West Nile virus detected in Harris County
No reported human infections yet in Texas
Contact(s): Dr. Mark Johnsen, 979-845-8597, m-johnsen@tamu.edu
Dr. Mike Merchant, 972-952-9204, m-merchant@tamu.edu
The virus was found June 9 in mosquitoes by Harris County’s mosquito control department, said Dr. Mark Johnsen, AgriLife Extension medical entomologist based in College Station.
The mosquito species that carries the virus, known as the southern house mosquito, is a common pest found in backyards and parks, Johnsen said.
“This mosquito species breeds in septic water found in roadside ditches, storm sewers, birdbaths or any container that holds water for more than seven days,” Johnsen said.
But there’s no need for anyone to panic, Johnsen said. AgriLife Extension officials made the announcement to make the public aware that the virus has returned, and people can take precautions.
The best defense against the pests through the late fall is to practice the four “Ds” of mosquito control, Johnsen said.
They include:
• Drain – dump, clean or cover all containers around homes and businesses that can hold water for more than three days.
• Dusk and Dawn – avoid outdoors during periods of peak mosquito activity.
• Dress – wear loose-fitting, light-colored, long-sleeved shirts and pants.
• DEET – use mosquito repellents that contain the active ingredient DEET during outdoor activities.
The virus was first identified in Uganda in 1937, Johnsen said. It was introduced in the U.S. in New York City in 1999 and resulted in 62 human cases and seven fatalities. The virus has since spread to the 48 contiguous states. Symptoms may be flu-like and include fever, headaches, skin rash and fatigue. Symptoms are treated as they arise as there is no vaccine for the virus.
More information about the mosquitoes can be found at: http://www-aes.tamu.edu/ .
Additional information can be found in English and Spanish by searching for mosquitoes at the online AgriLife Extension bookstore: http://agrilifebookstore.org/publications_search.cfm .
A Web site sponsored by AgriLife Extension also would be useful to people in areas that received recent rains, said Dr. Mike Merchant, AgriLife Extension urban entomologist in Dallas. The site, Mosquito Safari, can be found at http://mosquitosafari.tamu.edu/ .
“The core of the Mosquito Safari site is a virtual backyard that you can explore with your computer mouse,” Merchant said. “As you hit hot spots in the backyard, a window pops up and a narrator discusses what appears on the screen and how it relates to mosquito control.”
In addition to showing the most common places for mosquitoes to breed, the site discusses mosquito biology and control methods, including repellents for people and sprays for foliage. It describes what homeowners can do to prevent the insects from breeding in yards and alleys.
It also describes characteristics of six common mosquito species in the U.S., including their behavior and physical characteristics. Mosquito Safari was created as a user-friendly alternative to other Internet sites on the pests that are bogged down by “heavily text-oriented” pages, Merchant said.
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