The New York Times: It is not your imagination — more people you know are sick this winter, even people who have had flu shots. The country is in the grip of three emerging flu or flulike epidemics: an early start to the annual flu season with an unusually aggressive virus, a surge in a new type of norovirus, and the worst whooping cough outbreak in 60 years.

And these are all developing amid the normal winter highs for the many viruses that cause symptoms on the “colds and flu” spectrum.

Influenza is widespread, and causing local crises. On Wednesday, Boston’s mayor declared a public health emergency as cases flooded hospital emergency rooms.

Google’s national flu trend maps, which track flu-related searches, are almost solid red (for “intense activity”) and the Centers for Disease Control and Prevention’s weekly FluView maps, which track confirmed cases, are nearly solid brown (for “widespread activity”).

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