Masks return to some hospitals as respiratory illnesses increase in Mass.

One in six emergency room visits in Massachusetts is now due to respiratory infections, including flu and COVID-19, according to the latest data from state health officials.

It's not uncommon for illness to increase this time of year and continue through the spring, said Dr. Larry Madoff, medical director for the Bureau of Infectious Disease at the state's Department of Public Health.

"If it's like last year and some of our previous years, it will peak in January and tend down in the later winter," he said. "But every respiratory season is different."

In all, 16.7% of hospital admissions in the state last week involved some sort of respiratory illness, according to data released by the Massachusetts Department of Public Health. That includes cases of COVID (2.9%), flu (2.7%) and respiratory syncytial virus, better known as RSV (0.9%). The department did not have an illness-specific diagnosis for the majority of cases.

Madoff said the latest vaccines can help people protect themselves from the worst effects of these illnesses. But fewer than one in five Massachusetts residents has received the latest COVID vaccine booster, according to the state's vaccination data. And just over 38% of people have gotten the latest flu shot, down when compared to the same week in the previous three years.

The increase in respiratory illness is prompting new mask mandates at some health care facilities. In a statement, Mass General Brigham said its staff will wear masks "during direct interactions with patients" in clinical care areas like patient rooms. Mass General Brigham did not say how long the mask requirement for staff will stay in place.

The hospital system said it strongly encourages but does not require patients to wear masks while interacting with staff.