Uncertainties, work conditions and testing biases: Potential pathways to misdiagnosis in point-of-care rapid HIV testing in Zimbabwe

The future of HIV diagnostics: an exemplar in infectious diseases

Over the past 40 years, diagnostics have become the backbone of HIV prevention, treatment, and retention in care, and are central to the achievement of UNAIDS 95-95-95 targets. Over the next decade, the global HIV response will face difficult challenges. In addition to sustaining gains achieved in prevention and treatment, substantial gaps in care need to be addressed for underserved populations. Diagnostics will play an important role in control and prevention of HIV infection through novel technologies, digital solutions, and integrated service delivery innovations. The integration of diagnostics with digital health, machine learning, and generative artificial intelligence provides opportunities for more effective individual and public health disease control. These diagnostics and other futuristic innovations such as wearable technologies, omics, metaverse-based solutions, and quantum diagnostics could enable the achievement of the UNAIDS 95-95-95 targets; however, their use will face barriers related to health-care system financing, infrastructure, technological readiness and skills, and long-term sustainability. This Review highlights diagnostic strategies and innovations that could catalyse a new era in the management of the HIV pandemic.

Evaluating the accuracy of multiple rapid diagnostic tests for HIV detection in serum samples analysed during point-of-care proficiency testing assessments

BACKGROUND

HIV rapid diagnostic tests are crucial for timely diagnosis, especially in resource-limited settings. The World Health Organization recommends sensitivity ≥99 % and specificity ≥98 %. This study assessed RDT performance across South Africa's provinces using a proficiency testing program.

METHODS

From April to June 2023, 25,458 blinded serum samples were sent to testing facilities for screening and confirmatory testing. Sensitivity, specificity, predictive values, and concordance (Cohen's Kappa) were evaluated.

RESULTS

The response rate was 98.25 %. Sensitivity and specificity were both 98.7 %, with agreement at 98.7 % (kappa 0.97, p < 0.001). Northern Cape showed the lowest sensitivity (91.8 %) and specificity (92.0 %), while Gauteng, KwaZulu-Natal, and Mpumalanga exceeded 99 %.

CONCLUSION

Although national RDT performance met WHO standards, Northern Cape's results reveal the need for improved training, quality assurance, and proficiency testing to strengthen diagnostic accuracy.

Understanding health systems challenges in providing Advanced HIV Disease (AHD) care in a hub and spoke model: a qualitative analysis to improve AHD care program in Malawi

BACKGROUND

Despite tremendous progress in antiretroviral therapy (ART) and access to ART, many patients have advanced human immunodeficiency virus (HIV) disease (AHD). Patients on AHD, whether initiating ART or providing care after disengagement, have an increased risk of morbidity and mortality. The Elizabeth Glaser Pediatric AIDS Foundation (EGPAF) launched an enhanced care package using a hub-and-spoke model to optimize AHD care in Malawi. This model improves supply availability and appropriate linkage to care. We utilized a hub-and-spoke model to share health facility challenges and recommendations on the AHD package for screening and diagnosis, prophylaxis, treatment, and adherence support.

METHODS

This qualitative study assessed the facility-level experiences of healthcare workers (HCWs) and lay cadres (LCs) providing AHD services to patients through an intervention package. The study population included HCWs and LCs supporting HIV care at four intervention sites. Eligible study participants were recruited by trained Research Assistants with support from the health facility nurse to identify those most involved in supporting patients with AHD. A total of 32 in-depth interviews were conducted. Thematic content analysis identified recurrent themes and patterns across participants' responses.

RESULTS

While HCWs and LCs stated that most medications are often available at both hub and spoke sites, they reported that there are sometimes limited supplies and equipment to run samples and tests necessary to provide AHD care. More than half of the HCWs stated that AHD training sufficiently prepared them to handle AHD patients at both the hub and spoke levels. HCWs and LCs reported weaknesses in the patient referral system within the hub-and-spoke model in providing a linkage of care to facilities, specifically improper referral documentation, incorrect labeling of samples, and inconsistent availability of transportation. While HCWs felt that AHD registers were time-consuming, they remained motivated as they thought they provided better patient services.

CONCLUSIONS

These findings highlight the importance of offering comprehensive AHD services. The enhanced AHD program addressed weaknesses in service delivery through decentralization and provided services through a hub-and-spoke model, improved supply availability, and strengthened linkage to care. Additionally, addressing the recommendations of service providers and patients is essential to improve the health and survival of patients with AHD.

Temporal discrepancies in "rapid" HIV testing: explaining misdiagnoses at the point-of-care in Zimbabwe

BACKGROUND

Rapid diagnostic tests have revolutionized the HIV response in low resource and high HIV prevalence settings. However, disconcerting levels of misdiagnosis at the point-of-care call for research into their root causes. As rapid HIV tests are technologies that cross borders and have inscribed within them assumptions about the context of implementation, we set out to explore the (mis)match between intended and actual HIV testing practices in Zimbabwe.

METHODS

We examined actual HIV testing practices through participant observations in four health facilities and interviews with 28 rapid HIV testers. As time was identified as a key sphere of influence in thematic analyses of the qualitative data, a further layer of analysis juxtaposed intended (as scripted in operating procedures) and actual HIV testing practices from a temporal perspective.

RESULTS

We uncover substantial discrepancies between the temporal flows assumed and inscribed into rapid HIV test kits (their intended use) and those presented by the high frequency testing and low resource and staffing realities of healthcare settings in Zimbabwe. Aside from pointing to temporal root causes of misdiagnosis, such as the premature reading of test results, our findings indicate that the rapidity of rapid diagnostic technologies is contingent on a slow, steady, and controlled environment. This not only adds a different dimension to the meaning of "rapid" HIV testing, but suggests that errors are embedded in the design of the diagnostic tests and testing strategies from the outset, by inscribing unrealistic assumptions about the context within which they used.

CONCLUSION

Temporal analyses can usefully uncover difficulties in attuning rapid diagnostic test technologies to local contexts. Such insight can help explain potential misdiagnosis 'crisis points' in point-of-care testing, and the need for public health initiatives to identify and challenge the underlying temporal root causes of misdiagnosis.

Rituals of care: Strategies adopted by HIV testers to avoid misdiagnosis in rapid HIV testing in Zimbabwe

A growing number of studies highlight high levels of misdiagnosis in the scale-up of HIV rapid testing programmes, which often remain invisible to individual testers. Drawing on interviews with HIV testers and observations in four health facilities in Zimbabwe, we show that testers navigated the translation of the standardised, dis-embodied norms of laboratory-based testing into the body work of point-of-care testing through ritualisation of laboratory-practices in their daily clinical work. Yet, this was interrupted through the challenging work conditions the testers face. They ritualised careful procedures, forcing themselves to focus even if queues were long, and making quality assurance procedures part of their daily routine. They actively tried to reduce their workloads and double-checked and discussed unexpected results, especially when a test result did not match their evaluation of clients' circumstances or clinical status. This helped not only to increase confidence in the authenticity of their diagnosis, but also to share responsibility for potential errors. Existing approaches to tackle the problem of misdiagnosis through quality assurance (QA) procedures mainly focus on adjusting individual testers' performance and ensuring that basic testing resources were present, thus falling short of creating a work environment that is conducive to high quality testing.

The (in)visibility of misdiagnosis in point-of-care HIV testing in Zimbabwe

There is a global trend to introduce point-of-care diagnostic tests, enabling healthcare workers at any level to test, provide results, and initiate immediate treatment if necessary. This article explores how healthcare workers conducting rapid HIV tests - in contexts of limited external quality assurance mechanisms - ascertain the accuracy of their test results. Drawing on interview data and participant observations from health facilities in Zimbabwe, we open the black box of misdiagnosis (in)visibility and reveal a range of proxies and markers that HIV testers draw on to develop certainty, or question, the reliability of their diagnostic classifications.

Comprehensive investigation of sources of misclassification errors in routine HIV testing in Zimbabwe

INTRODUCTION

Misclassification errors have been reported in rapid diagnostic HIV tests (RDTs) in sub-Saharan African countries. These errors can lead to missed opportunities for prevention-of-mother-to-child-transmission (PMTCT), early infant diagnosis and adult HIV-prevention, unnecessary lifelong antiretroviral treatment (ART) and wasted resources. Few national estimates or systematic quantifications of sources of errors have been produced. We conducted a comprehensive assessment of possible sources of misclassification errors in routine HIV testing in Zimbabwe.

METHODS

RDT-based HIV test results were extracted from routine PMTCT programme records at 62 sites during national antenatal HIV surveillance in 2017. Positive- (PPA) and negative-percent agreement (NPA) for HIV RDT results and the false-HIV-positivity rate for people with previous HIV-positive results ("known-positives") were calculated using results from external quality assurance testing done for HIV surveillance purposes. Data on indicators of quality management systems, RDT kit performance under local climatic conditions and user/clerical errors were collected using HIV surveillance forms, data-loggers and a Smartphone camera application (7 sites). Proportions of cases with errors were compared for tests done in the presence/absence of potential sources of errors.

RESULTS

NPA was 99.9% for both pregnant women (N = 17224) and male partners (N = 2173). PPA was 90.0% (N = 1187) and 93.4% (N = 136) for women and men respectively. 3.5% (N = 1921) of known-positive individuals on ART were HIV negative. Humidity and temperature exceeding manufacturers' recommendations, particularly in storerooms (88.6% and 97.3% respectively), and premature readings of RDT output (56.0%) were common. False-HIV-negative cases, including interpretation errors, occurred despite staff training and good algorithm compliance, and were not reduced by existing external or internal quality assurance procedures. PPA was lower when testing room humidity exceeded 60% (88.0% vs. 93.3%; p = 0.007).

CONCLUSIONS

False-HIV-negative results were still common in Zimbabwe in 2017 and could be reduced with HIV testing algorithms that use RDTs with higher sensitivity under real-world conditions and greater practicality under busy clinic conditions, and by strengthening proficiency testing procedures in external quality assurance systems. New false-HIV-positive RDT results were infrequent but earlier errors in testing may have resulted in large numbers of uninfected individuals being on ART.