At least seven people have been diagnosed with West Nile Virus in California, the first confirmed cases of the disease this year, state and county health officials said Thursday.

The Los Angeles County public health department reported that two adults were hospitalized this month and three other blood donors were found to have infected blood.

State public health officials said two other confirmed cases -- from Glenn County and Sacramento County -- were also infected. All three patients are now recovering, health officials said. State officials have not yet confirmed the L.A. County cases. 

West Nile Virus is spread through mosquitoes, which get the virus by biting infected birds. It is more common in the summer. The disease typically causes mild or no symptoms, but in rare cases can lead to serious illness or death. Elderly people are more at risk of the disease and of complications.

“This is not a virus to take lightly,” Kenn Fujioka, district manager for the San Gabriel Valley Mosquito and Vector Control District, said in a statement.

Though these are the first human cases of 2013, the state has detected the virus in birds or mosquitoes in more 30 counties.

In L.A. County, officials have found West Nile Virus in 89 mosquito pools and 93 dead birds.

Health officials warned residents to use mosquito repellent, avoid areas with mosquitoes around dawn and dusk and to get rid of any standing water in pools, gutters or pet bowls. They also urged residents to report dead birds by calling (877) 968-2473.

For more information about West Nile Virus, call (800) 975-4448 or check this web site.

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