The start of West Nile virus season was marked by the county’s first reported case of the rare but potentially fatal human disease this year in a dead bird found in the Industrial City.
The dead bird was found by a resident in South San Francisco on May 15 and was taken by authorities to the <a title=”California Department of Health Services” href=”/Subject-California_Department_of_Health_Services.html” target=”_blank” onClick=”var s=s_gi('examinercom'); s.tl(this,'o','Entity Link'); ” >California Department of Health Services. The state agency determined Wednesday that the bird died from the West Nile virus, officials said.
After a total of two birds and a squirrel tested positive for the disease last year in San Carlos and San Mateo, the South City bird was the first infected animal found in 2008, said Chindi Peavey, vector ecologist for the county Mosquito and Vector Control District.
No human in the county has ever contracted the disease, which is typically transferred through infected mosquito bites, Peavey said.
If infected, humans can suffer severe headache, fever, chills, muscle weakness and can even enter a coma or, in rare cases, die.
“It’s nothing for people to panic about,” Peavey said. “Every year we get a few positive West Nile virus birds.”
Mosquito-catching devices will be placed around the area where the bird was found. The traps are one-quart vacuum flasks, underneath which hangs a battery-operated motor. The flask contains dry ice that emits carbon dioxide, tricking the mosquitoes into thinking it is a person.
When the bugs enter the flask, they get sucked through a three-foot tube and into a bag. Typically, 30 of those devices are hung on trees around the county twice per week.
The district also has technicians that spray and drop pellets and briquettes containing nontoxic, mosquito-specific bacteria in areas prone to the insects.
Typically, West Nile virus season begins in summer, Peavey said. The most common birds that acquire the virus are ravens, crows and blue jays.
Some other animals can become infected as well, but the only common one is a squirrel.
The Mosquito and Vector Control District relies on residents to report potentially infected species.
The district advises residents to call (877) WNV-BIRD if they find a dead bird or squirrel so it can be tested.