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For Immediate Release:

October 01, 2018

First Human Case of Saint Louis Encephalitis in Los Angeles County Since 1997
Residents urged to use mosquito repellent to protect from mosquito bites

LOS ANGELES— The Los Angeles County Department of Public Health (Public Health) has identified the first human case of Saint Louis encephalitis (SLEV) in Los Angeles County since 1997. This is the first SLEV case in the state this year. The patient is an elderly resident of San Fernando Valley who became ill in late August. Environmental monitoring for SLEV in Los Angeles County began in early spring, and to-date one mosquito sample from Playa Vista has tested positive for the virus.

“Since Saint Louis encephalitis is transmitted to people through the bite of an infected mosquito, the best way to prevent getting infected is to prevent mosquito bites,” said Muntu Davis, MD, MPH, Los Angeles County Health Officer. “Residents should protect themselves by using EPA- registered repellent to keep mosquitoes from biting you, and checking for items that collect standing water in their homes or yards where mosquitoes can breed to tip out the water.”

Saint Louis encephalitis virus is similar to West Nile virus and can affect the nervous system and result in infections of the brain, paralysis and cause death. While all county residents are at risk for Saint Louis encephalitis, the majority of people infected with Saint Louis encephalitis virus have no or mild symptoms. People over 50 years of age or individuals with lowered immune systems are at greater risk of experiencing severe symptoms when infected. Symptoms of severe disease include fever, headache, stiff neck, confusion and decreased alertness. There is no vaccine to prevent Saint Louis encephalitis, and only supportive treatment is available. Anyone with symptoms should contact their health care provider.

Decrease risk of infection:

More information and resources:

Where to call with questions about mosquitoes:

The Department of Public Health is committed to protecting and improving the health of over 10 million residents of Los Angeles County. Through a variety of programs, community partnerships and services, Public Health oversees environmental health, disease control, and community and family health. Nationally accredited by the Public Health Accreditation Board, the Los Angeles County Department of Public Health comprises nearly 4,100 employees and has an annual budget of $1 billion. To learn more about Los Angeles County Public Health, please visit www.publichealth, and follow LA County Public Health on social media at ublichealth, m/lapublichealth and lapublichealth.