West Nile Virus 2026: Early Season Detected in Texas, Louisiana & California | Virus Watcher
10 Active OutbreaksWest Nile Virus is showing early 2026 season activity across multiple states before the typical transmission season begins. Positive mosquito pools have been confirmed in Texas (San Antonio, Frisco), Louisiana (New Orleans), and six California counties. Human cases have already been confirmed in Colorado. Peak transmission season runs July through September β and an above-average season is projected for 2026. Most infections are mild or asymptomatic, but about 1 in 150 infected people develop severe, potentially fatal brain inflammation.
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What is West Nile Virus?
West Nile Virus arrived in the U.S. in 1999 and has since become the leading mosquito-borne disease in the country. It's transmitted by Culex mosquitoes that bite infected birds. While 80% of infected people have no symptoms, severe cases can cause encephalitis or meningitis with long-term neurological effects. Age over 60 significantly increases risk of severe disease.
Symptoms
- Mild (West Nile fever): Fever, headache, body aches, joint pain, vomiting, diarrhea, rash
- Severe: High fever, severe headache, stiff neck, disorientation, tremors, seizures
- Neurological: Muscle weakness, vision loss, paralysis, coma
- Long-term effects: Fatigue, memory problems, muscle weakness (can persist months/years)
Transmission
Transmitted through bites of infected Culex mosquitoes. Rarely through blood transfusion, organ transplant, mother to fetus, or breastfeeding. NOT spread person-to-person through casual contact.
Contagious Period: Not contagious person-to-person; can be in blood of infected person during illness
Prevention
- Use EPA-registered insect repellents (DEET, picaridin, IR3535, oil of lemon eucalyptus)
- Wear long sleeves and pants at dawn/dusk when mosquitoes most active
- Install/repair window and door screens
- Use air conditioning when possible
- Eliminate standing water (buckets, flower pots, bird baths, gutters)
- Change water in pet bowls, birdbaths weekly
- Treat or drain swimming pools, fountains
- Community mosquito control programs (spraying, larvicides)
- Avoid outdoor activities at dawn/dusk during peak season
Live West Nile Virus Global Case Map
3 countries with reported activity. Updated from real-time surveillance data.
United States β State Detail
1 state with reported activity. Click a state for detailed surveillance.
Active Outbreaks & Recent Cases
Real-time intelligence from global health monitoring and AI-powered surveillance
Data sources: BEACON, ProMED, WHO, CDC, and 50+ national health agencies
β Live data updated in real-time from global health sources
West Nile virus found in mosquitoes trapped at 2 Roswell parks, treatments underway
Dan Raby, the senior digital producer for CBS News Atlanta, has been covering everything happening around Georgia for more than a decade.
Treatments are underway in Roswell after more mosquitoes trapped in Fulton County have tested positive for West Nile virus.
On Monday, the city of Roswell announced that mosquito traps at Roswell Area Park and Garrard Landing Park tested positive for the virus.
In response to the positive tests, the county's mosquito control contractor treated the area withi
π° 143 news sources reporting on this story.
Map shows mosquito-borne West Nile virus spreading across US, killing eight
Cases of West Nile virus have been reported in 32 states this year as the mosquito-borne disease continues to infect people during the peak summer months, according to recent data from the U.S. Centers for Disease Control and Prevention (CDC).
As of August 18, the CDC's ArboNET surveillance system had recorded 222 human West Nile virus disease cases nationwide, including 156 neuroinvasive cases, the most severe form of the illness that can affect the brain and nervous system. The CDC's county-le
π° 20 news sources reporting on this story.
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West Nile virus spreads in Europe? Greece reports surge, Italy leads
Greece and Italy are reporting the highest West Nile virus activity in Europe this season.
The spread of West Nile virus -- a mosquito-borne disease transmitted primarily by infected mosquitoes -- in Greece is showing an upward trend, according to the National Public Health Organisation.
During the past week, 23 new cases of West Nile virus infection have been reported. In total, from the start of the transmission season in spring up to 5 August, 65 cases have been recorded, 54 of which present
π° 12 news sources reporting on this story.
West Nile virus deaths climb as US enters peak period for deadly infections
Americans are being urged to protect themselves from mosquito bites as deaths from the West Nile virus climb nationwide.
Public health authorities in Los Angeles County reported the area's first fatality linked to West Nile virus of the year this week, alongside a broader spike in infections statewide.
The victim lived in the San Fernando Valley and was hospitalized for a neurological condition resulting from a severe case of West Nile virus, the health department said. Details about the patien
π° 34 news sources reporting on this story.
First 2026 case of dangerous West Nile Virus detected in NYC: officials
A New Yorker has contracted the dangerous West Nile virus -- the first reported human case in the city this year, health officials revealed Wednesday.
The unidentified city dweller fell ill with the mosquito-borne disease after spending time outdoors around the city, and in several locations outside the Big Apple, health department officials said.
The diagnosis comes as 222 human cases of West Nile virus nationally have been reported by the US Centers for Disease Control and Prevention, largely
π° 23 news sources reporting on this story.
West Nile virus surge in Greece with Attica at the epicentre
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The epidemiological picture of the West Nile virus in Greece has deteriorated significantly over the summer of 2026, with the National Public Health Organization of Greece (EODY) recording dozens of new cases in just one week and highlighting the particularly intense circulation of the virus in Attica.
According to EODY's weekly epidemiological surveillance report, with data up to 12 August 2026, a total of 110 domestically a
π° 43 news sources reporting on this story.
3 deaths linked to West Nile disease in California as cases rise
Cases of the mosquito-borne West Nile disease are rising quickly in California this year, with 30 people sickened so far, nearly triple the five-year average for the same time period, according to the California Department of Public Health.
So far, three people have died from the disease, with all fatalities reported this month.
West Nile disease is a virus spread by mosquitoes. While the disease mainly circulates among infected birds, mosquitoes can spread the disease to humans after biting an
π° 16 news sources reporting on this story.
Virus warning in Spain issued after one person dies
Holidaymakers heading to Spain have been warned to take precautions after the country's first death this year from a virus - with experts fearing the disease could spread to more hotspots.
An 82-year-old man from Dos Hermanas, near Seville, has become Spain's first confirmed fatality from West Nile virus this year after being admitted to hospital with meningoencephalitis caused by the mosquito-borne infection. Spanish health authorities have confirmed at least 19 human cases this season, the vas
π° 48 news sources reporting on this story.
West Nile virus confirmed in Wayne County resident, health officials say
Joe Buczek is manager of digital content and promotion at CBS Detroit. He previously worked at WWTV, the Grand Traverse Insider, the Leader and the Kalkaskian, the Oakland Press and the Morning Sun.
Wayne County health officials on Wednesday reported the county's first human case of West Nile virus in 2026.
Health officials have not released further information on the specific case, but say the individual resides outside of Detroit.
"This is an important reminder that mosquito season is not ov
π° 131 news sources reporting on this story.
Cases of West Nile virus are climbing -- these products can help keep you protected
West Nile virus is most commonly spread through mosquitoes and symptoms can range from non-existent to severe.Getty
Summer isn't over yet -- and neither is mosquito season, which means you still have a very real chance of catching West Nile virus. In fact, every year, cases of this virus typically peak in late August to early September, according to the Centers for Disease Control and Prevention (CDC). And the rise in cases has already started -- in recent weeks, cases have been reported in 24 s
π° 37 news sources reporting on this story.
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Expert Resources & References
Trusted information from leading health organizations
CDC
Official guidance from the U.S. Centers for Disease Control and Prevention
View CDC Resources βWHO
Global disease surveillance and guidelines from the World Health Organization
View WHO Resources βMedically Reviewed Content
Disease information on Virus Watcher is reviewed by our Chief Epidemiologist, a former CDC lead analyst for FluSight forecasting. Outbreak data is aggregated from verified sources including BEACON, ProMED, WHO, CDC, and 50+ national health agencies. This information is for educational purposes and should not replace professional medical advice.
Last reviewed: 2026-09-04
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