Michigan health officials are urging residents of 11 counties to stay inside from dusk to dawn to avoid getting bitten by mosquitoes carrying a deadly virus that last year killed six people in the state.

The state Department of Health and Human Services announced Tuesday that a resident in Barry County in southwest Michigan was the state's first suspected human case of eastern equine encephalitis, called EEE.

That suspected case in a person comes after the virus has been found in 28 horses in 11 counties — twice as many animal cases as at the same time last year.

"EEE is one of the most dangerous mosquito-borne diseases in the United States," a state advisory said, noting that people can be infected from one bite of a mosquito carrying the virus and that people younger than 15 and over 50 are at greatest risk of severe disease following infection.

has had only five confirmed human cases of EEE this year, three in Massachusetts and two in Wisconsin, according to the Centers for Disease Control and Prevention.