SCOTTSBLUFF, Neb. (AP) — Officials have confirmed the first human case of West Nile virus this year in western Nebraska’s Scotts Bluff County.

The case was reported earlier this month.

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 68 human cases of West Nile virus and two deaths last year. In 2014, eight deaths were blamed on West Nile virus.