Laboratory testing and rapid HIV assays: applications for HIV surveillancein hard-to-reach populations

Most HIV surveillance has been performed through serologic surveys in relat ively stable, accessible populations. Similar surveillance, with or without counseling and testing, in populations that are hard-to-reach, presents lo gistical challenges, including the selection of laboratory testing strategy and algorithm. The advent of rapid serologic assays for HIV now allows for on-site testing, including confirmatory testing, and rapid prevision of te st results and counseling. The possibility of only a single contact makes r epeat sampling, which current diagnostic testing recommendations include, d ifficult. To address the logistical complexities in surveillance in hard-to -reach populations and the increased availability of rapid tests, we propos e adapting the testing strategies for HIV of the World Health Organization/ the joint United Nations Programme on HIV/AIDS in order to facilitate this surveillance, including, where carried out, the provision of test results b ack to individuals. The choice of enzyme-linked immunosorbent assay (ELISA) versus rapid testing for these settings is discussed, as is the choice of specimen - blood, oral fluid, or urine. Three appendices summarize: (1) tes t algorithms for the various testing strategies; (2) advantages and disadva ntages of ELISA and of rapid test formats, and (3) the characteristics and status of currently available rapid HIV tests. We also discuss the potentia l application of the recently developed 'detuned' methodology for estimatin g HIV incidence in hard-to-reach populations. (C) 2001 Lippincott Williams & Wilkins.