Los Angeles health officials issued a warning Wednesday after seeing a notable increase in dengue cases.
Three people in the Baldwin Park neighborhood were infected this month with no history of travel outside the United States.
Other localized cases have been traced to Pasadena and Long Beach.
“This is an unprecedented cluster of locally transmitted dengue in an area where dengue has not previously been transmitted by mosquitoes,” said Barbara Ferrer, director of the Los Angeles County Department of Public Health.
This case occurred just one year after the first case of locally transmitted dengue fever was reported in California.
Dengue fever is usually spread by infected Aedes aegypti mosquitoes in tropical climates, but authorities said the species has become common in urban areas, creating an environment ripe for localized outbreaks.
A photo of Aedes aegypti sucking blood on human skin. California public health officials are conducting outreach efforts within 150 meters of infected people’s homes. A photo of an Aedes mosquito sucking blood through human skin. California public health officials are conducting outreach efforts within 150 meters of infected people’s homes. Getty Images
Dengue fever, also known as “fracture fever” because it causes severe joint and muscle pain, has spread throughout the United States this year.
Nausea, patchy rash, and severe frontal headaches are also common.
Many believe that climate change is a major factor in the global surge in dengue cases.
As temperatures rise, the geographic range of mosquitoes expands, allowing the virus to spread to previously unaffected areas.
Florida, Puerto Rico, and the U.S. Virgin Islands have all recorded sharp increases in distribution.
According to the Centers for Disease Control and Prevention (CDC), there will be 3,085 dengue cases in the United States in 2023, 96% of which will occur in Puerto Rico, where a dengue epidemic has been declared.
Ferrer emphasized that Los Angeles, with its increasingly warmer climate, is not immune to these changes.
Stock photo of the coast of Long Beach, California. Localized cases of mosquito-borne dengue fever have been traced to Long Beach, Pasadena and Baldwin Park. Stock photo of the coast of Long Beach, California. Localized cases of mosquito-borne dengue fever have been traced to Long Beach, Pasadena and Baldwin Park. Getty Images
Dengue fever can cause a variety of symptoms, including high fever, severe headache, rash, and muscle, bone, and joint pain.
Although most people recover within a week, about 1 in 20 people with symptoms develop severe dengue fever, which can lead to life-threatening complications such as severe bleeding.
In Los Angeles County, public health officials have reported 82 dengue cases this year, all of which until recently were linked to travel to countries where the virus is endemic.
A total of 148 cases have been recorded across California this year.
Public health officials are now focused on contacting people within a 150-meter (492-foot) radius of infected people’s homes, the typical range of the mosquitoes that carry dengue, to prevent the spread.
Ferrer urged people to take simple measures, such as using insect repellents and eliminating standing water where mosquitoes breed.
The county has increased testing for dengue mosquitoes and continues to closely monitor the situation.
No mosquitoes have yet tested positive for the virus in the San Gabriel Valley, but officials fear the situation could spread if preventive measures are not taken.
Currently, it is estimated that 390 million dengue infections occur each year, of which more than 96 million cause clinical symptoms.
This article includes reporting from The Associated Press
