Maryland mosquito control crews planned unscheduled truck-based spraying after 9 p.m. on Wednesday, Sept. 16, in the Huntington and Kenilworth neighborhoods of Bowie and the Clinton View community of Temple Hills, citing a public health concern over the potential for mosquito-borne diseases, according to a Prince George's County notice. If bad weather interfered, spraying was to be moved to Thursday evening, Sept. 17.
The Sept. 15 notice from the Maryland Department of Agriculture (MDA) and the Prince George's County Health Department did not name a specific disease. MedicalDaily could not independently confirm whether the Wednesday spraying took place as planned. Residents can contact MDA's Mosquito Control Program at (410) 841-5870.
For households in those neighborhoods, the notice includes a practical change beyond the spraying itself. Any existing spray exemptions in the treatment areas are temporarily suspended, which affects residents who normally ask to be left out of mosquito control.
Spray Night Timing and Household Precautions
Crews use ultra-low volume equipment and a permethrin-based product that the U.S. Environmental Protection Agency has approved for public health mosquito control without unreasonable risks to human health, according to MDA. Out of an abundance of caution, the department recommends avoiding outdoor activities during spraying.
For families, that mainly means keeping children and pets indoors after 9 p.m. on the treatment night. Residents who usually rely on an exemption, including people with health concerns about pesticides, may want to call MDA with questions.
MDA also recommends long, loose-fitting, light-colored clothing; insect repellent used according to product labels; and avoiding mosquito-infested areas between dusk and dawn. The department advises installing, inspecting, and repairing window and door screens, regularly cleaning birdbaths and pet food and water bowls, and removing or emptying containers that hold water.
Emptying water alone may not be enough, because mosquito eggs cling to containers, Patch reported in a review of federal guidance. Scrubbing birdbaths, flowerpot saucers, toys, and pet bowls weekly, clearing gutters, and covering rain barrels can help. Patch also noted that Maryland's mosquito season usually lasts until the first hard frost, typically between late October and mid-November, citing The Old Farmer's Almanac.
Late-Season West Nile Activity in the Capital Region
In late July, MDA sprayed parts of Anne Arundel and Prince George's counties after detecting West Nile virus in mosquitoes there, The Baltimore Banner reported. Days later, on July 31, the Maryland Department of Health announced the state's first confirmed human West Nile case of 2026, in a resident of the Capital Region. That region includes Prince George's, Montgomery, and Frederick counties, according to Patch.
MedicalDaily previously reported that the state withheld the county where that patient lives, citing privacy. State officials later told Patch that a second human case had been confirmed in a Baltimore Metro resident. The newest notice does not say whether mosquitoes in Bowie or Temple Hills tested positive for any virus, and it does not report new human cases.
State and federal counts do not line up neatly. Patch reported that the CDC's latest national report listed 407 West Nile cases, including five in Maryland, which is higher than the two human cases the state had publicly confirmed. MedicalDaily could not reconcile the two Maryland figures.
For context, Maryland recorded 23 human West Nile cases in 2025 and 18 in 2024, the Banner reported. Nationally, Patch reported that by the end of June, the United States had recorded its earliest start to a West Nile season, and the most cases by that point, since 2004. Weather conditions this year have favored mosquitoes.
"We are in the season when the West Nile virus and other mosquito-borne viruses can spread in Maryland," said Dr. Meg Sullivan, the Maryland Department of Health's deputy secretary for public health services. "Your best defense against West Nile virus is to protect yourself from mosquitoes, such as using insect repellent, covering exposed skin, and eliminating standing water near your home."
Symptoms and Residents at Higher Risk
Up to 80% of people infected with West Nile virus have no symptoms, according to the Maryland Department of Health. Others develop mild symptoms such as fever, headache, and body aches, and sometimes a skin rash or swollen lymph glands. These symptoms can last a few days or as long as several weeks. The virus affects the nervous system, and the department says people older than 50 and those with weakened immune systems or underlying health conditions can become seriously ill.
West Nile is rarely fatal, but in a small share of cases it can cause meningitis or encephalitis, a dangerous inflammation of the brain, Patch reported. A sudden high fever, stiff neck, confusion, muscle weakness, or seizures can signal a serious infection and need emergency care. Milder symptoms after mosquito bites are worth a call to a clinician, especially for older relatives.
There is no human vaccine or antiviral treatment for West Nile virus, Patch noted, so preventing bites remains the main defense. In rare cases, the virus can also spread through organ donation, blood transfusion, breastfeeding, or from a pregnant mother to a fetus, according to the state health department.
Residents without insurance or a regular doctor can contact the Prince George's County Health Department for guidance on where to seek care. MDA posts routine spray schedules by county on its program website.
The confirmed facts are limited but useful: spraying was scheduled for specific neighborhoods, exemptions there were suspended, and officials did not name the disease involved. The most reasonable household response is to prevent bites through the rest of the season and watch for new county notices.
Key Questions Answered
Where was mosquito spraying scheduled? In the Huntington and Kenilworth neighborhoods of Bowie and the Clinton View community of Temple Hills, after 9 p.m. on Sept. 16, with Sept. 17 as the rain date.
Why is Maryland spraying? Officials cited a public health concern over the potential for mosquito-borne diseases. The notice did not name a specific disease.
Is the spray safe? MDA said the permethrin-based product is EPA-approved for public health mosquito control without unreasonable risks to human health, but it recommends avoiding outdoor activities during spraying.
What if I have a spray exemption? Existing exemptions in the treatment areas are temporarily suspended. Residents with questions can call MDA's Mosquito Control Program at (410) 841-5870.
What are the symptoms of West Nile virus? Up to 80% of infected people have no symptoms. Some develop fever, headache, and body aches. A stiff neck, confusion, weakness, or seizures require emergency care.
