Birds in Concord Test Positive for West Nile Virus

It's fall, but high temperatures have kept mosquitos buzzing around Contra Costa County, contributing to five more cases of West Nile virus in local birds.

The Contra Costa Mosquito & Vector Control District (CCMVCD) announced Thursday that five more birds and one chicken have tested positive for West Nile virus. The birds were found in Brentwood, Concord, Discovery Bay, Pleasant Hill, and Walnut Creek. The chicken is part of sentinel flock located in Oakley.

The latest birds tested positive as an early October heat wave pushed temperatures in many Contra Costa County communities into triple digits, according to CCMVCD. The heat plays a significant role in both mosquito and virus activity.

"The mosquitoes that can transmit West Nile virus thrive in warm weather because higher temperatures allow them to complete their life cycles more quickly," said the District's Scientific Program's Manager Steve Schutz, Ph.D., in a press release from CCMVCD. "Higher temperatures also allow the virus to grow rapidly, increasing the chances that birds or mosquitoes can become infected."

How to Prevent West Nile Virus

The Contra Costa Mosquito & Vector Control District is asking all Contra Costa County residents to be vigilant about avoiding mosquitoes, and recommends the following: 

• Wear repellent when mosquitoes are present. 
• Dump or drain any standing water to prevent mosquitoes from having a place to lay their eggs.
• Report dead birds because they are often the first sign of West Nile virus in a particular location.
• Report neglected swimming pools by calling 925-771-6195 or visiting www.ContraCostaMosquito.com. One neglected swimming pool can produce 1 million mosquitoes that can affect people up to five miles away.
• Avoid being outdoors when mosquitoes are present, typically dawn and dusk.

Since 2005, 39 people in Contra Costa County have been diagnosed with West Nile virus, according to CCMVCD. In 2006, two people died from the disease.

A recent study from the California Department of Public Health titled, "West Nile Virus: Keep it On Your Radar," shows that the majority of cases are undiagnosed and grossly under reported.

This year, a total of two people, 19 groups of mosquitoes, 56 dead birds, and seven chickens have tested positive for the virus, according to CCMVCD. The number of mosquitoes, birds and chickens have already surpassed the number of insects and animals that tested positive for the virus in all of 2011. 

For current West Nile virus activity and to receive  emails when the District fogs for adult mosquitoes, visit the The Contra Costa Mosquito & Vector Control District website and sign up for automatic email notification. 

Symptoms of West Nile Virus

According to information from the Centers for Disease Control and Prevention, West Nile virus symptoms of the mild form include fever, headache, tiredness, body aches, and swollen lymph glands. While the illness can last only a few days, even healthy people have reported being sick for several weeks.

Less than one percent of individuals (about 1 in 150 people) infected with West Nile virus will develop severe illness. The severe symptoms 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. West Nile virus infection can be fatal.