West Nile Virus Surges Nationwide, Prompting Hospitalizations and Fatalities
A 13-year-old's severe illness highlights the growing threat of mosquito-borne diseases across the U.S.
West Nile virus (WNV) cases are surging across the United States, leading to a rise in hospitalizations and fatalities. In Los Angeles County alone, as of October 1, there have been 180 reported cases, the highest number in nearly a decade. Of these, 160 have been diagnosed as neuroinvasive disease, a severe form of the illness where the virus affects the central nervous system.
Nationwide, 43 states have reported cases of West Nile virus, with the Centers for Disease Control and Prevention (CDC) tracking 987 cases and 750 instances of neuroinvasive disease. Last year, the U.S. recorded 2,167 total cases of West Nile virus, with 1,342 hospitalizations for neuroinvasive disease and 172 deaths.
The severity of WNV can range from asymptomatic infection to debilitating neurological conditions. Neuroinvasive disease can manifest as encephalitis (brain swelling), meningitis (inflammation of the membranes surrounding the brain and spinal cord), or acute flaccid paralysis. While most WNV infections are mild or asymptomatic, about one in 150 cases develop into neuroinvasive disease, which can be life-threatening.
A striking example of the virus's potential impact is the case of 13-year-old Joseph Vasquez from Long Beach, California. Vasquez was hospitalized at Children's Hospital Los Angeles with transverse myelitis (TM), a rare but serious complication of WNV. TM is characterized by sudden inflammation in the spinal cord that damages the protective myelin sheath around nerve fibers. Vasquez developed a full-body rash, headache, leg pain, and a low fever, which rapidly progressed to loss of mobility in his legs, severe abdominal pain, a stiff neck, and loss of bladder and bowel control.
Doctors diagnosed Vasquez with TM and determined that West Nile virus was the cause. He is currently being treated with steroids.
According to the County of Los Angeles Public Health, among the 160 neuroinvasive cases reported in the county this year, 122 are encephalitis, 28 are meningitis, and ten are acute flaccid paralysis. A total of 162 individuals have been hospitalized, and seven have died from the virus in Los Angeles County.
The spread of mosquito-borne diseases like West Nile virus is being exacerbated by several factors, including warmer temperatures, rapid urbanization, and increased global travel. These conditions are allowing mosquitoes carrying pathogens to expand into new regions and persist longer into the year. Many states are experiencing extended mosquito seasons, typically running from late spring through early fall.
While West Nile virus is most commonly found in states like North Dakota, South Dakota, Nebraska, and Colorado, it is now prevalent in major urban centers such as Los Angeles, Chicago, and the Dallas-Fort Worth area. The CDC data indicates that California has recorded 211 cases of West Nile virus.
Those most at risk for severe illness from West Nile virus include older adults, individuals with weakened immune systems, and those with pre-existing chronic conditions. Survivors of severe WNV infections may experience long-term complications, including memory problems, chronic fatigue, muscle tremors, or permanent neurological damage.
Preventative measures against West Nile virus primarily involve avoiding mosquito bites. The CDC recommends using EPA-registered insect repellents containing DEET, wearing long sleeves and pants when outdoors, and minimizing outdoor activity between dusk and dawn, when mosquitoes are most active. Vasquez's family has urged the public to take mosquito-borne illnesses seriously and to seek medical attention if concerning symptoms develop or worsen.