First Human Case of West Nile Virus Reported in LA County

adult mosquitoesNews Release from LA County Dept. of Public Health

All residents should take precautions against mosquitoes

LOS ANGELES – The Los Angeles County Department of Public Health (Public Health) confirms the first human case of West Nile Virus (WNV) infection in Los Angeles County for the 2015 season (excluding counts in Long Beach and Pasadena). A male youth from the South Bay area with no prior medical history was hospitalized for WNV disease mid-July. The patient is recovering at home.

“West Nile can appear anywhere in Los Angeles County, and we are urging people to take precautions, such as getting rid of pools of stagnant water around their homes, and using a repellent containing DEET when outdoors, especially around dawn or dusk,” said Jeffrey Gunzenhauser, MD, MPH, Interim Health Officer for Los Angeles County. “All residents should take the proper precautions to avoid and protect against mosquitoes.”

Public Health will continue surveillance activities for WNV, including continuing to collaborate with local vector control agencies to target areas for mosquito control activities as well as assisting them in health education activities. While agencies such as the Greater Los Angeles County Vector Control District and the San Gabriel Valley Mosquito and Vector Control District are actively treating areas with high mosquito populations, residents are urged to do their part.

“Vector control agencies in LA County cannot do it alone. It is imperative that the public help minimize the risk of being bitten by removing sources of water on their property that can breed mosquitoes. This is not a virus to take lightly.”Truc Dever, General Manager for the Greater Los Angeles County Vector Control District

About West Nile Virus:

WNV is primarily spread to humans through the bite of an infected mosquito; mosquitoes can become infected by biting a bird that carries the virus. Most mosquitoes do not carry the virus and most people bitten by a mosquito are not exposed to the virus. The virus is not spread through person-to-person contact or directly from birds to humans.

In most cases, people who are infected with WNV do not become sick or have only very mild symptoms that include fever, headache, nausea, body aches, and a mild skin rash. Symptoms of WNV could appear within three to 12 days after infection. Fewer than one in 150 people who are bitten by an infected mosquito become severely ill, according to the Centers for Disease Control and Prevention. In rare cases, the virus can cause encephalitis and death. The elderly and those with weakened immune systems are most at risk for developing severe symptoms, which may require hospitalization. Recovery from any infection with the virus can take months to years and include symptoms of fatigue, malaise, and depression. There is no specific treatment for this disease.

It is normal for the first case of WNV to occur at this time of the year.  Cases can continue for several months.

Decrease risk of infection:

  • Avoid mosquito-infested areas at dawn and dusk.
  • Wear long-sleeved shirts and long pants whenever you are outdoors.
  • Repellents containing DEET, picaridin, or oil of eucalyptus, when used as labeled, are effective defenses against mosquitoes.
  • Check your window screens for holes.
  • Do not allow water to collect and stagnate in old tires, flowerpots, swimming pools, birdbaths, pet bowls, or other containers. These are prime breeding grounds for mosquitoes.
  • Clean and chlorinate swimming pools; drain water from pool covers.
  • Stock garden ponds with goldfish or other mosquito-eating fish. These eat mosquito eggs and larvae.
  • Empty and wash birdbaths and wading pools weekly.

More information:

Where to call with questions about mosquitoes:

  • Greater Los Angeles County Vector Control District: (562) 944-9656
  • Los Angeles County West Vector Control District: (310) 915-7370
  • San Gabriel Valley Mosquito and Vector Control District: (626) 814-9466
  • Antelope Valley Mosquito and Vector Control District: (661) 942-2917
  • Compton Creek Mosquito Abatement District: (310) 933- 5321
  • Pasadena City Health Department: (626) 744-6004
  • City of Long Beach Health and Human Services: (562) 570-4132

Report dead birds online at or call (877) 968-2473. Stagnant swimming pools or “green pools” should be reported to the Public Health’s Environmental Health Division at (888) 700-9995, or to a local vector control agency.