Mosquitoes are among the most important insect pests affecting the health of people. They are not just annoying; they can also transmit many diseases. A rainy spring proceded by a mild winter, can lead to an active mosquito season.
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.
West Nile Virus Incidence
West Nile virus (WNV) infection is the most common vector-borne disease in the United States. In 2011, approximately 700 human West Nile virus cases were reported in the United States. During 2011, no human WNV cases were reported in Travis County.
However, in 2012 the United States experienced a large outbreak of West Nile virus with 5,674 human cases reported. The weekly number of reported cases peaked in late August 2012. Five percent (286 cases) of the reported cases died.
The outbreak in 2012 also impacted Texas and Travis County. Over 1,800 human WNV cases were reported in Texas. A total of 153 cases occurred in Travis County. A majority (62%) of the cases in Travis County were males. The cases ranged in age from 11 to 91 years; most (58%) were 50 years of age or older. Six of the cases in Travis County died. All six deaths occurred in persons 60 years of age or older
In Travis County, no human WNV cases were reported during 2013 and only six human WNV cases were reported in 2014.
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:
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:
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).
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