Flu season is arriving months early. Here's where it's spreading

Key Points:

• The 2023 flu season in the U.S. has started unusually early, with flu activity rising from late August to early September, earlier than the typical November onset, according to CDC data and wastewater tracking.
• Influenza A, particularly the A(H1N1)pdm09 subclade, is the dominant strain this season, accounting for 97% of confirmed cases, while overall flu hospitalizations remain low.
• Symptoms of the flu include fever, body aches, cough, runny nose, sore throat, headache, fatigue, and upset stomach, with preventive measures such as frequent handwashing, mask-wearing, and avoiding large indoor gatherings recommended.
• Health experts emphasize early flu vaccination, especially given the early season start; the American Academy of Pediatrics advises annual immunization by the end of October, with children under 9 requiring two doses if previously unvaccinated.
• Flu activity is currently highest on the West Coast, and despite increased cases, overall flu activity detected in wastewater remains categorized as "very low" nationwide, though some data reporting gaps exist due to testing contract changes.