HIV Incidence Assays

The discussion generated by this, quite complex topic, was stimulating. CDC reported that a dried blood spot sample gave comparable performance to a liquid serum/plasma sample, an obvious practical benefit in much of the world. They were reporting on performance for one of the available tests trying to infer recent infection rates, the Limiting-Antigen Avidity EIA. Then 2 other presenters raised issues about the rate of miscalculation of this recently licensed  LAg test, and the evidence that Clade D infection really confuses it. Finally, Alex Welte expressed his groups reservations about relying on any one of the 5 available tests yet, saying that viral suppression, by ART or being an elite suppressor, were 2 major causes of error. Issues then discussed were whether there was any agreement about what should be defined as the cutoff time for a recent infection, whether there should be an agreed viral load limit to incorporate in an algorithm, what would be an acceptable level of "False Recent Rate", how great the lag time would be between the current recent infection rate, and Incidence calculation "look back" rate, and whether combining 2 of the assays would make results reliable. Although work on improving these current tests and algorithms is proceeding in a somewhat cooperative way, new bio marker research is also being funded hoping to find a single novel marker to overcome current limitations. Bottom line, we could probably use these tools now if we didn't need to believe they were totally accurate. Abstracts  #1005,#1006, #1007, #1008