The following is a copy of the July 2016 Teleconference held by the Virginia State Secretary of Health.  For a copy of the letter from the State Secretary of Health which also contains the information below, click here.

Summary of Presenter Comments from Zika Teleconference on July 28 and 29
Dr. Laurie Forlano — Director, Virginia Department of Health Office of Epidemiology

Zika virus infection is primarily spread through the bite of an infected mosquito (Aedes species). Of those that are infected with the virus, 1 out of every 5 will become sick. The most commonly reported symptoms are fever, rash, joint pain and conjunctivitis. 80% of those who are infected will NOT become ill.

Zika virus primarily transmitted by mosquitoes

  • Mainly Aedes aegypti (Yellow fever mosquito)
  • Also by Aedes albopictus (Asian tiger mosquito)
  • Both also transmit dengue and chikungunya viruses
  • Both circulate in VA, especially the Asian tiger mosquito

Aedes aegypti mosquitoes are more likely to spread viruses like Zika, dengue and chikungunya than other types of mosquitoes such as Aedes albopictus mosquitoes.

These types of mosquitoes almost exclusively breed in containers of water; that is, man-made containers like flowerpots, birdbaths or other household containers often found on a person's property or backyard.

Aedes albopictus are the most common nuisance mosquito in Virginia and are present and common in every jurisdiction in the state. Although small, isolated populations of the Aedes aegypti mosquito are occasionally discovered in Virginia, but are extremely uncommon and therefore are a less significant vector.

Therefore, most efforts will be targeted on Aedes albopictus.

You may have seen some of the maps published by CDC, which show their best estimate of the potential range of Aedes aegypti and Aedes albopictus in the United States AND they show areas where mosquitoes have been previously found. What the maps do NOT indicate is the risk or likelihood that these mosquitoes will spread viruses in those areas depicted on the maps.

Zika is transmitted through the bite of an infected mosquito via a person to mosquito to person cycle. If a Virginia mosquito bites an infected individual while they are viremic that mosquito can become infected and potentially go on to bite another individual.

Therefore, during mosquito season in Virginia it's critical that individuals and communities take efforts to eliminate mosquito breeding habitats (i.e. dumping containers, etc) to help reduce the mosquito population and curb any potential transmission of the virus.

Further, in regards to mosquito-borne transmission, the overarching principle of controlling Zika virus disease is for persons with Zika virus circulating in their blood to avoid mosquito bites.

VDH will continue to work with its partners at local and state levels to ensure that disease prevention messages are widely disseminated, including messages about personal protection and strategies to implement on your properties and around homes.

General Recommendations for Mosquito Control of Zika Virus Vectors (Asian tiger mosquitoes):

  1. Short flight range, so work from patient's address outward at least 200 yards (preferably further)
  2. Collect adult specimens to assess local tiger population, test for virus, and estimate risk of local transmission.
  3. Do thorough yard inspections to identify and eliminate or treat breeding sites
  4. Educate homeowners and distribute Asian tiger literature
  5. Use either barrier or space sprays to reduce or eliminate adult (potentially infected) mosquitoes.
  6. If available, deploy truck-mounted ULV operations in general neighborhood
  7. Re-trap to assess efficacy of treatments.
Dreda Symonds — Director, Chesapeake Mosquito Control Commission
Overview of Chesapeake Mosquito Control action upon confirmation of Zika case

  1. Local HD learns of confirmed Zika case
  2. Epidemiologist interviews patient and strongly urges them to give permission for local mosquito control district to inspect the yard and apply pesticides.

    If permission is obtained...#3
    If permission is NOT obtained...49
  3. Mosquito control director is contacted and given patient's address and informed of consent.
  4. ASAP Director sends biologist to trap patient's yard (or very close by) for Asian tiger mosquitoes. Samples are separated, ID'ed and frozen for PCR testing.
  5. A normal service request for mosquito problems is created and technicians are sent to the home to perform a thorough breeding site inspection, eliminate or treat sites, educate homeowner, and spray yard if evidence of adult Asian tigers is found.
  6. It is normal procedure to "fan out" from a service request if there appear to be issues at neighboring properties, so they are inspected and treated if applicable.
  7. Truck-mounted ULV trucks are deployed in the neighborhood '/2 hour after sunset.
  8. Biologist re-traps the area to determine efficacy of treatments.
  9. Local HD informs MC director of general area where patient lives.
  10. Biologist finds public spot to deploy BG traps.
  11. Technicians are sent to area for general inspections and yard treatments
  12. Truck-mounted ULV trucks are deployed in the neighborhood '/2 hour after sunset.
  13. Biologist re-traps the area to determine efficacy of treatments.

Grant Kronenberg/Duncan Pitchford — Office of the Attorney General

Some of the relevant portions of the Code of Virginia concerning Mosquito Control Districts are listed below.

  • The governing body of any county, city or town, either alone or jointly with one or more other counties, cities or towns, may create one or more mosquito control districts.... (Va. Code § 32.1-187.)
  • Each mosquito control commission district shall ... have all the powers necessary to carry into effect all of the provisions of this article... (Va. Code § 32.1-190.)
  • Each mosquito control commission is empowered to employ all necessary personnel and to perform all acts necessary to control and eliminate mosquitoes in the district but such actions shall be subject to private property rights in the areas in which the work of the commission is performed. (Va. Code § 32.1-192)
  • Each mosquito control commission is vested with the power of eminent domain to the extent necessary to carry out the provisions of this article.... (Va. Code § 32.1-193)
  • The governing body of any county, city or town, the whole or a part of whose territory is contained within a mosquito control district, is hereby levy annual a special tax upon all real and personal property subject to local taxation within the territory located within such [locality] which is a part of such mosquito control district...and all funds received from any tax levy so made shall be paid to the mosquito control commission for the mosquito control district in which the property subject to levy is.... (Va. Code § 32.1-194.)
  • The Board [of Health] is hereby authorized to contribute annually to any mosquito control commission a sum not more than 25 percent of the gross amount obtained by such commission annually from any special tax levy authorized by this article or contributed to such commission annually by direct appropriation of any county, city, town or combination thereof, but any such amount so contributed by the Board shall not exceed $10,000 in any 1 year; except that where separate mosquito control commissions have been consolidated pursuant to § 32.1-188, such maximum amount shall be computed so as to allow a contribution to that consolidated district in an amount not less than was received prior to such consolidation by all of the separate districts. (Va. Code § 32.1-195.)

Mosquito Surveillance and Control Information for Teleconference Follow-up

Virginia Department of Health (VDH) will be conducting targeted mosquito surveillance throughout the state. Mosquito surveillance activities will be conducted by the Virginia Department of Health's Division of Environmental Epidemiology (DEE) and may include any or all of the following: property and neighborhood inspection for mosquito habitats; eliminating these habitats when possible (i.e., dumping containers); trapping mosquitoes for speciation and arboviral mosquito testing (when available); and dissemination of educational materials (as appropriate for the type of housing and areas where containers may be found). DEE has two mosquito surveillance specialists that are trained to conduct these surveillance activities. DEE works with local health departments to arrange for its mosquito surveillance specialist to conduct home/site inspections if the locality needs assistance. Localities with questions concerning mosquito surveillance should contact their local health department.

The majority of commercial mosquito control companies typically perform only barrier treatments. The cost per property treated is usually about $75.00 to $100 for properties that are about 1/4 to 1/2 acre in size.

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