The annual total of deaths from fungal disease worldwide has risen to 3.75 million, double the previous estimate, according to a global study.

The study, published in The Lancet Infectious Diseases, also calculates an annual total of about 6.55 million acute cases using data from over 80 countries.

Though fungal disease has multiple causes, the updated mortality figures nevertheless dwarf deaths from other single pathogens, killing six times more people than malaria, and almost three times as many as tuberculosis.

Previous estimates were imprecise, as many fungal diseases exacerbate an existing disorder, itself often severe, such as leukaemia or AIDS, argued Professor David Denning, a professor of infectious disease at The University of Manchester.

However, according to the study, of the deaths linked to fungal disease, around 68 percent—or 2.55 million were likely to have been directly caused by it.

Around 1.2 million deaths (32 percent) had other underlying disease, with fungal disease contributing. About a third of 3.23 million chronic obstructive pulmonary disease (COPD) deaths worldwide are linked to infection with the fungus Aspergillus, finds Professor Denning.

Though pulmonary tuberculosis was classified as the cause of death in 1.2 million people in 2019, as many as 340,000 (28 percent) of these could be fungal disease deaths. Of the estimated 311,594 leukaemia deaths globally in 2020, 14,000 (4.5 percent) could be attributable to aspergillosis, and some to other fungal infections.

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 percent) 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 995,000 deaths (63.6 percent) each year.

"This work is the first global comprehensive annual incidence estimate of fungal disease, yet many gaps and uncertainties remain,” Professor Denning said.

"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,” he said.