Six new laboratories in as many countries in Africa have joined the network to test the RT-LAMP technology to detect SARS-CoV-2. These laboratories joined a network of other four laboratories that first started this study in 2020.
From its official launch in February 2022, a network of 10 African reference laboratories established under the COVID-19+ project is testing research use only RT-LAMP technology, an isothermal colorimetric test for the detection of SARS-CoV-2 produced by New England Biolabs, to determine its broader applicability in COVID diagnostics. Recent additions to the network, reference laboratories in Angola, Burkina Faso, Ivory Coast, Senegal, Sudan and Zimbabwe, are testing the technology using nasopharyngeal swabs as samples, whereas longer-standing reference laboratories, namely those in Cameroon, Ethiopia, Kenya and Nigeria, have already completed the assessments on nasopharyngeal swabs and are now conducting the test on saliva samples. This multi-centric clinical study is evaluating the robustness of the RT-LAMP assay against the international standard of RT-qPCR and is based on samples from 3,000 patients across the 10 African participating countries, thus relying on a very diverse pool of samples processed under a variety of local conditions that should result in an extremely effective sensitivity assessment.
Factors such as simplicity of use and reliance on unsophisticated laboratory equipment make the RT-LAMP technology ideally suitable for deployment in low-resource settings, such as peripheral communities or remote rural areas, which are typically characterised by a paucity of reliable infrastructure and a skilled laboratory workforce. Dr. Eric Lelo, a project partner at the Kenyan Medical Research Institute (KEMRI), has been involved in the evaluation of RT-LAMP for the detection of SARS-CoV-2 since September 2020 and believes the technology is suitable for use in community labs, saying that the test is “straightforward, results are easy to interpret because of the use of a colour change and there is no need for computing or qPCR testing knowledge”.
The objective of the COVID-19+ project is ultimately to empower community laboratories by increasing their diagnostic capacity, using RT-LAMP technology as a first step. The straightforwardness of results and simplicity of use were important features to be considered when deploying the assay in low resource settings. “One issue with the assay, however, is its need for an RNA extraction step, as the necessary equipment may not be available in community labs” noted Dr. Djibril Wade from IRESSEF in Senegal, who is looking forward to testing the technology using saliva samples. In fact, lysis buffers created for saliva samples remove the need for an RNA extraction step, thus simplifying the approach and resulting in even more rapid testing. The use of saliva samples not only impacts the testing efficiency of diagnostic labs, but it also improves their surveillance capacity. As observed by Dr. Lelo “normally people are reluctant to give samples because the nasopharyngeal swabbing is very off-putting, so when we tested saliva, it was well-received by patients, because it is more user-friendly and it is less invasive”. This use now increases the number of tests that a single lab can provide, because now people are more open to providing samples and the reference lab can also now include many more samples in the evaluation, making it far more robust.
In addition to evaluating the reliability of the assay, reference laboratories are also applying to their national regulatory authorities for emergency use approval of RT-LAMP. In a parallel effort, the technology developer, the New England Biolabs, together with the ICGEB are applying to the WHO to obtain an Emergency Use Listing which would allow the technology to be swiftly deployed to community labs. The availability of the assay would allow community labs to conduct molecular analysis and to shorten the turnaround time when performing diagnostic testing during emergencies. “Most of our laboratories at the community level are not well equipped and the staff is not well trained when it comes to molecular analyses” said Dr. Lelo, “so the collaboration between these laboratories and ourselves and our partners will enhance the testing capacity of these laboratories, leading to their eventual autonomy such that they continue doing their work without needing to send samples to us”. In this sense, the purpose of the laboratory network is to foster collaboration and knowledge exchange as well as technology transfer amongst African labs. Dr. Bitew, a virologist and senior researcher at BETin in Ethiopia, commented on the importance of establishing this type of network by observing how community labs “are suffering mostly from the lack of up-to-date technologies for the diagnostics of infectious diseases, so the establishment and strengthening of the lab network will allow the sharing of new and up-to-date technologies for disease detection”. He continued, “it is easy to establish national and international laboratory standards and quality management systems while, at the same time, the network supports an easy adoption of diagnostic methods in the shortest possible time”.
Overall, as community laboratories are usually the first contact points with infected patients and are at the forefront of epidemics, their inclusion in such networks is vital. Prof. Maria Madalena Chimpolo, coordinator of the Genetic Unit at the Medical School of the University Agostinho Neto in Luanda, Angola, believes that community and reference labs should complement one another, where the former should be empowered to serve as sentinels in virus identification, sample collection, reception of samples and initial testing. Their involvement and role are fundamental, but, as she further highlighted, “to be more effective, they need to have more autonomy”.