The Los Angeles County Public Health Department said on Jan. 22 a pregnant woman is among a number of patients displaying symptoms of the Zika virus. Several doctors had reported patients with symptoms of the virus to the department.
The U.S. Centers for Disease Control and Prevention will carry out further tests on blood samples from the people affected. The CDC has so far has verified 12 cases in the U.S.
California does not have testing materials for the Zika virus, which was unheard of in the U.S. until recently, reports KNBC.
Cases of the mosquito-borne illness have been reported in Africa, Southeast Asia, the Pacific Islands and Central and South America. When it affects a pregnant woman, the disease is linked to microcephaly, where a baby's brain and skull do not develop properly.
On Jan. 22 the CDC added more countries and territories to its travel warning, which already includes most of the Caribbean and Latin America, including Mexico. The warning also applies to Puerto Rico and American Samoa.
The travel warning extends to Brazil, which is set to host the Olympic Games in summer 2016 in Rio de Janeiro, according to KNBC.
The number of people infected is quickly rising in Latin America with almost 4,000 cases in Brazil, according to KCAL.
“When you see a tenfold increase in the babies in Brazil of getting this birth defect, it is very real and it’s very much here,” said Sherry Ross, an obstetrician gynecologist at Providence Saint John’s Health Center in Santa Monica, California.
The CDC recommends those who must travel to the affected areas use mosquito repellant and cover exposed skin with long sleeves and pants.
Pregnant women must especially heed the advice of the CDC, as the virus could potentially pass through the placenta and infect the fetus.
Four of out of five adults who have the Zika virus do not show obvious symptoms. Symptoms in adults are often described as cold or flulike and are usually mild.
None of the potential Southern California cases have been established as Zika.
Around 5,000 doctors in Los Angeles have been contacted by the public health department as part of the Zika surveillance program being created, said Ben Schwartz, M.D., deputy director for the LA County's acute communicable diseases control program.
Zika is now considered "officially reportable as an unusual disease," Schwartz told KNBC.
Zika was originally a tropical disease and is carried by mosquitos of the genus Aedes. There is a recognized Aedes population in Los Angeles County, but no indication any have been infected with Zika, Schwartz told KNBC.
Returning travelers that may be infected with Zika are requested to stay indoors to reduce the risk of being bitten by a mosquito and becoming a carrier.