Infections with the infectious yeast Candida auris are increasingly occurring in Germany. In 2023, the National Reference Center for Invasive Fungal Infections recorded 77 cases nationwide in which weakened people were colonized or infected with the pathogen – six times as many as in previous years. Three outbreaks in hospitals were primarily responsible. In order to contain the further spread of the fungus, researchers are calling for more comprehensive reporting requirements.
It was only a few years ago that the infectious yeast Candida auris was first described. Discovered in Japan in 2009, it is increasingly spreading worldwide. It is particularly dangerous for weakened people in hospitals and nursing homes. Invasive fungal infections can lead to, among other things, blood poisoning, wound infections and inflammation of prostheses and can be potentially fatal. Because Candida auris is resistant to most common disinfectants and antifungal agents, infections are difficult to treat. In addition, special care is required to ensure that the fungus is not spread from person to person through smear infection.
More evidence than in previous years
In Germany, the National Reference Center for Invasive Fungal Infections recorded a total of 77 cases in 2023. This is reported by a team led by Alexander Aldejohann from the Julius Maximilian University of Würzburg. According to this, 58 people were only colonized by the fungus, 13 experienced an infection. No further information was available for six cases. The most common invasive infections involved wound and tissue infections, followed by blood poisoning and catheter infections. In two cases there was inflammation of prostheses.
This means that the fungus was detected more frequently within a year than ever before in Germany. Since the first reports in 2015, there have been a total of 39 cases through 2022, twelve of them in 2021 and 2022. “The enormous increase in 2023 surprised us,” says Aldejohann. “The decisive factor here is outbreaks in hospitals. If these are not recognized early and combated adequately, they are very difficult to get under control later.” In addition to 28 cases in which no direct infection was recorded, 49 cases could be assigned to one of a total of four outbreaks.
Outbreak caused by late diagnosed case
The most serious was an outbreak in a hospital at the end of 2023 with at least 42 infected people. The outbreak originated in a person with an ear infection in which Candida auris was only late identified as the cause. This allowed the pathogen to initially spread unhindered, so that cases occurred in several other wards of the hospital. While most patients were only asymptomatically colonized by the fungus, there were also two prosthesis infections and one bloodstream infection. In the other recorded outbreaks, Candida auris was diagnosed more quickly, so that only one or two people were infected at a time. There have been no deaths in Germany so far.
Invasive Candida auris infections have been reportable in Germany since July 2023. However, the researchers assume that the observed increase in detections is not due to improved detection, but rather reflects an actual increasing spread of Candida auris. The majority of cases registered in 2023 were not subject to reporting requirements under current legislation. So far, this only applies to detection of Candida auris in the blood and other sterile materials such as cerebrospinal fluid samples. Colonizations with the fungus, however, only have to be reported if they are the result of transmission in hospitals and similar facilities.
Plea for more comprehensive reporting requirements
Given the observed increase in infections, the research team suggests considering a general reporting requirement for all cases of Candida auris. In this way, colonizations that are not initially clinically relevant could be detected early, so that further spread can be prevented. However, general Candida auris screenings are not yet necessary given the comparatively low number of cases so far.
“We have to assume that Candida auris cases in Germany – as in other countries – will continue to increase,” says Aldejohann’s colleague Oliver Kurzai. “The longer we can delay this, the better. A general legal reporting requirement for every laboratory detection of Candida auris could help here – especially in the current phase, when the number of cases is still very low.”
Source: Alexander Aldejohann (Julius Maximilians University of Würzburg) et al., Epidemiological Bulletin, doi: 10.25646/12004