A review of the use of lateral flow testing in the wake of the SARS-CoV-2 pandemic

In a recent review published in nature review, Researchers evaluated the changing landscape of lateral flow testing (LFT) and the development of next-generation LFTs based on lessons learned from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.

Background

The feasibility and acceptability of LFT for large-scale SARS-CoV-2 testing to improve population health was observed during the 2019 coronavirus disease (COVID-19) pandemic. However, LFT has some limitations, which are obstacles to the development of next-generation LFT. Identifying and addressing shortcomings and bottlenecks will accelerate the development of LFT and improve the diagnostic context for viral infections and potentially epidemic diseases such as COVID-19, especially those caused by antibiotic-resistant causative organisms. may expand.

About reviews

In the current review, researchers describe the evolution of LFT testing, LFT strengths and weaknesses, and identify obstacles in developing next-generation LFTs based on lessons learned from the COVID-19 pandemic.

The changing landscape of LFT diagnosis

LFT was initially used as a radioimmunoassay and latex agglutination test, enabling a paper-based dipstick test for urinary glucose quantification. Ultimately, these tests were used for pregnancy-related serological evaluation and diagnosis of human immunodeficiency virus (HIV) infection.

The period of COVID-19 has accelerated the development of LFT, during which cases of pneumonia of unknown cause were reported in Wuhan, gene sequencing information was shared, and the World Health Organization (WHO) issued interim recommendations on the use of rapid antigen tests. announced guidelines.

Ultimately, rapid antigen testing was performed in and outside health service settings in combination with reverse transcription-polymerase chain reaction (RT-PCR) analysis. However, of the 3 billion SARS-CoV-2 tests conducted by mid-2022, only 0.40% were conducted in low-resource settings, raising ethical concerns and leading to a mass pandemic. It affects your ability to respond.

LFT before the COVID-19 pandemic used HIV antibodies, antigen and antibodies. This test used gold nanoparticles and latex beads, obtained results manually, and was used for self-examination, clinical diagnosis, and screening in home, clinic, and community-based settings. During COVID-19, LFT used the SARS-CoV-2 antigen and its use has been extended to surveillance activities. Since then, LFT has been used in additional settings such as large gatherings, schools, borders, and workplaces using quantum dots in addition to other materials. However, the method of obtaining results remained manual.

Lessons learned from the SARS-CoV-2 pandemic

The sensitivity of LFT is reported to be lower than RT-PCR analysis, ranging from 34.0% to 88.0% in detecting SARS-CoV-2, with a specificity of 99.6%. 1-10 million SARS-CoV-2 genome copies per ml can be detected with rapid antigen tests. In contrast, molecular techniques such as RT-PCR analysis can identify 1.0–100.0 genome copies/ml and the presence of SARS-CoV-2 1–2 days before LFT. However, due to the high contagiousness and short incubation period of SARS-CoV-2, LFT was successfully used to assess the infectivity or transmission risk of SARS-CoV-2 during COVID-19.

Molecular testing, although highly accurate, is disadvantageous for large-scale use and requires long time for centralized testing and report generation, while LFT can provide rapid testing with high scalability. Sensitivity is lower. In 2021, LFT will be rapidly adopted in the UK, surpassing the use of PCR. Major obstacles in the development and use of LFT include lack of access to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, and poor cost.Effectiveness Evidence, regulatory process delays, and centralized manufacturing of materials.

Multiplexing and use of quantum and nanomaterials, nucleic acid-based LFTs, machine learning, and CRISPR (clustered regularly spaced short palindromic repeats) may improve LFT connectivity and accuracy there is. Observations from the pandemic show that large-scale LFT self-testing is associated with early detection and rapid self-isolation, improved accessibility to diagnostic testing, increased testing frequency, improved compliance with public health measures, reduced viral transmission, etc. , has been shown to offer several advantages. Prevents infections and promotes early recovery. However, access to self-tests is unequal and adoption in low- and middle-income countries is much lower.

Bioengineering efforts may improve specimen preparation. nucleic acid-Based amplification and detection enables multiplexing, digital connectivity with mobile health (m-Health) databases and healthcare systems, and green manufacturing of products with high accuracy, ease of use and cost-effectiveness Create a simple next generation LFT. Rapid testing with improved digital connectivity, especially to identify infections caused by antibiotic-resistant microbes.

Next generation LFT will use AMR (antimicrobial resistance) panels and quick response (QR) codes to identify antigens, Target antibodies, and molecules. It uses ultrasensitive materials such as enzyme nanoparticles and nanodiamonds to capture digitized results. Data may be linked to healthcare systems. Incorporating molecular detection improves diagnostic accuracy. Cas-based reactions can be combined with enzyme-amplified LFT, and spin-enhanced quantum nanodiamond sensing and background subtraction can be used for ultrasensitive detection. Machine learning enables automatic classification of LFT results.

In conclusion, based on the review results, next-generation LFT can provide a means of rapid and decentralized testing with high sensitivity and specificity at mass scale. However, incorporating biotechnological approaches, machine learning, digitization, and multiplexing requires global collaboration, regulatory harmonization, and funding to improve research infrastructure and increase the availability of suitable reagents. need an increase. Efforts are needed to overcome the shortcomings of his LFT, such as high false-negative rates, equitably distribute next-generation diagnostic LFTs worldwide, and improve global preparedness against pathogens.