Indicating a disturbing rise in deaths from fungal diseases worldwide, a global study using data from 80 countries including India has said that the annual total of mortalities from such ailment is now estimated at 3.75 million, a figure that doubles previous estimates, and outnumbers deaths from malaria six-fold and from tuberculosis three-fold.
Fungal diseases can be particularly problematic in individuals with weakened immune systems, such as those with HIV/AIDS, cancer patients undergoing chemotherapy, and organ transplant recipients. There are about 12 million species of fungi thriving in marine, freshwater, desert, forests and almost all other ecosystems on the earth. Of these, a fraction cause infections in humans.
The research, published in the journal Lancet Infectious Diseases, calculated an annual total at about 6.55 million acute cases.
The work is the result of a collaboration of over 300 professionals across the world who contributed to published estimates for their country and individual fungal diseases.
Previous estimates were imprecise as many fungal diseases exacerbate an existing disorder, itself often severe, such as leukaemia or AIDS, said David Denning, a professor of infectious disease at The University of Manchester, UK.
However, according to the study, of the deaths linked to fungal disease, around 68 per cent or 2.55 million were likely to have been directly caused by it. Around 1.2 million deaths (32 per cent) had other underlying disease, with fungal disease contributing.
“This work is the first global comprehensive annual incidence estimate of fungal disease, yet many gaps and uncertainties remain,” said Denning.
Around a third of 3.23 million chronic obstructive pulmonary disease (COPD) deaths worldwide are linked to infection with the fungus Aspergillus, the researcher explained.
Though pulmonary tuberculosis was classified as the cause of death in 1.2 million people in 2019, as many as 340,000 (3.4 lakh) of these could actually be fungal disease deaths, the researchers said.
Of the estimated 311,594 (3.1 lakh) leukaemia deaths globally in 2020, 14,000 (4.5 per cent) could be attributable to aspergillosis, and some to other fungal infections, they said.
Lung and bronchus cancer annual deaths stand at 1.8 million, with the new estimate indicating that aspergillosis is implicated in 49,000 deaths (2.7 per cent) of them.
Candida -- another type of fungal infection -- is a serious problem in intensive care, complex surgical patients, diabetes, cancer and renal failure, as well as premature babies.
The researchers estimate that about 1.57 million people suffer from Candida bloodstream infection or invasive candidiasis with 9,95,000 (9.9 lakh) deaths (63.6 per cent), each year.
“Our prior estimates of annual mortality were 1.5 to 2 million, yet we now find the probable number dying with or of a fungal infection is double this at about 3.75 million,” Denning added.
Fungal diseases, also known as mycoses, can affect various parts of the body and can range from mild to severe, depending on the individual’s immune system and the specific type of fungus involved. Common fungal infections include candidiasis, aspergillosis, cryptococcosis, and others.