Mosquitoes at East Wetlands test positive for West Nile

Mosquitoes in the East Wetlands Park have tested positive for West Nile Virus, prompting the Yuma County Pest Abatement District to issue a warning about going to the Colorado River at night.

“We had several positive samples from the East Wetlands mosquito sampling there during the last few days so it is probably best if people not have a lot of activity down in that area at night, and if they do, to make sure and use a lot of mosquito repellent,” said John Loghry, an administrator with Yuma County Pest Abatement District.

According to the Center for Disease Control, data available from the U.S. Environmental Protection Agency (EPA) has identified products that provide repellent activity sufficient to help people avoid the bites of disease carrying mosquitoes.

Products containing DEET, Picaridin or IR3535 work the best and are safe on the skin or clothing, the CDC reported.

According to the CDC, after being bitten by an infected mosquito, people typically develop symptoms between 3 and 14 days later. About one in 150 people will develop serious symptoms which can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent.

Up to 20 percent of people will develop milder symptoms including fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks, The CDC said.

The good news is that most people, about 80 percent, will develop no symptoms at all.

“It seems to be a recurring problem every year,” Loghry said. “There have been (a few deaths) in the state so far. Most people if they get bitten by a mosquito that has the virus, it doesn't affect them very much at all. There is just a small minority of people that can get some severe flu like symptoms like old people or very young children who don't have much resistance. Every once in a while they can die from it.”

According to the Center for Disease Control there have been 43 reported cases of West Nile and 3 deaths in Arizona so far in 2010.

That is by far the highest rate in the country with California coming in at second with 12 cases and no deaths reported.

“What we do is put up traps at dusk and bring them in at dawn,” Loghry said, explaining how data is collected.

“We run the samples — and we don't sample every mosquito — but if the presence of West Nile Virus is detected we try to get the word out.”

The presence of the disease can be found at other parts of the Colorado River as well, Loghry said.

“The positive samples have been found along the river at the East Wetlands and also on 8th street on the west end of town.”

There isn't much danger of becoming infected while the sun is shining, Loghry said.

“Its not a problem as far as West Nile Virus during the daylight hours. The variety of mosquito that transmits the West Nile Virus is actually only active from dusk until dawn. There are six types of mosquitoes that are widely found in this area but there is only one specific variety that carries the disease and can transmit it.”

If anyone has been bitten by a mosquito and develops flu like symptoms, they should seek a doctor, Loghry said.

Chris McDaniel can be reached a cmcdaniel@yumasun.com or 539-6849.