County to Spray for Mosquitoes in Area Near Travel-related Zika Case

Image Credit: CDC
An Aedes aegypti mosquito

The County of San Diego’s Vector Control Program plans to hand-spray a two-city-block area in San Diego as a preventive measure after a person in the area tested positive for travel-related Zika virus and Aedes mosquitoes were found in the same area.

The person recently traveled to a country where tropical mosquito-borne illnesses including Zika virus are active and developed symptoms upon returning home. State officials have confirmed the person had the Zika virus, which was not acquired in the United States.

County Vector Control inspectors found Aedes mosquito larvae and adult mosquitoes near the person’s residence, and as a result, plan to spray early next week to kill any adult mosquitoes.

Adult Aedes mosquitoes can transmit tropical diseases, including chikungunya, dengue, yellow fever and the Zika virus. However, no Aedes mosquitoes have ever been found in San Diego County or California carrying any infections.

The County is acting to prevent mosquitoes from being introduced to any potential disease.

“Travel to Zika-affected countries is common, and actions to prevent Zika from spreading to local Aedes mosquitoes are vital to inhibit locally acquired human cases of this disease,” said Wilma Wooten, M.D., M.P.H., County public health officer.

County Vector Control workers notified residents in the Mount Hope neighborhood Saturday, and to conduct hand-spraying in the neighborhood on Tuesday or Wednesday. The affected area is bordered by F Street on the north, Raven Street on the east, Market Street to the south and Quail Street to the west.

Vector Control will spray within the area bound by F Street, Raven Street, Market Street and Quail Street.
Vector Control will spray within the area bound by F Street, Raven Street, Market Street and Quail Street.

The pesticide, Pyrenone® 25-5, poses low risks to people and pets. However, people who would prefer to avoid or minimize their exposure to the pesticide can take simple steps:

  • Stay inside and bring pets indoors if possible
  • Close doors and windows, and turn off fans that bring outdoor air inside the home
  • Cover ornamental fishponds to avoid direct exposure
  • Rinse fruits and vegetables from your garden with water before cooking or eating
  • Wipe down or cover outdoor items such as toys and cover barbecue grills
  • Beekeepers and those with insects kept outdoors are encouraged to shelter hives and habitats during treatments
  • You may resume normal activities 30 minutes after the treatment

Vector Control will continue to conduct trapping for Aedes mosquitoes in the area and nearby locations for several weeks.

Information about the Zika virus, chikungunya, and dengue and can be found on the National Centers for Disease Control and Prevention’s website.

Two types of Aedes mosquitoes — the Aedes aegypti, yellow-fever mosquito and the Aedes albopictus, Asian tiger mosquito — are not native to San Diego. They were found in San Diego County for the first time in 2014 and 2015. To date, they have been found in relatively low numbers.

They differ from our County’s native mosquitoes in a number of ways. They not only live in people’s backyards, but also inside their homes, and can breed in a thimble-full of water.

They’re smaller than native mosquitoes, have distinctive black and white markings, are known as aggressive biters and — unlike our native mosquitoes that prefer to feed between dusk and dawn — like to bite and feed during daylight hours as well.

County officials reminded the public that they can protect themselves from Aedes and native mosquitoes by following the County’s “Prevent, Protect, Report” advice.

Prevent mosquito breeding

Dump out or remove any item inside or outside of homes that can hold water, such as plant saucers, rain gutters, buckets, garbage cans, toys, old tires, and wheelbarrows. Mosquito fish, available for free by contacting the Vector Control Program, may be used to control mosquito breeding in backyard water sources such as unused swimming pools, ponds, fountains and horse troughs.

Protect yourself from mosquito bites

Protect yourself from mosquito-borne illnesses by wearing long sleeves and pants or use repellent when outdoors. Use insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535. Make sure screens on windows and doors are in good condition and secured to keep insects out.

Report possible mosquito activity

Report if you are being bitten by mosquitoes during daylight hours, or if you find mosquitoes that match the description of Aedes mosquitoes by contacting the Vector Control Program at (858) 694-2888.

For more information about mosquito-borne illnesses virus, go to San Diego County’s “Fight the Bite” website. The County has also released the public service announcement below to promote mosquito prevention.