Health officials in New Mexico have confirmed the state’s first human case of West Nile virus for 2025, involving a Valencia County resident who required hospitalization but has since been discharged.
The New Mexico Department of Health announced the case Thursday, marking the beginning of what has historically been an active season for the mosquito-borne illness in the state. Over the past five years, New Mexico has averaged 32 West Nile virus cases annually.
In addition to the human case, the virus has been detected in three horses across southeastern New Mexico this year – two in Lea County and one in Eddy County. The animal cases often serve as an early warning system for human infections, as horses and humans are considered “dead-end” hosts that don’t spread the virus but indicate its presence in local mosquito populations.
With peak mosquito season underway, health officials are urging residents to take protective measures to reduce their risk of infection. The department recommends using EPA-approved insect repellents containing DEET, picaridin, IR3535, or oil of lemon eucalyptus when spending time outdoors.
Residents should also wear long sleeves and pants during dawn and dusk hours when mosquitoes are most active, and eliminate standing water around their properties where mosquitoes breed. This includes regularly draining water from birdbaths, plant saucers and other containers, and ensuring rain barrels have tight-fitting screens.
“Check for water-holding containers where mosquitoes lay their eggs, such as old tires, empty cans, and other unneeded outdoor items that can hold water,” the health department advised.
West Nile virus typically causes mild symptoms in most people, including headache, fever, muscle and joint aches, nausea, and fatigue. However, less than 1% of infected individuals develop severe neurological complications that can include neck stiffness, disorientation, coma, tremors, convulsions, muscle weakness and paralysis.
People over 50 and those with underlying health conditions face the highest risk of serious illness or death from the virus. Currently, no medications exist to treat West Nile fever, and no vaccines are available to prevent human infections.
The virus is transmitted through the bite of infected mosquitoes that have previously fed on infected birds. Humans and horses cannot spread the virus to others through casual contact.
For more information about mosquito bite prevention, residents can visit the Centers for Disease Control and Prevention website.
