After the holiday season and an uptick in travel, California faces a rise in respiratory illnesses, prompting health experts to talk of a “quad-demic.” The term refers to the simultaneous spread of four major viruses: COVID-19,

Care for the flu is generally supportive — meaning rest, hydration, and over-the-counter medication, but as the Mayo Clinic points out, if you're in a group at high risk of complications — such as pregnant, older, or asthmatic — you may be prescribed an anti-viral medication such as Tamiflu.

COVID-19, influenza, RSV, and norovirus—have created what experts are calling a "quad-demic" in the U.S. Here's what to know and how to stay well.

Cook your food thoroughly (especially seafood and shellfish) to at least 145 degrees Fahrenheit. Clean and sanitize surfaces and objects that are touched frequently (kitchen and bathroom counters, toilets, toys, remote controls, computers, tablets, gaming consoles, etc.). Something containing bleach is most effective.

Most U.S. states are reporting high or very high flu-like activity, while COVID-19 rates remain lower than this time last year.

Health experts are warning of a 'quad-demic' this winter, as four viral infections spread simultaneously in the UK and US.

Viral sicknesses have risen in early 2025 amid the ongoing “quad-demic” in the U.S., referring to three respiratory viruses and one gastrointestinal disease, according to the Centers for Disease Control and Prevention (CDC) data.