The 2023-2024 flu season is in full swing, with four major respiratory viruses spreading across the country. At least 15 states have “very high” levels of influenza, according to the Centers for Disease Control and Prevention (CDC). Wastewater monitoring systems reported high levels of flu nationwide for the week ending January 4.
Experts attribute the surge in flu rates to colder temperatures weakening the immune system and drier air allowing respiratory viruses to thrive. This can lead to increased spread of illnesses during winter months when people spend more time indoors.
The CDC uses wastewater testing as an early warning system to prevent outbreaks, detecting changes in illness levels across states. Even without symptoms, community residents can be tested for infectious diseases through wastewater analysis.
As flu hospitalization rates rise, so do the numbers: 5.3 million illnesses, 63,000 hospitalizations, and 2,700 deaths reported this season. Differentiating between flu, COVID-19, and cold symptoms can be challenging, but experts emphasize key differences, including fever, muscle aches, and headache with flu and COVID-19, and dry cough with COVID-19.
Source: https://eu.usatoday.com/story/graphics/2025/01/16/2025-flu-season/77729060007