Local mosquitoes are responsible for the dengue fever cluster reported in Los Angeles County.

On Wednesday, health officials in Los Angeles County, California, issued a warning about an "unprecedented" increase in dengue fever cases among residents who have not recently traveled abroad.

Local mosquitoes in the Baldwin Park neighborhood east of downtown Los Angeles have resulted in at least three cases of dengue among residents, according to Los Angeles County public health officials.

Dengue has not previously been transmitted by mosquitoes in the region where a new cluster of locally acquired dengue cases has been reported, according to Barbara Ferrer, director of the Los Angeles County Department of Public Health.

A year ago, the first locally acquired case of dengue was reported in California.

This year, dengue has been reported to spread from mosquito bites in Florida, the U.S. Virgin Islands, and Puerto Rico, where officials have declared a dengue epidemic.

This year, in the U.S., there have been 3,085 cases of a particular condition, with 96% of them occurring in Puerto Rico, as stated by the U.S. Centers for Disease Control and Prevention.

According to public health officials, dengue fever can manifest through symptoms such as high fever, intense headache, eye pain, muscle and joint aches, skin rash, and light bleeding.

Though symptoms may resemble those of other viruses, such as the flu, officials emphasize that the most severe cases of this virus can lead to shock, severe bleeding, and severe organ impairment, necessitating immediate medical attention.

The county health department, along with other agencies and the city of Baldwin, is conducting a door-to-door campaign to inform residents about the dangers of dengue and how to prevent mosquito bites.

Mosquito trapping is being intensified by officials to identify and test mosquitoes, thereby minimizing the risk of further spread in the community.

The Associated Press contributed to this report.