West Nile Virus InformationThe 4 D's of Prevention from Tarrant County Public Health
Spraying for Mosquitoes in Tarrant CountyTarrant County has received comments and questions about aerial spraying in our area. We want to do our best to ensure that people understand Tarrant County’s current response, which can include ground or aerial spraying.
West Nile Virus is a real threat in the counties across North Texas. Tarrant County Public Health (TCPH) is following a series of progressive steps to address West Nile Virus, following the recommendations of the Texas Department of State Health Services, the Centers for Disease Control and Prevention (CDC) as well as input from Tarrant County cities. These steps include:
- Working with cities that trap mosquitoes for testing by public health’s lab;
- Education and outreach by TCPH and the affected cities in areas with positive mosquito samples;
- Treating areas with infected mosquitoes by using larvicide to kill the mosquito eggs and/or using Gambusia minnows to eat the eggs in areas where there is standing water;
- Investigating and reporting human case data to Tarrant County cities;
- Encouraging residents, businesses, and governmental agencies to look for and drain any standing water in their respective areas; and
- Recommending targeted education in cities with human cases – like Reverse 9-1-1 or the Code Red communications systems.
Ground spraying to eliminate adult mosquitoes when they are active is one of the progressive steps available. Currently, ground spraying is occurring or is planned in parts of Bedford, Benbrook, Euless, Fort Worth, Hurst and North Richland Hills. Aerial spraying is part of the progression if targeted ground spraying is not effective. Grand Prairie -- located mostly in Dallas County -- is participating in aerial spraying.
At this time, aerial spraying is not the preferred response in Tarrant County due to a number of reasons:
- Dallas County has a higher incidence of the more severe form, the neuro invasive type, of West Nile Virus, which can have a higher mortality rate than the fever. In contrast, West Nile Fever is the predominant form of the illness in Tarrant County
- Cases of people who have tested positive for the virus are also concentrated in one large area in Dallas, while, in Tarrant, the cases are spread across a wide area of the county. In Dallas County, the areas where aerial spraying is being considered have 40-50 percent of the reported cases in the entire county
- Aerial spraying is recommended for spraying large areas all at once and where localized disease has been identified, while ground spraying can be effective when addressing small pockets of disease, or clusters. Recently, small pockets have been identified in Fort Worth and Arlington and concentrated ground spraying is being considered.
Spraying by the aerial or ground methods can be effective, but one of the most effective steps in the progression begins with individuals eliminating mosquito breeding areas around their home and neighborhood. Other steps include using repellent, dressing appropriately to avoid being bitten when outdoors and avoiding being outside from dusk to dawn.