Los Angeles County health officials have reported a concerning increase in dengue fever cases among residents who have not traveled outside the U.S. mainland. This month, at least three people in the Baldwin Park neighborhood, located east of downtown Los Angeles, contracted dengue fever after being bitten by local mosquitoes.

The spike in cases is alarming, especially in a region where dengue had not been previously transmitted by mosquitoes. Barbara Ferrer, director of the Los Angeles County Department of Public Health, highlighted that this cluster is unprecedented and has prompted increased vigilance among health authorities.

Dengue fever, typically associated with tropical and subtropical regions, is caused by one of four types of dengue viruses spread through the bite of an infected mosquito, specifically the Aedes species. Symptoms can include high fever, severe headaches, muscle pain, nausea, and rash, with severe cases leading to life-threatening complications.

The rise in dengue cases in Los Angeles is part of a broader trend across the U.S., driven by warmer weather due to climate change, which allows mosquitoes to expand their range. This year, California has reported nearly 1,000 dengue cases, with 82 cases in Los Angeles County alone, primarily among travelers. However, the recent local transmissions in Baldwin Park mark a significant shift.

To combat the spread, residents are urged to take preventive measures, such as using insect repellent, wearing protective clothing, and eliminating standing water where mosquitoes breed. Public health officials are also enhancing mosquito control efforts in affected areas.