Whatever comes to mind, the fact is that when most of us think of fungal infections, we think of something mild and unpleasant at best.
Of course, it’s not the superficial infections like athlete’s foot that are killing millions. There are certain kinds of fungal infections that can invade our blood, lungs and other organs within the body — and there are a lot of them out there.
“Almost nobody has heard of Cryptococcus, Candida, or Aspergillus, but the three of those probably account for more than a million deaths every year,” says Gow.
He estimates that the fungus Cryptococcus, which mainly affects people with HIV in sub Saharan Africa, is killing between 200-600,000 people every year.
When Pneumocystis is added to the mix, these four fungi account for more than 90% of fatal fungal infections worldwide, says Gow.
And importantly, they aren’t rare. In fact, most of us are in contact with them regularly.
“Somewhere between 100 to 300 spores of a fungus called Aspergillus get in our lungs every day,” says Gow, “We deal with it perfectly well because our lungs are full of immune cells, which patrol around looking for these spores, and they swallow them up and kill them.”
People with asthma and cystic fibrosis — a genetic condition that can lead to excess mucous in the lungs — are also more susceptible to lung disease from Aspergillus, which can cause pneumonia-like symptoms for them, such as coughing up mucus and wheezing.
These fungi are also some of the most misdiagnosed infections in intensive care units in the UK according to Denning, which, when coupled with late diagnosis and the presence of severe underlying diseases, is what makes them deadly.
From mild to deadly
Not all infections are fatal. Treatable skin infections, or dermaticites, could be considered the most common fungal infection of all, affecting as many as 1-2 billion people, and resulting in ringworm, athlete’s foot and even dandruff, says Gow.
But even seemingly mild fungi like candida can prove deadly when immune systems are weakened. People living with HIV/AIDS, organ transfer patients, or cancer patients undergoing chemotherapy are vulnerable to this range of fungal infections that would normally be harmless or treatable.
“Prevention is better than a cure,” says Gow. “One of the things about fungi is that they’re quite difficult to dislodge once they start to grow.
“There’s not a single vaccine against any fungus at the moment.”
Without the option of a vaccine, hospitals have to work hard to avoid exposure: patients can be given drugs to help prevent infection, some hospital wards may not allow flowers because of the risk of fungal spores spreading, and they can also use air filtration barriers to protect patients. But the public also need to be informed to avoid exposure.
“It’s still the case that this information is not really even understood, and not fully appreciated by all members of even the professional community of microbiologists, and certainly not by the general public,” says Gow.
The hope is that these little known infections will gain more recognition for what they really are — global killers.