Real-life evaluation of a human immunodeficiency virus screening algorithm using a single combined p24 antigen–antibody assay

• Published in: European journal of clinical microbiology & infectious diseases Vol. 32; no. 3; pp. 425 - 430
• Main Authors: Fanmi, A. N., Ramière, C., Tardy, J. C., André, P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.03.2013; Springer; Springer Nature B.V
• Subjects: Algorithms; Antibodies; Antigens; Architects; Automation; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Clinical Laboratory Techniques - methods; Diagnostic Errors - statistics & numerical data; Enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - methods; Enzymes; France; HIV; HIV Antibodies - blood; HIV Core Protein p24 - blood; HIV Infections - diagnosis; Human immunodeficiency virus; Human immunodeficiency virus 1; Human viral diseases; Humans; Immune system; Immunoassay; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; Immunopathology; Infection; Infections; Infectious diseases; Internal Medicine; Laboratories; Male; Mass Screening - methods; Medical Microbiology; Medical sciences; Polymerase chain reaction; Real-Time Polymerase Chain Reaction; RNA; RNA, Viral - blood; Sensitivity and Specificity; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids; Virology; Virology - methods; France; Germany; Human Immunodeficiency Virus Screening; Human Immunodeficiency Virus Infection; Grey Zone; Human Immunodeficiency Virus; Gp36 Antibody; Immunopathology; Microbiology; Retroviridae; AIDS; Medical screening; Enzyme immunoassay; Immune deficiency; Lentivirus; Algorithm; Infection; Virus; Viral disease; Human immunodeficiency virus
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-012-1760-1

Since May 2010, human immunodeficiency virus (HIV) screening in France has been performed using a single combined fourth-generation assay. One of our major concerns is to verify that this screening strategy is able to diagnose HIV primary infection as soon as possible. Thus, the sensitivity and specificity of this strategy were evaluated on 49,623 serum samples, including 29 primary infections, received for routine HIV testing between September 2010 and November 2011. Specimens were screened using the Enzygnost HIV Integral II enzyme-linkedimmunosorbent assay (ELISA) kit. All positive sera, according to the manufacturer’s recommendations [signal-to-cutoff ratio (S/CO) ≥ 1] were retested using the Architect HIV Ag/Ab Combo. Moreover, we defined a grey zone (0.5 < S/CO < 1) and sera within this grey zone were retested using the VIDAS HIV DUO Ultra test and HIV-1 RNA was checked by the Abbott RealTime PCR kit. Screening tests were positive for all primary infections. All samples within the grey zone proved VIDAS HIV DUO Ultra and HIV-1 RNA negative. Overall, the ELISA test sensitivity and specificity were 100 and 99.79 %, respectively. The false-positive rate was higher when S/CO was in the low range (1 to 5). Adding a second screening test for positive sera reduced the false-positive rate from 0.20 to 0.02 %. HIV screening with a single combined assay did not miss any documented primary infection during this evaluation period, even without extending the positivity zone.