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Public Health Awareness Advisory – Mosquitoes & Other Vectors

by Shelly Wolfberg05/07/2018 12:00 AM
Updated: 04/03/2019

EN_ZIKA_Website_Graphic_500x300_general - CopyPublic Health Advisory Overview

The Los Angeles County West Vector & Vector-Borne Disease Control District (District)  would like to share information on vectors and vector-borne diseases encountered in Los Angeles County and instructions on what to do and who to call.  Residents and visitors should follow the recommendations described in the following documents to reduce the risk of exposure to the following vectors and vector-borne diseases.

Public Health Awareness Advisory Mosquitoes & Other Insects and Vectors in Los Angeles County

Mosquitos and Other Insects and Vectors

West Nile Virus Advisory

Los Angeles County West Vector Control District and Vector-Borne Disease Map

Mosquitoes and West Nile Virus

West Nile virus (WNV) is primarily transmitted by infected mosquitoes. Since 2004, WNV activity has been detected in all 58 counties in California and surveillance efforts have shown that the virus remains active and is endemic throughout Los Angeles County. An endemic disease is a disease that is always present in a certain population or region. In 2017, 553 human infections and 44 deaths were recorded throughout the state. In 2017, in Los Angeles County, there were 266 human West Nile virus infections and 27 deaths.  The District joins public health agencies throughout the state to raise awareness and educate Californians about the threat mosquitoes can pose to local residents and families.  Residents of the District need to continue to be aware of mosquitoes and mosquito-borne diseases such as West Nile virus and Zika. Eliminating mosquito breeding in and around your home is the best way for residents to protect themselves and their families.  West Nile virus is transmitted to humans via the bite of infected mosquitoes, which become infected when feeding on birds carrying the virus. West Nile virus infections are often mild or asymptomatic, but the virus can cause significant cognitive and neurological symptoms in some patients, and possibly death.  The invasive Aedes mosquitoes are capable of transmitting deadly viruses such as Zika, chikungunya, and dengue fever. While these viruses are not currently being transmitted by mosquitoes locally in Los Angeles County, care should be taken not to allow breeding in and around your residence.  Residents can reduce the risk of mosquito bites by wearing repellent containing DEET®, Picaridin, Oil of Lemon Eucalyptus, or IR 3535 when outside during periods of mosquito activity, and ensuring window screens are in good condition. Residents should also regularly inspect the yard for standing water; tip out the water and toss out the source.

Invasive Aedes Mosquitoes and Zika Virus

Zika virus is primarily transmitted by Aedes aegypti (yellow fever mosquitoes) and possibly Aedes albopictus (Asian tiger mosquitoes). These non-native, invasive species primarily bite during the day and are now found throughout much of California, including Los Angeles County. Local transmission of Zika virus by these mosquitoes has not occurred thus far in California. All California cases have been in people who were infected while traveling outside the U.S.

For the latest information on the Zika virus, visit:

Los Angeles County Department of Public Health Website

California Department of Public Health Website

Centers for Disease Control Website

Africanized Honey Bees

Los Angeles County has been completely colonized by the Africanized honey bee since April 1999. The Los Angeles County West Vector Control District will remove non-structural beehives and swarms in the District's jurisdiction Monday through Friday from 8:30 a.m. to 3 p.m. with the exception of some height and safety limitations. If you wish to request removal of a bee swarm or colony outside a home or business in your area, please call (800) 825-3400.

Ticks & Lyme Disease

Lyme disease is a bacterial infection transmitted by the bite of the western black-legged tick, Ixodes pacificus. Studies have shown that approximately 1%-2% of western black-legged ticks found in the Santa Monica Mountains, Palos Verdes Peninsula, and other rural areas of Los Angeles County carry the Lyme disease bacteria. The adult western black-legged tick is most active from late November through May.

Red Imported Fire Ants

The red imported fire ant (RIFA) is a species of ant known for its aggressive behavior and painful sting. Red imported fire ant colonies have now been found in five Southern California counties, including Los Angeles. RIFA may infest lawns, gardens, golf courses and parks, where they pose a health threat to people, pets and wildlife. If a RIFA infestation is suspected in your area, please call (310) 915-7370 for a free inspection of the property.

Website & Public Education

We recommend that you visit the LA County West Vector Control District website for additional information on vectors and other services provided by the District.  Learn about the mosquito life cycle, the five “Ds” of defense, mosquito repellents, backyard breeding sites, mosquito fish, rain barrels, and mosquito-borne diseases such as West Nile virus, Zika, Dengue, Chikungunya, Yellow Fever, and Heartworm disease. There is even a Senior Center & Long Term Care recommendation and infection control risk assessment worksheet for the management of these type of facilities to use to identify areas of concern on their site. The website also provides weekly updates on West Nile virus activity within LA County and the LA County West Vector Control District by zip codes.

Public education is accomplished through the means of informational brochures, fact sheets, city bulletins, public speaking engagements, public service announcements, informational booths at community events, and the District website. District staff has an education program in the public and private elementary schools through a cooperative effort with the teachers.  The District provides each class with student and teacher workbooks, brochures, bookmarks, videos, and visual aids. District staff trains the teachers and encourages them to include the program as part of their yearly science curriculum. 

Please contact the District to schedule an event or if you are aware of an organization that may benefit from receiving the latest information regarding mosquitoes, West Nile virus, Zika, Lyme disease, or other vector-borne diseases.  For free hard copies of printed “Mosquito & Other Insects & Vectors” booklets, warning signs, or for further information, please contact Heather Teodoro or call her at (310) 915-7370 ext. 225.  The public may call 310-915-7370 to file a service request for an inspection or for personal assistance with any of the items listed above.

  1. Updated: 04/03/2019
  2. Updated: 05/31/2018