A human case of West Nile virus has been reported in the Bear River Health District, but it is unclear if this is the first case nationwide in 2026 as other areas, including Mississippi, Nebraska, and California, are also reporting their first cases of the year. West Nile virus activity appears to be present in multiple states, with mosquito samples in Placer County, California, testing positive for the virus. The geographic extent of West Nile virus cases and their timing in 2026 is not entirely clear, with different regions reporting their own initial cases.