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19 clusters · 59 sources · 55 days · First seen about 2 months ago · Last updated about 4 hours ago

West Nile virus spreads in Europe and North America

Overview

In the United States, West Nile virus (WNV) continues to impact equine populations and is increasingly detected in mosquito populations. In Florida, an under-vaccinated 16-year-old Quarter Horse in Indian River County was euthanized after testing positive for both WNV and Eastern equine encephalitis (EEE), exhibiting neurological symptoms such as ataxia and extreme somnolence. In Colorado, a vaccinated yearling Paint filly in Weld County was also euthanized following neurological signs. Recent reports from the Colorado State Veterinarian’s Office confirm two additional cases: a 2-year-old Quarter Horse mare in Pueblo County exhibiting anorexia, abnormal mentation, and ataxia, and an unvaccinated 4-year-old Quarter Horse gelding in Montrose County showing muscle twitching, teeth grinding, weakness, and ataxia. Both horses remain alive. New equine cases have emerged in Washington, Kentucky, and Wyoming. In Franklin County, Washington, a 2-year-old filly is recovering under veterinary care. In Washington County, Kentucky, an unvaccinated 3-year-old Tennessee Walking Horse mare was euthanized, marking the first confirmed equine WNV case in Kentucky for 2026. In Fremont County, Wyoming, the State Animal Health Official confirmed a WNV case in a horse. Additional mosquito detections have emerged in Illinois and Idaho. In Perry County, Illinois, the first positive mosquito sample of the season was confirmed near the Tamaroa Sewage Treatment Plant. In Bannock County, Idaho, a mosquito pool in the Swan Lake area tested positive; local officials have increased larvicide and adulticide efforts, noting that dry, hot weather has created stagnant water conditions. In Europe, France has recorded a record number of autochthonous West Nile virus cases. Between early May and September 21, 2026, 117 infections were identified in mainland France.

Entities

Equine Disease Communication Center · France · Wyoming · Santé publique France · Utah

Timeline

about 4 hours ago

[HEALTH] 2 sources
Wyoming official confirms West Nile virus in Fremont County horse
West Nile virus has been confirmed in a horse in Fremont County, Wyoming. The virus is mosquito-borne and can result in mortality rates of 30-40% in horses.
5 days ago

[HEALTH] 3 sources
West Nile virus cases reach record high in France
France has reached a record 117 autochthonous West Nile virus cases since May 2026, spreading across 21 departments and seven regions via Culex mosquitoes.
7 days ago

[HEALTH] 2 sources
West Nile virus detected in horses in Washington and Kentucky
Two new equine West Nile virus cases have been reported in Washington and Kentucky, involving a recovering filly and a Tennessee Walking Horse mare that was euthanized.
18 days ago

[HEALTH] 2 sources
Colorado reports two equine West Nile virus cases
Two horses in Colorado's Pueblo and Montrose counties have tested positive for West Nile virus. Both animals are alive following symptoms such as ataxia and muscle twitching.
20 days ago

[HEALTH] 5 sources
Ministry of Health reports three West Nile virus cases
The Ministry of Health reported three West Nile virus cases and issued warnings on symptoms and prevention, emphasizing mosquito bite avoidance as there is no vaccine.
22 days ago

[HEALTH] 3 sources
West Nile virus cases rise in France
France has recorded 39 autochthonous West Nile virus cases across four regions. Health authorities recommend eliminating standing water and using mosquito nets to reduce transmission via Culex mosquitoes.
26 days ago

[HEALTH] 7 sources
West Nile virus detected in mosquito samples in Illinois and Idaho
West Nile virus has been detected in mosquito samples in Perry County, Illinois, and Bannock County, Idaho, prompting increased monitoring and prevention efforts by local health officials.
27 days ago

[HEALTH] 3 sources
Equine West Nile and EEE cases reported in Florida, Colorado, and Utah
New cases of West Nile virus and Eastern equine encephalitis have been reported in Florida, Colorado, and Utah, affecting multiple horses.
about 1 month ago

[HEALTH] 11 sources
West Nile virus cases reported across multiple U.S. states
West Nile virus cases are being reported in humans and animals across several U.S. states, including Illinois, Massachusetts, Utah, and Minnesota, prompting public health warnings.
about 1 month ago

[HEALTH] 3 sources
West Nile virus detected in horses in Wyoming and Utah
Three new equine West Nile virus cases have been reported in Wyoming and Utah, resulting in the euthanasia of two unvaccinated horses in Utah.
about 1 month ago

[HEALTH] 3 sources
West Nile virus cases rise among horses in France
France reports 93 confirmed equine West Nile virus cases, surpassing previous years. The mosquito-borne virus can cause severe neurological symptoms and potential paralysis in horses.
about 1 month ago

[HEALTH] 2 sources
West Nile virus detected in horses in Gran Canaria
The West Nile virus has been detected for the first time in the Canary Islands after three horses in Gran Canaria tested positive. No human cases have been reported.
about 1 month ago

[HEALTH] 3 sources
West Nile virus confirmed in horses across three US states
Unvaccinated horses have tested positive for West Nile virus in Idaho, Indiana, and Louisiana, with symptoms including ataxia and muscle twitching.
about 1 month ago

[HEALTH] 4 sources
West Nile virus confirmed in unvaccinated horses in Washington and Oregon
Unvaccinated horses in Washington and Oregon have tested positive for West Nile virus, a mosquito-borne illness with mortality rates reaching 30-40% in equines.
about 1 month ago

[HEALTH] 8 sources
West Nile virus detected in Dutch blood donor
A blood donor in the Netherlands has tested positive for West Nile virus, prompting Sanquin to expand blood screening in Utrecht and the Gooi and Vechtstreek regions.
about 2 months ago

[HEALTH] 5 sources
West Nile virus detected in mosquito samples in Boston and Montana
West Nile virus has been detected in mosquito samples in Boston's Jamaica Plain and Roosevelt County, Montana, prompting health officials to issue bite prevention warnings.
about 2 months ago

[HEALTH] 2 sources
West Nile virus confirmed in Belgian horse
Belgium has confirmed its first case of West Nile virus in a horse in Vilvoorde. Authorities advise mosquito prevention as the virus is transmitted via bites and can cause neurological issues.
about 2 months ago

[HEALTH] 5 sources
West Nile Virus Detected in Utah Horses and Delaware Chickens
West Nile virus was found in two Utah horses and in a Delaware sentinel chicken flock, prompting health alerts and urging horse vaccination and mosquito control across the US.
about 2 months ago

[HEALTH] 4 sources
West Nile Virus Spreads Among German Horses Amid Rising Insect Activity
Germany's wet winter fuels mosquito and tick growth, driving West Nile virus spread in horses; severe cases affect 8% with up to 50% mortality, prompting more owners to vaccinate.

Sources

augsburger-allgemeine.de · bakercityherald.com · be.com · bellaradio.it · bjelke.no · columbuscountynews.com · conflittodinteresse.it · desotocountynews.com · durhampost.ca · election-presidentielle.linternaute.com · elkhornmediagroup.com · equimanagement.com · equusmagazine.com · fairfieldsuntimes.com · finans.gazetevatan.com · fox2detroit.com · gazeta.eu · giynikgazetesi.com · gloucestercitynews.net · goudsdagblad.nl · halkinsesikibris.com · healthywildlife.ca · horseandrider.com · horses.nl · hudsonvalleycountry.com · kbsi23.com · kekbfm.com · kibrisgercek.com · kibrismanset.com · lejournaldugers.fr · localnews8.com · malattiaioftalmica.it · mccookgazette.com · medonet.pl · modesettravaux.fr · moncloa.com · my-angers.info · nationalezorggids.nl · newsday.com · newstalk1079.com · noticaballos.com · NRC.nl · oesterreich.orf.at · phillyvoice.com · rmf24.pl · royalexaminer.com · rtvfocuszwolle.nl · skipr.nl

This summary has been updated 22 times: see revision history