Microscopic yeast strain Candida auris, also known as C auris, has been detected in over half of American states since first emerging in the US in 2016.
Health officials issued a warning about the fungus on Monday, flagging that the hospital infection had tripled in recent years and grown resistant to multiple drugs.
The Centers for Disease Control and Prevention (CDC) already described the infection, which kills up to 60 percent of people it infects, as an ‘urgent threat’ in 2019.
Symptoms of the fungus may not be noticeable because patients with C auris are usually already ill with another serious condition and often in hospital.
Most transmission occurs in healthcare facilities, especially among residents of long-term care facilities or among persons with indwelling devices – such as catheters, tracheostomies, or wound drains – or on mechanical ventilators.
Fever and chills
Symptoms depend on the infected body part, but the most common sign seen in patients with Candida auris is persistent fever and chills.
A fever is defined as a temporary increase in average body temperature above 99°F to 99.5°F. But with a C auris infection, the higher temperature will not go away.
The most frequently seen sign in patients with Candida auris is a persistent fever and chills
Chills are the body’s way of raising its core temperature through shivering.
Fever and chills are the most common symptoms for bloodstream infections from C auris. Bloodstream infections can also cause confusion and disorientation.
C auris can also live on the skin or other parts of the body such as the ear or wounds without causing an active infection and making you ill.
But in some patients, the fungus can enter the bloodstream and spread throughout the body, resulting in potentially fatal invasive C auris infections such as in the blood or internal organs.
This usually occurs when a medical device is inserted into the skin or gastrointestinal tract, such as a catheter or an IV.
Antibiotics not working
Another telltale sign of C auris is that the fever and chills cannot be treated with antibiotics for a suspected bacterial infection.
Antifungal medication may also be ineffective. Some C auris infections have been resistant to all three types of antifungal medications: azoles, echinocandins, and amphotericin B. Echinocandins are the first line of therapy given to treat C auris.
Both antibiotics and antifungal medication may be ineffective against C auris infections
Multidrug-resistant strains of C auris have become more common in recent years.
Research by the CDC found that cases of the fungus resistant to echinocandin had also risen — in 2021 there were about three times the number of cases than in each of the previous two years.
If the C auris fungus has reached the ear, patients may have a sharp or dull pain in the ear canal.
There may be a sense of ‘fullness’ in the ears and impaired hearing due to muffling. Drainage and nausea may also occur.
Patients may lose partial functioning of their ears if a C auris infection takes hold in the ear canal
The first case of C auris was found in the ear discharge of a 70-year-old female inpatient at Tokyo Metropolitan Geriatric Hospital in Japan in 2009.
The fungus kills more than one in three people with invasive C auris, where it has spread to cause an infection such as in the ear.
C auris can infect an existing open wound that is healing.
The skin around the wound may become inflamed and red. This is due to irritation causing dilatation of the blood capillaries.
Skin around an existing wound may become inflamed and red if the patient contracts C auris
Yellowish or orange pus may also be discharged from the wound.
The wound will be more painful and tender to touch and will take longer to heal.
There may also be an accompanying fever.
General tiredness and malaise
General tiredness and malaise is another sign of a bloodstream infection caused by C auris.
The feeling of fatigue is thought to be a signal to the body to stop physical activity in order to recover.
General tiredness and malaise during a C auris infection may be a signal to the body to stop physical activity
Bloodstream infection can also cause sepsis — which can be life-threatening. It occurs when chemicals in the bloodstream to fight an infection set off inflammation throughout the body.
This can lead to multiple organ systems being damaged and shutting down.
Symptoms of sepsis include struggling to breathe, low blood pressure, increased heart rate and mental confusion.
C auris infections have been growing rapidly recently, and cases in the US rose from 1,310 in 2020 to 4,041 in 2021. Last year, there were 5,754 cases.
The CDC does not keep track of how many people died from C auris and it can be tricky to know if patients died from the fungus as it usually infects people who are already very sick.
CDC data shows fungal infections caused 7,000 deaths in 2021 in the US and 1.5million worldwide.
The hardest hit states are the ones with the highest number of hospitals — the breeding ground for C auris.
The fungus does not form germ tubes and is rarely detected in the natural environment.
Healthy people do not usually get sick, but among the frail and vulnerable, it kills up to 60 percent.
People catch C auris by touching an infected person. It may also be passed on by touching contaminated surfaces or equipment, where it can survive for weeks.
C auris emerged over a decade ago in hospitals in India, South Africa and South America simultaneously. Researchers do not know why but speculate that climate change could have played a part.
Fungi usually cannot tolerate the warmer temperature of the human body, but scientists think C auris might have adapted to survive in a warming environment.
Another theory suggested in 2019 was that C auris might have existed as a plant fungus that adapted due to global warming to exist in salty water as well as hotter temperatures.
The type of plant would have been a saprophyte — which does not have chlorophyll but instead gets its food from dead organic matter.
Researchers from the University of Texas speculated it could have then been transmitted by birds from saltmarshes across the world to rural parts where birds and humans are often in contact.
Researchers theorized emergence of C auris
C auris could have jumped into humans during activities such as farming, and then eventually into hospitals and healthcare systems as humans migrated to cities.
A research team in India pointed to C auris originating from a tropical wetland and gaining antifungal resistance after coming into contact with humans.
There are roughly 1,500 types of yeast, which are single-celled fungi. They are found globally in soil and on plants. Hundreds of varieties are used to make things like bread, beer and wine.
Some yeasts are dangerous pathogens to humans and other animals, particularly Candida albicans, which C auris is a type of.