West Nile is still the main one, but others show up

West Nile virus is by far the most common mosquito-borne disease in the US, but a few others like Eastern equine encephalitis and La Crosse virus are out there.

West Nile has been circulating in the lower 48 since 1999 and pops up every summer, mostly in the Midwest and South. Most people don’t even get symptoms, but about 1 in 150 get serious neurological stuff. It’s the one you should actually worry about.

Eastern equine encephalitis (EEE) is scarier — kills about a third of people who get it — but it’s rare. You’ll see a handful of cases per year, mostly in Florida and the Northeast. La Crosse virus is more of a Midwest thing, mostly in kids, and usually mild.

Dengue and Zika? Not really circulating in the mainland US beyond occasional travel-related cases and small local outbreaks in Texas, Florida, or Hawaii. Zika’s not the threat it was in 2016. Malaria? The US eliminated it decades ago, though you’ll get a few locally acquired cases each year from someone who traveled and got bit here. Not enough to call it “circulating.”

So in practice: if you live in the continental US, your realistic worry is West Nile. The others are statistical noise unless you’re in a hot spot.