Record number of West Nile virus cases since 2004, CDC warns ahead of holiday weekend
A Culex mosquito, primary vectors for several viral and parasitic diseases inside a house in Tehatta, West Bengal, India, March 3, 2026. (Soumyabrata Roy/NurPhoto via Getty Images)
(NEW YORK) — A record number of West Nile virus cases have been recorded for this time of year, the Centers for Disease Control and Prevention (CDC) warned on Wednesday ahead of the upcoming holiday weekend.
At least 48 cases of West Nile have been reported so far this year compared to an average of 10 typically by the end of June. This is the highest number of infections reported at this point in year since 2004, according to the federal health agency.
Additionally, at least 23 states are reporting West Nile activity, which is the highest number recorded over the last 10 years, CDC data shows.
The illness is the leading cause of mosquito-borne disease in the contagious U.S., with several thousand cases and over 100 deaths reported on average each year.
With millions gathering outside for Fourth of July, the CDC is urging Americans to take precautions and reduce their risk of mosquito bites.
Since 1999, the disease has killed more than 3,300 Americans. Cases have historically peaked in August and are mostly reported from June through October.
While many people infected do not develop symptoms, about one in five do. Symptoms include fever, headache, body aches, vomiting, diarrhea or rash, according to the CDC. Most symptoms soon disappear, though weakness and fatigue may last for weeks or months.
Fewer than 1% of people infected develop severe illness that affects the central nervous system, including inflammation of the brain (encephalitis) and the membranes around the brain and spinal cord (meningitis), the CDC says.
Risk of severe disease, hospitalization and death increase with older age; certain medical conditions including cancer, high blood pressure and kidney disease; and a weakened immune system.
There are currently no vaccines for West Nile virus, nor disease-specific treatments. The CDC recommends rest, fluids and over-the-counter medications to treat the infection. Those with severe illness may need to be hospitalized and receive additional support treatments, such as intravenous fluids.
Cyclospora cayetanensis is a unicellular parasite that causes an intestinal infection called cyclosporiasis. (CDC)
(WASHINGTON) — Federal health officials have been investigating five different clusters of cyclosporiasis cases since the start of parasite season in May, the Food and Drug Administration (FDA) said during a press conference on Monday.
Three of those clusters are considered over, acting FDA Commissioner Kyle Diamantas said. Meanwhile, the largest cluster, linked to shredded iceberg lettuce served at Taco Bell locations in five states, has seen cases as recently as last week.
The majority of cases have been reported in Michigan, where there are now 6,148 cases, according to an update Monday morning from the Michigan Department of Health and Human Services (MDHHS). This is an increase of more than 1,000 cases since Friday.
“I want to stress that our investigation continues, including into other potential sources and commodities for other clusters of illnesses,” Diamantas said during Monday’s press conference.
So far, the CDC has confirmed 1,644 infections linked to the outbreak in Indiana, Kentucky, Michigan, Ohio and West Virginia, and has advised the public not to eat shredded iceberg lettuce served at Taco Bell locations in those five states.
The agency said the true number of cases in the outbreak is “likely much higher than the number reported” because many people recover from the illness without medical care and are not tested for the Cyclospora parasite.
Diamantas also addressed a false positive test result over the weekend from a sample of iceberg lettuce from Taylor Farms de Mexico.
Last week, Taylor Farms de Mexico issued a voluntary recall of all iceberg lettuce sourced from central Mexico, with the recall affecting 27 states. The recalled products were distributed from June 29 through July 16 and have a best-by dates up to Aug. 3.
Over the weekend, the FDA said a sample of shredded iceberg lettuce supplied by Taylor Farms, which was not part of the recall, tested positive.
However, the agency later clarified that during a re-review of the sample results, it determined the result was a false positive. Taylor Farms issued a statement on Sunday, saying “we were informed that FDA made a mistake.”
“To be clear, at this moment, FDA has not identified a single positive product test result for Cyclospora,” Taylor Farms wrote in its statement Sunday.
“Based on initial information provided by health officials, in an abundance of caution, we completed a voluntary recall of iceberg lettuce from central Mexico. Recalled product was limited to iceberg lettuce grown and processed in central Mexico,” the Taylor Farms statement continued. “All other Taylor Farms products, including all Taylor Farms brand products available for purchase, are not involved in the recall.”
Diamantas said Monday that the false positive did not change the FDA’s findings that linked cases to shredded lettuce from Taylor Farms.
“I also want to be clear that our weakened communications around a false positive test result do not change the basis for FDA’s ongoing outbreak investigation or the epidemiological data supporting the current voluntary recall by Taylor Farms,” Diamantas said.
The FDA similarly shared a post on X Monday afternoon, saying that the epidemiological data supporting the Taylor Farms lettuce recall was “overwhelming.”
“FDA’s traceback investigation and outbreak data continue to converge on shredded iceberg lettuce from Taylor Farms locations in central Mexico,” the FDA’s post read, in part. “FDA will continue to work with federal and state partners to investigate this multistate outbreak and ensure products implicated in this outbreak have been removed from the market.”
The CDC said it’s also investigating other cyclosporiasis outbreaks and illnesses unrelated to the larger outbreak. At least 29 other states have confirmed domestically acquired cases since May 1, the CDC reports.
Additionally, 440 cases in 35 states have been confirmed among people who ate or drank food or water that made them sick while traveling outside the U.S. in the days before they came ill, according to the CDC.
(NEW YORK) — Kenya’s Health Cabinet Secretary Aden Duale has halted construction of the U.S.-backed Ebola quarantine facility at Laikipia Air Base after being found in contempt of court for allowing work to continue despite a court order.
Duale appeared before the High Court in Nairobi on Tuesday and said he directed “the immediate and complete cessation of any intended construction, site preparations or related activities” concerning the facilitly.
“It was never the intention of the ministry or myself as the Cabinet Secretary to disregard, undermine, or act in defiance of the orders,” he said.
Duale also told the court he would be “the last person to disregard a court order” and “the last person to violate any constitutional order given by any court.”
The court accepted Duale’s apology and discharged him with a warning, saying that he would face sentencing if there was any indication he disobeyed its orders again. The injunction stopping construction was extended until a hearing on July 23.
“Today was an important moment for justice in Kenya,” Nora Mbagathi, executive director of Kenya’s Katiba Institute, an organization formed to support the country’s constitution that challenged the U.S. plan, told ABC News in a WhatsApp message.
“By appearing in court and confirming that construction of the quarantine facility has been halted, Duale has affirmed the government’s recognition that they are not above the Constitution,” the message continued. “His apology to the Court and the people of Kenya is an important moment not just for our courts but for our democracy and rule of law.”
This is a developing story. Please check back for updates.
Female Aedes mosquitoes, including the Asian tiger mosquito (Aedes albopictus) and the yellow fever mosquito (Aedes aegypti), are observed feeding on human blood in Tehatta, West Bengal, India, on May 01, 2026. These mosquitoes are known to transmit diseases such as dengue, chikungunya, Zika, yellow fever, and West Nile virus. Rising temperatures are contributing to their survival. (Photo by Soumyabrata Roy/NurPhoto via Getty Images)
(TEXAS) — Texas health officials on Tuesday confirmed the state’s first human West Nile virus case this year, an indication that mosquito season is beginning in the United States.
Public health officials have been warning that rising temperatures have allowed mosquitoes to thrive, increasing the risk of the diseases that they spread, including West Nile.
Last year, the U.S. reported 2,076 cases of West Nile across 47 states, according to data from the Centers for Disease Control and Prevention. Colorado had the highest number of cases (285), followed by Illinois, Texas, Minnesota and California.
The Texas Department of State Health Services said the patient was a resident of Harris County, which includes Houston, but no other information about the patient was made available.
“West Nile and other mosquito-borne illnesses are a fact of life in Texas in the warmer months, and all Texans should take precautions against mosquito bites to stay safe and healthy,” Texas DSHS Commissioner Dr. Jennifer A. Shuford said in a press release. “By removing standing water around the home, people can eliminate mosquito breeding grounds and reduce insect populations in their area.”
Since 1999, West Nile virus has killed about 2,900 Americans, according to the CDC. Cases are typically reported between June and October, historically peaking in August.
The virus is spread through the bite of an infected mosquito. Risk increases with older age, certain medical conditions — such as cancer, high blood pressure and kidney disease — and a weakened immune system.
Symptoms include fever, headache, body aches, vomiting, diarrhea and a rash. Severe illness can affect the central nervous system and result in hospitalization or death, according to the CDC.
There is currently no vaccine that protects against West Nile virus, and preventing mosquito bites is the best way to protect yourself, the CDC says.
No specific treatments are available. Doctors recommend patients rest, drink fluids and take pain medication to help relieve some symptoms. People with severe illness may need to be hospitalized for supportive treatment, according to the CDC.
The CDC says most people infected with West Nile virus are believed to have lifelong immunity. However, some with weakened immune systems or certain conditions may have their immunity wane over time.
