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

Abstract

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.

Experiences and Lessons Learnt from the HIV Treat All Pilot Phase Implementation in Zimbabwe

“…However, the problem of HIV testing misclassification in our setting might not be bad as initially thought. 28,29…”

Stunting Status and Exposure to Infection and Inflammation in Early Life Shape Antibacterial Immune Cell Function Among Zimbabwean Children

“…Research nurses visited households at baseline (approximately 2 weeks after enrolment), 32 weeks’ gestation and 1, 3, 6, 12 and 18 months after birth. Maternal anthropometry (height, weight, mid-upper-arm circumference (MUAC)), haemoglobin (HemoCue, Ängelholm, Sweden), Schistosoma haematobium (urinary microscopy), and HIV status ( via the Zimbabwe National HIV testing algorithm ( 22 )) were measured, blood and stool samples collected and maternal and household characteristics assessed by questionnaire at baseline. Birthweight (Tanita scales; Amsterdam, Netherlands) and delivery characteristics were recorded at birth.…”

Malaria, HIV and TB in Zimbabwe: Epidemiology, Disease Control Challenges and Interventions

“…Low levels of training and high workloads of health care staff has contributed to poor data documentation, treatment deferral, and loss to follow up (LTFU) of patients overall (Global Fund, 2020;Nyakura et al, 2019). HIV testing misclassification errors have been reported, which can lead to failure to provide ART in the case of false-negatives or inappropriate ART initiation in the case of false-positives (Gregson et al, 2021;Rufu et al, 2018). Particular groups also suffer from less access to services: HIV programming, for example, has largely been orientated to adults, with less attention to the needs of children, adolescents, and young people living with HIV (Taramusi et al, 2018).…”

“…Misclassification errors have been reported in rapid diagnostic HIV tests in Zimbabwe (Gregson et al, 2021). HIV infection may be wrongly diagnosed as a result of poor quality control, administrative errors and lack of training and supervision of staff, which poses a risk for the 'Test and Treat' approach 5 (Rufu et al, 2018).…”

“…False-HIV-negative results can lead to failure to provide ART, PMTCT and early infant diagnosis (EID) services, which can cause increased morbidity, mortality and new infections. At the same time, false-HIV-positive test results can lead to inappropriate ART initiation, causing unnecessary side-effects, stigma and psychological distressand a substantial waste of health care resources 6 (Gregson et al, 2021). For further discussion, see Surveillance challenges below.…”