A Southern House Mosquito, one of a number of breeds of mosquitos known to carry the West Nile Virus.

Mosquitoes trapped in Birmingham Township have tested positive for West Nile Virus (WNV), the Chester County Health Department reported Thursday.

Tests on mosquitoes collected in Birmingham, Schuylkill, Thornbury, Upper Uwchlan and Uwchlan Townships represented the first positive results in Chester County for the 2013 season, a Health Department news release said. The mosquito traps were placed in various locations in the county as part of routine surveillance by Health Department officials, who will continue to monitor these and surrounding areas and will consider control activities when appropriate, the release said.

The chance of contracting WNV from an infected mosquito is small and chances of becoming seriously ill are even smaller; however, the Health Department recommends that individuals take precautions to minimize the possibility of being bitten by infected mosquitoes. This includes staying indoors at dawn or dusk when mosquitoes are most active, wearing long-sleeve shirts and long pants when outside, and using insect repellents when mosquitoes are active. The heightened concern will probably remain until the first frost which usually occurs in mid-October, the release said.

The Health Department recommends the following precautions to reduce mosquito breeding:

• Dispose of open containers that may collect water, such as tin cans, plastic containers, ceramic pots, etc.
• Drill holes in the bottom of outdoor recycling containers so that water will not collect.
• Keep your property clear of old tires.
• Clean roof gutters, particularly if leaves from surrounding trees have a tendency to plug drains.
• Turn over plastic wading pools when not in use.
• Turn over wheelbarrows and don’t let water stagnate in birdbaths.
• Aerate ornamental pools or stock them with fish.
• Clean and chlorinate swimming pools when not in use. A swimming pool left untended by a family on vacation for a month can produce enough mosquitoes to result in neighborhood-wide complaints. Mosquitoes may even breed in the water that collects on pool covers.
• For stagnant pools of water that cannot be removed or drained, homeowners can buy Bti products, such as mosquito dunks at lawn/garden, outdoor supply, home improvement and other stores. This naturally occurring bacterial product kills mosquito larvae but is safe for people, pets, aquatic life and plants.