CDC Reports Low Flu Activity in Most US States

New data from the U.S. Centers for Disease Control and Prevention indicates that influenza activity remains low across most of the country as of last week, with high levels reported only in Colorado, Louisiana, New Jersey and New York. Officials described the season's severity as increasing but still consistent with a mild outbreak, even as winter gatherings drive up transmission of respiratory illnesses including colds, flu and norovirus, a virus causing vomiting and diarrhea whose cases have risen over the past month.

The CDC's Friday update highlights three key respiratory viruses under close monitoring: influenza, respiratory syncytial virus and COVID-19. For influenza, the previous season was particularly severe, recording the highest hospitalization rates since the 2009 H1N1 pandemic and 288 pediatric deaths, a figure matching that pandemic's toll after a late-reported case. This season's first child flu death was announced this week, raising concerns about potential escalation.

The predominant strain so far is influenza A H3N2, which has historically led to the most hospitalizations and fatalities among older adults. Of the H3N2 cases analyzed, 89 percent involved a...