Public Health Confirms Case of Locally Acquired Dengue

Dengue Fever Zika mosquito image from "Collections."

The Los Angeles County Department of Public Health Sept. 9 confirmed a case of locally acquired dengue in a resident in the City of Baldwin Park, who has no history of travel to areas where dengue is endemic. Cases of locally acquired dengue were previously confirmed by Long Beach and Pasadena in fall 2023. No additional suspected locally acquired cases have been identified at this time.

While the potential risk for widespread dengue virus transmission in Los Angeles County remains low, these cases highlight the presence of infected mosquitoes locally and underscore the importance of preventive measures to control the spread of this virus.

Dengue fever, transmitted primarily through the bite of infected Aedes mosquitoes, can cause flu-like symptoms including high fever, severe headache, pain behind the eyes, joint and muscle pain, rash, and mild bleeding. In severe cases, it may lead to dengue hemorrhagic fever or dengue shock syndrome, both of which require immediate medical attention.

Public Health is encouraging healthcare providers to be vigilant for dengue fever in patients with acute febrile illness and test for and report suspect cases of mosquito-borne diseases and to routinely discuss prevention strategies with patients and travelers.

Public Health is working with local vector control agencies, and its field teams are providing door-to-door information on dengue risk and mosquito bite prevention and control measures in the local area. In addition, the San Gabriel Valley Mosquito and Vector Control District has increased mosquito trapping for identification and testing and abatement operations to reduce the risk of additional spread in the affected neighborhood.

“This case further indicates that dengue fever is present in our community. While the likelihood of widespread transmission is low at this time, we must remain vigilant and prevent further cases through public education and mosquito control efforts,” said Muntu Davis, MD, MPH, Los Angeles County Health Officer.

Dr. Muntu continued to say, mosquitos thrive in hot weather, increasing the risk of bites and mosquito-borne diseases. People should follow these simple steps to reduce their exposure to mosquitoes and risk for mosquito bites:

1) Use insect repellent on you and your family;

2) Remove standing water outside your home where mosquitoes can lay eggs and breed; and

3) Use, install, or repair window and door screens to prevent mosquitoes from entering your home.

About Dengue

Dengue is a disease caused by a virus that spreads through the bite of an infected mosquito. Dengue is common in tropical and subtropical regions such as the Caribbean (including Puerto Rico), Central and South America, Southeast Asia, and the Pacific islands. Because the types of mosquitoes that spread dengue are common throughout many areas of the United States, local spread of dengue can occur. However, dengue is not commonly spread by mosquitoes in LA County. Most cases in LA County have been identified among those who have traveled to areas where dengue commonly occurs.

Symptoms of dengue typically last two to seven days. Most people will recover after about a week. About one in twenty people with dengue can develop severe disease which can be life threatening.

The most common symptoms of dengue are fever and one or more of the following:

Eye pain
Headache
Muscle, bone or joint pain
Nausea or vomiting
Rash

There are no specific medicines to treat dengue. There are supportive medicines to help with fever and pain. There is a vaccine for dengue, but it is NOT approved for use in U.S. travelers who are visiting but not living in an area where dengue is common.

The best way to reduce the risk of dengue and other diseases spread by mosquitoes is to avoid mosquito bites and take steps to prevent mosquito breeding:

Protect yourself: Mosquito repellents can keep mosquitoes from biting you. EPA-registered repellents containing DEET, picaridin, IR3535, 2-undecanone, and oil of lemon eucalyptus are the longest lasting and most effective. They are available as sprays, wipes, and lotions. Consider wearing long-sleeved clothes and pants when outside.
Mosquito proof your home: Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.
Reduce mosquitoes: Mosquitoes lay their eggs on standing water.
- Empty items that hold water inside and outside your home once a week
- Cover water storage containers such as buckets and rain barrels. If no lid, use wire mesh with holes smaller than an adult mosquito
- Clear standing water in flowerpots, saucers, birdbaths and other outdoor containers
- Clean and maintain swimming pools, spas and drain water from pool covers
- Throw away old items in your patio or yard that can hold water, e.g., old car tires and children’s toys
- Call 2-1-1 or visit www.socalmosquito.org to report persistent problems to your mosquito control district