BALDWIN PARK, Calif. — Two more locally acquired cases of the mosquito-borne illness dengue have been detected in Baldwin Park residents, in addition to one announced last week, health officials said Wednesday, representing an "unprecedented" cluster of such cases in the region.

According to the county Department of Public Health, none of the patients had any history of travel to areas where dengue is endemic.

What You Need To Know

  • Two more locally acquired cases of dengue have been detected in Baldwin Park residents, in addition to one announced last week

  • Health officials noted that the symptoms of dengue often mirror those of other viruses, and they urged health-care providers to be "vigilant for dengue fever in patients"

  • The illness is generally spread by a bite from an infected Aedes mosquito

  • In October and November of last year, single locally acquired cases of dengue were confirmed by health officials in Pasadena and Long Beach

The cluster of three cases in Baldwin Park "is an unprecedented number of locally transmitted cases for a region where dengue has not previously been transmitted by mosquitoes," according to DPH.

In October and November of last year, single locally acquired cases of dengue were confirmed by health officials in Pasadena and Long Beach.

"These additional cases of local virus transmission are a stark reminder for all Los Angeles County residents that simple steps to prevent mosquito breeding and mosquito bites can lower the risk of mosquito-borne diseases and prevent more sustained transmission in the future," health officials said in a statement.

The illness is generally spread by a bite from an infected Aedes mosquito. Most patients never exhibit any symptoms, but one in four will develop signs including fever, nausea, vomiting, rash and aches and pains to the eyes, joints or bones.

The symptoms generally last no more than a week, and people usually fully recover within two weeks. Deaths from the virus are extremely rare, health officials said.

"Reducing exposure to mosquitoes and the risk for mosquito bites are crucial to preventing transmission of mosquito-borne disease, including dengue fever," Dr. Muntu Davis, Los Angeles County health officer, said in a statement. "This can be as simple as using insect repellent to prevent mosquito bites, eliminating any standing water around your home where mosquitoes can breed, and keeping your home mosquito-free by using or fixing screens on your doors and windows. These straightforward measures can significantly reduce the risk of mosquito-borne disease for both you and your neighbors."

Public Health officials said they are working with the City of Baldwin Park and the San Gabriel Valley Mosquito and Vector Control District to provide outreach to residents and offer information about dengue and ways to prevent mosquito bites. The Vector Control District is also increasing mosquito-trapping efforts in the area.

"The city will continue to update the community throughout this process," Baldwin Park Mayor Emmanuel J. Estrada said in a statement. "In the meantime, we urge all residents to use EPA-registered insect repellent, eliminate standing water around your homes and ensure your window and door screens are in good condition. Let's demonstrate the strength of the Baldwin Park community by working together to protect our community and limit the spread of dengue."