Norovirus cases continue to climb in the US, especially in the Northeast, CDC data shows CNNNorovirus cases soar in California. Here are signs to watch for San Francisco ChronicleIt’s peak norovirus season. Here’s what you can do to avoid getting sick WPRI.comNorovirus cases on the rise in New England WGMEHow is the rise of norovirus in the northeast affecting the Philadelphia region? CBS Philly