So far, only the second one of the Dallas County cases has been transmitted locally. The other five cases were contracted from mosquitoes in South and Central America and the Caribbean. Although the county health department has released almost no details about any of the Dallas County residents with Zika, a report from the CDC sheds new light on the local, sexually transmitted second Zika case.
In January, a man returned to Dallas from a weeklong trip to Venezuela, which is enduring an ongoing Zika outbreak. Two days after returning to Dallas, he developed a fever, rash and pink eye, all of which are potential effects of catching Zika. His symptoms lasted three days. Both the day before and the day after he became symptomatic, the man had unprotected sex with a Dallas man who developed Zika symptoms on the seventh day following the first man's return from South America.
The CDC says that there have been five instances of Zika being sexually transmitted in the United States, but the January Dallas case was the first to occur from man-to-man sexual contact. There has not been a mosquito-based Zika transmission anywhere in the continental U.S., but mosquito season has yet to warm up. Dallas County is home to both the Aedes aegypti mosquito, which has already proved an effective transmitter of Zika, and the Aedes albopictus mosquito, which researchers say could also transmit the virus.
Anyone traveling to areas in which a mosquito-based Zika outbreak is already occurring has been advised by Dallas County Health and Human Services to avoid mosquitoes upon their return to Dallas County. The county's Zika preparation will face a major test in August, when the Summer Olympics are set to kick off in Brazil.