U.S. cases of a deadly fungus nearly doubled in recent years

U.S. cases of a deadly fungus nearly doubled in recent years

A fungus that recently evolved to infect humans is spreading rapidly in health care facilities in the United States and becoming harder to treat, a study from the U.S. Centers for Disease Control and Prevention finds.

Candida auris infections were first detected in the United States in 2013. Each year since, the number of people of infected — though still small — has increased dramatically. In 2016, the fungus sickened 53 people. In 2021, the deadly fungus infected 1,471 people, nearly twice the 756 cases from the year before, researchers report March 21 in Annals of Internal Medicine. What’s more, the team found, the fungus is becoming resistant to antifungal drugs.

The rise of cases and antifungal resistance is “concerning,” says microbiologist and immunologist Arturo Casadevall, who studies fungal infections. “You worry because [the study] is telling you what could be a harbinger of things to come.” Casadevall, of Johns Hopkins Bloomberg School of Public Health, was not involved in the CDC study.

In tests of people at high risk of infection, researchers also found 4,041 individuals who carried the fungus in 2021 but were not sick at the time. A small percentage of carriers may later get sick from the fungus, says Meghan Lyman, a medical epidemiologist in the CDC’s Mycotic Diseases Branch in Atlanta, possibly developing bloodstream infections that carry a high risk of death.

Starting in 2012, C. auris infections popped up suddenly in hospitals on three continents, probably evolving to grow at human body temperature as a result of climate change (SN: 7/26/19). The fungus, typically detected through blood or urine tests, usually infects people in health care settings such as hospitals, rehabilitation facilities and long-term care homes. Because people who get infected are often already sick, it can be hard to tell whether symptoms such as fevers are from the existing illness or an infection.

Those most at risk of infection include people who are ill; those who have catheters, breathing or feeding tubes or other invasive medical devices; and those who have repeated or long stays in health care facilities. Healthy people are usually not infected but can spread the fungus to others by contact with contaminated surfaces, including gowns and gloves worn by health care workers, Lyman says.

Growing drug resistance

Infections can be treated with antifungal drugs. But Lyman and colleagues found that the fungus is becoming resistant to an important class of such medications called echinocandins. These drugs are used as both the first line and the last line of defense against C. auris, says Casadevall.

Before 2020, six people were known to have echinocandin-resistant infections and four other people had infections resistant to all three class of existing antifungal drugs. That resistance developed during treatment using echinocandin. None of those cases passed the resistant strain to others. But in 2021, 19 people were diagnosed with echinocandin-resistant infections and seven with infections resistant to multiple drugs.

More concerning, one outbreak in Washington, D.C., and another in Texas suggested people could transmit the drug-resistant infections to each other. “Patients who had never been on echinocandins were getting these resistant strains,” Lyman says.        

Some health care facilities have been able to identify cases early and prevent outbreaks. “We’re obviously very concerned,” Lyman says, “but we are encouraged by these facilities that have had success at containing it.” Using those facilities’ infection control measures may help limit cases of C. auris, she says, as well as reducing spread other fungal, bacterial and viral pathogens.

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Oxygen on early Earth may have come from quartz crushed by earthquakes

Oxygen on early Earth may have come from quartz crushed by earthquakes

Veins of white quartz in granite on the north-east coast of the US

Richard Berube / Alamy Stock Photo

Earthquakes and other geological processes may have enabled oxygen-producing reactions that shaped the evolution of some of Earth’s earliest organisms.

Today, oxygen makes up around a fifth of Earth’s atmosphere, with most of it produced by plants and microbes. It didn’t start that way. There was very little oxygen in the atmosphere until levels spiked during the Great Oxidation Event between 2.4 billion and 2.3 billion years ago thanks to the rapid spread of microbes that release oxygen through photosynthesis.

However, the widespread presence of antioxidant enzymes across the tree of life suggests a common ancestor that existed prior to the Great Oxidation Event was exposed to some amount of oxygen.

Mark Thiemens at the University of California, San Diego, and his colleagues ground up quartz rock and exposed it to water under chemical conditions similar to those on Earth prior to high levels of oxygen. The researchers used quartz because it is the simplest and most common silicate mineral.

They found that the broken crystals on the surface of quartz can react with water to form molecular oxygen and other reactive oxygen species, such as hydrogen peroxide. Also known as free radicals, these molecules would have been critical to early evolution because they can damage DNA and other components of cells, says Timothy Lyons at the University of California, Riverside, who wasn’t involved with the work.

“Life was able to develop very early the enzymatic capabilities of dealing with the harmful effects of these species,” he says.

In nature, quartz and other silicate minerals could be similarly abraded by earthquakes, erosion or moving ice. They could then interact with water to produce those same oxygen molecules. The researchers estimated that seismic processes alone could have generated 100 billion times more hydrogen peroxide than atmospheric reactions, another possible source of abiotic oxygen.

Adaptations to this seismic source of oxygen may have helped some organisms survive the radical shift in Earth’s chemistry that accompanied the Great Oxidation Event hundreds of millions of years later, says Lyons.

The researchers add that similar geological processes on other planetary bodies, such as sandstorms on Mars or tidal fluctuations on Saturn’s moon Enceladus, could also produce oxygen, which could be an important factor for detecting life on those worlds.


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Is someone lying to you? A lack of detail may give them away

Is someone lying to you? A lack of detail may give them away

Woman looking at man

Does maintaining eye contact mean someone is less likely to be lying?

Anna Tolipova/Alamy

An investigation into the best way to identify lies has found that focusing on the level of detail in what people say, while ignoring all other cues, is the most successful method – but if liars know that, they might more easily deceive you.

People trained to detect lies often rely on multiple cues, such as eye contact, length of responses and the details in what people say, but studies have shown that assessing a wide range of behavioural information …

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Astonishing 3D footage of ants recorded using 54-camera set-up

Astonishing 3D footage of ants recorded using 54-camera set-up

The new camera set-up has been used to film harvester ants

Nature Picture Library/Alamy

Stitching video together from 54 cameras using AI produces incredibly detailed three-dimensional videos. The technique has been used to film many tiny creatures at once.

To understand why large groups of small animals, like ants or flies, behave the way they do, researchers want to see what every individual in the group is doing in each moment. But recording devices can normally capture either a single animal in great detail or many animals without those details, says Kevin Zhou

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Stephen Hawking's final theorem turns time and causality inside out

Stephen Hawking's final theorem turns time and causality inside out


Stephen Hawking with Thomas Hertog, in Hawking's office

Thomas Hertog (left) collaborated with Stephen Hawking for many years

Courtesy of Thomas Hertog

IT WAS common knowledge among students at the University of Cambridge that whoever obtained the best marks in the final part of the mathematical tripos exams would be summoned to see Stephen Hawking. I had just got my results and had come top. Sure enough, I was invited for a discussion with him.

I made my way to his office deep in the labyrinth of the department of applied mathematics and theoretical physics, which was housed in a creaking Victorian building on the banks of the river Cam. Stephen’s office was just off the main common room, and even though it was noisy there, he liked to keep his door ajar. I knocked, paused and slowly pushed it open.

I didn’t quite know what to expect on the other side of that door. I knew, of course, that Stephen was famous for his work on black holes and that he had even got into trouble for some of his ideas about what happens when they explode. But it turned out that he was musing on a different question: why is the universe just right for life to arise?

Pondering this question would turn into a long quest for us both. For the next two decades, until his death, Stephen and I worked shoulder to shoulder on novel ideas that suggest a radically new understanding of why the universe is the way it is. In our conception, the laws of physics themselves have, in a sense, evolved to be the …

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The mystery of Christiaan Huygens’ flawed telescopes may have been solved

The mystery of Christiaan Huygens’ flawed telescopes may have been solved

17th century scientist Christiaan Huygens set his sights on faraway Saturn, but he may have been nearsighted.

Huygens is known, in part, for discovering Saturn’s largest moon, Titan, and deducing the shape of the planet’s rings. But by some accounts, the Dutch scientist’s telescopes produced fuzzier views than others of the time despite having well-crafted lenses.

That may be because Huygens needed glasses, astronomer Alexander Pietrow proposes March 1 in Notes and Records: the Royal Society Journal of the History of Science.

To make his telescopes, Huygens combined two lenses, an objective and an eyepiece, positioned at either end of the telescope. Huygens experimented with different lenses to find combinations that, to his eye, created a sharp image, eventually creating a table to keep track of which combinations to use to obtain a given magnification. But when compared with modern-day knowledge of optics, Huygens’ calculations were a bit off, says Pietrow, of the Leibniz Institute for Astrophysics Potsdam in Germany.

One possible explanation: Huygens selected lenses based on his flawed vision. Historical records indicate that Huygens’ father was nearsighted, so it wouldn’t be surprising if Christiaan Huygens also suffered from the often-hereditary affliction.

Assuming that’s the reason for the mismatch, Pietrow calculates that Huygens had 20/70 vision: What someone with normal vision could read from 70 feet away, Huygens could read only from 20 feet. If so, that could be why Huygens’ telescopes never quite reached their potential.

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