Flu season may be mostly behind us, but a nasty, highly contagious stomach bug is rising. In recent weeks, hikers in Southern California have been hit with norovirus, according to the Pacific Crest Trail Association. Outdoor enthusiasts along the iconic trail aren’t the only ones suffering. Recent wastewater surveillance reveals an upward trend to “high” levels of norovirus across much of the country, with rates currently rising in the Northeast. From Aug. 1 to May 7, the Centers for Disease