Three horses in the Pyrénées-Orientales tested positive for West Nile virus in August 2026, following a human case detected in July. The virus, transmitted by Culex mosquitoes, has prompted public health warnings about prevention measures and vaccination for equine populations.
The West Nile virus (WNV) has emerged as a public health concern in the Pyrénées-Orientales, with three horses confirmed infected in Perpignan, Saint-Estève, and Elne. This follows a human case reported in mid-July 2026, marking the first human infection of the 2026 season in the region. The virus, primarily transmitted by Culex mosquitoes, circulates between wild birds and mosquitoes, with horses and humans serving as hôtes accidentels
— accidental hosts who cannot spread the virus further, according to local authorities.
Transmission and Symptoms
WNV is transmitted through the bite of infected Culex mosquitoes, which become infected by feeding on wild birds carrying the virus. Horses and humans are hôtes accidentels,
meaning they do not contribute to the virus’s spread. In humans, the infection is often asymptomatic, but can cause fever, headaches, muscle pain, or a rash. Less than 1% of cases lead to severe neurological complications, necessitating immediate medical attention, as emphasized by the local prefecture.
Among horses, the virus poses a greater risk. In 2024, two equines in the Camargue died after contracting WNV, highlighting the severity for animals. Symptoms in horses include fever, muscle pain, and neurological signs like coordination issues or blindness. The prefecture stresses that
The prefecture stressed that any sudden onset of these symptoms must lead to immediate medical consultation.
urging horse owners to act swiftly if their animals show signs of infection.
Prevention Measures
Authorities have issued specific guidelines to curb WNV transmission. For the general public, wearing long, light-colored clothing, using repellents, and eliminating stagnant water around homes are critical. The prefecture and Regional Health Agency (ARS) also recommend mosquito nets for vulnerable groups, including newborns, pregnant women, and immunocompromised individuals.
Horse owners face additional precautions. The prefecture advises keeping equines indoors at night, removing standing water, and using mosquito traps. Vaccination is highlighted as
authorities stated that the most effective means of prevention.
with officials urging owners to consult veterinarians for tailored strategies.
officials emphasized that vaccination remains the most effective means of prevention.
a statement repeated across multiple sources, underscores the emphasis on immunization.
Expert Warnings and Vaccination
Despite the lack of a human vaccine, public health officials stress that the virus is not airborne or transmissible between humans or horses. However, the seasonal nature of WNV means vigilance is needed from May to October. The prefecture also called for reporting
The prefecture called for reporting any suspected mortality of wild birds.
to the Office Français de la Biodiversité (OFB) between July and November, highlighting the interconnectedness of wildlife, livestock, and human health.
Regional Context and Surveillance
The 2026 outbreak aligns with a broader pattern of WNV activity in southern France. The virus, which appears each year in Occitanie, has seen increased circulation in recent years.
The Pyrénées-Orientales outbreak highlights the importance of early detection and prevention. With three equine cases confirmed and a human case reported, local authorities are urging both residents and livestock owners to remain vigilant. As Dr. Paindaveine noted,
Dr. Paindaveine noted that horses often play the role of sentinels.
serving as early indicators of viral activity. Their protection, alongside public health measures, remains critical to preventing further spread.
