The U.S. is seeing a "quad-demic" as cases of COVID-19, flu, RSV and norovirus spread at the same time. Experts said this is what you need to know.

The levels of COVID-19 present in wastewater around the country is on the rise, new data from the U.S. Centers for Disease Control and Prevention (CDC) reveals. 20 U.S. states (plus D.C.) had ...