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HIV Incidence Surveillance 

The goal of HIS is to provide national and area specific population-based estimates of the number of new HIV infections per year. HIS is a national effort developed and funded by the Centers for Disease Control and Prevention (CDC) and is a fully integrated component of routine HIV/AIDS case reporting/surveillance.  

Relying on diagnoses alone, routine HIV/AIDS case reporting is only able to provide a minimum estimate of HIV prevalence, the number of HIV-infected individuals in the population at a specific point in time, regardless of when they were infected.

By measuring new infections rather than only new diagnoses, and by applying a statistical algorithm to adjust for under-reporting and other relevant parameters, incidence estimates provide a window into the epidemic at an earlier stage of disease.  This makes it possible to more accurately assess the scope of the epidemic, its reach into population subgroups, and current indicators of HIV transmission risk.

Importance: HIV incidence estimates will be useful to

  • Estimate new infection rates overall and in demographic and geographic sub-groups
  • Identify trends in HIV transmission
  • Inform funding agencies and the community about the HIV epidemic
  • Allocate federal and state funds for HIV prevention and care services
  • Plan, implement, and evaluation HIV prevention and care services

Information needed to estimate HIV incidence from information and strategies to obtain this information

  • Results from a special laboratory test called the Serologic Testing Algorithm for Recent HIV Seroconversion (STARHS), which is able to distinguish between recent and long-standing HIV infection at the population level. These results are linked to newly reported HIV cases by:
    • Database linkage between the remnant specimen inventory and eHARS using accession numbers
    • Database linkage between electronic laboratory reports and eHARS using name and date of birth to identify additional accession numbers for the linkage above.
  • The patient’s HIV testing and treatment history, which includes information about the frequency of HIV testing and any antiretroviral therapy received prior to the first positive HIV test.  This information comes from:
    • Addendum forms supplementing the standard HIV/AIDS case report form (matched using the unique eHARS ID found in both eHARS and the addendum database)
    • Database matching between eHARS and the AIDS Regional Information and Evaluation System (ARIES) which contains testing history on some clients
    • Database matching between eHARS and syphilis/gonorrhea surveillance data (which records prior HIV testing history for some cases)
    • Database matching between eHARS and the Local Evaluation Online (LEO) system

For more information about HIS please contact:

Jessica Brown
HIS Project Coordinator
email: Jessica.Brown@cdph.ca.gov
phone: (916) 445-9231


Last modified on: 9/11/2014 1:17 PM