Dallas County Health and Human Services confirms that mosquito samples collected in Dallas County have tested positive for West Nile virus.

The positive samples were collected from the 75115 ZIP code in DeSoto and the 75104 ZIP code in Cedar Hill.

West Nile virus is the leading cause of mosquito-borne disease in the continental United States, per the CDC. It most commonly spreads to people through the bite of an infected mosquito.

Mosquito season starts in the summer and continues through the fall.

“Dallas County is currently experiencing the early stages of mosquito season, and residents are advised to take necessary precautions when spending time outdoors to avoid mosquito bites that may cause West Nile Virus,” per a press release.

The director of Dallas County Health and Human Services (DCHHS), Philip Huang, recommends following the “four Ds” to prevent mosquito bites.

  • Deet: Whenever outside, use insect repellents with the active ingredient DEET or other EPA-registered repellents, and always follow label instructions.
  • Dress: Wear long, loose, and light-colored clothing outside.
  • Drain: Drain or treat all standing water in and around your home or workplace where mosquitoes could lay eggs.
  • Dusk to dawn: Limit your time outside from dusk to dawn when mosquitoes are most active.

Residents can help reduce potential mosquito breeding areas around the home by draining standing water and consistently using EPA-approved larvacide where standing water cannot be eliminated.

There are no vaccines to prevent or medicine to treat West Nile virus. Only about 20% of humans infected with the virus experience symptoms, which may include fever, headache, rash, and diarrhea. However, for some persons, the virus can cause severe illness.

“It can be very serious. It can lead to very serious infection and even death,” Huang told The Dallas Morning News. “It’s from something as seemingly innocuous as a mosquito bite. So it’s certainly, you know, a reason to avoid mosquito bites.”

Samples collected in Arlington in Tarrant County have also tested positive for the virus.

To keep track of the confirmed positive samples in Dallas County, visit DCHHS’s interactive map. No human cases of the virus have been reported so far this season.

The Dallas Express reported on two deaths last year in Dallas County that were caused by the contraction of West Nile virus.