A team of researchers in Portugal has identified the first cases of the superbug “Candida auris” in the country. This infection is invasive and can reach the blood and vital organs such as the heart or brain. It can cause deadly infections in people with weakened immune systems.
The cases were detected in 2023 at a hospital in northern Portugal. According to the researchers, three patients died, but none of the deaths were attributed solely to Candida auris, with all affected patients suffering from severe underlying conditions.
It is a type of invasive yeast that has infected at least 7,000 people across 27 US states, according to the Centers for Disease Control and Prevention.
In a statement, the Faculty of Medicine of the University of Porto (FMUP) emphasised the importance of hospital vigilance to prevent the spread of the superbug, which is resistant to drugs and is considered a threat to global public health.
“It is essential that institutions dedicated to teaching and research liaise with hospitals and ULS [Local Health Units] towards integrated translational research, in order to strengthen the capacity to respond to emerging public health challenges based on evidence,” said Sofia Costa de Oliveira, the FMUP lecturer who coordinated the study, the results of which were published in the Journal of Fungi in October 2025.
The researchers identified eight cases of “Candida auris” infection that occurred in 2023 in a hospital in the northern region of Portugal. According to the summary shared with the Lusa news agency, “none of the three deaths from the reported cases of invasive infection were exclusively associated with the infection, but rather with severe patient comorbidities”.
This fungus spreads in hospitals and not in the community, and is easily “transmitted in healthcare units and resistant to some antifungal drugs, which justifies increased vigilance”, explained Sofia Costa de Oliveira.
What is Candida auris?
According to the Portuguese health provider CUF, “Candida auris” is a fungus that was identified in 2009 in Japan and has since appeared in other countries. This infection is mainly present in patients admitted to hospitals or living in nursing homes, and is associated with high mortality rates worldwide.
Candida auris is able to enter the bloodstream and invade the entire body, colonising the skin and causing invasive infections. It is also resistant to multiple antifungal drugs and can persist on surfaces and equipment.
Between 30 and 60 per cent of patients who contracted this infection died, but it is crucial to bear in mind that most of these people had other serious health problems. Candida auris is currently found in around 60 countries.
How is the diagnosis made?
In terms of diagnosis, it is often necessary to use specific techniques and sensitivity tests to determine the most effective antifungal drugs. This is because common laboratory methods may not be able to identify the presence of “Candida auris”.
This fungus is easily transmitted through direct contact with infected individuals, including those who are asymptomatic, or contaminated surfaces.
In order to prevent its spread, it is important to sanitise your hands thoroughly and disinfect hospital surfaces and medical devices. If an infection is suspected, medical attention should be sought immediately.
Spain, Greece, Italy, Romania, and Germany have seen the most cases in the last decade.
The study into the presence of this fungus in Portugal brought together Isabel Miranda, from FMUP and RISE-Health, Dolores Pinheiro, José Artur Paiva and João Tiago Guimarães, from FMUP and ULS São João, Micael Gonçalves, from CESAM, and Sandra Hilário, from FCUP.
In September 2025, the European Centre for Disease Prevention and Control (ECDC) warned of the rapid spread of this fungus and called for containment measures.
The ECDC indicated that between 2013 and 2023, more than 4,000 cases of “Candida auris” infections were recorded in European Union countries, including Iceland, Liechtenstein and Norway.
It also highlights a significant increase in the number of infections by this fungus in 2023, when over 1,300 cases were reported in 18 countries.