Monitored Implementation of COVID-19 Rapid Antigen Screening at Taxi Ranks in Johannesburg, South Africa.

Mohammed Majam,Sanjida Karim,Paula Akugizibwe,Michael Rademeyer,Wendy Susan Stevens,Vanessa Msolomba,Lesley Erica Scott,Rigveda Kadam,Trish Kahamba,François Venter,Tanya Van Tonder

doi:10.3390/diagnostics12020402

Abstract

Digital tools can support community-based decentralized testing initiatives to broaden access to COVID-19 diagnosis, especially in high-transmission settings. This operational study investigated the use of antigen-detecting rapid diagnostic tests (Ag-RDTs) for COVID-19 combined with an end-to-end digital health solution, in three taxi ranks in Johannesburg, South Africa. Members of the public were eligible if they were aged ≥18 years, could read, and had a cellphone. Over 15,000 participants, enrolled between June and September 2021, were screened for COVID-19 risk factors. A digital risk questionnaire identified 2061 (13%) participants as moderate risk and 2987 (19%) as high risk, based on symptoms and/or recent exposure to a known case. Of this group referred for testing, 3997 (79%) received Ag-RDTs, with positivity rates of 5.1% in the “high-risk” group and 0.8% in the “moderate-risk” group. A subset of 569 randomly selected participants received additional PCR testing. Sensitivity of the Ag-RDT in this setting was 40% (95% CI: 30.3%, 50.3%); most false negatives had high cycle threshold values (>25), hence low viral loads. Over 80% of participants who tested positive completed a 2-week phone-based follow-up questionnaire. Overall, the digital tool combined with Ag-RDTs enhanced community-based decentralized COVID-19 testing service delivery, reporting and follow-up.

Highlights

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has proven difficult to control, during periodic peaks and waves of infection
Results from the antigen-detecting rapid diagnostic tests (Ag-RDTs) were captured in the digital tool and sent directly to the participant’s phones via WhatsApp and SMS
The project started during the peak of the third COVID-19 wave in South Africa, which began in May 2021, where the average number of nationwide daily cases reached around 18,000, with a weekly test positivity rate of between 25% and 30% [33]

Summary

Introduction

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has proven difficult to control, during periodic peaks and waves of infection. South Africa has reported around 3.46 million COVID-19 cases and 91,000 directly associated deaths as of December 2021 [1]. South Africa’s second wave of COVID-19, which peaked in January 2021, saw the emergence of the Beta variant as the predominant strain of the virus [2]. A third wave of COVID-19 started in the country in June 2021 dominated largely by the Delta variant, followed by the emergence of the Omicron variant in November 2021 [2,3]. Difficulties in accessing timely COVID-19 tests, vaccines and treatments have complicated control of COVID-19 in the country

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Conclusion