Updated: Mosquito Samples Positive for West Nile Virus in 78628

Oct 27, 2015

Updated 2015/10/29: New maps added; Areas have been sprayed Wednesday and Thursday mornings and will be sprayed Friday morning (Oct 30), weather permitting.

Mosquito samples collected last week from two locations in the 78628 zip code in Georgetown have tested positive for West Nile Virus. The two positive tests were indicated in lab results received yesterday afternoon from the Texas Department of State Health Services lab in Austin.

The samples were collected in traps on October 20. The species of mosquito that tested positive for West Nile Virus was Culex quinquefasciatus, also known as the Southern house mosquito. This species of mosquito has a flight range of about one mile.

Due to the number of children and adults who will be outside in the evening for trick-or-treating on Saturday, the City is implementing insecticide spraying in the vicinity of positive samples. (See maps of spray areas at right. Click on the maps to see a larger version.) A City vehicle will use a permethrin-based insecticide along the street right-of-way and in public parks from 1 to 5 a.m. on Wednesday, Thursday, and Friday, weather permitting. The use of the insecticide is to reduce the adult mosquito population in the area. The City is developing a schedule with details on neighborhoods where spraying will be done and will publicize that schedule as soon as it is available.

The mosquito sampling and control effort is part of a county-wide program each year by the Williamson County and Cities Health District to trap and test the insects for West Nile Virus. The City of Georgetown participates with the health district in the program.

The City also continues to use larvicide tablets to treat standing water found on public property. “Every week in the warmer months, our employees are putting larvicide disks in standing water on public property,” says Ed Polasek, transportation services director. “We really need residents to help us by draining pans and flower pots and putting larvicide disks in puddles or ponds on private property.”

There have been no reports of human cases of West Nile Virus in Williamson County this year.

“With the recent rains and warm days ahead, I don’t expect our mosquito populations to drop for several weeks,” says Catherine Zettel Nalen, integrated mosquito management program specialist with WCCHD.

The City and the health district remind residents to practice the Four Ds to reduce the risk of bites or WNV exposure:

Dawn and Dusk are the times to try to stay indoors since those are times mosquitoes are most active.
Dress in long sleeves and pants when outdoors.
Drain standing water in flower pots, pet dishes, or clogged gutters so mosquitoes don’t have a place to breed.
Defend by using an EPA-approved insect repellent.

Eliminating places where mosquitoes can breed and reducing the chances of mosquito bites are the best lines of defense against exposure to West Nile virus.

For more information on West Nile Virus, go to the WCCHD website at wcchd.org or visit the Texas Department of State Health Services West Nile website at txwestnile.org.