A Commitment to HIV Diagnostic Accuracy - a comment on "Towards more accurate HIV testing in sub-Saharan Africa: a multi-site evaluation of HIV RDTs and risk factors for false positives 'and' HIV misdiagnosis in sub-Saharan Africa: a performance of diagnostic algorithms at six testing sites".

Amy S Kravitz Del Solar,Dianna Edgil,Joel Kuritsky,Bharat Parekh,John Nkengasong,Meaghan O'Keefe Douglas

doi:10.1002/jia2.25177

Abstract

As part of the global response to the HIV/AIDS epidemic, the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) is committed to the provision of high‐quality services and ensuring testing accuracy. Two recently published papers focusing on HIV testing and misdiagnosis in sub‐Saharan Africa by Kosack et al. report on evaluations of HIV rapid diagnostic tests (RDTs) and found lower than expected specificity and sensitivity on some tests when used in certain geographic locations. The magnitude of PEPFAR's global HIV response has been possible due to the extensive use of RDTs, which have made HIV diagnosis accessible all over the world. We take the opportunity to address concerns raised about the potential implications that these findings could have on real‐world HIV testing accuracy. PEPFAR supported countries adhere to the normative guidance by World Health Organization (WHO) supporting algorithms which require sequential positive tests for diagnostic accuracy. An analysis of Médecins Sans Frontières (MSF) RDT site‐specific data applied to PEPFAR in‐country protocols demonstrate a variation in the diagnostic accuracy of the testing algorithms, but with a very small population‐level effect. The data demonstrate, with the use of these algorithms, that the RDT outcomes found in the study by Kosack et al. would be largely mitigated and would not be expected to have a significant impact on diagnostic accuracy and overall programming in most countries. Avoiding any misdiagnosis is a priority for PEPFAR, and it remains vital to gain a deeper understanding of the causes and the extent of diagnostic errors and any misclassification. Extensive quality control mechanisms and continued research are essential. With a focus on epidemic control and ensuring diagnostic accuracy, PEPFAR recommends that all countries use WHO pre‐qualified RDTs within the recommended strategies and algorithms for HIV testing. We also support validation of HIV testing algorithms using in‐country specimens to determine optimal performance, and the reverification testing of all people diagnosed with HIV prior to starting treatment as an essential quality assurance measure.

Highlights

The recently published papers, Towards more accurate HIV testing in sub-Saharan Africa: a multi-site evaluation of HIV RDTs and risk factors for false positives and HIV misdiagnosis in subSaharan Africa: performance of diagnostic algorithms at six testing sites by Kosack et al describe evaluations of several HIV rapid diagnostic tests (RDTs) and confirmatory assays both alone and in series
Validation of the testing-specific algorithms used in each individual setting requires parallel testing of a status quo testing algorithm in comparison with a candidate testing algorithm to determine rate of misdiagnosis, and so the data obtained by Kosack et al cannot be accurately applied to the broader context
As President’s Emergency Plan for AIDS Relief (PEPFAR) works in five of the six sites analysed by Kosack et al, and has details about the site-specific performance information, including algorithm usage and prevalence data, our analysis at those five sites demonstrates the practical impact of the individual RTK results in a real-world setting

Summary

Introduction

The recently published papers, Towards more accurate HIV testing in sub-Saharan Africa: a multi-site evaluation of HIV RDTs and risk factors for false positives and HIV misdiagnosis in subSaharan Africa: performance of diagnostic algorithms at six testing sites by Kosack et al describe evaluations of several HIV rapid diagnostic tests (RDTs) and confirmatory assays both alone and in series. While the tests evaluated in this study had all previously passed World Health Organization (WHO) performance criteria (≥99% sensitivity and ≥98% specificity), the evaluation showed that the individual “RDTs performed more poorly than in the WHO evaluations.”. Since its inception in 2003, PEPFAR has shown an unwavering commitment in the response for the global HIV/AIDS crisis, working in nearly 60 countries. As of September 2017, PEPFAR has provided testing services to 85.5 million people, and 13.3 million HIV-positive men, women and children are supported on life-saving antiretroviral treatment [3].

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