Last month, Texas health officials announced the state's first locally-contracted Zika case after a woman living in the Brownsville area, at the southernmost tip of the state, tested positive for the virus. Then, last week, officials with the Texas Department of State Health Services announced four more homegrown Zika cases, saying those additional patients who tested positive for Zika lived in "very close proximity to the first case."
It was enough for federal health officials on Wednesday to issue a travel advisory, telling pregnant women to avoid the Brownsville area if they can. In a statement Wednesday, the U.S. Centers for Disease Control and Prevention said that while there's no sign of "widespread, sustained" Zika outbreak in deep South Texas, the region's climate is conducive to a mosquito-borne spread and that "the risk of continued local spread cannot be ruled out."
"With the new information that there has been local spread of Zika for at least several weeks, we conclude that pregnant women should avoid the Brownsville area – and make every effort to prevent mosquito bites if they live or work there,” said CDC Director Tom Frieden in a prepared statement. “Together with Texas officials we are working to protect pregnant women from the potentially devastating effects of this virus.”
Scientists have linked Zika in pregnant women to children born with microcephaly, a condition where an infant is born with an unusually small head that doesn't grow and leads to stunted brain development. This summer, Houston-area health officials blamed the death of an infant there on Zika-related complications; the child's mother, who was from El Salvador, had become infected in Central America and arrived in Harris County during her second trimester. Later in the summer, state health officials reported Texas' first ever case of inter-state Zika transmission when an El Paso resident came down with the virus after a visit to Miami, where officials have battled local transmission of the virus for many months.
Luckily, according to state health officials, none of the people who contracted Zika around Brownsville were pregnant. You can see the CDC's full advisory here