DOVER, Del. (AP) — Delaware public health officials are reporting the first case of West Nile virus infecting a human since 2015.

Officials said Thursday that a 70-year-old Kent County woman was briefly hospitalized but is now recovering at home.

West Nile Virus is transmitted by mosquitoes, with a peak transmission period from mid-August to mid-October. The vast majority of people infected with the virus will not become ill, and others might experience only minor symptoms, but the virus can lead to West Nile encephalitis or meningitis, which are severe, life-threatening infections.

Officials say the virus is still showing up in sentinel chickens monitored for mosquito-borne diseases, and that mosquitoes remain very active, especially given the unseasonably warm weather.

Symptoms of severe infection include headache, high fever, stiff neck, and/or tremors and muscle weakness