One week after confirming the city’s first case of the dengue virus, Long Beach health officials Thursday announced the first local case of another rare mosquito-borne ailment — St. Louis Encephalitis.

It is the first documented human case of the illness in Long Beach since 1984, according to the city Department of Health and Human Services.

The unidentified patient was hospitalized but is now recovering at home, health officials said, and no other cases have been identified.

According to city health officials, a total of 12 human cases of St. Louis Encephalitis have been confirmed across all of California this year.

“We are working diligently with healthcare providers to educate the community to prevent more cases of SLEV,” Mayor Rex Richardson said in a statement. “Mosquito control is a shared responsibility and residents must take an active role in reducing the threat of mosquito-borne illnesses in their neighborhoods.”

St. Louis Encephalitis is spread by culex mosquitoes, and the illness is in the same family as West Nile virus, with generally the same type of symptoms, Long Beach health officials said.

Most people who get infected with the virus do not develop symptoms, but those who do will generally experience fever, headache and nausea. People over age 50 or with underlying health conditions are more prone to experiencing more severe symptoms.

“Severe SLEV affects the brain and nervous system and can cause stiff neck, confusion, dizziness and sometimes death,” health officials said in a statement.

There are currently no vaccines or medicines to treat the disease, they added.

Health officials again urged residents to take steps to prevent and reduce mosquito populations, such as:

  • Eliminating standing water in clogged rain gutters, rain barrels, discarded tires, buckets, watering troughs, or anything that holds water for more than a week.
  • Ensuring that swimming pools, spas, and ponds are properly maintained.
  • Changing water in pet dishes, birdbaths, and other small containersweekly.
  • Reporting neglected swimming pools to vector control district.
  • Wearing insect repellent containing CDC and EPA-approved active ingredients such as DEET, picaridin, IR3535, or oil of lemon eucalyptus.
  • Wearing loosely fitted, light-colored, long-sleeved shirts and long pants.

Last week, Long Beach health officials announced the city’s first locally acquired case of the mosquito-borne dengue virus, which is normally associated with people who have traveled outside the country.

The local case was only the second of its type reported in California, with the first being reported roughly two weeks earlier by health officials in Pasadena.

Long Beach officials insisted the risk of exposure to both illnesses remains low.