This winter, California is grappling with an unusually severe flu season, marked by a significant rise in hospitalizations. As the outbreak continues, concerns mount that it could last for several weeks.
The situation is particularly dire in the Bay Area, where Dr. Peter Chin-Hong, an infectious disease expert at UCSF, describes flu activity as reaching alarming levels. “2025 is the year of flu in the Bay Area,” he said, highlighting the overwhelming number of cases impacting emergency departments.
In local clinics, more than 70% of respiratory virus tests are coming back positive for influenza, surpassing the combined totals of RSV, COVID-19, and the common cold.
According to the California Department of Public Health, the flu test positivity rate surged to 27.8% as of February 1st. In contrast, the rate for RSV dropped to 5%, and COVID-19 held steady at 2.4%. Notably, no bird flu viruses were detected in humans in the latest report, despite 68 confirmed human cases nationwide, including 38 in California, mostly linked to exposure to infected poultry or cattle.
With rising flu hospitalizations, especially affecting vulnerable populations such as the elderly and young children, health experts are urging immediate action. “Get the flu vaccine if you haven’t gotten it yet — there is still time,” advised Dr. Chin-Hong.
The flu season typically lasts until May, but it takes a couple of weeks for the vaccine to take full effect. Getting vaccinated can reduce the risk of hospitalization and lessen the severity of symptoms. The flu vaccine protects against three flu strains, including H1N1 and H3N2, known for causing more severe illnesses.
Dr. Chin-Hong noted, “Although COVID tends to disproportionately affect the very old, flu can cause children to get very ill and even die.” California has reported at least 10 pediatric flu deaths this season, including three in San Diego County.
Dr. Ankita Kadakia, San Diego County’s interim public health officer, expressed concern over these recent flu deaths, emphasizing the tragic nature as the peak of flu season approaches. To reduce the risk of flu, doctors recommend simple precautions such as frequent hand washing and wearing a mask in crowded or poorly ventilated spaces.
The flu spreads through tiny droplets released when an infected person talks, sneezes, coughs, or laughs. These droplets can land on surfaces like doorknobs, transferring to others who touch them and then touch their faces. If you feel unwell, staying home is crucial to prevent spreading the virus.
Flu symptoms generally appear within one to four days of exposure, and individuals can be contagious before symptoms manifest. Common symptoms include fever, chills, coughing, headaches, muscle aches, and fatigue. People with the flu are typically contagious for about a week.
For those who contract the flu, Dr. Chin-Hong recommended antiviral medications, such as Tamiflu, noting that they are most effective if taken within the first 48 hours of symptoms.
Nationwide, emergency room visits for the flu are high, while RSV cases remain moderate and COVID-19 cases are low, according to the latest data from the U.S. Centers for Disease Control and Prevention.
This week, 16 more pediatric deaths linked to the seasonal flu were reported, raising the total to 47 for the 2024-25 season. The CDC estimates that there have been at least 20 million flu cases, 250,000 hospitalizations, and 11,000 flu-related deaths so far this season.
The flu test positivity rate has risen to 31.6%, while RSV test positivity is declining at 6.6%, and COVID-19 positivity has decreased to 4.9%.
Since October, the U.S. has reported at least 24 million flu cases, with up to 650,000 hospitalizations, marking the highest level since 2017. Many parts of the country are seeing “high” or “very high” flu activity, and school districts in at least 10 states have temporarily closed classrooms due to outbreaks.
Despite the severe flu resurgence, vaccination rates remain concerningly low. Nationally, only 44.5% of children and 46% of adults have received the flu vaccine, well below the levels needed for widespread protection. Experts believe that lingering effects from the COVID-19 pandemic, including behavioral changes and a reduced sense of urgency about flu prevention, may be contributing to the decline in vaccinations.
With the flu’s resurgence, public health experts fear the impact on hospitals will be severe, especially if vaccination rates remain low. In California, the flu has surpassed COVID-19 in its impact for the first time since the pandemic began.
