THD's mosquito surveillance program detects mosquitoes that transmit West Nile virus


TULSA, OK -[May 31, 2024] – Tulsa Health Department (THD) officials confirmed that a mosquito sample from a trap in Tulsa County tested positive for West Nile virus (WNV). It is important for residents to remember to take precautions against WNV and other mosquito-borne diseases. So far this year, no cases of WNV in humans have been confirmed in Tulsa County.

Mosquitoes can transmit diseases such as West Nile virus, so health officials strongly recommend using insect repellent containing DEET for protection.

THD operates a nationally recognized mosquito surveillance program to determine when mosquito-borne diseases are occurring in the community. Mosquito traps are set weekly at various locations throughout Tulsa County. Samples are collected weekly and tested for the presence of mosquito-borne diseases. The Tulsa Health Department has an efficient budget to control mosquito populations during the spring and summer through surveillance and treatments rather than spraying.

The goal of surveillance is to detect mosquito presence, determine frequency and species, conduct a risk assessment, and provide a basis for control. Control methods include larval control and spraying when necessary. Public health is the most important factor in preventing disease infection in Tulsa County.

Typically, the risk for WNV infection in Oklahoma is highest during the months of July through October, but THD proactively begins a mosquito surveillance program in late April or May.

“As part of our surveillance program, we set mosquito traps in early May to detect West Nile virus and identify all infected mosquitoes as early in the season as possible,” said Michael Morrison, vector control coordinator. “Our mosquito control program recognizes the importance of preventing mosquito-borne diseases by educating the public on bite prevention, removing standing water and identifying problem areas. THD is prepared to respond to affected areas as soon as weather conditions permit.”

West Nile virus is transmitted through the bite of an infected mosquito, which feeds on infected birds and then transmits the virus when it bites humans, horses, and some other mammals. Symptoms of WNV include sudden onset of fever, headache, dizziness, and muscle weakness.

“Over the past few years, West Nile virus has been detected in mosquito tests and in human cases in Tulsa County and has unfortunately caused illness and death in some cases,” Morrison said. “It is important to take steps to prevent mosquitoes from biting you and your family. Prevention is easy with a few simple steps.”

You should take the following precautions against mosquito bites:

  • Empty and drain items such as buckets, cans, pool covers, flower pots and tires to prevent standing water from accumulating and providing a breeding ground for mosquitoes.
  • Use an insect repellent containing DEET or other CDC-approved agents on exposed skin and clothing when you go outdoors, especially if you are outdoors between dusk and dawn when the likelihood of mosquito bites is higher. (Insect repellents containing permethrin should only be used on clothing.)
  • Wear long-sleeved clothes and long pants that are loose-fitting and made in light colors.
  • Repair or install window and door screens to keep mosquitoes out of your home.
  • Ask your friends and neighbors to dispose of sewage and use repellents.
  • Regularly remove leaves and debris from gutters to ensure they are not clogged.

To file a complaint about mosquitoes in your area or to report standing or stagnant water in your area, please call 918-582-9355 or submit an online environmental complaint form. A report does not guarantee immediate action, but it does provide data to the vector control team to determine locations for traps. Trapping and testing will continue until mosquito numbers decline in the fall months.

“It is very important that community members do their part to pump out standing water to prevent mosquito breeding sites,” Morrison said. “Standing water can occur in many places, such as birdbaths, toys, wading pools, trash cans, buckets, upside-down grill lids, planters, bowls, etc. Our department is available as a resource if you need help inspecting your property for possible mosquito breeding sites.”

Click here to go to our interactive data page which includes a map of WNV-positive trap locations in Tulsa County. This is updated weekly, typically on Fridays during mosquito monitoring season.

The 2024 mosquito season in numbers:

1 Trap samples tested positive for West Nile virus
144 Trap samples tested so far this season
7,623/6,972* Mosquitoes collected for testing/Mosquitoes tested *approximately
0 Human cases of WNV in Tulsa County
0 human WNV case in Oklahoma