West Nile death in Idaho prompts health alert

West Nile virus can cause fever and serious brain and spinal infections.

Idaho confirms first West Nile virus related death in 2025

Twin Falls County, Idaho, records the state's first West Nile virus related death in 2025. The decedent was over 65, and officials say the death was due to West Nile virus encephalopathy. The virus has been detected in mosquitoes across seven southern Idaho counties and in Malheur County, Oregon, though not every county tests mosquitoes.

Public health officials urge people to protect themselves from mosquito bites. Prevention measures include wearing loose clothing, using EPA registered repellents, treating clothing with permethrin, netting for strollers, repairing screens, and removing standing water around homes. The EPA offers tools to find suitable repellents, and the CDC provides guidance resources. Most people infected show no symptoms; a smaller share develop fever with additional symptoms, and severe illness affecting the brain or spinal cord occurs in about 1 in 150 infections. About 10% of those with severe disease die. Older adults and people with certain medical conditions are at higher risk, and recovery can take weeks or months.

This death highlights the ongoing risk of mosquito borne disease as warm weather lingers. It also reveals how testing and surveillance can vary by county, since not all areas test local mosquitoes. The message to protect against bites is practical, but it requires consistent effort from residents and local leaders alike.

Looking ahead, the situation may hinge on weather patterns and local mosquito control efforts. Public health guidance from the EPA and CDC helps families plan protections, but the real work happens in everyday choices—from draining standing water to checking home screens and applying repellent in the evenings. A calm, steady public health response can keep communities safer without causing alarm.

Highlights

Vigilance remains essential as mosquito season continues.