The fungal pathogen Candida auris can spread so quickly

It initially seemed like a routine case when a patient came to a clinic in Liguria, Italy. Diagnosis: Aortic aneurysm, an enlargement of the main artery. The doctors wanted to treat her with a stent. However, due to complications, the previously ill woman came to the intensive care unit. On the 17th day, she developed a fever and her condition worsened. Blood samples were also taken again and again. On day 31, the sample was positive: the patient had been infected with the fungal pathogen Candida auris.

That is why the fungal pathogen Candida auris is dangerous

The pathogen was first identified in 2009 in a 70-year-old Japanese woman in a Tokyo hospital. Almost at the same time in other regions of the world, which scientists cannot explain to this day. Basically, the fungus does not harm healthy people, even if they are infected. However, an infection becomes dangerous for people who are already ill or have a weakened immune system. Here the fungus can spread more easily in the body, enter the bloodstream and affect several organs. It can also cause sepsis (blood poisoning).

Sepsis is a medical emergency and must be treated immediately. Every hour without medical care increases the risk of death by seven percent. “Our experience shows that any infection with Candida Auris is difficult to treat and potentially life-threatening for patients,” said microbiology Alexander Aldejohann from the University of Würzburg to the “RND”. As the WHO writes, the probability of dying after an infestation of the internal organs is between 29 and 53 percent.

In addition, Candida auris is resistant to common antifungal drugs and, unlike other fungi, can easily spread from person to person. In addition, it can sometimes survive on surfaces for months. This poses a great risk, especially in clinics, intensive care units and care facilities.

Rapid increase in the number of cases in the USA, also several cases in Europe

In Italy, the patients were quickly isolated in 2019, but it was apparently too late. Since then, Candida auris has continued to spread there. 277 cases have occurred in at least eight health facilities in Liguria, and eleven more in facilities in the neighboring region of Emilia-Romagna. “In view of the high number of cases, the spread of C. auris in various health facilities in Liguria and the interregional Emilia-Romagna and the difficulty in containing the outbreak, the risk of further spread in Italy is classified as high,” judges the European health authority ECDC. The case shows how quickly candida auris can get out of control.

The number of cases is also increasing rapidly in the USA: from 53 (2016) clinical cases to 476 (2019) and 1471 (2021). The US health authority CDC (Centers for Disease Control and Prevention) already classified the fungus as an “urgent threat” in 2019 and introduced a reporting obligation.

In Europe, larger outbreaks in hospitals have now been reported from Spain, Italy and Greece – and repeatedly from England. In 2015/2016, 50 cases occurred in a cardiac surgery ward in a London hospital, 9 of which involved the bloodstream of humans. The outbreak dragged on for 16 months. And in an intensive care unit at Oxford University Hospital, an outbreak that affected 70 patients even lasted 2.5 years.

Oliver Kurzai from the University of Würzburg, head of the National Reference Center for Invasive Fungal Infections, explains why such outbreaks can last longer with the fact that the undemanding pathogen is not only difficult to eliminate in humans, but that it can sometimes survive on surfaces for months.

“Significant increase” in cases in Germany – expert calls for reporting obligation

In Germany, only twelve infections with Candida auris were recorded in 2021 and 2022. But in a current analysis in the “Deutsches Ärzteblatt”, experts still see an urgent need for action. Although there is no obligation to report this fungus in Germany, there has been a “significant increase”.

It is inevitable that Candida auris will also spread in Germany, Kurzai tells the “Spiegel”. “The only question is: how long will it take for us to have the number of cases as high as in the USA?” he says. “Until we no longer have individual cases imported mainly from abroad and a few transmissions in hospitals – but larger outbreaks and a spread in nursing homes? We have to make sure that it takes as long as possible until then.”

The aim is to find an effective remedy against Candida auris. Because the fungal pathogen is “not a killer germ against which nothing can be done”, according to Kurzai. In order to be able to better monitor the development in Germany, Kurzai and other experts recommend reporting evidence of the fungus. In the specialist journal “Mycoses” they also recommend a whole bundle of measures, including screenings in clinics, hygiene rules and special disinfection strategies.