Already on a record-setting pace for bird infections, the county on Tuesday announced the year's first confirmed case of West Nile virus in a human.

A 24-year-old San Diego man had the flulike symptoms typical of West Nile before he developed meningitis and encephalitis -- swelling of the spinal cord and brain -- as a result of the mosquito-borne virus, said Dr. Wilma Wooten, county health officer. Wooten said the man was recovering in the hospital Tuesday.

"He spends a lot of time hiking on a regular basis, so it's quite likely he could have been exposed that way -- or anywhere he was spending time outdoors," she said.

In 2007, the county's first human case -- one of 15 -- wasn't diagnosed until the fifth week of August.

Since a red-shouldered hawk from Escondido tested positive on Jan. 10, there have been 120 confirmed West Nile bird deaths in the county -- more than all of 2007, which had 118 dead birds, according to county statistics.

Even in 2005, which had a total of 162 dead birds infected with the virus, only three of those birds had been found by August, said Chris Conlon of the county's vector control division.

"We've already got them coming in hot and heavy and we haven't even reached peak season," said Chris Conlon of the county's vector control division. Peak season is late August and early September.

"We could end up with a much longer season for transmission to humans," Conlon said.

Dead birds have been found all over the county this year, a disproportionate number of them in Oceanside.

In that city, 21 dead birds have tested positive. Tied for second place are El Cajon and Carmel Valley, each with seven dead birds.

West Nile primarily affects birds, but the virus can be transmitted to humans and other animals by mosquitoes that have fed on infected birds.

Most people infected with the virus don't get sick. But in rare cases, West Nile can cause serious brain swelling and lead to paralysis and even death.

Health officials urged the public to take precautions to avoid being bitten by mosquitoes, including wearing long clothes, using insect repellent and avoiding outdoor activity at dawn and dusk.

Standing water -- including inactive swimming pools, ponds, flower pots and puddles -- could be breeding spots for mosquitoes and should be eliminated or reported, county officials said.

To report dead birds or mosquito-breeding sites, call the county's West Nile Virus information line at (888) 551-INFO or visit the county's Web site at www.sdfightthebite.com.