Last week, we reported that Dallas would spray insecticide from low-flying planes in an effort to curb the mosquitoes that are causing the area’s West Nile outbreak. The disease has prompted a state of emergency in the Texas city; 21 people in the region have died from it this year.

Seriously. How gross are these things?* (Photo by Alvesgaspar.)

Nationally, West Nile cases are at three times normal levels — the worst outbreak ever in the U.S. since the disease appeared in 1999.

So far, 1,118 illnesses have been reported, about half of them in Texas, according to the Centers for Disease Control and Prevention. In an average year, fewer than 300 cases are reported by mid-August. There have also been 41 deaths this year. …

Grist thanks its sponsors. Become one.

Never before have so many illnesses been reported this early, said [Lyle] Petersen, who oversees the CDC’s mosquito-borne illness programs.

Most infections are usually reported in August and September, so it’s too early to say how bad this year will end up, CDC officials said.

Grist thanks its sponsors. Become one.

Infected people take several weeks to display symptoms, so some people may be carrying the virus without realizing it. According to USA Today, 80 percent of carriers will never show signs of the illness.

As we noted earlier this month, the advent of climate change is likely to increase the spread of West Nile. While this year’s outbreak is not directly linked to climate change, it could very well be a sign of what we can expect in the future.

* If I could, I would punch every mosquito right in its gross little face. I would punch each and every one. Line them up, and punch them, wham! right in the proboscis.