associated fungal deaths. In 2018-19, an average of 399 fungal deaths per month were recorded, and 423 fungal deaths occurred during the peak of the first COVID-19 wave (April 2020). Nonetheless, it peaked in January 2021 and October 2021 with 690 and 718 fungal deaths, respectively, coinciding with the COVID-19 mortality peak(s).
Most deaths from fungal infections in 2020-21 were recorded in men (59.7%) and those aged 65 and over. Age-adjusted rates for COVID-19-associated fungal deaths were higher in people who were non-Hispanic American Indians or Alaska Natives (AI/AN). [1.3]Hispanic (0.7) and Black (0.6) than non-Hispanic White (0.2) and non-Hispanic Asian (0.3).
For non-COVID-19-related fungal deaths, age-adjusted death rates were consistently higher among AI/AN (3), Hispanic (1.9), and non-Hispanic Hawaiian Natives (NHPI). [2.4] and Black populations as White (1,1) or Asiatic (1,2) individuals. The gross death rate from fungi was higher among people from non-metropolitan areas than among metropolitan residents.
Age-adjusted fungal death rates were lower in the US Census Divisions Mountain (2.1) and Pacific (2) but in the New England Division (1.3). Mountain and West South-Central Divisions showed higher rates (0.5) of non-COVID-19 related deaths, while they were lower in New England Division (0.2).
Researchers observed that more people died from yeast infections in 2020-21, an upward trend compared to previous years. COVID-19-associated fungal deaths led to this increase, underscoring the critical importance of fungal infections in COVID-19 patients. Fungal deaths increased in parallel with the COVID-19 spikes in January and October 2021, but not in April 2020.
In summary, the study showed that fungal infections are a significant burden in the United States. These findings could help inform efforts to identify, treat, or prevent serious fungal infections in COVID-19 patients, particularly in some ethnic and racial groups and geographic regions.