Acute Detection and Early Prevention Trial

Terry Cunningham, San Diego County Health and Human Service Agency; Susan Little, UC San Diego
Basic-Applied Clinical

Critical insights about how to better design and implement HIV prevention interventions may come from better methods of identifying individuals with very recent HIV infection, since the risk of HIV transmission has been positively correlated with blood HIV RNA level and specifically primary infection. A recent study among discordant partners from Rakai, Uganda indicates that there is a 12-fold higher rate of HIV transmission from acutely and very recently HIV-infected individuals compared to individuals in the chronic, asymptomatic stage of infection [Wawer MJ, et al. JID, 2005].

The County of San Diego Public Health Services (PHS) and the University of California San Diego (UCSD) propose to evaluate the expansion of a pilot program of nucleic acid testing (NAT) to screen for acute HIV infection at five Rapid HIV testing and counseling sites in the County of San Diego. Currently, the County of San Diego PHS and UCSD are collaborating in the conduct of a NAT screening program for acute HIV infection named the "Early Test." The Early Test program uses Gen-Probe TMA FDA-approved technology to exponentially amplify captured HIV-1 and HCV RNA in blood samples. This assay allows for the simultaneous detection of all known HIV-1 and HCV subtypes with sensitivities designed to reduce the window period of false negative results from standard rapid HIV antibody testing (EIA). This pilot project has obtained Institutional Review Board approval and developed and implemented protocols and systems for: 1) training of HIV test counselors, 2) educating and consenting individuals presenting for NAT screening, 3) collecting demographic and risk behavior data from clients in a study database, 4) collecting, processing, shipping and tracking blood samples for NAT, 4) reporting negative NAT results to clients by novel automated voice mail and web systems, 5) reporting positive NAT results by contact tracing, 6) engaging NAT-positive clients into the County of San Diego funded programs for medical care, case management, and risk reduction services, and 7) Partner Counseling and Referral Services (PCRS) of partners of NAT-positive clients to interrupt subsequent HIV transmissions.

Terry Cunningham, as Chief of the HIV, STD, and Hepatitis Branch of PHS for the County of San Diego will serve as Principle Investigator, and Dr. Susan Little will serve as Co-Principle Investigator for UCSD. Expansion of this pilot project to multiple PHS HIV testing and counseling sites will allow us to evaluate the implementation, coordination, and costs of NAT systems in different locations, and the cost-effectiveness of NAT screening based on the prevalence of acute HIV infection in different testing populations. We will address the following specific aims: 1) expand the pilot NAT screening program for the identification of acute HIV infection to five County of San Diego HIV testing and counseling sites to perform 3,600 NAT screens over the course of the project; 2) perform an evaluation of the expansion of the NAT project in collaboration with Dr. Marcello Pagano at the Harvard School of Public Health; and 3) integrate the study evaluation with San Francisco-based collaborators (Dr. Klausner and Dr. Pilcher) to facilitate coordinated cross-cohort analyses of HIV incidence rates, transmission of HIV during primary infection, cost-effectiveness of NAT screening, and characterization of the demographics of acutely HIV infected clients.