You may have heard of the city of McKinney’s efforts to ramp up mosquito spraying this month after a mosquito pool tested positive for West Nile virus in late July.

First, it’s important to understand that although the disease can be scary, it is relatively rare—states reported roughly 2,000 human cases to the Centers for Disease Control and Prevention in 2016.

That said, in the 1 percent of human cases that result in a serious neurological condition, the disease can be life-threatening, according to the CDC. People age 60 and older bear the most risk.

As a result, cities take reports of West Nile seriously, regularly trapping mosquitoes throughout the city and testing them for the virus. Cities also take the preventive step of spraying each neighborhood in which a West Nile test comes up positive.

To minimize risks posed by West Nile, the city recommends draining bodies of standing water, where mosquitoes breed. Residents can also use deet-based repellent and stay indoors at dusk and dawn.