According to the San Antonio Metro Health District, San Antonio is in the midst of a syphilis epidemic.
From 2011 to 2012, the number of cases of syphilis in adults went up 80 percent.
And with 500 cases accounted for last year, San Antonio has the highest rates in Texas, over Houston and Dallas.
"Every city has sexually transmitted diseases that are generated by sex that is traded for money and drugs," said Dr. Thomas Schlenker, with the San Antonio Metropolitan Health District. "And we have that here, too, in San Antonio, but why that is generating so much syphilis, that is something we don't know."
Schlenker said while it's unclear exactly why there is an overall increase, he said the lack of prenatal care may be to blame for the rise in the the number of babies being born with congenital syphilis.
In San Antonio in 2011, eight cases were reported to Metro Health. In 2012, there were 18. Five of the 18 were stillborn.
"Of those that survive, most of them will have serious, permanent injury," said Schlenker. "That can be apparent at birth (and) they may have heart defects (or) they may be deformed."
However, Metro Health is calling on all doctors to make sure that women give birth to healthy babies by making sure they get tested and treated while they are pregnant.
"Treatment for syphilis during pregnancy is very effective and safe," said Dr. Donald Dudley, with the University of Texas Health Science Center. "The most important work we have as physicians is to identify women who have syphilis."