OMAHA, Neb. (AP) – Omaha-area health officials have confirmed Douglas County, Nebraska’s first human case this year of West Nile virus. The Douglas County Health Department says the infected person is a woman under 40. Officials say she was not hospitalized and is recovering. State health officials say it’s the ninth human case confirmed in Nebraska so far this year.

Experts say most people who are infected have no symptoms or experience only mild, flu-like symptoms. The most vulnerable people are those who are at least 50 or have weakened immune systems. The virus is transmitted to humans through mosquitoes, which acquire the virus by feeding on infected birds.

Nebraska reported 95 human cases of West Nile virus last year, including one death.