An alternative strategy to western blot as a confirmatory diagnostic test for HIV infection.

Background: In China, western blot (WB) is the recommended procedure for the diagnosis of HIV infection. However, this technique is time consuming and labor intensive, and its complexity restricts wide application in resource-limited regions.

Objective: The aim of this study was to evaluate the efficacy of a dry blood spots (DBS)-urine paired enzyme-linked immunosorbent assay (ELISA) test, instead of WB, for HIV antibody detection.

Study Design: Plasma, DBS, and urine samples were collected from 1213 subjects from different populations. Two diagnostic testing strategies were conducted in parallel. The equivalence of the paired ELISA and WB strategies was assessed.

Results: A diagnosis of HIV was determined in 250 subjects according to the paired ELISA test, and in 249 according to the WB strategy. The discordant case was judged HIV-positive during follow-up. In total, 18 subjects were diagnosed with possible HIV using the paired ELISA test, among whom, 11 subjects tested negative with WB, and one was confirmed to be HIV-positive during follow-up. For the remaining 945 subjects, both strategies indicated a negative result. The kappa test indicated good conformity (kappa=0.954) between the two diagnostic strategies.

Conclusion: The DBS-urine paired ELISA could be applied as an alternative to WB in HIV diagnosis, which would be valuable in resource-limited regions owing to the associated affordability and ease of use.