TITLE:
HIV Diagnosis in Resource Constrained Setting: How Good Is the Current Algorithm?
AUTHORS:
Nayana Ingole, Purva Sarkate, Supriya Paranjpe, Rahul Sarode, Sameer Shinde, Preeti Mehta
KEYWORDS:
HIV; Indeterminate; Discrepant; Rapid Tests; Western Blot; Algorithm
JOURNAL NAME:
World Journal of AIDS,
Vol.4 No.1,
March
4,
2014
ABSTRACT: Background: The
conventional HIV testing algorithm in most of the developed countries consists of two tests: an HIV enzyme immunoassay capable of
identifying HIV-1 and HIV-2 antibodies and a confirmatory HIV-1 Western
blot or immunofluorescence assay. However, the current algorithm for HIV
diagnosis in India uses three sequential antibody assays. There has always been
doubt regarding the benefits of this algorithm. Objective: To determine the
utility of the current diagnostic algorithm and to find out the proportion of
indeterminate or discrepant results. Methods: Retrospective analysis of HIV
antibody testing data was carried out over a period of five years after
institutional ethics committee approval. The
specimens positive with the screening test and negative with both the
supplemental tests were labeled as discrepant. Specimens positive with any of
the two tests (screening and one of the supplemental tests) and negative with
the remaining supplemental test were labeled as indeterminate. These
indeterminate specimens were confirmed by immunoblotting. Results: A total of 141,296
samples were tested. Of these, 71 (0.05%) samples were indeterminate and 292
(0.21%) were discrepant. Western blot was done on 60 indeterminate
samples of which 10 (16.67%) were positive for HIV 1 antibodies, 14 (23.33%)
were negative for HIV antibodies and 36 (60%) had indeterminate result.
Conclusion: In view of the low numbers of
indeterminate and discrepant results, the current algorithm appears to be
appropriate in our resource constrained setting. However, the algorithm for HIV
testing should also include DNA PCR testing facility to resolve western blot
indeterminate results.