Respiratory virus season in the US isn’t over yet

After a few weeks of decline, some measures show that flu activity is starting to pick up again and respiratory virus levels remain high overall in the United States.

After a few weeks of decline, some measures show that flu activity is starting to pick up again and respiratory virus levels remain high overall in the United States. During the week ending January 27, more than 82,000 people who visited an emergency department were diagnosed with influenza, according to data from the US Centers for Disease Control and Prevention — an 8% bump, or about 6,000 more than the week before. The test positivity rate for flu also ticked up in the US overall. A second surge of flu activity after the winter holidays is common, but experts say it’s notoriously difficult to predict exactly how long or how severe the full season will be. Sometimes this surge is the start of a full second wave, but it could also be a minor blip before a more consistent decrease, the CDC says. A traditional second wave of influenza usually comes after a more significant downturn, when influenza B viruses start to overtake influenza A viruses that were predominantly circulating, said Alicia Budd, who leads domestic flu surveillance for the CDC. There’s no evidence of that happening yet, but it’s too early to rule anything out, she said. “We’re still at the midpoint of the season,” Budd said. “It’s too early to tell exactly where we are in our ultimate trajectory. We just don’t know yet. But we are still seeing a lot of activity right now.”