The United States is likely to see outbreaks of the Zika virus, with perhaps dozens of people affected, according to the director of the U.S. National Institute of Allergy and Infectious Diseases (NIAID).

Dr. Anthony Fauci, director of NIAID, explained how the U.S. has seen over 350 cases of people who were infected abroad but has yet to confirm a case where someone was infected within the country’s borders.

“It is likely we will have what is called a local outbreak,” he said on Fox News Sunday. "There are only individual case reports of significant neurological damage to people not just the fetuses but an adult that would get infected.”

“Things that they call meningoencephalitis, which is an inflammation of the brain and the covering around the brain, spinal cord damage due to what we call myelitis," he said. "So far they look unusual, but at least we've seen them and that's concerning."

Zika, which is spread by the Aedes aegypti mosquitoes, primarily threatens pregnant women. The mosquito is present in about 30 U.S. states.

Despite growing concerns, Dr. Anthony Fauci said there is no cause for alarm for pregnant women in the United Stated about its spread but that women who are considering getting pregnant should take the travel warnings seriously and avoid affected countries.

Men who travel to Zika-affected areas also need to be careful, Fauci said, because it's now been confirmed that Zika can be transmitted from person to person sexually.

The Zika outbreak was first detected in Brazil and is spreading through the Americas. It has been linked to thousands of cases of microcephaly, a birth defect in which infants are born with brains of a smaller-than-normal size.

In February, the World Health Organization declared a global health emergency.

Fauci said the Center for Disease Control and Prevention is working on multiple ways to combat the virus, including working to develop a vaccine, controlling mosquito populations and working with state and local health authorities.