Approximately eleven years ago, my colleagues and I projected that roughly 2 million individuals worldwide succumbed to fungal infections annually. A recent assessment indicates a nearly doubled figure today, estimating around 3.8 million deaths.
For perspective, fungal infections contribute to approximately 6.8% of the global death toll. Comparatively, coronary heart disease is likely accountable for 16% of total global deaths, followed by stroke at 11%. Smoke-related lung disease (COPD) constitutes 6% of total deaths, with fungal infections contributing to about one-third of these 3,228,000 fatalities.
Comparing global death statistics, pneumonia is reported at 2,600,000 (some fungal-related), and tuberculosis at 1,208,000, where mostly undiagnosed fungal disease likely contributes to 340,000 deaths.
To calculate these estimates, as reported in Lancet Infectious Diseases, I assessed the proportion of fungal cases diagnosed and treated versus those that go undetected. Despite significant advancements in fungal disease diagnostics in the past decade or so, both access to and utilization of these tests remain restricted—not only in low-income countries.
For instance, South Africa boasts a commendable diagnostic service for fungal (cryptococcal) meningitis and bloodstream fungal infection (Candida). However, there are no diagnostics available for infections caused by another prevalent fungus, Aspergillus. These gaps significantly contribute to avoidable fatalities. Swift diagnosis of severe Aspergillus infections, ideally within 48 hours, has the potential to save millions of lives annually.
The most significant deadly fungi include Aspergillus fumigatus and Aspergillus flavus, both responsible for causing lung infections. Individuals affected encompass those with lung conditions like asthma, TB, and lung cancer, as well as individuals with leukemia, organ transplant recipients, and those in intensive care.
Tragically, many of these individuals succumb because their medical professionals either fail to recognize their fungal disease or diagnose it too late. Moreover, a considerable number of deaths result from sluggish or non-existent diagnostic testing and a scarcity of effective antifungal medications. Tests relying on fungal cultures can only identify approximately a third of individuals with an actual fungal infection.
Infections caused by Candida contribute to sepsis and are detected in the bloodstream. They are associated with diabetes or renal failure, or a combination of both, and may also arise following significant surgery or trauma. While this fungus is a natural component of the gut microbiome, it can traverse the gut wall into the bloodstream during severe illness.
With over 1.5 million individuals globally affected by life-threatening Candida infection, resulting in nearly 1 million annual deaths, there is an urgent need for improved diagnostic tests. Present blood culture tests only detect 40% of life-threatening Candida infections.
Approximately 50% of the roughly 600,000 AIDS-related deaths, as indicated, are caused by fungal infections. There are concerted global efforts to eliminate cryptococcal meningitis as a leading cause of death, with active involvement from entities such as the US Centers for Disease Control and Prevention and the World Health Organization.
Within the context of AIDS, there is a pressing need for extensive research on histoplasmosis in Africa and Southeast Asia, employing more effective diagnostic tests. Many of these patients are inaccurately diagnosed with TB, or they experience a dual infection with TB, with the lethal Histoplasma infection often going unnoticed and untreated.
Black Fungus
India experienced the world’s initial large-scale outbreak of mucormycosis following the COVID pandemic, commonly referred to as black fungus. The fungi responsible for mucormycosis obstruct the blood supply to tissues, leading to tissue necrosis, hence the colloquial term “black fungus.”
In 2012, my colleagues and I projected around 10,000 cases of mucormycosis globally. However, the COVID pandemic in India resulted in a staggering increase with at least 51,000 reported cases. This surge can be attributed to factors such as the excessive use of steroids for COVID (both in dosage and duration) and poorly managed diabetes.
Aspergillus and Candida infections were notably prevalent among COVID patients in intensive care globally. It’s crucial to note that the surge in fungal diseases during the COVID pandemic was not considered when compiling these recently published incidence and mortality figures. As a result, the actual numbers could be even higher.
Double Whammy
Individuals admitted to intensive care with influenza also face a heightened risk of life-threatening Aspergillus infection, doubling the likelihood of death even when Aspergillus is diagnosed. Indeed, there is concern among doctors and scientists about the potential for a simultaneous epidemic of fungal infections and influenza or another respiratory illness, presenting a double threat.
There exists a robust connection between fungal allergy and severe or inadequately managed asthma.
Asthma is prevalent and becomes more challenging as individuals age. Those with fungal asthma typically require multiple medications and undergo episodes of exacerbation, leading to emergency room visits and hospitalizations.
Despite extensive efforts to manage asthma, an estimated 461,000 individuals succumb to it each year or have it as a contributing factor in their final illness, globally.
Fungal diseases are a persistent presence. They encompass our surroundings, residing in our gastrointestinal tract and on our skin.
No vaccines exist for fungi. Severe fungal diseases typically affect individuals who are already unwell, with only a few exceptions among healthy people and those residing or working in mouldy homes or workplaces. This underscores the urgent need for accurate and timely diagnosis, emphasizing the critical importance of taking fungal infections seriously.
This article has been reissued from The Conversation under a Creative Commons license.
