Seven children have died from influenza as more cases of flu and flu-like illnesses are being reported, leading researchers at the Centers for Disease and Control and Prevention to declare that the 2018-2019 influenza season has started.

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Sustained elevated cases of influenza that have been reported in the past few weeks in spots across the country have led the CDC to not only declare the start of flu season but to remind people it's not too late to get an influenza vaccination.

>> 11 things parents need to know about the flu, the vaccine, how long kids need to stay out of school

The flu type seen most often so far this year is the H1N1 subtype of the influenza A strain of the illness.

Seven pediatric deaths have been reported to CDC so far this season, according to the agency. The latest pediatric influenza-related death, reported last week, was associated with an influenza A infection. The other pediatric deaths have been associated with a mix of H1N1, H3N2 and influenza B virus infections.

Influenza A is one of four types of influenza viruses and is the most common flu type. H1N1 is a subtype of influenza A. 

This time of year is typically when the CDC begins to see an increase in flu activity.

Georgia, Alabama, California, Delaware, Massachusetts and New York have reported widespread flu activity, with another 37 states reporting either local or regional outbreaks of flu, the CDC reported.

Georgia and Colorado have reported the largest numbers of flu activity. States with “moderate” activity include Alabama, Arizona, Arkansas, Kentucky, Louisiana, Missouri, New Jersey, South Carolina, Virginia and New York City.

According to the CDC, most of this season’s flu activity has been driven by illness in school-aged children. Hospitalization rates among children younger than 5 years old are now the highest among all age groups, the agency reported.

The CDC tracks information about the spread of the flu using data sent from state health departments to create and maintain an influenza surveillance map. The map shows the number of flu cases reported to each state's health department and where the flu is hitting the hardest.

Below are the links to each state's health department, where localized information about influenza can be found. Click on the website and look for a listing called "Surveillance Reports," or "Surveillance Maps," then look for the week's report to give you the latest information.

Click here for more information on the H3 strain of the flu, and here for information for parents about children and the flu.

SAN FRANCISCO, CA - JANUARY 22:  A sign advertising flu shots is displayed at a Walgreens phramacy on January 22, 2018 in San Francisco, California. A strong strain of H3N2 influenza has claimed the lives of 74 Californians under the age of 65 since the flu season began in October of last year. People are being encouraged to get flu shots even through the vaccine has been only 30% effective in combating the influenza.  (Photo by Justin Sullivan/Getty Images)

Credit: Justin Sullivan

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Credit: Justin Sullivan