The computer illustration of Candida fungi. Both C. albicans and C. auris have the same appearance. C. albicans can be found on the skin and mucus of the mouth, genitals, respiratory tract, and digestive tract. Vaginal candidiasis is the most common disease caused by C. albicans. In 2009, C. auris was first identified. It causes serious infections in hospitalized patients and has high mortality rates.
There are a lot of things that keep you awake at night. If you're anxious like me, you could probably rattle off a long list of additional fears: getting hit by a car, cancer, being poisoned by an ill-advised gas station meal, and getting caught in a wildfire. It's likely that fungi isn't high on your list. That might be changing.
A patient in Japan developed a new disease in 2009. Within a few years, cases started emerging in Venezuela, Iran, Russia, and South Africa, as the highly transmissible Candida auris fungus had been previously unknown to science.
The scientists were surprised to find that the strains weren't related at all, even though they assumed the spread was due to human travel. Scientists were seeing multiple infections of an unknown disease, all at the same time. There have been thousands of cases in 47 countries, and about a third of people die from the infection within 30 days. The sudden boom in global cases is thought to be a sign of things to come.
Humans are lucky that they don't have to worry about infections. "If you were a tree, you'd be afraid of the fungi," says Dr. Casadevall. If you were a fish, a reptile, or an Amphibian, you would have a lot of fears, would you be able to enumerate them? There are diseases that wipe out snakes, fish, corals, insects, and more. Over 500 amphibian species have been decimated by chytrid, with some scientists estimating that the disease is responsible for the decline. That's around one out of every 16 amphibian species known to science.
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One of the reasons for the high incidence of infections is the fact that fungi are ubiquitous. You know the Sting song 'Every Breath You Take', but I'm dating myself. According to a medical mycologist at Washington University School of Medicine in St. Louis, every breath you take is between 100 and 700,000 spores. They've arrived at the space station. They are everywhere.
One of the leading causes of death for people with HIV are infections caused by the fungus athlete's foot. Humans are hot, so people are unlikely to fall to a fungus. If you want to be the pedant at a party, you might enjoy learning that humans are generally not cooler than 98.6 Fahrenheit (37 C). The number comes from a German study. The global average for human body temperature is between 97.5 and 97.9 Fahrenheit (36.4 and 36.6C.), which seems to have been cooling recently. Warm-blooded environments tend to be too warm for a fungus to survive. Casadevall's studies estimated that 95 percent of the species can't survive at average human temperature.
When you look at animals that are hibernated, you can see that the temperature barrier is in action. Bats have recently suffered huge declines due to white nose syndrome, which causes them to be cooler than usual.
The findings support Casadevall's theory that the animal world has a long history with fungi. He believes that our warm-blooded natures may have evolved to avoid the kinds of infections that can wipe out cold-blooded populations.
Being warm-blooded costs. A lot of food is required to keep your body at a high temperature. Warm-blooded animals have to eat more than cold-blooded ones in a single day. Constantly seeking out food increases your risk of being eaten by animals. If you can bask in the Sun, why do you have to use all that energy?
