Journal des maladies infectieuses et de la thérapie

Abstrait

Utilizing a COVID-19 Antigen Rapid Test to Screen Specific Populations Facilitates 'Early Detection' of Omicron Variants

Zhang Lei, Yang Feng, Zhu Junzhe

Background: COVID-19 is caused by the SARS-CoV-2 virus. It is part of the coronavirus family, which includes Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). Like many other respiratory viruses, coronaviruses are transmitted mainly through person-to-person contact with an average incubation period of about 4 days.

Since the World Health Organization (WHO) declared the SARS-CoV-2 pandemic, the virus of COVID-19 has spread to 223 countries, with over 593 million confirmed cases and over 6 million reported deaths worldwide. The most recent WHO epidemiological report states that more than 200 countries worldwide have reported worrisome variants of SARS-Co-V-2, including Omicron VOC (Variant of Concern). Omicron VOC is currently reported as the predominant circulating VOC since November 2021. However, morbidity and mortality rates are influenced by factors such as age, underlying pre-existing medical conditions and disease severity, and vary significantly between countries.

The clinical spectrum of COVID-19 ranges from asymptomatic or oligosymptomatic forms to clinical conditions characterized by acute respiratory failure, infectious shock and multi-organ failure. It is estimated that between 17.9% and 33.3% of infected patients will remain asymptomatic. In contrast, most symptomatic patients usually present with fever, cough and shortness of breath, and less commonly with sore throat, loss of smell, taste disturbances, anorexia, nausea, malaise, myalgia and diarrhea.

On serology, the initial infection is characterized by elevated specific IgM antibodies within 3 days-7 days of onset and elevated IgG antibodies 5 days-10 days later. Therefore, Polymerase Chain Reaction Techniques (RT PCR) or SARS-CoV-2 nuclear capsid protein antigen testing are used within the first 5 days to diagnose neocoronavirus.

Objective: The main objective of this study is to investigate the performance of the Citest COVID-19 antigen rapid test kit for the qualitative detection of SARS-CoV-2 virus in self-collected nasal swab specimens from symptomatic/ asymptomatic individuals as an aid to the diagnosis of COVID-19 infection in suspected patients.

Methods: Run a rapid chromatographic immunoassay to detect SARS-CoV-2 nucleocapsid protein antigen in human nasal swab specimens and compare with the gold standard RT-PCR (nasopharyngeal swab) test for performance verification.

Results: 97.0% Sensitivity-In total 665 PCR confirmed positive samples: 645 PCR confirmed positive samples were correctly detected by Citest COVID-19 antigen rapid test. There are 20 false negative cases.

>99.9% Specificity-In total 332 PCR confirmed negative samples: 332 PCR confirmed negative samples were correctly detected by Citest COVID-19 antigen rapid test. There are 0 false positive case.

98.0% Accuracy-In total 997 PCR confirmed samples, 977 PCR confirmed samples were correctly detected by Citest COVID-19 antigen rapid test.

Conclusion: The COVID-19 antigen rapid test (Swab) is a qualitative membrane-based Immunoassay for the detection of SARS-CoV-2 nucleocapsid protein Antigens in human nasal swab specimens.

The test kit is simple to use and has been validated against the RT PCR test, the gold standard for nucleic acid detection. Results are available 15 minutes after testing. The results of 997 nasal specimens tested in clinical trials show an overall accuracy of 98.0%, a relative specificity of >99.9% and a relative sensitivity of approximately 97%. Patients can use the test kit to obtain accurate results and determine whether they are infected with SARS-CoV-2.