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PUBLIC NOTICE: Unscheduled Mosquito Control Spraying in Worcester County

Treatment scheduled for Thursday Evening in response to Eastern equine encephalitis-positive mosquito pool

ANNAPOLIS, MD – The Maryland Department of Agriculture will conduct unscheduled mosquito control spraying in response to an Eastern equine encephalitis-positive mosquito pool in Worcester County. The department will use Ultra-Low Volume (ULV) truck-based spraying to control adult mosquitoes within a two-mile radius of where the positive sample was found in Whaleyville.

Spraying will occur Thursday after 7:30 p.m. In the event of inclement weather, spraying will be re-scheduled for the next available evening. Any existing spray exemptions in the area will be temporarily suspended.

Mosquito Control personnel will use a permethrin-based solution that the EPA has approved for use in public health mosquito control programs without posing unreasonable risks to human health. However, out of an abundance of caution, the department recommends avoiding outdoor activities during spraying.

The department’s Mosquito Control Office, in cooperation with the Maryland Department of Health, has been conducting surveillance activities throughout the state to collect and test mosquitoes for West Nile virus, Eastern equine encephalitis, and several other mosquito-borne diseases. These diseases are endemic in Maryland and are transmitted through the bite of a mosquito.

According to the Centers for Disease Control and Prevention (CDC), human cases of Eastern equine encephalitis, or EEE, are rare. EEE disease occurs primarily in areas close to swamps and marshes with high mosquito populations. On average, seven human cases of EEE are reported annually in the U.S. Approximately 30 percent of people infected with EEE die and many survivors have ongoing neurologic problems. People most at risk for developing severe disease are those over 50 and younger than age 15. EEE infection can result in one of two types of illness, systemic or encephalitic. Systemic infection has an abrupt onset and is characterized by chills, fever, malaise, arthralgia, and myalgia, lasting one to two weeks. Signs and symptoms in encephalitic patients are fever, headache, irritability, restlessness, drowsiness, anorexia, vomiting, diarrhea, cyanosis, convulsions, and coma. Individuals reporting these symptoms should be referred to their health care provider. Symptoms usually occur four to 10 days after exposure to a mosquito carrying the virus.

While not all mosquitoes carry these diseases, the Maryland Department of Agriculture suggests that residents take precautions to minimize their exposure to mosquito bites. These measures include:

  • Wear long, loose fitting, light colored clothing
  • Wear insect repellents according to product labels
  • Avoid mosquito-infested areas during prime periods of activity (between dusk and dawn)
  • Install, inspect, and repair window and door screens in homes and stables
  • Regularly clean bird baths and bowls for pet food and water
  • Remove or empty all water-holding containers

Currently there is no EEE vaccine for humans. There are, however, effective vaccines for horses. Horse owners are encouraged to vaccinate and keep current vaccinations up-to-date in consultation with their veterinarian.

All Marylanders are encouraged to follow the department’s Twitter feed @MdAgMosquito that will post unscheduled spray events and other timely information about mosquito control in Maryland. Routine spray program schedules are available by county on the program’s website.

For more information, call the Maryland Department of Agriculture’s Mosquito Control Program at 410-841-5870.

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Follow Maryland Department of Agriculture Mosquito Control on Twitter @MdAgMosquito

Contact Information

If you have any questions, need additional information or would like to arrange an interview, please contact:

Jason Schellhardt
Director of Communications
Telephone: 410-841-5888

Megan Guilfoyle
Public Information Officer
Telephone: 410-841-5889

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