By Betty Yu

Berkeley (CBS SF) — A pregnant woman in Berkeley is now being tested for the Zika virus.

The Center for Disease Control says that the virus, which is carried by mosquitoes, has been linked to birth defects and that cases are on the rise.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases said that when Zika virus hits, There is an alarming incidence of what we call microcephaly in the fetus of the baby. And that is a developmental abnormality of small brain and many of these children die or if they’re born, they have a real difficult time following birth.”

At least five states have reported confirmed cases of the virus: Florida, Hawaii, Illinois, New Jersey and Texas. All patients were likely infected while abroad.

Dr. David Marinoff, an obstetrician at Alta Bates Summit Medical Center said the pregnant Berkeley woman who is being tested “was in an area where Zika has been reported — she came home after traveling and about a week after she got home she got a fever, she got a rash — potential Zika symptoms.”

The virus has hit Latin America and the Caribbean islands the hardest. Authorities in Brazil are reporting nearly 4,000 cases within the past year.

The CDC is urging pregnant women to hold off on traveling to 14 countries and territories where the virus has been detected. For the CDC’s list of those locations, click here.

Marinoff suggested that anyone in an area where Zika is prevalent should “use mosquito repellents – all the standard precautions – long sleeve clothes, long pants.”

The symptoms of the Zika virus are similar to those of dengue and chikungunya, which are diseases caused by other viruses spread by the same type of mosquitoes, according to the CDC.

Right now, there’s no treatment for the virus.

Doctors say the Berkeley woman won’t know if she has the Zika virus for certain, for about a week. They’re still awaiting confirmation from the CDC.