‘Super flu’ risk in Bay Area increasing ahead of holidays

Experts are warning about the rise of a global “super flu” strain that could hit the Bay Area hard ahead of the holidays.

Newly released data from the California Department of Public Health shows the Bay Area has the highest levels of influenza A in the state, according to wastewater data released Friday. Additionally, flu positivity test rates for the region are now double what they were at the end of November, although they remain relatively low overall.

In Marin County, about 40 students, or a third of the student body of the Bolinas-Stinson Union School District, were out sick this week thanks to flu-like symptoms, according to a report from the San Francisco Chronicle. (The Chronicle and SFGATE are both owned by Hearst but have separate newsrooms.)

Flu activity in California is currently “moderate,” according to the latest data from the Centers for Disease Control and Prevention. 

What is cause for some concern this season, though, is a new mutated strain of influenza A called H3N2 subclade K, which was detected in the U.S. this September after spreading globally. The new strain was dubbed the “super flu” by U.K. health officials, who warned it could push their health care system into a “worst case scenario.” In the U.S., nearly 90% of H3N2 flu viruses tested since September were found to be this new mutated strain. 

Dr. Farrell Tobolowsky, the medical director for communicable diseases at the San Francisco Department of Public Health, told SFGATE that the department is monitoring the situation and that viral activity in San Francisco still remains far lower than peak levels. 

“Where we are right now is that test positivity and wastewater are low, but definitely increasing,” Tobolowsky said. “In terms of hospitalizations, we’re still low, but we know that they usually lag behind.” 

Tobolowsky said this time of year is a prime time for flu to spread as people travel for the holidays. This year, a record 122 million people in the U.S. are expected to travel between Dec. 20 and Jan. 1, according to AAA. 

Even though the mutated strain means the current vaccine isn’t as strong a match as previous years, Tobolowsky emphasized the vaccine is still the “most effective tool” to prevent severe symptoms that can lead to hospitalizations. 

Those at highest risk for severe illness include infants, toddlers and older adults, in addition to people with compromised immune systems. 

“We would encourage people, if you’re sick, especially if you’re at higher risk of severe illness, to promptly get to your health care provider to get tested and get treatment,” she said. 

This breaking news story has been updated.