A 46-year-old man from south San Joaquin County tested positive Thursday for the West Nile virus making him the first human case this year, after last year’s recorded 10 human cases.

According to the county's Public Health Services Department, the man caught the neuroinvasive form of the illness, showing symptoms that could last for weeks, maybe resulting in neurological damage.

Officials would not say whether he is hospitalized but did mention he is receiving treatment.

The West Nile virus is spread by mosquitoes. Spraying actions to control adult mosquitoes populations will be carried out in Tracy on Saturday.

"There's a heightened alert for mosquitoes with the heat wave that we went through last week and all the foreclosures," said Karen McConnell, Public Health Services representative.

Some of the deserted homes have "green pools," which are swimming pools that are not being maintained thus becoming ideal breeding grounds for mosquitoes, said McConnell.

"We're trying to get people to realize it could be a bad year for West Nile," she added.

Approximately one in 150 people that have contracted the virus may develop West Nile neuroinvasive malady. Symptoms, which may persist several weeks, include neck stiffness, confusion, coma, tremors, convulsions, muscle weakness, numbness and possibly paralysis. According to the Public Health Services, neurological damage may be permanent.

According to Aaron Devencenzi of the San Joaquin County Mosquito & Vector Control District, the first mosquito and bird that tested positive for the West Nile virus in the county this year were located in the Tracy region. Three more people have been identified in California with West Nile virus, two of them in Stanislaus County and one in Tulare County, according to the info on California Department of Public Health's Web site.