Around 3.8 million people currently die from fungal diseases every year, as a new survey shows. That’s almost twice as many as a decade ago. This trend could be due, among other things, to the corona pandemic.
Fungi are an often underestimated threat to our health. The microorganisms can attack our body in a variety of ways – from superficial and relatively harmless skin fungi such as itchy ringworm to life-threatening infections with the resistant pathogen Candida auris, which can cause serious organ damage. But how many people are affected by fungal diseases is poorly documented.
Lack of diagnostics
Even in wealthy countries, appropriate test kits for common fungal infections are often not available, are not used, or do not reliably detect all infections. Because of a missing or late diagnosis, those affected are often not treated in a timely manner. The infectious disease doctor and mycologist David Denning from the University of Manchester has now taken a closer look at the situation.
In order to find out how many people die worldwide as a result of a fungal infection, he tried to determine the number of unreported cases. To do this, he compiled figures on officially diagnosed fungal infections from 2010 to 2023 from 120 countries and compared them with death rates and survival rates for treated and untreated infected people. He also analyzed the countries’ respective patient guidelines and which diagnostic tests were available.
Number of fungal deaths almost doubled
The result: Around 6.5 million people worldwide become infected with a pathogenic fungus every year. Around 3.8 million people die as a result of a fungal disease. Eleven years ago (2012), there were around two million deaths, about half as many as today, as Denning reports. Accordingly, the number of fungal infections resulting in death has increased dramatically. “According to figures, fungi are now responsible for 6.8 percent of all deaths worldwide. For comparison: Heart disease and stroke account for around 16 and eleven percent of all deaths, respectively,” says Denning.
The fatal outcome of many fungal infections is primarily due to previous illnesses and a weakened immune system of those affected. According to Denning, around half of all AIDS deaths are caused by a fungal disease, often unrecognized and untreated. The cause of death is, for example, meningitis caused by cryptococci or histoplasmosis caused by the fungus Histoplasma capsulatum.
Fungal infections of the lungs and blood
Undetected fungal infections also play a major role in lung diseases, as Denning discovered. Around 30 percent of those who died from tuberculosis or smoking-related lung disease were also infected with a fungus. The microorganisms were not the cause of the lung disease, but contributed to the death of the patient.
The most dangerous fungi that infect the lungs include the molds Aspergillus fumigatus and Aspergillus flavus. Around 1.8 million people die from them every year. They primarily affect people with a previous lung disease – including asthma, tuberculosis and lung cancer – or another previous illness such as blood cancer. Even after an organ transplant and in an intensive care unit, people are more susceptible to Aspergillus infection, as Denning reports.
Other potentially fatal pathogens include fungi of the genus Candida. “Around one million people worldwide die from a Candida infection every year,” says Denning. In the bodies of seriously ill people, these common intestinal fungi overcome the intestinal wall and enter the bloodstream, where they can cause blood poisoning. “Patients with diabetes and kidney failure as well as people after major surgery or trauma are particularly often affected.”
Connection to the corona pandemic
But why have the number of infections increased so drastically in the past decade? This could, among other things, be related to the corona pandemic, as Denning reports. For example, the so-called black fungus first appeared on a large scale after the spread of Covid-19 in India. In the mucormycosis it causes, the fungus blocks the blood supply to affected parts of the body, causing tissue to die. “While there were only about 10,000 known cases of this disease worldwide in 2021, after the pandemic there were 51,000 in India alone,” said the researcher.
Denning cites possible causes as diabetes patients being monitored and treated worse during the pandemic and Covid patients being treated with excessive amounts of steroids. This made both groups more susceptible to the “black fungus”. Infections with Aspergillus and Candida have also increased in Covid patients in intensive care units, but also in influenza patients. A simultaneous epidemic of infectious diseases facilitates the spread of fungi.
Early diagnosis is crucial
Since fungi occur naturally everywhere in our environment and even in our intestines and on our skin, fungal infections will continue to be unavoidable. “In addition, there are no vaccines against fungi and in some cases no effective medications,” reports Denning. Similar to bacteria, fungi are also becoming increasingly resistant to common active ingredients. The use of fungicides in agriculture, among other things, contributes to this.
In order to enable treatment where effective medicines are available and to prevent the spread, an accurate and timely diagnosis is urgently needed, warns Denning. “We have to take mushrooms very seriously.”
Source: David W. Denning
By Claudia Krapp