Infections with the fungus Candida auris are increasing rapidly


Infection with Candida auris can be life-threatening for people with a weakened immune system. Cases are increasing in Europe, and in the US they have quadrupled since 2020 – a cause for concern for medical professionals.

Infection with Candida auris can be life-threatening for the seriously ill

In the USA there are more and more infections with the fungus Candida auris: While there were 1,310 cases in 2020, 5,754 cases were counted last year.

Even if that seems small in relation to the total population in the USA, physicians are concerned. As early as October 2022, the WHO included Candida auris in the list of the 19 most dangerous fungal infections, the Funfal Priority Pathogens List, FPPL .

In Europe, infections with the fungus are becoming more common, especially in Italy and Spain, and there have already been a few cases in Germany. 

Candida auris mainly affects people with a weakened immune system

< p>People whose immune system is weakened, for example due to surgery, chemotherapy or other health reasons, are particularly at risk of becoming infected with Candida auris. That is why the fungus spreads mainly in care facilities and hospitals.

“The weakness or failure of the immune system paves the way for the fungus and can affect different regions of the body,” explains Oliver Cornely from the Infectious Diseases Study Center at Cologne University Hospital. The bloodstream is part of it, wounds, the digestive tract and various tissues, “If the fungus infects the bloodstream, this can lead to sepsis, among other things. If the fungus penetrates the tissue, it eventually gets into a blood vessel and is then transported further via the blood and can thus get into all organs.” Mold in the organs – dangerous invasive fungal infections 

Invasive fungal diseases, such as those caused by Candida auris in some people, are among the most common infectious diseases worldwide. More than a billion people contract it every year. Around 1.5 million die.

Fungal infection: when the mold infects organs

Candida auris can survive for a long time

The fungus was first described in 2009. The fungal infection appeared in several places around the world at the same time. The reason for this phenomenon is not known, and the fungus has only recently become more prevalent. “Candida auris is the newest of the yeast fungi that can colonize humans. We all carry different types of fungi in our bodies. They are usually balanced out by our immune systems, so healthy people don't have any problems with them,” explains Cornely.

Candida auris has special features that make the fungus very dangerous for people with a poorly functioning or non-functioning immune system. This includes resistance. “Resistance does not only develop during therapy and through the pathogen getting used to antimycotics. This fungus is resistant almost from birth. That makes it more difficult to fight it,” says Cornely.

And another important property characterizes Candida auris: the fungus can survive on surfaces. “You can touch a contaminated surface and not even know that you then have the fungus on your skin. For example, if you then shake hands with an immunocompromised patient, you can immediately transmit the fungus to that person,” says Cornely.

And with this extraordinarily high survivability, the increasing numbers can also be explained, the scientist continues. Don't panic, but the fungal infections should be taken seriously and better diagnostic methods should be developed.

The symptoms are non-specific

Anyone infected with Candida auris gets  often chills and fever first. In a hospital ward, it is not uncommon for patients to develop a fever and their immune system to be at least temporarily weakened.

These symptoms are typical of many diseases. Diagnosing a fungal infection is therefore often difficult. They can also develop in different parts of the body or inside tissues where they are not visible. All of this delays the diagnosis.

If there is a suspicion of a fungal infection, a smear is taken and a fungal culture is created, which is determined molecular-biologically and morphologically. However, days can pass before a clear result is available – days in which the fungus can spread further. During this time, the chances of survival for the patient decrease. 

“If a patient spends 24 hours is treated incorrectly or not at all, because one does not yet know which fungus it is, it is possible that the patient has already suffered organ damage,” explains Cornely.

However, if it is clear which fungus is involved, appropriate antimycotics, i.e. antifungal agents, are administered. But there are only a few of them, and they are not equally effective for all fungal infections. There is a lack of new drugs. They urgently need to be developed, but – according to scientists – research on fungal infections is neglected far too much, even though they have a high potential for danger.

The most dangerous fungi< /h2>

On the WHO list of the most dangerous fungal pathogens, there are three other fungal pathogens in addition to Candida auris under the classification “Critical Priority”. These have been known for a long time and are now easier to diagnose. All of these fungi primarily affect people with a serious medical condition.

One of these is Candida Albicans, a yeast fungus that is commonly found in the body. It mainly inhabits the skin, the mouth and the intestines. As long as it lives in harmony with other microorganisms, it usually doesn't cause any problems.

However, high doses of antibiotics or poor hygiene carry the risk of serious infection by the fungus. The most common symptoms in this case are, for example, itching and redness, in the worst case the infection spreads to organs.

The second most common pathogen is Aspergillus fumigatus. We can inhale it through the air and absorb it in the body. The widespread mold fungus can be found in the soil or in decaying plant material. In the worst case, it leads to a lung infection such as the so-called invasive aspergillosis. 

The Cryptococcus neoformans fungus can also get into the lungs by inhalation, from there spread to the brain and lead to neurological problems in addition to severe headaches. For example, a so-called cryptococcal meningitis with seizures, fever and even paralysis can occur.

Fungi are very adaptable

Fungi are the second largest kingdom of organisms after animals. They are on our skin, in the lungs and mouth, in the intestines and in the vagina. Not all fungi are pathogenic or even deadly.

Researchers estimate that there are around three million different fungi worldwide, of which 300,000 are known. Only 150 to 300 have been described as human pathogens and are responsible for around 90 percent of all deaths from fungal infections.