Implementation of Opt-Out Testing and Change from 3rd to 4th Generation HIV Test Increases Acute HIV Diagnosis in an Urban Children’s Hospital

Background: The incidence of HIV infection is rising fastest among youth and approximately 59% of US youth aged 13-24 are unaware of their infection, compared with 16% in the general population with HIV. In 2006, the CDC recommended opt-out HIV testing in patients 13-64 years old regardless of risk, yet few pediatric hospitals have adopted this recommendation.  UCSF Benioff Children’s Hospital Oakland gradually implemented routine opt-out HIV testing in May/June 2014 and changed from the 3^rd generation (3^rd gen) to  the 4^th generation (4^th gen)HIV test almost exclusively in July 2014.

Methods: Opt-out testing was implemented in seven sites. The 3^rd gen test was used exclusively through June 2014 when 4^th gen test was initiated. A network of clinician champions increased buy-in and incorporated an electronic medical record prompt.  We compared testing method, the number of HIV tests performed and the incidence of Acute HIV Infection (AHI) from 2013 to early 2015 and projected numbers for the remainder of 2015.

 

Results: The implementation of opt-out testing increased the number of HIV tests from  1971 to 3176 between 2013 and 2014. To date in 2015, 1494 tests have been performed (projected to 4482 for all of 2015)(Figure 1). In 2013, 100% of testing was 3^rd gen. In 2014 and 2015, 4^th gen rapidly became the test of choice (55.3% and 90.8%, respectively).   No new HIV infection was identified in 2013, 4 new infections  in 2014 for a seroprevalence rate of 0.13%, and 1 new infection in 2015 (seroprevalence of 0.07%). One HIV infection was identified in 2014 with a 3^rd gen test.  The remaining 4 new infections were identified with 4^th gen.  Three of the five infections were AHIs (Figure 2).  Of note, 4 of 5 tests were false positive with 3^rd gen, while only 1 of 5 was false positive with the 4^th gen test. Linkage to care was successful for 80% of patients.

Conclusion: The move to opt-out testing increased the number of HIV tests performed in all sites.  The change from 3^rd to 4^th gen tests significantly increased identification of HIV infection and, more importantly, AHI while also decreasing the rate of false positive results. Identification of AHI in this population could have a dramatic impact on decreasing transmission at a time when the viral load is high.