As the winter season continues, there's an increased chance of infections from COVID-19, influenza and respiratory syncytial virus. But, the U.S. Centers for Disease Control and Prevention predicted hospitalizations will be similar to or lower than last fall and winter.

Though symptoms of a cold and the flu are similar, key differences set them apart. The two illnesses develop at different rates, with colds often beginning slowly and the flu taking hold more quickly. Colds are typically a mild illness, while the flu can become severe and, in some cases, deadly.

The Milwaukee Health Department tracks COVID-19, flu and RSV levels through public wastewater testing. Officials provided a behind-the-scenes look.

Illinois health officials advised of an uptick in respiratory illnesses on Monday as families geared up for holiday celebrations in the following days.

Is COVID going around again? The CDC's wastewater surveillance system suggests the virus is growing in prevalence.