A comparative analysis of the different HIV testing techniques used in Zambia: data from a clinical performance study

The study compared the effectiveness of HIV testing methods used in Zambia, focusing on third-generation rapid diagnostic tests (RDTs) versus fourth-generation laboratory assays. Samples from 2,564 participants in Lusaka, were tested using OraQuick ADVANCE Rapid HIV-1/2 Antibody Test and Abbot Determine™ HIV-1/2 antibody test,  with reactive results confirmed using Uni-Gold™ Recombigen® HIV-1/2 rapid test. Blood samples were also sent to a laboratory and tested using the Abbott Architect HIV Ag/Ab Combo fourth-generation assay, treated as the gold standard. 

Results showed that while third-generation RDTs had high specificity (about 99.8 to 100%), their sensitivities were lower (about 91.8 to 93.3%). Of the 2 564 samples tested, 267 (10.4%) were positive by the laboratory standard. The rapid tests detected slightly fewer positives about 245 to 249 and the confirmatory rapid test detected 247. When compared with the laboratory test, the three rapid tests missed approximately 18 positive cases (about 6.7% of true positives). In practical terms, this means that roughly 1 in every 15 infected people would get a false‑negative result if only the rapid tests were used.

The findings showed that relying only on antibody-based rapid tests risks missing early HIV infections, when people are most infectious. The study supports revising national testing algorithms to incorporate fourth-generation or similarly sensitive methods to improve early diagnosis, speed linkage to treatment, and reduce onward transmission. Strengthening testing strategies is essential for better epidemic control in high-burden settings such as Zambia.