2006 HIV incidence and prevalence in Houston/Harris County, TX

In the past, incidence of HIV infection was often derived from back-calculation, summarized in retrospective chart review studies or measured in longitudinal cohort studies. These methods are often expensive, time consuming, logistically complicated, or inaccurate.

In the last decade, improved laboratory technology to measure the incidence of HIV infections has been developed for public health use. Serologic Testing Algorithm for Recent HIV Seroconversions (STARHS) can be performed on HIV-positive specimens to differentiate new infection from long-standing infections. When combined with testing history information which can be collected through public health surveillance system, STARHS results can provide an HIV incidence estimate at a population level.

Houston Department of Health and Human Services (HDHHS) will use HIV/AIDS Reporting System (HARS) surveillance and incidence surveillance data to generate HIV prevalence and incidence estimates. Multiple imputations and sensitivity analyses will be employed to generate HIV incidence estimates for the public sector and for the private sector if the data is available.

For the first time, the STARHS technology gives us an opportunity to determine whether newly diagnosed HIV individuals acquired the HIV virus within six months prior to testing at a population level. Comparing HIV incidence to prevalence data will allow us to track the leading edge of the HIV epidemic. Estimating the number of new HIV infections is crucial in HIV prevention planning, risk behavior assessment and resource allocation.