Pasadena Reports Extremely Rare Case of Locally-Acquired Dengue; Exposure Risk to Local Residents Remains Very Low

PASADENA, Calif.— Pasadena Public Health Department (PPHD) reports a case of dengue in a Pasadena resident who did not travel outside the United States. This is the first confirmed case of dengue in California not associated with travel and is instead an extremely rare case of local transmission in the continental United States. The risk of exposure to dengue for residents is very low and standard precautions are effective at preventing all mosquito-borne illnesses, including dengue.

PPHD is conducting surveillance and field teams have visited a Pasadena neighborhood to offer information for preventing mosquito breeding around their homes and preventing bites. In addition, the San Gabriel Valley Mosquito and Vector Control District has deployed traps to assess the mosquito population and, importantly, testing to date has not identified any Dengue infected mosquitos. Testing of mosquitos from additional traps will continue over the next few weeks.

A person can be infected with the dengue virus from an infected Aedes mosquito. Although Pasadena is home to the Aedes mosquito, the disease is not established (endemic) in California. In the U.S., dengue cases are typically seen in travelers who have visited countries where dengue is found.

“Pasadena Public Health Department has been conducting surveillance and investigation of mosquito-borne diseases in Pasadena for years,” stated Dr. Matthew Feaster, PPHD Epidemiologist. “Our work so far, in partnership with the Vector Control District, gives us confidence that this was likely an isolated incident and that there is very low risk of additional dengue exposure in Pasadena.”

Reducing mosquito populations decreases the chances of mosquito-borne diseases such as dengue and West Nile Virus. Mosquitos only need a small amount of stagnant water to breed, which can quickly result in mosquito breeding sites around your home and yard.

We urge the community to follow standard precautions to reduce mosquito populations and the risk of mosquito-borne diseases:

  • Eliminate standing water in clogged rain gutters, rain barrels, discarded tires, buckets, watering troughs, or anything that holds water for more than a week.
  • Ensure that swimming pools, spas, and ponds are properly maintained.
  • Change the water in pet dishes, birdbaths, and other small containers weekly.
  • Report neglected swimming pools in your neighborhood to your vector control district.

To prevent mosquito bites, PPHD recommends:

  • Wear insect repellent containing CDC and EPA approved active ingredients: DEET®, picaridin, IR3535, or oil of lemon eucalyptus.
  • Wear loosely fitted, light-colored, long-sleeved shirts and long pants.

Symptoms of dengue may be mild or severe and include fever, nausea, vomiting, rash, and body aches. Symptoms typically last two to seven days and although severe and even life-threatening illness can occur, most people recover after about a week. There are no specific medicines or vaccines to prevent this disease. Treatment is supportive and may include rest, fluids, and monitoring for early signs.

“Pasadena is working with healthcare providers to raise awareness of the signs and symptoms of dengue infection and is coordinating prevention efforts with local and state public health officials,” stated Interim Health Officer, Dr. Parveen Kaur. “Eliminating mosquito breeding sources is essential to reducing the spread of mosquitoes and the diseases they carry.”

To find your local vector district agency and for tips on mosquito prevention and approved mosquito repellents visit SoCalMosquito.org. Additional information regarding dengue is available from the California Department of Public Health and the Centers for Disease Control and Prevention.

The Pasadena Public Health Department is coordinating with the Los Angeles County Department of Public Health and the City of Long Beach Department of Health and Human Services, two partner local health jurisdictions in the Los Angeles region. On Saturday, Oct. 21, San Gabriel Valley Vector Control District is available to answer concerned resident calls from 7 a.m. to 7 p.m. at (626) 814-9466.

Stay connected to the City of Pasadena! Visit us online at CityOfPasadena.net; follow us on TwitterInstagram and Facebook; or call the City Service Center Monday through Friday during business hours at (626) 744-7311.