Fungus

Fungal pathogens typically struggle to survive human body temperatures, but researchers hypothesize that global warming conditions will force fungi to adapt to hotter temperatures, with implications for their ability to also survive within our bodies. That type of evolutionary adaptation would lead to more dire health threats for humans.

Estimates derived from health insurance claims, death certificates, and hospitalization data suggest that fungus is a significant medical issue. Each year, fungal diseases kill some 7,300 people—roughly the same number of deaths attributed to motor vehicles striking pedestrians. Around 130,000 people are hospitalized with fungal diseases, and the total national cost from fungal diseases is estimated to be about $19B—a figure that roughly matches Jamaica’s entire gross domestic product.

In 2022, this global health body issued its first-ever list of top fungal threats to human health. It said fungal threats are spreading and occurring more frequently. The WHO’s list included 19 fungal pathogens to watch, and said that the most dangerous ones to public health are Cryptococcus neoformans, Aspergillus fumigatus, Candida albicans, and Candida auris. There are only a handful of classes of medication currently available to combat fungal pathogens, with few others in the pipeline even though antimicrobial resistance is growing.

This inhalable, microscopic pathogen is found worldwide. It rarely causes illness, but it can take root in those with compromised immune systems, including people with advanced HIV/AIDS. Symptoms of cryptococcal infection—such as a stiff neck, vomiting, and confusion—can begin weeks or months after breathing in spores, though sometimes symptoms won’t appear for years. There are no known cases of transmission between people or between people and animals.

Most people breathe in hundreds of Aspergillus fumigatus spores daily without getting sick—it’s a common microscopic fungus in our environment. But people who are severely ill, including those who have undergone an organ transplant, are at risk of developing infections from these spores.

This fungus is naturally occurring on the body, but C. albicans can become a problem when the natural balance of bacteria on the body is off-kilter, allowing this yeast to spread. It can cause anything from diaper rash to a yeast infection in the throat or vagina. It’s typically treated with doctor-prescribed antifungal medications.

This fungus has spread rapidly in healthcare settings since the first US case was reported in 2016, and it has grown increasingly resistant to echinocandins, the antifungal medicine most commonly used to treat it. Often, it’s resistant to multiple antifungal drugs, contributing to its high death toll. It can most readily infect those with invasive medical devices like intravenous catheters and those with frequent or long-duration stays in healthcare facilities.

Explore the data showing how the fungus C. auris has spread in the US, with more than 10,000 reported cases since 2016. Recommended steps to prevent infections and limit their spread have been successful in some areas, but infection control remains complicated because the fungus is often now multidrug-resistant.

We breathe in airborne spores frequently, but they often don’t make us sick. This video details how certain concerning fungal changes can occur and discusses the role of mycologists—scientists who study fungi—in helping to improve human health.

Though it depicted a fictional world with a collapsed society due to a fungal pandemic, this television series (based on an earlier video game) helped raise awareness about fungal threats. It even prompted the US Centers for Disease Control and Prevention to publicly comment on it—clarifying the show’s plausibility. The mind-controlling fungal species in the show is based on a real-life Cordyceps species, a fungus that modifies its host’s behavior before killing it.