CITYWIDE — County health officials issued a warning to Santa Monica residents after two dead birds found in the past three months in the city tested positive for the West Nile Virus.
The country has been experiencing the biggest outbreak of the disease since it first appeared in the United States in 1999, although half of the cases of human infection have appeared in Texas.
So far, 34 people in California have been infected compared to 19 at this time last year, according to a state-run website. The number of dead birds reported has also risen from 229 as of Aug. 22, 2011 to 805 reported birds so far this year.
The most recent bird to test positive from Santa Monica was an American crow found on July 23 in the 90402 zip code. American crows are members of the corvid family, which are particularly susceptible to the West Nile Virus.
The other, of unknown type, was found in May.
The presence of the two birds means that the virus could be in the community, said Dr. Nick Komar, a vertebrate ecologist with the arbovirus branch of the Centers for Disease Control and Prevention.
Officials from the Los Angeles County West Vector and Vector-Borne Disease Control District, based in Culver City, say that birds can die as many as 10 miles away from the actual infection site.
"I think we are lucky that the crows serve as the canary in the coal mine," Komar said.
The virus causes multiple organ failure in the birds, killing them.
"It allows us to see that there's activity out there," Komar said. "It takes something that's microscopic and turns it into something macro."
Scientists believe that the increase in the number of cases seen this year may have something to do with the heat.
Mosquitoes breed more quickly when it's hot outside and the virus itself grows more quickly in warm conditions, Komar said.
The two factors increase the chance that a person will be bitten by an infected mosquito.
Even so, chances of contracting the disease and showing symptoms are low.
People infected with West Nile Virus can have headaches, high fever, tiredness and body aches or a skin rash with swollen lymph glands anywhere between two and 15 days after they are infected.
According to the Control District, around 80 percent of the people who are infected with the virus will show no symptoms at all, and up to 20 percent will have mild aches or fever.
Only 1 percent will contract a severe infection, which results in convulsions, muscle weakness, stupor, disorientation, coma, tremors, paralysis and sometimes death.
An 88-year-old woman in Kern County was the first reported fatality from the virus this year.
People can avoid the virus entirely by mosquito-proofing their lives.
Use repellents like DEET, picaradin or the oil of lemon eucalyptus — all long-lasting products suggested by county health officials — to ward off the bugs, particularly at dawn and dusk when mosquitoes are most active.
Make sure that there are no bodies of standing water near the home, like water bowls for pets, rain gutters or old car tires in which mosquitoes can breed, and ensure that doors and windows have tight-fitting screens to keep them out.
Residents can also help by calling 1-877-WNV-BIRD to report dead birds, said Robert Saviskas, executive director of the Control District.
"What happens is that they'll get an operator who will take information about how long a bird has been there and what city it's in," Saviskas. "The bird cannot be dead for more than 24 hours for us to detect the virus."
ashley@www.smdp.com