Since the first years of the HIV/AIDS epidemic, the Department of Public Health has conducted surveillance to closely monitor the epidemic in our county. With new developments in laboratory technology, we continue to enhance our HIV/AIDS surveillance system. The Serologic Testing Algorithm for Recent HIV Seroconversion (STARHS) was developed to differentiate between long-standing and recent HIV infection. STARHS testing is the foundation of HIV Incidence Surveillance (HIS), a system that allows us to better identify groups currently at risk of acquiring HIV infection.
Estimate the number and rate of new HIV infections in LA County
Use these population-based estimates to:
Identify emerging epidemics,
Monitor trends in transmission,
Target prevention resources and interventions, and
Evaluate programs designed to prevent HIV transmission
Calculation of an accurate HIV incidence rate estimate requires data from both laboratories and HIV testing providers for every newly diagnosed HIV-positive individual.
HIV Incidence Data Components
Laboratories are asked to forward remnant blood from HIV positive tests for STARHS testing. Because people test at different frequencies, some individuals are more likely to test during the STARHS window period. To reduce this bias and increase the accuracy of the STARHS result, the calculation for the HIV incidence rate estimate incorporates HIV testing and treatment behavior data. We rely upon HIV testing providers to collect this information from every newly diagnosed HIV-positive client.
Testing and Treatment History consists of 4 data elements:
- The date of the first positive HIV test.
- The date of the last negative HIV test.
- The number of HIV tests in the two years prior to the first positive.
HIV Incident Estimates:
- Any history of antiretroviral use in the 6 months prior to the first positive.
2010 updates to the HIV Incident Estimate are forthcoming.
Incidence Surveillance Coordinator