A warning has been issued by the American College of Physicians (ACAP) about a "particularly concerning" form of black fungus.
Canada auris, which is better known as C auris, is a type of fungus that's resistant against antibiotics and can be deadly if it's picked up by humans.
Cases have been rising fast over the past couple of months, which has left experts worried that it may have the potential to kick off another deadly condition and spread it around the world.
The Mirror reports that the Centers for Disease Control and Prevention (CDC) had already described it as an "urgent threat" in 2019, but statistics show that numbers have increased over the last four years.
And new research from the CDC shows that cases more than tripled across the US between 2020 and 2021, with antibiotic-resistant strains becoming more and more common.
The fungus is thought to have a death-rate of 60 percent of the people it infects.
People can get infected after having direct contact with an object that's been contaminated. The fungus spreads amongst humans through direct contact too. Some of the symptoms include fever and chills, which don't get better over time.
To limit the spread, it's recommended that you wash your hands as frequently as possible.
The latest study considered the number of confirmed and probable cases which were reported to state and local health facilities between 2016 and 2021.
Fungal infections caused 7,000 deaths in the US in 2021, according to the CDC, with 1.5 million deaths worldwide. It has been suggested by some experts that this is due to the changing climate, which is ideal for the fungus to thrive.
Researchers found infections had risen from 1,310 in 2020 to 4,041 in 2021, while clinical cases of C auris increased to 2,377 with 5,754 screening results last year.
Authors of the CDC study said the findings "highlight the need for improved detection and infection control practices to prevent spread of C auris".
They also added that the spread of the fungus could have been "exacerbated by pandemic related strain on the health care and public health systems".
Echinocandin is an antifungal drug and is the first line of therapy given to treat cases of C auris.
It was first reported in America in 2016 but was given the highest level of concern by the CDC due to its frequent resistance to many drugs, the ease of the spread in healthcare settings and the high death rate.
The fungus can cause different kinds of infection and it's believed that the number of C auris cases may be underestimated in the study, since testing isn't uniformly conducted across the country.
New York City and Chicago were reported to be the worst affected, but cases of C auris have now occurred in more than half of US states. Most of the spread of cases has been in long-term care hospitals and nursing homes.
Three states — Oregon, Minnesota and Michigan — all reported their first case of the fungus in 2021. Meanwhile, areas with previous cases but limited spread, such as California, Texas and Florida, had new and increasing transmission.
Don't miss the latest news from around Scotland and beyond - sign up to our daily newsletter here .