A male youth from the South Bay area is the first human case of West Nile Virus (WNV) infection in Los Angeles County for the 2015 season, according to health officials.

The patient, who had no prior medical history, was hospitalized for WNV disease mid-July and is currently recovering at home.

Los Angeles County map/Thadius856
Los Angeles County map/Thadius856

In 2014, Los Angeles County reported 253 human WNV cases with only Orange County reporting more.

One week ago, California reported the first WNV death in a Nevada County senior citizen.

“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,” said Truc Dever, General Manager for the Greater Los Angeles County Vector Control District. “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. Additionally, residents should report dead birds, and also report sources of standing water to their local vector control agencies.”

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.

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