A chicken from the San Gabriel Valley Mosquito and Vector Control district tested positive for the West Nile Virus last month.
The chicken was part of the district’s vector borne disease surveillance system.
The chicken was discovered with antibodies of the West Nile Virus, commonly known as WNV, and blood tests from the California Department of Health Services and Rickettsial Disease Laboratory confirmed the results.
“Antibodies is the sign that the chickens are infected,” said Kelly Middleton, a spokeswoman for the San Gabriel Valley district.
The district keeps flocks throughout the city in order to prevent outbreaks.
“As part of the vector surveillance system, we keep 10 flocks of chicken throughout the city,” Middleton said.
The vector borne surveillance system is part of the district’s Integrated Pest Management program, also known as IPM.
According to the district’s Web site, the IPM is responsible for conducting “long-range and environmentally sound vector control.”
The program includes the vector surveillance system, “breeding source prevention and reduction, biological and chemical control, and public education.”
The chickens from the surveillance system are “tested every 10 days for antibodies,” Middleton said.
“Chickens don’t die like other birds do; like crows, they develop antibodies,” Middleton said.
The chickens from the surveillance system are also used to test for other diseases transmitted by mosquitoes such as the St. Louis encephalitis and the Western equine encephalomyelitis.
Wild birds like the sparrows and finches also help prevent disease breakouts.
Bird traps are placed near the chicken coops with food and water inside.
When the birds enter the traps a small blood sample is taken from them before they are released.
These blood samples are also tested for antibodies.
Although the chicken was the only one in the area to test positive, a great concern arose.
“WNV has potential to be year round,” Middleton said. “We are doing intense hunting trying to catch mosquitoes.”
As part of the surveillance system, technicians collect mosquitoes from pools by using carbon dioxide light traps.
According to the Web site, these attract “host seeking female mosquitoes. Trap counts of 50 or more per species allow…laboratory testing to determine if the mosquitoes are infected.”
“People should not panic. Mosquito populations are low,” Middleton said.
The district has used several methods to keep population levels low.
The Web site encourages districts to “minimize or eliminate the creation of sites capable of holding water” since female mosquitoes lay eggs in standing water.
When the sites of standing water cannot be eliminated, the district places artificial sites of standing water where mosquitofish are released.
According to the Web site, “these fish can eat up to 100 larvae per day per fish.”
Because the fish can only be released in artificial standing water, the district uses pesticides to control population levels.
These pesticides are environmentally safe, targeting mosquitoes at the larvae stage.
According to the Web site, “The naturally occurring bacteria…are highly specific and have been shown to have no harmful effects on non-target organisms.”
Although there have been no alerts of the West Nile Virus in the city of La Verne, residents are encouraged to take all preventative measures: Keep an eye out for standing water, keep pools and fountains clean, use repellents, and always contact the district in case of any suspicious activity.
“The vector control system has not requested to send any alerts,” said Steven Johnson, a councilman for the city of La Verne.
“It’ll become necessary if the system says it is…they have been aggressive to eradicate the West Nile Virus,” Johnson said.
Although the vector district has not sent out official alerts, some have been taking precautions on their own.
“In order to protect ourselves we need to keep ourselves informed through the media, news and organizations such as this one,” liberal studies major Diane Martinez said.
“People need to know that the WNV is out there in the environment…it has potential to be year round,” Middleton said.
Priscilla Segura can be reached at firstname.lastname@example.org.