Houston Health Department

Houston Health Department stresses mosquito-bite prevention as peak months for West Nile Virus near


July 29, 2019

HOUSTON - As the peak months of mosquito season approach, the Houston Health Department reminds residents to take precautions against mosquito-borne illnesses such as West Nile Virus.

August and September are the months when the health department has confirmed the highest number of people in Houston with West Nile Virus infection since the disease emerged locally in 2002. Nine of the 11 West Nile human cases confirmed by the department during the last three years occurred in either August or September.

“Late summer is the most crucial period during mosquito season” said Dr. David Persse, Houston’s local health authority and EMS director. “It’s the time when people must redouble their efforts to protect themselves against mosquito bites.”

The health department encourages people to use the “3D Defense” to prevent mosquito bites and reduce the risk of infection:

  • Drain: Drain standing water around your home so mosquitos don’t have a place to breed.
  • DEET: Apply EPA-approved insect repellent with the ingredient DEET.
  • Dress: Dress in long sleeves and pants while outdoors to limit exposed skin.

West Nile virus infection in severe cases can result in illnesses such as encephalitis (an inflammation of the brain) or meningitis, an inflammation of the membranes surrounding the brain and spinal cord. About one in 150 people infected with the virus develop severe illness affecting the central nervous system.

Severe infections can cause high fever, headache, stiff neck, disorientation, coma, tremors, muscle weakness, and paralysis. However, most people infected with the virus either don’t develop any symptoms or only experience mild illness such as flu-like symptoms including fever, headache, body aches and occasionally skin rash and swollen lymph glands.

Symptoms usually develop three to 15 days after infection with the virus.

Although the elderly and people with certain medical conditions such as cancer, diabetes, hypertension and kidney disease are at highest risk of severe illness, the virus poses a risk to everyone.

Mosquitos in the Houston area tested positive for the virus earlier this summer. Other diseases spread by mosquitoes include dengue, Zika and chikungunya.