Background:  Since 2002, North Carolina’s Division of Public Health has used a novel HIV testing strategy under its Screening & Tracing Active Transmission (STAT) program. For all HIV tests performed at publicly funded testing sites, samples that are negative by enzyme immune assay (EIA) and Western blot are pooled and screened for HIV RNA to exclude acute HIV infection. Positive RNA results trigger urgent follow-up and partner notification. In 1 year, 23 acute HIV cases were identified. Average cost per test and case follow-up was $2.31 and $6564 respectively. The HIV⁺ rate with conventional testing was 0.55%. Our objective was to assess whether this was a cost effective use of resources for HIV prevention. 

Methods:  We excluded all positive cases found by conventional testing, and used a decision analysis modeling approach to estimate the parameters of interest. A decision tree provided the structure for linking program outcome and cost data with data on risk of HIV transmission by sexual, intravenous, and vertical means. We estimated the quality-adjusted survival and cost for the108,667 patients for 1 year with and without the program.

Results:  The expected savings from averting new HIV cases offset 22% of the testing costs. Reflecting conservative assumptions, we estimated 0.65 adult sexual or intravenous drug user partner infections and 0.20 vertical transmissions averted by 1 year of screening. We estimated 82 years of survival (or 44 discounted quality-adjusted life-years [QALY]) resulting from the averted cases. At a cost per QALY of $4345, the program appears to be well below the cost-effectiveness threshold of $50,000, which is often used as an indicator of good public health investment opportunities in the United States.

Conclusions:  Screening negative samples for acute HIV infection using a pooled RNA testing approach should be considered in all settings with at least a 0.55% positive HIV test rate where urgent notification and follow-up are possible.