The Oklahoma State Department of Health on Thursday reported a seventh flu death during this year's flu season.

An Oklahoma County resident was in the 65-or-older age group and died during the past week as a result of the flu, according to the department's website.

About two dozen people had died of the flu during the same time period in 2011.

The department said there were 38 new cases of the flu during the week to bring the total number of confirmed cases to 283. That's down from 846 confirmed cases at the same time last year.

State epidemiologist Dr. Kristy Bradley has said the decline is likely due to a combination of factors including the mild winter and the late onset of the flu season.

"Another likely factor is that more of the population has previously encountered the flu viruses that are circulating this season, notably the 2009 H1N1 virus, and are now immune," Bradley said.

Confirmed cases were reported in 50 of the state's 77 counties. The largest numbers were reported in the state's most populous counties, with 74 cases in Oklahoma County and 63 in Tulsa County.

Cleveland County, with 18 cases, and Comanche County, with 10, were the only other counties with 10 or more confirmed cases.

The federal Centers for Disease Control has classified influenza as "widespread" in Oklahoma, a designation Bradley said is due to the confirmed cases covering a large area.

Copyright The Associated Press