Dallas County will be closed Monday, May 27th, in observance of Memorial Day.

-A A A+

West Nile Virus

Dallas County Health and Human Services - 2377 N. Stemmons Freeway, Dallas, TX 75207

Telephone: 214-819-2000

Fight The Bite with DCHHS Online Mosquito Services

FightTheBiteDCHHS is committed to protecting the health and welfare of the communities we serve from mosquitoes and vector-borne disease. Residents experiencing a mosquito problem may call 214-819-2115 or click here to set up a free service request. Click here to check if mosquitoes have tested positive for West Nile in your zip code.

Week 44 ending November 3, 2018

WNV report week 44

West Nile Watch

West Nile Watch contains up-to-date daily information on prevention tips, positive mosquito traps and human cases. Click here for current issue

Mosquito Season

There are more than 40 mosquito species in Dallas County.  While mosquitoes can be active year round, generally, mosquito season is from May to November.  During the winter Culex quinquefasciatus overwinter as adults in sheltered areas while Aedes species overwinter as eggs in flood prone environments.  Seasonally, with warm temperatures and proper water conditions, these species developed or emerge from their winter habitats.  It is during the summer months when the risk of mosquito-borne disease transmission is greatest from July-August.

What is West Nile virus?

West Nile virus (WNV) is a disease that is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed on the blood from infected birds.

The infected mosquitoes can then transmit WNV to humans and animals. West Nile disease can vary in severity. People over 50 years of age have the highest risk of severe disease.

Severe WNV infections can cause neurologic complications such as encephalitis. Milder symptoms include fever, headache and muscle aches.

Frequently Asked Questions (FAQs) about WNV

  • Is it contagious?
    No. WNV is not spread through contact from person to person or from animal to person.
  • How is it diagnosed?
    Diagnosis of WNV requires a special blood test. Anyone who experiences symptoms of severe WNV illness should see a physician as soon as possible.
  • What is the treatment?
    There is no specific treatment for WNV infection. Patients receive supportive medical care and rehabilitation if needed.
  • What if I’m not experiencing any symptoms?
    Most infected people will show no symptoms. Symptoms typically develop between 3 to 14 days after a mosquito bite.
  • For other FAQs about WNV
    click here for English | click here for Spanish
Reports and Profiles

Click here for more reports and health advisories

WMV 2012 - Last Season

Download WNV educational and prevention materials:

Each file contains English & Spanish versions

DCHHS WNV poster

DCHHS Fight the Bites flyers 
general public
 | children

DCHHS WNV brochure in English

DCHHS WNV brochure in Spanish

DCHHS WNV Fact Sheet in Various Languages


To report mosquito activity, request service and search past treatments: click here.

More Information

DCHHS PSA: West Nile and Zika Viruses

Texas Department of State Health Services information on WNV

CDC information on WNV

Texas A&M AgriLife Extension -  Presentation - Introduction to Mosquito Biology and Key North Texas species

Texas A&M AgriLife Extension Mosquitoes and Disease Newsletter

Take a virtual tour of a home with potential mosquito breeding sites at http://mosquitosafari.tamu.edu/.

For the Media and News Updates