By Dennis Thompson

HealthDay Reporter

(HealthDay)

TUESDAY, Aug. 16, 2016 (HealthDay News) -- In what appears to be the first case of Zika infection traveling across state lines, Texas health officials report that a resident of that state who visited Miami recently has tested positive for the virus.

The unidentified traveler had returned from the area of Miami where local transmission of the mosquito-borne virus has been reported, and sought testing after becoming ill, state health officials said in a statement Monday.

The Zika virus is typically transmitted via mosquitoes and can cause a transient illness. It is most dangerous to pregnant women, due to the virus' link to microcephaly, a devastating birth defect where babies are born with too-small heads and underdeveloped brains.

While there haven't been any reported cases of Zika being spread by mosquitos within Texas, health officials added that they are also prepared for that possibility. State efforts to curb any spread of Zika have been underway since January, according to the Texas Department of State Health Services.

Things are much worse in the U.S. territory of Puerto Rico, where federal health officials declared a public health emergency on Friday because Zika is spreading so rapidly among residents there. The number of Zika cases there now total 10,690, 1,035 of those being pregnant women.

The continental United States is also experiencing its first-ever local outbreak of Zika, in a one-square-mile Miami neighborhood called Wynwood. Florida health officials say there have been at least 28 local Zika infections.

The U.S. Centers for Disease Control and Prevention is urging pregnant women and their partners to stay away from Wynwood -- the first time the CDC has ever warned against travel to an American neighborhood for fear of an infectious disease.

The more than 1,800 Zika infections so far reported in the United States mainly have been linked to travel to countries with Zika outbreaks in Latin America or the Caribbean.

Most of the thousands of Zika infections recorded globally have so far occurred in Latin America and the Caribbean. Brazil, especially, has reported the vast majority of cases of Zika-linked microcephaly.

Meanwhile, the Obama administration said last week that it will transfer $81 million from existing federal health programs so there's enough money to continue trials of a Zika vaccine.

Money for the Zika vaccine research was to run out at the end of the month, USA Today reported.

Health and Human Services Secretary Sylvia Mathews Burwell said she will transfer $34 million from her agency to the U.S. National Institutes of Health and will transfer another $47 million to the Biomedical Advanced Research and Development Authority, the newspaper reported.

President Barack Obama had asked Congress back in February for $1.9 billion to help fight Zika, but lawmakers haven't been able to agree on a spending plan.

In other news, research on a potential vaccine for the Zika virus entered early clinical trials last week. Those trials are aimed at assessing the vaccine's safety in humans.

The DNA-based vaccine contains genetic pieces of the Zika virus. It is intended to promote an immune response that would protect against the mosquito-borne virus that can cause devastating birth defects, according to a statement from the U.S. National Institute of Allergy and Infectious Diseases (NIAID).

"A team of scientists here at NIAID worked tirelessly to rapidly develop this vaccine for clinical testing," Dr. John Mascola, director of NIAID's Vaccine Research Center, said in the statement.

At least 80 healthy volunteers aged 18 to 35 are to receive doses of the vaccine on differing schedules as part of a phase 1 clinical trial, the agency said.

Researchers will observe the volunteers during a 44-week period after their first dose, to monitor their health and determine if the vaccine is safe.

During follow-up visits, the study team also will take blood samples for lab testing to measure whether the vaccine is prompting an immune response sufficient to protect humans against Zika, the NIAID statement said.

U.S. officials said they don't expect to see a Zika epidemic in the United States similar to those in Latin America. The reason: better insect control as well as window screens and air conditioning that should help curtail any outbreaks.

In addition to mosquitoes, the Zika virus can be transmitted through sex. These infections in the United States are thought to have occurred because the patients' partners had traveled to countries where Zika is circulating, the CDC said.

The CDC advises pregnant women not to travel to an area where active Zika transmission is ongoing, and to use insect repellent and wear long pants and long-sleeved shirts if they are in those areas. Partners of pregnant women are advised to use a condom to guard against sexual transmission during pregnancy.

More information

The U.S. Centers for Disease Control and Prevention provides more information on mosquito-borne diseases.

This Q & A will tell you what you need to know about Zika.

To see the CDC list of sites where Zika virus is active and may pose a threat to pregnant women, click here.