U.S.
Español
Arabic
Story highlights
- Fungal diseases kill 1.5 million people every year
- People with reduced immune systems are most vulnerable to serious infections
Vital Signs is a monthly program bringing viewers health stories from around the world.
(CNN)What do you think of when you hear the word fungi? Mushrooms? Athlete's foot? General mold?
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.
But these tiny organisms can be fatal and kill an estimated 1.5 million people globally each year. It's a shockingly high figure and is greater than the number of people who die from malaria, more than twice the number of women who die from breast cancer, and an equivalent number to those who die from tuberculosis, or HIV, each year, according to professor Neil Gow, President of the Microbiology Society.
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.
Matching the number of deaths each year, there are around 1.5 million species of fungi -- tiny microbes found in soil, air and water -- and we interact with them every day. Three hundred of these are known to make people sick, with some proving to be fatal.
Fatal fungi
"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.
Experts warn that a global health crisis is on the horizon as drugs available for once treatable diseases lose their edge. A dreaded superbug has just been found for the first time in a U.S. woman and a recent report stated that 10 million deaths will be caused each year due to resistance if nothing is done by 2050.
Go through the gallery to find out which infections are becoming, or have already become, a concern.
Read: How to stop superbugs from killing 10 million people a year
Go through the gallery to find out which infections are becoming, or have already become, a concern.
Read: How to stop superbugs from killing 10 million people a year
Hide Caption
1 of 11
Gonorrhea – In the United States, over 350,000 cases of this sexually transmitted infection were reported in 2014, caused by the bacterium Neisseria gonorrhoeae. Resistance to antibiotics began to occur soon after their introduction in the 1930s and has continued to rise with resistance now seen against at least five of the drugs once used to treat it -- which include the commonly used antibiotics penicillin and tetracycline.
Hide Caption
2 of 11
Enterococcus – Hospitals are one of the main places superbugs are causing concern, as doctors are running out of viable options for antimicrobials. Leading the way are a group of bugs known as the ESKAPE pathogens, the first of which is Enterococcus faecium.This bacteria is commonly found in the intestines and female genital tract, but can sometimes cause infections. In some cases it has become resistant to the vancomycin antibiotic used to treat infections and mostly in hospitals. Keeping hands clean is the main way to prevent transmission.
Hide Caption
3 of 11
Staphylococcus aureus – Staphylococcus aureus (staph) is a common type of bacteria which is often found on the skin, in nostrils and in the throat. According to the CDC, one in three people carries it in their nose without being affected by it. It can cause mild infections of the skin, but if the bacteria gets into the bloodstream it hast the potential to become life threatening by poisoning blood.
Multidrug-resistant Staphylococcus aureus (MRSA) has been a concern for many years in hospitals. People with infected with this form of the bacteria are estimated to be 64% more likely to die than people with a non-resistant form of the infection.
Multidrug-resistant Staphylococcus aureus (MRSA) has been a concern for many years in hospitals. People with infected with this form of the bacteria are estimated to be 64% more likely to die than people with a non-resistant form of the infection.
Hide Caption
4 of 11
Klebsiella – Klebsiella bacteria have also developed a high level of resistance to antibiotics, such as carbapenem. The bacteria naturally occurs in the intestines where it does not usually cause disease, but it can cause pneumonia, bloodstream infections and meningitis.
It's unlikely that healthy people are affected by the bacteria, but patients in hospitals who use a ventilator, intravenous catheters or long courses of certain antibiotics are at higher risk of becoming infected.
It's unlikely that healthy people are affected by the bacteria, but patients in hospitals who use a ventilator, intravenous catheters or long courses of certain antibiotics are at higher risk of becoming infected.
Hide Caption
5 of 11
Acinetobacter – Acinetobacter is a type of bacteria mostly found in soil and water. It can cause human disease, particularly in people with weakened immune systems or diabetes.
Outbreaks usually happen in intensive care units and healthcare settings, with the bacteria becoming resistant to most commonly used antibiotics. Treatment has to be decided on a case-by-case basis.
Outbreaks usually happen in intensive care units and healthcare settings, with the bacteria becoming resistant to most commonly used antibiotics. Treatment has to be decided on a case-by-case basis.
Hide Caption
6 of 11
Pseudomonas – Pseudomonas bacteria can be deadly for patients who are in critical care. According to CDC it's the cause of about 51,000 healthcare-associated infections in the United States each year. More than 6,000 of these cases are multi-drug resistant, leading to around 400 deaths per year. The most serious Pseudomonas infections usually occur in hospitals, affecting patients who are on breathing machines, using catheters or with wounds from surgery.
Hide Caption
7 of 11
E. coli – The bacteria Escherichia coli (E. coli) naturally occurs in your gut, and while most strains are harmless, some can cause severe foodborne diseases, with symptoms ranging from fever, nausea and vomiting to bloody diarrhea. The infections are transmitted by eating or drinking contaminated food and water.
Multi-drug resistance in E. coli has been increasingly reported in urinary tract infections (UTIs). According to the WHO, the most widely used oral treatment -- fluoroquinolones -- are also becoming ineffective. A U.S woman was reported to be infected with a rare kind of E. coli infection that is resistant to antibiotics, even one used as a last resort.
Multi-drug resistance in E. coli has been increasingly reported in urinary tract infections (UTIs). According to the WHO, the most widely used oral treatment -- fluoroquinolones -- are also becoming ineffective. A U.S woman was reported to be infected with a rare kind of E. coli infection that is resistant to antibiotics, even one used as a last resort.
Hide Caption
8 of 11
Tuberculosis – Tuberculosis almost disappeared in the majority of the Western world as countries developed. But the disease persists globally, with an estimated 9.6 million people developing TB in 2014 and 1.5 million dying from it.
The bacterium behind the disease, Mycobacterium tuberculosis, has developed into multidrug resistant (MDR) forms, which require an additional pool of more toxic drugs to treat it. In 2014, there were 480,000 cases of MDR-TB worldwide and extensively drug-resistant (XDR) TB had been reported in 100 countries. India is one country that reported patients with total resistance to all drugs available. With few new drugs in the pipeline to control the bacteria, total resistance could spread.
The bacterium behind the disease, Mycobacterium tuberculosis, has developed into multidrug resistant (MDR) forms, which require an additional pool of more toxic drugs to treat it. In 2014, there were 480,000 cases of MDR-TB worldwide and extensively drug-resistant (XDR) TB had been reported in 100 countries. India is one country that reported patients with total resistance to all drugs available. With few new drugs in the pipeline to control the bacteria, total resistance could spread.
Hide Caption
9 of 11
Influenza – Influenza virus types A and B sweep through countries annually in the winter months; they cause fever, headaches and muscular pain in most cases, but also cause three to five million cases of severe illness and 250,000 to 500,000 deaths each year. The antiviral drugs oseltamivir and zanamivir are the main means of fighting infection. Preventative antivirals amantadine and rimantadine were once used to control seasonal spread, but high levels of resistance means their use is no longer recommended.
Resistance to zanamivir has also been reported. While the majority of viruses found globally are still sensitive to the key drugs, the resistant forms could easily spread as no other drug options remain available.
Resistance to zanamivir has also been reported. While the majority of viruses found globally are still sensitive to the key drugs, the resistant forms could easily spread as no other drug options remain available.
Hide Caption
10 of 11
Typhoid Fever – Immunization remains the weapon of choice in controlling typhoid fever. The disease still affects approximately 21 million people worldwide, with 222,000 deaths occurring annually, most of them children. The bacterium behind the disease, Salmonella typhi, can be killed with various antibiotics, but resistance is now arising to multiple antibiotics.
Most cases are reported in developing countries but increased global travel means the disease has potential to spread. The United States sees over 5,000 people infected each year after consuming contaminated food and drink abroad.
Most cases are reported in developing countries but increased global travel means the disease has potential to spread. The United States sees over 5,000 people infected each year after consuming contaminated food and drink abroad.
Hide Caption
11 of 11
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."
But for people with weakened immune systems, Aspergillus can cause lung disease and can kill after as little as 10-14 days, according to David Denning, professor of Infectious Diseases in Global Health from the University of Manchester. "It's fairly uncommon, but still life-threatening," he says.
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.
Many healthy people also naturally carry the species of yeast-like Candida fungi in, and on, their bodies, without it being harmful. Candida can also cause superficial infections like vaginal thrush and while this is treatable, it remains a burden for many, with 100 million women suffering four or more episodes annually.
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.
The burden on healthcare systems is equally huge, with hospitalization costs estimated to range from $11,000 to $57,000 for a patient with an invasive fungal infection -- and experts are warning that the issue needs more attention.
Preventing infection
"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.