An emerging fungal infection that can prove fatal in communal health settings spread further and became more drug-resistant during the pandemic, a Centers for Disease Control review of surveillance data found.

Why it matters: The timing suggests the spread of Candida auris could have been exacerbated by COVID-related stresses like staff and equipment shortages, increased antimicrobial use and changes in patient movement.

• The increase in cases underscores the importance of infection control in hospitals and long-term care facilities, researchers said.

What they found: The number of C. auris clinical cases tripled from 2019 to 2021, to 1,471 in 2021.

• Most U.S. cases are found in post–acute settings, especially long-term acute care hospitals.
• While many early cases were contracted abroad, C. auris has been detected in more than half of the states and is endemic in some areas.
• There were 3,270 clinical cases in the U.S. through 2021, along with 7,413 detected through screening.

Between the lines: The CDC is still studying how the fungus spreads, but it's been primarily detected in sick patients, particularly those with weaker immune systems or in need of catheters or feeding tubes.

• Drug-resistant varieties varied by region, but the number of cases resistant to the first-line therapy echinocandins substantially increased in 2021, researchers said.
• "Several new antifungal medications are in development, but more research is needed to understand outcomes for patients with these highly resistant strains and to guide treatment," they wrote in the Annals of Internal Medicine.