Human immunodeficiency virus testing pitfalls and clinical suspicion.

Area of Science:

• Infectious Diseases
• Virology
• Clinical Diagnostics

Background:

• Universal human immunodeficiency virus (HIV) screening was recommended in 2012, aiming to improve early detection and patient outcomes.
• Despite advancements in HIV testing technologies over the past decade, the identification of all HIV-infected individuals in the United States remains suboptimal.
• Current diagnostic strategies face challenges in detecting all cases, particularly in individuals with atypical serological profiles.

Observation:

• A case is presented of a man with clinical and laboratory evidence of acquired immunodeficiency syndrome (AIDS) who consistently tested seronegative for HIV.
• Standard diagnostic methods, including third-generation HIV enzyme immunoassays (EIAs) and Western blot tests, yielded nonreactive results.
• The patient's seronegativity persisted despite clear signs of advanced HIV infection.

Findings:

• Diagnosis was ultimately achieved using fourth-generation EIA testing, which detects both HIV antibodies and the p24 antigen.
• This contrasts with third-generation EIAs and most rapid HIV tests, which primarily detect antibodies.
• The fourth-generation EIA's ability to detect the p24 antigen likely facilitated the diagnosis in this seronegative individual.

Implications:

• This case underscores the critical need for frontline healthcare providers to possess a thorough understanding of various HIV screening methodologies and their inherent limitations.
• It emphasizes the importance of maintaining a high index of clinical suspicion for HIV infection, even in the presence of repeatedly negative standard test results.
• The findings suggest that fourth-generation HIV testing may be crucial for diagnosing cases that are missed by conventional antibody-based assays, improving diagnostic accuracy and patient care.