Fungal threats on the rise?

This exercise is a part of Educator Guide: Fungal Infections and Climate Change / View Guide

Directions for teachers: After your students read “Climate change may raise the risk of deadly fungal infections in humans. One species is already a threat,” ask them to answer the following questions.

1.  What fungal species has recently been found to infect people? (Take notice and use the correct format for writing the name of a species.) When and where did infectious versions of the fungus appear?

Candida auris, or C. auris. Infectious strains arose between 2012 and 2015 in Africa, Asia and South America. In the United States, officials began reporting cases of C. auris infections in 2016. More than 30 other countries have also reported cases of C. auris infections.

2.  What makes scientists think the fungus wasn’t spread by infected travelers? Explain the scientists’ reasoning.

The strains in Africa, Asia and South America were genetically distinct. If travelers were transporting the fungus from one place to another, the genetics would reveal a closer relationship among the fungi.

3.  Why have humans and other mammals largely been spared from infections by fungi?

In addition to powerful immune systems that fight off invaders, mammals have body temperatures that are too high for most fungi to replicate.

4.  Who is Arturo Casadevall?  What is his hypothesis for how the fungus became infectious in humans? What role does he think climate change has played?

Arturo Casadevall is a microbiologist at Johns Hopkins Bloomberg School of Public Health. He thinks that as the climate warms, the fungus may have adapted to warming temperatures in its natural environment. That may have given some strains of C. auris the ability to tolerate humans’ average body temperature of 37° Celsius, allowing those strains to replicate in and thus infect people. 

5.  Why are infections of this fungus a threat to people? 

The fungus can infect the blood, brain, heart and other parts of the body and some infections can be fatal. Some strains of the fungus are resistant to antifungal medications.

6.  How does Casadevall predict other fungi will react to a warmer world?

Other fungi in the wild may similarly adapt to warmer temperatures. He predicts that some species will adapt the ability to withstand humans’ body temperature, making the fungi potential threats.

7.  People have historically used soapboxes as informal platforms to stand on while giving speeches. Why do you think Science News has included this article in a category of story labeled “Soapbox”?

The story is labeled “Soapbox” because Casadevall is sharing his viewpoint on an important issue. Rather than presenting only the scientific evidence, he is using evidence to make an argument that fungi are poised to become a threat to humans as the climate changes. That argument is not yet fully tested or supported.

8.  Aside from reporting Casadevall’s viewpoint, what information does Science News journalist Aimee Cunningham provide about the fungus and other fungal diseases?

The article includes the data about the number of confirmed cases of C. auris in the United States. Cunningham also highlights other animals and plants affected by fungal diseases, including frogs, snakes, bats and trees.