Significant Increase in Fungal Infections with Candida Auris in Germany

For healthy people, colonisation with the Candida auris fungus is generally harmless - most people don't even notice it. For other groups - such as people with a weakened immune system or patients in intensive care units - the risk is greater. If Candida auris enters their bloodstream, there is a risk of blood poisoning, which is fatal in a good half of all cases. The fungus therefore poses a particular threat to hospitals, care facilities and retirement homes.

Sharp Increase in 2023

Scientists at the National Reference Centre for Invasive Fungal Infections (NRZMyk) have now registered a significant increase in the number of Candida auris cases in Germany. While twelve cases were reported to the reference centre in each of the previous years, there were 77 last year.

The research team has now published these figures in the Epidemiological Bulletin. Dr Alexander M. Aldejohann from the Institute of Hygiene and Microbiology at Julius-Maximilians-Universität Würzburg (JMU) and scientists from the NRZMyk and the Robert Koch Institute were responsible for the study. Professor Oliver Kurzai, Director of the Institute of Hygiene and Microbiology at JMU and Head of the NRZMyk, was also involved in the study.

In their study, the authors not only take a look at the overall figures. They also take a detailed look at their development and the individual transmission events. They differentiate between pure colonisation and invasive infection.

Numerous Cases in Hospitals

According to the study, 58 of the 77 cases described involved colonisation of the patients, with 13 cases resulting in infection. In six cases, the status remained unclear. Of the patients with initial colonisation or unclear infection status, five developed an invasive infection over the course of the disease.

In addition to a relevant increase in individual infections without proven direct infection of other people, four independent outbreaks were also detected. The majority of the detected cases could subsequently be attributed to a specific outbreak. Due to the current reporting obligation, these cases initially lacked infectiological relevance, meaning that the outbreak initially remained undetected and the transmission events could ultimately not be stopped at an early stage.

"The huge increase in 2023 took us by surprise. Outbreaks in hospitals are the main reason for this. If these are not detected early and adequately combated, they are very difficult to get under control later on," says Dr Alexander M. Aldejohann, assessing these figures.

General Statutory Reporting Obligation is Suggested

According to the participants, the statutory reporting obligation, which will not be introduced until 2023, should be discussed. This would only cover a small proportion of cases. This is primarily due to a high proportion of clinically irrelevant cases, which are not subject to mandatory reporting under the current Infection Protection Act. At present, colonisations only have to be reported if they are the result of transmission in hospitals and similar facilities.

The authors therefore suggest considering a general reporting obligation for all Candida auris cases. In their opinion, further spread of Candida auris could be effectively countered with early and consistent screening and hygiene measures for all cases, regardless of their clinical relevance.

"We have to assume that Candida auris cases in Germany - as in other countries - will continue to increase," fears Oliver Kurzai. Because infections caused by this fungus are often difficult to treat, the longer we can delay it, the better. A general legal obligation to report any laboratory evidence of Candida auris could help here - especially in the current phase, when the number of cases is still very low," says the head of the NRZMyk.

Candida Auris

Since the yeast Candida auris was first described in Japan in 2009, a continuous increase in the number of cases has been observed worldwide. The fungus is now widespread worldwide and is endemic in some regions such as India and South Africa and regionally also in Spain and Italy.

Unlike other Candida species, this type of yeast regularly causes outbreaks that are difficult to contain, particularly in healthcare and nursing facilities, through direct and indirect contact.

The treatment of Candida auris infections is made considerably more difficult by the pathogen's potential to develop resistance to all available classes of antimycotics. These characteristics led, among other things, to the inclusion of the fungus in the highest prioritisation category of the American Centers for Disease Prevention and Control (CDC) and the World Health Organization (WHO).

In Germany, since July 2023, both the detection of Candida auris from blood and primary sterile materials and outbreaks of the pathogen have been subject to mandatory reporting in accordance with Sections 6 and 7 of the Infection Protection Act.

The National Reference Centre for Invasive Fungal Infections

The National Reference Centre for Invasive Fungal Infections (NRZMyk), appointed by the Robert Koch Institute and the Federal Ministry of Health, is the point of contact for doctors and microbiologists with questions regarding the diagnosis of invasive fungal infections. It advises on all aspects of invasive fungal infections, carries out special diagnostic procedures for the detection of fungal diseases and co-operates with other reference laboratories worldwide.

The NRZMyk has been based at the Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI) in Jena since January 2014. It also works in close cooperation with associated partners - the Institute of Medical Microbiology and the laboratories of the Clinic for Skin Diseases at Jena University Hospital and the Molecular Biology Laboratories of the Medical Clinic II at Würzburg University Hospital.

Original Publication

Increase of Candida auris in Germany in 2023. Aldejohann, Alexander M.; Hecht, Jane; Martin, Ronny; Walther, Grit; Kurzai, Oliver. Epidemiological Bulletin 2024; 02 May 2024; DOI: 10.25646/12004

Contact

Prof Dr Oliver Kurzai, Chair of Medical Microbiology and Mycology, University of Würzburg, T: +49 931 31-46160, oliver.kurzai@uni-wuerzburg.de