About HIV/STD Team

About Us

The HIV/STD Serology Team performs serological screening and confirmatory testing for clinics, hospitals, blood and plasma centers and physicians across the state of Texas. Five staff members perform testing to identify HIV (Human Immunodeficiency Virus), Sexually transmitted Diseases (STD)/Treponema pallidum, Hepatitis C, Chlamydia and Gonnorrhoeae. Specimens for HIV testing are serum, oral fluid and DBS (dried blood spot). Specimens for CT/GC (chlamydia/gonnorrhoeae) testing are urine, vaginal fluid, endocervical and male urethral swabs. Specimens for Hepatitus C and syphilis testing are serum.

Approximately 38,000 tests are performed per year for HIV (Human Immunodeficiency Virus) with a positivity rate of ≤1.5 percent. All initial reactives are tested an additional two times to verify. The HIV COMBO procedure (enzyme immunoassay) is an update from the older HIV procedure, which now includes testing for HIV-2, HIV-2 and the p24 antigen. This allows earlier detection of HIV and reduces the spread. All HIV reactive specimens are confirmed with the HIV Multispot. The team also tests ORAL fluid and DBS specimens. Oral fluid and DBS specimen testing are performed manually and the reactives are repeated in duplicate. These specimens are then verified by performing the Western Blot testing.

The HIV/STD Team syphilis (Treponema pallidum) testing totals approximately 26,000 per year with a less than 5 percent positivity rate. Syphilis is screened using a Syphilis IgG procedure. Reactives are confirmed using RPR (Rapid Plasma Reagin) and TP-PA (Treponemal pallidum Particle Agglutination). For a complete list of the tests performed in this section, along with descriptions of each disease, see the Serology Tests page.


Contact Us

Questions about testing or interpretation of results may be addressed to the HIV/STD Team at (512) 776-7657.

Last updated October 24, 2016