State health officials say the first human case of West Nile Virus for this year has been reported in Yellowstone County.
RiverStone Health and the Department of Public Health and Human Services say the woman in her 50s was diagnosed last week in Billings. She did not require hospitalization and was expected to fully recover.
Mosquitoes started testing positive for WNV in Montana in mid-July and the first horse cases were reported in late August.
Most people exposed to the virus experience no symptoms. Some develop a mild illness, while fewer than 1 in 150 may become severely infected with encephalitis or meningitis.
In the United States this year, nearly 500 human cases of West Nile Virus have been reported to the Centers for Disease Control and Prevention. Twenty of those people have died.