RAPIDCoV - Cross-sectional evaluation of rapid antibody tests for the diagnosis and management of COVID-19 in sub-Saharan Africa
The global pandemic of COVID-19 has developed rapidly, with over 1.7 million cases globally in just three months. Even the world's wealthiest countries are struggling to mount an effective public health response, and there is much criticism about the slow up-take of the gravity of the situation and insufficient preparedness. In particular, the lack of capacity to run molecular diagnostics on a large scale to rapidly identify COVID-19 cases and isolate those spreading the virus, has led to sustained community transmission. Africa is several weeks behind on the epidemic curve, but there are now cases of community transmission in most African countries.
A major barrier to mounting and effective public health response is the global shortage of common materials and reagents required for sample preparation and performing RT-PCR testing. Furthermore RT-PCR testing of large numbers of patients is beyond the capacity of referral labs in most settings (even in high-income countries). Across Africa, the number of people tested (per million population) is dramatically lower than in Europe and the U.S, and is restricted to suspected cases with travel history and their close contacts. There is a need for evaluations of novel point-of-care rapid diagnostic tests in the African setting, to rapidly identify cases, to guide available case finding capacity and inform on targeted public health measures.
We propose that busy referral centres are soon going to become the front line in the fight against the pandemic across Africa. Severely ill patients with COVID-19 from the community, will start appearing at emergency departments in the coming weeks, and will spread the infection to other vulnerable patients and staff, whilst they wait for RT-PCR results that are already stretched to maximum capacity. Recent analysis by Public Health England has suggested rapid antibody tests for SARS-CoV-2 perform very well in severely ill patients, with IgM and/or IgG being readily detectable. We will conduct a multi-centre evaluation of two affordable and available antibody-based RDTs at five referral hospitals screening adult admissions with severe respiratory tract infection. We will determine their positive predictive value for RT-PCR-confirmed active infection, and model their potential for rapid triage to quickly separate COVID-19 cases from other admissions. Results will be published and updated online on a weekly basis, providing the global community with the latest possible information. We will also document the course of COVID-19 and outcomes in a HIV & TB endemic setting.
To implement a cross-sectional diagnostic evaluation to compare two rapid antibody tests with gold-standard RT-PCR, in adults admitted with severe respiratory tract infection in a high HIV/TB burden setting.
Specific Objectives & Hypotheses
- To evaluate the accuracy of two Ab rapid diagnostic tests (RDTs) in adult admissions presenting with severe respiratory tract infection, with RT-PCR as gold-standard - We hypothesize that Ab RDTs might be 80% sensitive in being able to predict RT-PCR positive cases of COVID-19
- To document the clinical course of COVID-19 in a high HIV/TB burden setting and identify factors associated with poor outcomes – We hypothesize that mortality at 1 month will be higher among those with COVID-19 and that co-morbidities such as HIV and TB will be differentially distributed between those with and without COVID-19.
- To model triage screening algorithms for COVID-19 using clinical and diagnostics results – drawing on data from the proposed trial, and all other data available globally during the latter half of the project – We hypothesize that a diagnostic algorithm can be developed that utilizes Ab RDTs to provide rapid triage and reduce the burden on RT-PCR services.