BALTIMORE (WBFF)-- The World Health Organization says Zika virus, spread through mosquitos in Central and South America and parts of the Caribbean, are present in at least 30 countries.
"We should definitely be concerned," said Dr. Matthew Laurens, associate professor at the Institute for Global Health's Center for Vaccine Development at the University of Maryland Medical Center.
"For most people who end up with Zika virus they are not actually symptomatic, so 80 percent won't even show symptoms, but there is also a danger there because they're the same people who could transmit the virus via mosquitos to other people in the community," Laurens said.
According to the Centers for Disease Control, the first case of Zika acquired in the U.S came Tuesday in Dallas, Texas.
Health officials confirmed a patient had sex with an infected traveler who returned from Venezuela.
In Florida, a warning has been issued in four counties because of the potential of mosquitoes spreading the virus there.
The virus has been linked to babies born with underdeveloped brains.
"Zika hasn't been a focus of research or vaccine development until very recently, just because we didn't know much about the virus or it wasn't much of a public health threat or it wasn't perceived to be," Laurens said.
The World Heath Organziation reports the mosquito-borne virus was first identified in Uganda in 1947 and later identified in humans in 1952 in Uganda and the United Republic of Tanzania. Outbreaks later occurred in Asia, Africa, the Americas and the Pacific.
Large outbreaks in French Polynesia and Brazil in 2013 and 2015 were linked to possible neurological issues linked to Zika, like microcephaly.
"The concern that microcephaly might be associated with Zika is definitely concerning and the increase in the number of cases of microcephaly in Brazil and in Colombia is something we should investigate," Laurens said.
The major concern is for pregnant women or women who are considering getting pregnant.
Laurens says health officials are recommending they avoid travel to areas where Zika is circulating.
Laurens says there are efforts at the National Institutes of Health to develop a vaccine, but obtaining a vaccine is a long road to development.
Health leaders say take precautions like using repellent, long sleeved shirts, or sleeping in screened rooms.
"For the concern about Zika reaching our shores and coming to the U.S. we should definitely be concerned. We should do what we can to inform ourselves and educate ourselves and try and understand more about the virus and the potential side effects," Laurens said.