(NEXSTAR) – Respiratory illness around the country spiked last week, just as families and friends gathered to celebrate the holidays. Tracking by the Centers for Disease Control and Prevention shows a 16% jump in people testing positive for influenza last week, plus a substantial rise in reports of other respiratory illnesses like COVID-19 and RSV.
New data released Friday shows 13 states, plus New York City, have “very high” levels of respiratory illness. Another 18 states and Washington, D.C. are classified as “high.”
The map below shows the severity of respiratory illness in every state as of Dec. 23. The darker the shade of red, the higher the spread of sickness is.
Seven states are shaded in purple to indicate they are in the highest tier tracked by the CDC, level 13: Alabama, Georgia, Louisiana, Mississippi, New Mexico, South Carolina and Tennessee. Just three weeks ago, no states or jurisdictions were in that category. (See more from the CDC’s interactive map here.)
Two states, Alaska and North Dakota, did not report sufficient data to the CDC last week.
The CDC determines each state’s level of flu activity by comparing the current data from health care providers to what’s normal for that area outside of flu season.
The data is based on the number of people reporting to a health care facility with flu symptoms – fever, plus a cough or sore throat. It is not based on lab-confirmed influenza cases.
That means it could be including cases that turn out to be other respiratory illnesses, like COVID or RSV, but it also could be underreporting cases where people are staying home and fighting the sickness on their own.
The three major viral illnesses listed above – COVID, RSV and influenza – have lots of overlapping symptoms, which can make it hard to know what you have without a test. (We compare the symptoms here to help you narrow it down.)
The flu, which is especially dangerous for the elderly, immunocompromised people and young children, has killed an estimated 4,500 so far this season. Twenty of those deaths were children.
The Associated Press contributed to this report.