More findings of West Nile virus in Murieta

No mosquitoes trapped in Rancho Murieta have yet tested positive for West Nile virus, the Sacramento-Yolo Mosquito and Vector Control District reported Wednesday.  The district placed traps to test mosquitoes after a dead bird found in Rancho Murieta earlier this month tested positive for the virus. Additional testing was done after a sentinel chicken tested positive last week, according to the district, and a second dead bird was found to have the virus.

In addition to the infected dead heron found July 6 near Laguna Joaquin, the district's West Nile activity map locates the infected sentinel chicken in the Fairways and a second infected dead bird, a western scrub jay collected Monday, on Murieta South Parkway near the South Gate.  The map approximates the locations to within 500 feet.

Sentinel chickens help researchers monitor viruses. The chickens are placed in different locations and their blood is tested regularly for antibodies.

West Nile virus is transmitted by infected mosquitoes to humans, birds, horses and other animals. Mosquitoes get the disease from infected birds while taking blood and can later pass it on when they bite animals or humans.

The district advises you to always use mosquito repellent when outdoors, especially at dawn and dusk, when mosquitoes are most active.  And inspect your home for any mosquito-breeding sources, like pools of standing water, even small ones.

While the risks should be taken seriously, this is not a cause for panic.

The district's online information says even in areas where mosquitoes carry the virus, very few mosquitoes are infected.  For people bitten by an infected mosquito, fewer than 1 percent will become infected and become seriously ill.  About 80 percent will experience no problems.

As for your pets, the district says they don't seem to exhibit the same symptoms as humans.  "It is unlikely that most pet owners would notice any unusual symptoms or behavior in cats or dogs that become infected...." the district says.  On the other hand, horses are very susceptible to the virus, and about one-third that become ill die or are euthanized.

Information about West Nile is available on the district's web site, fightthebite.net, where you can report a dead bird and download brochures.

Previous coverage

• Dead bird in RM tests positive for West Nile (July 20, 2012)