One vs. Many: The Accuracy Of HIV Rapid Diagnostic Tests
Médecins Sans Frontières (MSF) has carried out an assessment of the HIV tests accuracy in five sub-Saharan African countries conducted in collaboration with the Institute of Tropical Medicine in Antwerp and co-investigators from the respective ministries of health. The study has confirmed the necessity to accurately choose multiple HIV rapid diagnostic tests in an algorithm/sequence for performing an HIV diagnosis.
The eight HIV rapid diagnostic tests were assessed in this first systematic head-to-head evaluation using samples from Kenya, Democratic Republic of Congo, Uganda, Cameroon, and Guinea. The key findings, which were issued in the Journal of the International AIDS Society in March 2017, were as follows:
- All eight HIV rapid diagnostic tests that were evaluated showed very high sensitivity (i.e. capacity of correctly detecting an individual with HIV infection), varying from 98.8% to 100%.
- However, the specificity (i.e. the tests’ ability to correctly identify individuals without HIV infection) varied considerably ranging from 90.4% to 99.7%
- Numerous factors, including provider-initiated testing, gender and the geographical origin of specimens, were associated with false-positive results. Additional investigations are needed to explore this.
These findings prove that HIV diagnosis should not be based on results from a single HIV rapid diagnostic test. A combination of HIV tests and more specifically an algorithm/sequence of tests of two or three different HIV rapid tests is obliged to obtain an HIV-positive diagnosis according to the World Health Organization (WHO) recommendations and followed by MSF in its programs.
“This publication reports on the performance of individual HIV rapid tests, but not the accuracy of entire HIV testing algorithms,” says MSF’s Dr. Cara S Kosack, author of the article in the Journal of the International AIDS Society. “The results underscore the challenges in designing accurate testing algorithms, and the need for local validation to be part of the design process.”