HIV misdiagnosis in sub-Saharan Africa: performance of diagnostic algorithms at six testing sites

J Int AIDS Soc. 2017 Jul 3;20(1):21419. doi: 10.7448/IAS.20.1.21419.

Abstract

Introduction: We evaluated the diagnostic accuracy of HIV testing algorithms at six programmes in five sub-Saharan African countries.

Methods: In this prospective multisite diagnostic evaluation study (Conakry, Guinea; Kitgum, Uganda; Arua, Uganda; Homa Bay, Kenya; Doula, Cameroun and Baraka, Democratic Republic of Congo), samples from clients (greater than equal to five years of age) testing for HIV were collected and compared to a state-of-the-art algorithm from the AIDS reference laboratory at the Institute of Tropical Medicine, Belgium. The reference algorithm consisted of an enzyme-linked immuno-sorbent assay, a line-immunoassay, a single antigen-enzyme immunoassay and a DNA polymerase chain reaction test.

Results: Between August 2011 and January 2015, over 14,000 clients were tested for HIV at 6 HIV counselling and testing sites. Of those, 2786 (median age: 30; 38.1% males) were included in the study. Sensitivity of the testing algorithms ranged from 89.5% in Arua to 100% in Douala and Conakry, while specificity ranged from 98.3% in Doula to 100% in Conakry. Overall, 24 (0.9%) clients, and as many as 8 per site (1.7%), were misdiagnosed, with 16 false-positive and 8 false-negative results. Six false-negative specimens were retested with the on-site algorithm on the same sample and were found to be positive. Conversely, 13 false-positive specimens were retested: 8 remained false-positive with the on-site algorithm.

Conclusions: The performance of algorithms at several sites failed to meet expectations and thresholds set by the World Health Organization, with unacceptably high rates of false results. Alongside the careful selection of rapid diagnostic tests and the validation of algorithms, strictly observing correct procedures can reduce the risk of false results. In the meantime, to identify false-positive diagnoses at initial testing, patients should be retested upon initiating antiretroviral therapy.

Keywords: HIV; RDT; algorithm; diagnostic; misdiagnosis; test.

Publication types

  • Evaluation Study
  • Multicenter Study
  • Review

MeSH terms

  • Adult
  • Africa South of the Sahara
  • Algorithms*
  • Counseling
  • Diagnostic Errors*
  • Diagnostic Tests, Routine* / methods
  • Female
  • HIV Infections / diagnosis*
  • HIV-1
  • Humans
  • Immunoenzyme Techniques
  • Male
  • Mass Screening / methods
  • Polymerase Chain Reaction
  • Prospective Studies
  • Sensitivity and Specificity
  • Uganda
  • World Health Organization
  • Young Adult

Grants and funding

MSF’s Innovation Fund provided funding for sample collection at the study sites, shipment to the central laboratory and analysis at the ITM central laboratory. The study sponsor had no role in the study design, data collection, analysis and interpretation of the data or in the decision to submit for publication. The corresponding author had access to all data and final responsibility for the decision to submit for publication.