AUGUSTA, Maine (AP)   Health officials say Maine has experienced its worst flu season in at least five years.

The Portland Press Herald reports the Maine Center for Disease Control and Prevention tallied 9,018 reported cases in 2017-18. Officials say the number of reported cases increased 55 percent compared to 2016-17. Flu season runs from October to late May.

State epidemiologist Dr. Siiri Bennett attributed part of the increase to better reporting by doctors and health agencies. Bennet says the season was “vigorous” despite improved communication.

Health officials say activity in Maine reflected a nationwide trend. The CDC reported 223,487 positive tests for the flu this past season.

The National Institutes of Health said in April that scientists are developing a new flu vaccine that will offer “broad protection” against multiple virus strains.