Prolonged second diagnostic window for human immunodeficiency virus type 1 in a fourth-generation immunoassay: Are alternative testing strategies required?

Abstract

Diagnosis of acute HIV is done by patient history and examination and testing of RNA, proviral DNA, and serology using fourthgeneration antigen/antibody detection assays. We describe an HIV-1 primary infection with a second diagnostic window of 18 to 34 days on a fourth-generation immunoassay, which would have been missed using some current algorithms. Caution must be exercised when fourth-generation HIV-1 immunoassays are interpreted in isolation, and additional testing should be considered depending on patient risk assessment.