Enlarge / Orange amphipods caught the eye (and interest) of Brown University graduate students conducting field research. (credit: David Johnson)

Scour the salt marshes of Plum Island Estuary in Massachusetts and you're likely to spot bright orange shrimp lurking among the vegetation and detritus. That unusual hue is a sign that a shrimp has been infected with a parasitic worm, which also seems to affect the shrimp's behavior. Infected shrimp typically become sluggish and spend more time exposed in the open marsh, easy pickings for hungry birds. Now biologists at Brown University have sequenced the DNA of these shrimp to hone in on the molecular mechanisms behind the changes, according to a recent paper published in the journal Molecular Ecology.

“This may be an example of a parasite manipulating an intermediate host to ensure its own transmission between hosts,” said co-author David Rand of Brown University, drawing an analogy to how malaria spreads to humans via the intermediary of mosquito bites. “Rabies could be another relevant example: it drives infected individuals ‘mad’ so they bite others and infect the next host. Learning the molecular mechanisms of these kinds of host-parasite interactions can have important implications for how to manage pathogens generally, and in humans.”

Parasites that control and alter the behavior of their hosts are well-known in nature. Most notably, there is a family of zombifying parasitic fungi called Cordyceps —more than 400 different species , each targeting a particular insect species, whether it be ants, dragonflies, cockroaches, aphids, or beetles. In fact, The Last of Us game co-creator Neil Druckmann has said the premise was partly inspired by an episode of the BBC nature documentary Planet Earth (narrated by Sir David Attenborough) portraying the "zombification" of an ant in vivid detail . Scientists are keen to study Cordyceps to learn more about the origins and intricate mechanisms behind these kinds of pathogen-based diseases.

Enlarge / A Trichophyton indotineae infection on the back of an Indian man. (credit: Uhrlaß, S. et al. Journal of Fungi )

A dermatologist in New York City has reported the country's first known cases of highly contagious ringworm infections that are resistant to common anti-fungal treatments—and caused by a newly emerging fungus that is rapidly outstripping other infectious fungi around the world.

In February, the dermatologist reported two cases to health officials in the state, which are described in a brief case study published Thursday in the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.

The two cases occurred a year apart and had no connection to each other. The first, from the summer of 2021, was in a 28-year-old pregnant woman who had no recent international travel history, no underlying medical conditions, and no known contact with anyone who had a similar rash. The case suggests that the fungus is quietly spreading in the community.

Enlarge / This micrograph shows the presence of the fungal agent Blastomyces dermatitidis, 1978. (credit: Getty | CDC/Dr. Libero Ajello )

Toxic fungal spores wafting around a Wisconsin neighborhood—possibly spread by recent construction in the area—sparked an outbreak of rare infections that left one person dead, state health officials reported Friday in the Morbidity and Mortality Weekly Report .

In all, the outbreak cluster included five pet dogs and four people, with the onset of symptoms spanning from October 2021 to February 2022. While two of the cases in people were mild, the other two required hospitalization, including the fatal case. The five dogs were reported to have mild to moderate cases.

The outbreak was caused by the poorly understood fungus Blastomyces ( B. dermatitidis and B. gilchristii ), which lurks in moist soil and decomposing organic matter, such as wood and leaves, often near water. The Centers for Disease Control and Prevention estimates the fungus could exist throughout the eastern US , but its distribution is uneven. It's often found around the Ohio and Mississippi River valleys and the Great Lakes. Parts of Wisconsin and Minnesota are considered hotspots.

Enlarge / The director of Germany's National Reference Centre for Invasive Fungal Infections holds a petri dish containing the yeast Candida auris in a laboratory at Wuerzburg University. (credit: Getty | Nicolas Armer )

A deadly, drug-resistant fungus emerging in the US gained ground faster and picked up yet more drug resistance amid the COVID-19 pandemic, researchers at the Centers for Disease Control and Prevention reported Monday.

The yeast Candida auris has been considered an "urgent threat"—the CDC's highest level of concern—since it was first reported in the US in 2016. The yeast lurks in health care settings and preys upon vulnerable patients, causing invasive infections with a fatality rate of between 30 to 60 percent.

In 2019, before the pandemic began, 17 states and Washington, DC, reported a total of 476 clinical cases. But in 2020, eight additional states reported cases for the first time, with the national clinical case count jumping 59 percent to 756. In 2021, 28 states were affected, with the clinical case count nearly doubling to 1,471. Asymptomatic cases detected through patient screening also jumped amid the pandemic, tripling from 1,310 cases in 2020 to 4,041 cases in 2021. The data appeared Monday in the Annals of Internal Medicine.