The Chelan-Douglas Health District (CDHD) confirmed a case of Sin Nombre virus (SNV) Hantavirus in a Chelan County resident, according to a press release dated February 2026.
Health officials stated the exposure most likely occurred in or around the resident's home where mice were encountered. The case is unrelated to recent Andes Virus Hantavirus cases tied to the MV Hondius cruise ship.
CDHD Public Health Officer Dr. James Wallace noted that Sin Nombre virus Hantavirus cases typically range from one to five per year in Washington residents. He emphasized that HPS is rare but serious, with about one in three diagnosed cases resulting in death. The health district urged residents to take precautions when cleaning areas where rodents may be present.