West Nile Virus Is Off to Its Worst Start in 20 Years, CDC Says
The CDC has confirmed 48 West Nile cases by June 30, far above the usual 10, with Arizona hardest hit as officials urge simple precautions over the July 4 weekend.
By the end of June, the United States usually counts around 10 West Nile virus cases. This year the tally already stands at 48.
That gap is why federal health officials spent the week before Independence Day urging Americans to reach for bug spray. In a statement on Wednesday, the Centers for Disease Control and Prevention said it had confirmed at least 48 cases as of 30 June, 38 of them severe, in what is shaping up as the earliest and worst start to a West Nile season in more than two decades. Twenty-three states have reported the virus, the most in 10 years.
The numbers land just as families head outdoors.
"These findings serve as an important reminder that mosquito season is well underway. As families gather outdoors to celebrate Independence Day, we encourage everyone to enjoy their holiday while taking simple steps to protect themselves and their loved ones from mosquito bites."
Dr. Erin Staples, CDC expert on insect-borne diseases
The burden is not spread evenly. Most of the cases so far are in Arizona, which has recorded 32, with 29 of those in Maricopa County around Phoenix. The county has also reported four deaths from the virus this year. Local officials there asked residents to use repellent containing DEET, mend torn window screens, and drain anything holding water. Even an overturned bottle cap can hold enough water for mosquitoes to breed,
said Melissa Kretschmer, a county health department official.
It helps to keep the risk in proportion. West Nile arrived in the U.S. in 1999 in New York and spread west from there, peaking in 2003 with nearly 10,000 cases. Most people who are infected never know it, with either no symptoms or mild ones such as headache, body aches, joint pain or a rash. The danger sits at the tail: in severe cases the virus attacks the central nervous system, causing potentially deadly inflammation of the brain or spinal cord. Adults over 60 and people with weakened immune systems face the highest risk.
Set against a normal year, the current figures are an early spike rather than a catastrophe, and the CDC cautions that its ArboNET counts are preliminary and that mild cases are routinely undercounted. Over the past decade the agency has logged about 2,000 cases annually on average, including roughly 1,200 neuroinvasive illnesses and about 100 deaths. The season has months left to run, which is precisely why an early surge is worth acting on now rather than watching.
The protective steps are unglamorous and effective, and they are the same ones the CDC recommends every year: an EPA-registered repellent, long and loose clothing, and, where you can manage it, staying in around dusk and dawn when the mosquitoes that carry West Nile bite most. None of it requires panic. It requires a can of spray and emptying the flowerpot saucer before the weekend. Current case counts are published on the agency's surveillance page, and the season's fuller picture, as reported by the Associated Press, will sharpen through the summer.
