Wuerzburg. There are just 43 cases by the end of 2022 in Germany that are causing concern for researchers. That doesn’t sound like much, but a team of scientists from Würzburg, Jena and Berlin is now calling for an obligation to report infections with the yeast Candida Auris. Because the fungus species, which has only been known since 2009, has it all: It can develop resistance to all available antifungal agents – of which there are only a few anyway. Microbiologist Alexander Aldejohann from the University of Würzburg warns: “Our experience shows that any infection with Candida auris is difficult to treat and potentially life-threatening for patients.”

Germany may soon be threatened with one fungal infection wave? The research team around Aldejohann is particularly concerned about the “dramatic increase” in Candida auris infections in the USA. Within a year, the number of known cases tripled there. The US health authority CDC classifies Candida auris as an “urgent threat”. This is the highest category at multidrug-resistant pathogens. This year the mushroom species landed as one of only four fungal pathogens in a list of the World Health Organization (WHO) also at the highest warning level. Exactly where Candida auris comes from has been a mystery to scientists so far.

“Warning signal to be well prepared”

In Germany, the numbers have so far been at a low level compared to the USA. But also in this country, infections with Candida auris have doubled from 2020 to 2021. “The other countries are well ahead of us when it comes to the number of infections,” explains Aldejohann. “We should take that as a warning signal to be well prepared.”

In the USA, the CDC has already introduced a laboratory reporting requirement for the fungus species. Germany should follow suit here, according to the research team, which carried out its analysis in the “German Medical Journal” published. “In my view, this can be implemented with reasonable effort and, in addition to a precise recording of the epidemiology, would also make it possible to initiate infection control measures at an early stage,” says Kurzai, who heads the National Reference Center for Invasive Fungal Infections (NRZMyk).

Aldejohann and his colleagues assume that the number of unreported infections is high. “We cannot rule out that the 43 known cases in Germany are just the tip of the iceberg,” says the microbiologist. Of these observed infections, four out of five fungal strains were highly resistant to fluconazole, a common antifungal drug.

Candida auris: Danger for patients in the intensive care unit

At the same time, Aldejohann warns against fueling fears. “Candida auris poses no danger to the majority of the normal population,” he emphasizes. In their most recent study, he and his team were able to determine for the first time that there was already transmission from person to person in hospitals in Germany. Previously, only cases were known in which the sick had probably been infected abroad. The yeast fungus becomes a life-threatening danger when it encounters an already seriously ill or immunocompromised patient, often in the intensive care unit. It can cause blood poisoning and severe organ damage.

The fungus spreads via a so-called dirt or smear infection, explains Aldejohann. “A transmission via aerosols, as in the case of Corona, can be ruled out with a probability bordering on certainty.” Instead, Candida auris can migrate from patient to patient via contaminated surfaces, infected nursing staff or shared medical equipment.

Aldejohann reports on a case in Berlin: The same intubation spatula was probably used in two infected patients. Not every disinfectant is effective against the dangerous pathogen. What makes the fungus particularly insidious is that people can carry it around undetected for six months or longer. In the worst case, this could lead to uncontrollable outbreaks in clinics or nursing homes.

The research team has therefore published a clinical guide to prevent this as far as possible. For example, hospitals should keep an eye on risk factors and check disinfectants. A ray of hope for Aldejohann is that research is currently being carried out on new antifungal agents. They should be on the market soon. As a first measure, however, the scientists are hoping for mandatory reporting. According to Aldejohann, a corresponding process is now to be initiated at the Robert Koch Institute, as he has learned. There is still time to prevent conditions like those in the USA. The microbiologist is convinced: “I don’t think that Candida auris will disappear from Germany again.”