Los Angeles County health officials have confirmed the county’s first case of West Nile virus for the 2018 season, using the diagnosis as a warning to residents to again step up efforts to prevent the spread of mosquitoes that can carry the disease. 

According to the county Department of Public Health, the patient lives in the San Gabriel Valley and was hospitalized in mid-May. 

Further details about the patient, including the person’s current condition, were not released Friday with the initial report. 

The county Department of Public Health does not cover the cities of Pasadena or Long Beach, which have their own health agencies, but neither city has yet reported any human West Nile cases. Riverside County officials confirmed two human cases Thursday. 

According to the California Department of Public Health, one other human case — in Kern County — has been reported so far this year, for a total of four statewide. 

“The announcement of the first human case of West Nile virus in San Gabriel Valley should serve as a reminder to residents to take steps to prevent mosquito bites and eliminate mosquito breeding on their property,” said Jared Dever, district manager of the San Gabriel Valley Mosquito and Vector Control District. “Taking just a few minutes to remove any standing water from your yard, apply recommended mosquito repellents and ensure your window and door screens are free of holes can help protect you and your community from this dangerous disease.” 

The virus is spread by mosquito bites. While many people who contract the disease may never show symptoms, people over age 50 or who have chronic medical problems are considered to be at higher risk of developing more serious health issues. 

The virus “can affect the nervous system and result in meningitis, encephalitis, paralysis and even death,” said Dr. Jeff Gunzenhauser, the county’s interim health officer. 

According to the county, an average of 221 annual cases of West Nile virus have been confirmed in the Department of Public Health’s coverage area over the past five years. Many of the reported cases have led to severe illnesses, and about 7 percent of patients with severe complications have died. 

Symptoms of the disease include fever, headache, nausea, body aches and a mild skin rash. 

   Health officials recommended that residents take precautionary steps such as: 

— avoiding mosquito-infested areas at dawn and dusk, when mosquitoes are more active; 

— wearing long-sleeved shirts and long pants while outdoors, particularly in areas where more mosquitoes are present; 

— using repellents containing DEET, picaridin, or oil of lemon eucalyptus; 

— checking window screens for holes; 

— dumping stagnant water; 

— cleaning and chlorinating swimming pools; 

— draining water from pool covers; 

— stocking garden ponds with goldfish or other mosquito-eating fish; 

— emptying and washing birdbaths and wading pools weekly; and 

— covering rain barrels and empty weekly.