First Zika infection transmitted in Texas, health officials suspect
Nov. 29--A woman in Cameron County on the Mexico border was likely infected with the Zika virus from a mosquito in Texas, the Department of State Health Services said Monday.
The woman is not pregnant and said she had not recently traveled to Mexico or other countries known to have "ongoing Zika virus transmission."
"We knew it was only a matter of time before we saw a Zika case spread by a mosquito in Texas," department Commissioner John Hellerstedt said in a news release. "We still don't believe the virus will become widespread in Texas, but there could be more cases, so people need to protect themselves from mosquito bites, especially in parts of the state that stay relatively warm in the fall and winter."
Authorities from Cameron County and the city of Brownsville have assessed the woman's home and are testing mosquitoes in the area.
"Health workers from Cameron County and DSHS will be going door to door in the area around where (the woman) lived beginning this evening to educate the public about Zika, help people reduce potential mosquito breeding habitat on their property, and collect voluntary urine samples to determine whether other infections are present," the department said in an email Monday.
Texas had 254 reported cases of Zika as of Nov. 22, all of which were associated with out-of-state travel. Zika in pregnant women has been linked to microcephaly, which is a birth defect that reduces the size of the baby's head and brain, and other problems.
Until now, only Florida has reported a localized transmission of the virus.
Dr. Peter Hotez, dean for the National School of Tropical Medicine at Baylor College of Medicine, has said for months that Zika has likely been spreading quietly in Texas, in part because the federal government was late in providing funding for active screening of patients.
He wasn't surprised by the report out of Brownsville.
"And don't be surprised if we see additional transmissions this year," said Hotez, noting that aedes aegypti mosquitoes, which transmits the virus, remain active through most of December in the warmth of South Texas. "It's not going to wind down immediately."
Most people infected with Zika show no symptoms, another reason why it's challenging to track the disease, said Dr. Scott Weaver, director of the Institute for Human Infections and Immunity at the University of Texas Medical Branch in Galveston.
The four most common symptoms among those who do become ill are fever, itchy rash, joint pain and eye redness.
"Almost certainly other people have been infected," said Weaver, who began studying Zika a decade ago, long before it began spreading rampantly in South America. "The best thing to do now is to make sure health care providers think Zika if they see someone with a rash."
Pregnant women and their partners also need to take special care, Weaver said. The disease can be transmitted sexually.
Hotez said it's likely that the virus is spreading more quickly in Mexico, where fewer people have screened windows and air conditioning.
"We were expecting this," said Esmeralda Guajardo, Cameron County's health administrator. "It was only a matter of when. So we're telling people not to panic, just take precautions."
Pregnant women and anyone showing symptoms will be offered a blood test, Guajardo said.
DSHS has delivered laboratory supplies, educational materials and mosquito traps to Cameron County. The federal Centers for Disease Control and Prevention also is providing assistance.
Once overnight temperatures are regularly below 60 degrees, Weaver said, peak season for the spread of mosquito-borne illnesses has passed. But the threat is likely to re-emerge in the spring.
"At this point, there's no reason to start testing people all over the region or all over Texas," Weaver said. "Not yet."
Houston Chronicle Staff Writer Mike Hixenbaugh contributed to this report.