Extremely Rare Case Of Dengue Fever Reported In SoCal

LOS ANGELES, CA — California recorded its first-ever case of locally transmitted dengue fever in Los Angeles County, health officials announced. Dengue fever is extremely rare on the West Coast, and until now, it's only ever been linked to international travelers returning from countries where dengue is found.

The mosquito-borne disease is not endemic in California. The infected person lives in Pasadena, according to health officials.

"Our work so far, in partnership with the Vector Control District, gives us confidence that this was likely an isolated incident and that there is very low risk of additional dengue exposure in Pasadena," said Dr. Matthew Feaster, Pasadena Public Health Department Epidemiologist.

According to the PPHD, field teams are conducting surveillance and visiting a Pasadena neighborhood to offer information about preventing mosquito bites and breeding around their homes. Traps deployed by the San Gabriel Valley Mosquito and Vector Control District have not detected any mosquitos infected with dengue.

This year, more than 1,200 cases of dengue fever have been recorded in the U.S., with most cases detected in East Coast states such as Florida and New York, according to the Centers for Disease Control and Prevention. There have been 38 reported cases of dengue in California, according to the CDC — almost all linked to international travel.

See related: Mosquito-Borne Dengue Fever Cases On The Rise: What To Know In CA

People can be infected with the virus from a newly arrived Aedes aegypti, also known as an ankle-biter mosquito. Since they were first detected in California over the last decade, they've entrenched themselves statewide.

Atypical of other mosquitos that usually go for just one bite at dawn or dusk, Aedes mosquitos are aggressive and love to bite people during the day according to Aaron Arugay, Executive Director of Los Angeles County West Vector Control.

These mosquitos breed quicker in smaller containers than others. Their eggs can be found in any container with standing water, even something as tiny as a bottlecap.

"Anything that can hold water could be a breeding ground for the mosquitos," Arugay said. "A person could have 25 planters in their backyards and every single saucer could hold these mosquitos."

See related: CA Endures Worst Mosquito Season In Years. When Will It End?

The population of Aedes mosquitos exploded in California after Tropical Storm Hilary, which created more humid conditions across the state that allowed mosquitos to thrive.

Concerned about what the future holds, officials are studying new approaches to control the spread of mosquito-borne diseases, Susanne Kluh, General Manager of Greater Los Angeles County Vector Control District told Patch in September.

One approach would be to release sterilized males much like a similar, successful approach to managing the fruit fly population. Male mosquitoes don’t bite. It’s the females that bite to provide blood meals for their eggs.

“In Los Angeles and Orange counties, we have partnered up to assess whether we can irradiate male mosquitoes and release those to mate with wild females, resulting in sterile eggs,” she said.

That and similar approaches for reducing the mosquito population are a ways off from becoming a reality, said Kluh. However, Kluh said researchers are optimistic about the approach if it can be scaled to have widespread impact.

To combat the spread of Aedes mosquitos, vector control agencies recommended people get rid of all standing water. Most mosquitos lay eggs on the surface of the water, but Aedes mosquitos lay their eggs on the sides of containers so simply dumping out the water may not eliminate the bugs.

It's recommended that residents do away with plant saucers and keep repellant handy to help control the spread of the Aedes mosquito.

"We really stress people to get rid of all standing water," Arugay said.

Symptoms of dengue include fever, nausea, vomiting, rash and body aches. Symptoms usually last two to seven days and most people recover after about a week, though severe and life-threatening illness can occur, PPHD said.

There are no medicines or vaccines to prevent dengue fever, and most treatment includes rest, fluids and monitoring for early signs.

“Pasadena is working with healthcare providers to raise awareness of the signs and symptoms of dengue infection and is coordinating prevention efforts with local and state public health officials,” stated Interim Health Officer, Dr. Parveen Kaur. “Eliminating mosquito breeding sources is essential to reducing the spread of mosquitoes and the diseases they carry.”