Resolution of Indeterminate HIV-1 Test Data Using the Department of Defense HIV-1 Testing Program

Abstract

The Department of Defense HIV-1 Test Program was designed to provide timely, accurate, and cost-effective HIV-1 testing services for military personnel. This program incorporated a comprehensive quality assurance and quality improvement program in conjunction with large-scale commercial contracts. Definitive diagnostic data were provided for all sera, and nondiagnostic data were resolved as either reactive or nonreactive using the described guidelines and test system. The program used Food and Drug Administration (FDA)-approved HIV-1 ELISA and Western blot methodologies in conjunction with CBre3 recombinant protein and radioimmunoprecipitation (RIPA) assays. The program has evaluated over 4.7 million serum samples. The ELISA repeat reactive rate was approximately 0.6%, and when Western blot and CBre3 tests were performed with the specified criteria, nondiagnostic Western blot data were reduced from 10% to 1%. The remaining nondiagnostic serum samples were analyzed with the third confirmatory procedure, RIPA, which successfully resolved all but 19 samples (0.0004%). These remaining samples were eventually resolved when additional serum samples were retested as previously described. The overall HIV-1 prevalence was determined to be 0.33/1,000, and the program at an average test cost of $4.55 successfully identified over 2,500 infected individuals. This testing program, which required the analysis of two separate specimens, had a false-positive rate estimated at 1 in 1,000,000.