In the Los Angeles area, the number of people bitten by mosquitoes that cause dengue fever is increasing

LOS ANGELES (AP) — Health officials warned Wednesday that there are more dengue fever cases in the Los Angeles area among people who have not left the mainland U.S., a year after the first such case was reported in California.

Public health officials said at least three people appeared to have contracted dengue fever this month after being bitten by mosquitoes in the Baldwin Park neighborhood east of downtown Los Angeles.

“This is an unprecedented cluster of locally transmitted dengue cases in a region where dengue has not previously been transmitted by mosquitoes,” said Barbara Ferrer, director of the Los Angeles County Health Department.

Other cases attributed to mosquito bites from the United States have been reported this year in Florida, the U.S. Virgin Islands and Puerto Rico, where authorities have declared a dengue epidemicAccording to the U.S. Centers for Disease Control and Prevention, there have been 3,085 such cases in the United States this year, 96% of which have been in Puerto Rico.

Cases of dengue fever have increased worldwide because climate change brings warmer weather, which allows mosquitoes to expand their range.

Dengue fever is often transmitted in tropical regions through the bite of infected Aedes mosquitoes. Although Aedes mosquitoes are widespread in Los Angeles County, local infections were not confirmed until last year, when cases were reported in Pasadena and Long Beach.

Previously, all cases in California were traced to travel to regions where dengue fever is widespread, such as Latin America, says Aiman ​​​​Halai, head of the department's vector-borne diseases division.

So far this year, 82 such cases have been reported in Los Angeles County among people returning from travel, Halai said. There have been 148 cases across California.

Dengue can cause high fever, rashes, headaches, nausea, vomiting, muscle aches, and bone and joint pain. About one in four infected people develop symptoms, which usually appear within five to seven days of being bitten by a dengue-transmitting mosquito. One in twenty people with symptoms develops severe dengue fever, which can lead to severe bleeding and be life-threatening.

Public health officials will visit households within 150 meters of the homes of those bitten, which is the typical flight range of the mosquitoes that transmit the virus, according to Ferrer.

Ferrer recommends that people use insect repellent and eliminate standing water around their homes, as these can be breeding grounds for mosquitoes.

Officials have tested mosquitoes for the disease but have not yet found any dengue cases in the San Gabriel Valley.