LOS ANGELES — Health officials warned Wednesday that the Los Angeles area is seeing more cases of dengue fever in people who have not traveled outside the continental United States, a year after the first such case was reported reported in California.
Public health officials said at least three people apparently became ill with dengue this month after being bitten by flies in the Baldwin Park neighborhood east of downtown Los Angeles.
“This is an unprecedented cluster of locally acquired dengue for a region where dengue has not previously been transmitted by mosquitoes,” said Barbara Ferrer, director of the Los Angeles County Department of Public Health.
Other cases stemming from mosquito bites originating in the United States have been reported this year in Florida, the U.S. Virgin Islands and Puerto Rico, where officials. they declared a dengue epidemic. There have been 3,085 such cases in the United States this year, of which 96% were in Puerto Rico, according to the US Centers for Disease Control and Prevention.
Dengue cases have been growing worldwide as climate change brings warmer weather that allows mosquitoes to expand their reach.
Dengue fever is commonly spread through the bite of infected Aedes mosquitoes in tropical areas. While Aedes mosquitoes are common in Los Angeles County, local infections were not confirmed until last year, when the cases. were reported in Pasadena and Long beach
Before then, the cases in California were all associated with people traveling to a region where dengue is commonly spread, such as Latin America, said Aiman Halai, director of the Unit of Disease Transmitted by Vectors of the department.
So far this year, 82 such cases have been reported in LA County by people returning from travel, Halai said. In California, there have been 148 cases.
Dengue fever can cause high fever, rashes, headache, nausea, vomiting, muscle pain and bone and joint pain. About one in four infected people will have symptoms, which usually appear within five to seven days of being bitten by a mosquito that carries dengue. One in 20 people with symptoms develop severe dengue, which can lead to severe bleeding and can be life-threatening.
Public health officials will conduct the spread to homes within 150 meters (492 feet) of the homes of the people who have died. It is the typical flight range of the mosquitoes that transmit the virus, according to Ferrer.
Ferrer recommended that people use insect repellent and eliminate stagnant water around their homes where mosquitoes can breed.
Officials have tested mosquitoes for the disease and so far have not found any in the San Gabriel Valley with dengue.