Deadly, drug-resistant Candida yeast infection spreads in the US

An emerging fungus could become the latest hospital-acquired infection we have to worry about. On 16 March, the US Centers for Disease Control and Prevention (CDC) reported that 53 people in the US have been taken ill with Candida auris – most of them in New York state. A further 27 healthy carriers of the fungus have been identified in three states where clinical cases were detected.

People at highest risk are those with weak immune systems including premature babies, people with diabetes, people on dialysis, and those who have had recent transplants or other invasive surgery.

Unlike most common yeast infections, C. auris doesn’t usually cause thrush, but results in bloodstream, wound or ear infections instead – triggering organ failure in the worst cases.

Although information isn’t available for all patients, the death rate could be as high as 60 per cent.  However, because patients usually contract the infection while hospitalised with other major illnesses, it’s difficult to be sure whether any deaths can be attributed solely to C. auris.

C. auris was first identified in Japan in 2009. Since then, infections have also been reported in countries including Canada, Colombia, Germany, India, Israel, Kenya, Kuwait, Norway, Pakistan, Spain, South Africa, South Korea, the United Kingdom and Venezuela. Between May 2013 and August 2016, the first 13 cases were reported in the US. Since then, the number of infections has tripled, signalling a spike in reported cases.

Some strains of the fungus are resistant to all three major classes of antifungal drugs. “It’s pretty difficult to find new antibiotics. It’s harder to find new antifungals,” says David Denning at the University Hospital of South Manchester, UK.

Humans and fungi share many common metabolic pathways, so lots of agents that kill fungi are too toxic for human use.  “C. auris has the potential to be a really difficult problem,” Denning says.

However, he stresses that the majority of people don’t need to worry about becoming infected. “The ordinary person coming into the hospital to have a hernia operation or have a breast lump or their diabetes checked is not at risk. Neither are patients out in the community.”

Few drug manufacturers are currently focusing on developing antifungal compounds, but Denning says some promising oral and intravenous treatments are being developed in the UK, Japan and Sweden. It remains to be seen whether they will work against this stubborn infection.

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