ANAHEIM (CBSLA) – Several neighborhoods in Anaheim and Buena Park were sprayed this week to combat mosquitoes infected with West Nile Virus and other diseases.

Orange County Mosquito and Vector Control District crews conducted the spray for three consecutive nights, Tuesday through Thursday, running from 10 p.m. to 3 a.m., in a 4 1/2 square-mile area with more than 8,800 properties.

The area of Buena Park and Anaheim being sprayed for mosquitoes. (Orange County Mosquito and Vector Control District)

It comes after several mosquitoes tested positive for West Nile between North Dale Avenue and Euclid, south of the 91 Freeway to Ball Road.

The crews sprayed the insecticide DeltaGuard using truck-mounted application equipment. The pesticide will not harm people or pets, the district says. Residents do not need to do anything to prepare for the application.

Last month, a Tustin woman in her 50s was diagnosed with West Nile, the first such case in Orange County this season.

The Southland has seen more mosquito activity than usual this summer thanks in part to the record rainfall the region received this past winter. A similar pesticide spray was done in the Watts neighborhood of L.A. two weeks ago. That spray was targeting Aedes mosquito populations which can transmit diseases such as Zika, dengue, chikungunya and dog heartworm.

In July, two people in L.A. County were diagnosed with West Nile Virus, the first two cases there. West Nile is transmitted through the bite of an infected mosquito. The virus is mainly transmitted by mosquitoes in the Culex genus.