Flu activity rises early on the US West Coast

Flu activity is increasing earlier than usual in the United States, with notable surges occurring along the West Coast. Typically, flu season begins in the South and Southeast during October or November before moving north and west. However, data from the Centers for Disease Control and Prevention (CDC) shows activity rising as early as August.

In the period between September 19 and October 3, the flu positivity rate rose from 2.5 percent to 3.6 percent, a significant increase compared to the 0.6 percent recorded during the same period last year. Emergency department visits related to the flu also doubled during that timeframe. In Los Angeles County, activity began rising in September, well ahead of the typical early November start.

Experts suggest the early surge may be linked to the H3N2 subclade K strain, a mutated version of a previous strain. While the early start does not necessarily indicate a more severe season, health officials emphasize the importance of vaccination. Available options include traditional shots, nasal sprays, high-antigen vaccines for those over 65, and mRNA vaccines.