What is HIV Incidence Surveillance?
HIV Incidence Surveillance (HIS) is an expanded HIV/AIDS surveillance activity funded by the Centers for Disease Control and Prevention (CDC). The objective is to provide national and local population-based estimates of the number of new HIV infections per year.
Incidence Surveillance employs the serological testing algorithm for recent HIV seroconversion (STARHS). Leftover serum from the HIV positive diagnostic specimen is tested with a special assay that detects HIV-specific antibody. A person's HIV testing and treatment history is gathered in conjunction with the completion of the HIV case report. Both the result of the antibody test and the testing and treatment history of each newly diagnosed person are necessary components of the STARHS algorithm that is used to estimate HIV incidence.
The laboratory assay that measures the concentration of HIV-specific antibody present in the leftover diagnostic serum is called the BED assay. The result may provide an indication that the infection occurred recently.
Laboratories conducting Western blot or other HIV confirmatory tests are requested to submit leftover sera for incidence surveillance. Incidence surveillance is a part of HIV/AIDS case surveillance conducted under Washington Administrative Code legal authority (WAC 246.101).
In early 2005, the BED assay replaced the less sensitive EIA (LS-EIA) as the official STARHS assay. Because the BED assay was designed solely for surveillance purposes, patient consent is not required and results are not allowed to be returned to patients or their healthcare providers.
This article describes the development of the BED assay:
Quantitative detection of increasing HIV Type I antibodies after seroconversion: A simple assay for detecting recent HIV infection and estimating incidence (PDF)
Testing and treatment history:
Information about a person's HIV testing and treatment history is collected for each person who is newly diagnosed with HIV. This information is collected on the adult HIV/AIDS case report form. A person's frequency or pattern of HIV testing is important for knowing the probability that a person would be identified as recently infected.
National HIV incidence
In 2008, the CDC published the first national HIV incidence estimate this methodology. The analyses showed that in 2006, an estimated 56,300 new HIV infections occurred (abstract).