Mosquitoes are present in Central Texas year-round, but the population is largest and most active from April through September. During this period, the Austin/Travis County Health and Human Services Department monitors the population and tests for mosquito-borne viruses. Mosquitoes carrying the West Nile Virus (WNV) are of particular concern.

Mosquito Pools

Travis County has seen a total of 128 mosquito pools testing positive for WNV in 34 zip codes as of  Oct. 26, 2012--the highest number of positive pools detected since surveillance activities began in 2003.

West Nile VIrus Incidence

In Travis County, there have been a total of 153 human WNV cases and six deaths reported from Jan. 1 to Dec. 18, 2012. In Texas, there were 1,834 human WNV cases and 86 deaths in 127 counties reported from Jan. 1 to Nov. 30, 2012. The majority of the statewide cases reside in the Dallas area.  

West Nile Virus Update

The health department has been actively working with community partners to increase awareness about the situation and promote preventive practices that can decrease transmission of the virus. An alert was sent to the Travis County Medical Society to remind physicians of West Nile virus symptoms that patients might present, and tips have been provided through an Austin Energy utility bill insert, news releases, media interviews, web postings and other social media vehicles.

Symptoms

Photo by John Tann

Helpful Links Austin / Travis County Health and Human Services Department Vector Control Program Earth Wise Guide to Mosquitos West Nile Virus: What you need to know, Center for Disease Control and Prevention West Nile Virus in Texas, Texas Department of State Health Services Mosquitos and the Diseases They Transmit, Texas Cooperative Extension To report a mosquito problem, call 512-978-0370

Most people who are infected with the West Nile virus will not have any type of illness. However, it is estimated that 20 percent of people who become infected will develop West Nile fever with mild, flu-like symptoms including:

• Fever
• Headache and body aches
• A skin rash on the trunk of the body
• Swollen lymph glands. 

About one in 150 people infected with WNV will develop severe illness. Persons older than 50 are at higher risk for severe disease. The severe symptoms can include:

• High fever
• Headache
• Neck stiffness
• Stupor
• Disorientation
• Coma
• Tremors
• Convulsions
• Muscle weakness
• Vision loss
• Numbness
• Paralysis.

These symptoms may last several weeks, and neurological effects may be permanent. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.

Read more about symptoms from the Centers for Disease Control and Prevention (CDC).

Prevention

Reducing the number of mosquitos in areas where people work and play is the most important step in preventing West Nile virus. Mosquitoes can only breed in standing water. By draining all sources of standing water in and around your property, you reduce the number of places mosquitoes can lay their eggs and breed.

Using insect repellents and wearing protective clothing can reduce risk of exposure. These guidelines are consistent with recommendations for effective mosquito control from the CDC and the Texas Department of State Health Services (DSHS)

Remember to always follow the four Ds: 

• Dusk and Dawn: Try to stay indoors at dusk and dawn. That is the time when mosquitoes likely to carry the infection are most active.
• Dress: Wear pants and long sleeves when you are outside. Wear light colored, loose fitting clothing; mosquito repellent clothing is also available
• DEET: Apply insect repellent that contains DEET. Read and follow label instructions. Spray both exposed skin and clothing with repellent.
• Drain: Get rid of standing water in your yard and neighborhood. Old tires, flowerpots, clogged rain gutters, birdbaths and wading pools can be breeding sites for mosquitos. 

Eliminate mosquito breeding sites:

• Reduce standing water around your home and neighborhood (including old tires, bottles, buckets and clogged gutters)
• Replace water at least once a week in pet dishes, bird baths and watering troughs
• Repair leaky outside faucets and pipes
• Consider mowing or pruning dense vegetation to reduce mosquito habitat
• Keep window and door screens in good repair
• Fill in tree holes with sand and low spots in lawn with soil
• Stock permanent water areas with mosquito-feeding fish (Gambusia affinis can be bought in pet stores and bait shops)
• Carefully screen rainwater harvesting cisterns to exclude mosquitos
• Use “mosquito dunks” (Bacillus thuringiensis israeliensis)  to reduce mosquitos in rain barrels and permanent bodies of water. These products slowly release a biological larvicide that kills the pest
• Consider installing nesting boxes to attract bats and birds that feed on mosquitos