Why Did Flu Season Start So Early This Year? - Scientific American
The U.S. influenza season has arrived much earlier than usual. The Centers for Disease Control and Prevention first detected the early increases of flu activity in mid-October. The agency noted that the phenomenon was happening in most of the country, but more intensely in the Southeast and in south-central regions. A month later, levels of the virus continue to rise steeply. According to the latest CDC flu report, 25 states or jurisdictions now experience high or very high levels of outpatient visits for influenza-like illness, which is characterized by fever plus cough or sore throat.
Infectious disease expert William Schaffner, a professor at the Vanderbilt University School of Medicine, says the rise came four to six weeks earlier than usual. Each flu season is different, but the season’s early arrival was still unexpected. “It was a very big surprise, even to the experienced influenza watchers, that influenza appeared, rose dramatically and became very widespread so early in the season,” he says.
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