Sept. 02--Torrential rainfall this spring is to blame for a significant increase in the number of mosquitoes testing positive for West Nile virus in York County.
York leads the state with 112 positive mosquito tests for West Nile virus, a potentially serious illness spread by the bite of infected mosquitoes, according to statistics provided by the state's Department of Health.
So far, that's an increase of 22 positive tests when compared to the number of York's positive tests in 2010.
All confirmed cases this year were found in mosquitoes, and no humans or birds have tested positive for the virus in York, said Tom Smith, coordinator of the York County West Nile Virus Program.
The state's first probable human case of West Nile this year was recently reported in an elderly Lebanon County woman who was hospitalized with a high fever and neurological symptoms, according to the state's Department of Health.
The wet weather conditions and warmer-than-usual temperatures in the spring prompted the county's West Nile Virus Program to start collecting
mosquito samples in the last week of April, rather than the third week of May, said Smith.
A high number of foreclosed homes and cluttered yards in York are also to blame for the increased mosquito population this year, he said.
"When homes are vacant, no one is there to take care of duties like emptying out containers and clutter that's filled with water from rain," he said, explaining mosquitoes are prone to laying eggs in containers filled with water.
Numbers climbing: Over the past two years, the number of positive West Nile tests in York have increased by more than 90, according to state numbers.
Mosquito cases of West Nile in York County rank significantly higher when compared to other counties because York does more surveillance than any county in the state, said Smith.
Several counties across the state experienced environmental staff reductions in wake of the state's budget cuts, he said. However, York County was able to keep its full seasonal staff to track West Nile virus, he said.
The increase is alarming because it suggests county residents aren't doing their part in controlling the population, Smith said.
For instance, so far this year, the county has sprayed for mosquitoes 16 times, compared to only four times last year, he said. However, if people don't eliminate places where mosquitoes lay their eggs, spraying for mosquitoes is only a temporary solution, he added.
"A tire or bucket filled with water on someone's property can produce thousands of mosquitoes," Smith said.
The county sprays for mosquitoes in an effort to reduce human risk of contracting the virus, he said, explaining the importance of residents cooperating with reducing clutter and emptying containers.
The danger: About one in 150 people infected with West Nile Virus will develop severe illness, with symptoms including high fever, disorientation or severe weakness, according to the Centers for Disease Control and Prevention.
Healthy people are generally able to fight off West Nile just as they fight off the flu and colds, he said.
However, people over the age of 50 or with weakened immune symptoms are at high risk of developing serious illness from West Nile, said Smith.
Mosquito tips:Tips residents can take to help reduce the mosquito population include:
-- Dispose of tin cans, plastic containers, ceramic pots, discarded tires or any object that could collect standing water. Drill holes in the bottom of recycling containers left outdoors
-- Have roof gutters cleaned every year, particularly if the leaves from nearby trees have a tendency to clog the drains
-- Turn over plastic wading pools and wheelbarrows when not in use
-- Don't let water stagnate in birdbaths
-- Aerate ornamental pools or stock them with fish
-- Clean and chlorinate swimming pools and remove standing water from pool covers
-- Use landscaping to eliminate standing water that collects on your property
-- Standing water that cannot be eliminated should be treated with Bti products, which can be found at outdoor supply, home improvement and other stores. Bti is a naturally occurring bacterium that kills mosquito larvae but is safe for people, pets, aquatic life and plants.
-- Reach Lauren Whetzel at 505-5432 or lwhetzel@yorkdispatch.com.
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