The three cases of West Nile virus in San Diego County so far this year is a far cry from the number of cases in Orange County and the state as a whole, the county Department of Environmental Health reported Monday.
The three human infections locally is the most in five years, according to the county. West Nile virus, a potentially fatal illness passed to humans by mosquitoes, is found in the warmer months, generally through October.
By comparison, 157 West Nile virus cases have been reported in Orange County, 87 in Los Angeles County and 428 statewide, the DEH said.
"People need to remember to use insect repellents, wear long-sleeved shirts and pants if they're out at dawn or dusk when mosquitoes are most active, and to clear their yards of standing water where mosquitoes can breed," Department of Environmental Health Director Elizabeth Pozzebon said.
The infected in San Diego County were a 73-year-old La Mesa man and a 44- year-old El Cajon woman who became ill but recovered, health officials said. A 43-year-old man from Santee suffered no symptoms; his infection was detected when he tried to give blood.
County officials said they have found 21 dead birds infected with the disease — a dozen since the end of August — and two batches of mosquitoes that tested positive.
Of those who become infected with West Nile virus, 80 percent will have no symptoms, according to county health officials. About one in five people who are infected will develop only a mild illness that includes a headache, fever, nausea, fatigue, skin rash or swollen glands.
One in 150 will suffer serious neurologic complications that can become life-threatening. The risk of complications increases for those over age 50, and for people with weakened immune systems.
County officials urged people to prevent mosquito breeding by draining or removing backyard items that can hold water, such as plant saucers, rain gutters, buckets, garbage cans, toys, old tires and wheelbarrows.
Mosquito fish, available for free from county Vector Control, can be used to control breeding of the insect in water sources such as neglected swimming pools, ponds, fountains and water troughs.
Window and door screens should also be checked to make sure they are in good condition and secured.
Dead crows, ravens, jays, hawks and owls that don't show an obvious cause of death can be reported to Vector Control at (858) 694-2888.
Vector Control also will take reports on neglected swimming pools, which mosquitoes use for breeding.
