Fast and accurate Covid-19 diagnosis tool needed

Share on facebook
Share on google
Share on twitter
Share on linkedin
Illustration by detik news

Coronavirus disease (COVID-19) is an infectious disease caused by the latest coronavirus strain, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which first appeared in Wuhan, China in the end of 2019. This disease spreads rapidly to various parts of the world, so it was declared by WHO as a global pandemic. The diagnosis of COVID-19 is based on clinical symptoms, such as fever, dry cough, and shortness of breath, supported by confirmation of SARS-CoV-2 infection. Some of the tests used to confirm this disease include serological tests for IgG and IgM antibodies, and molecular examinations using Real-time Reverse Transcriptase Polymerase Chain Reaction (rRT-PCR) as the gold standard. As of now, the pathogenesis of COVID-19 is still unclear, but it is known that the most common symptoms affect the lower respiratory tract.

The virus is recognized as an antigen that will stimulate the immune system and form antibodies against SARS-CoV formed as IgM and IgG. IgM will disappear after 12 weeks, while IgG will last for a long time. COVID-19 is spreading very rapidly, indicating that the number of samples is inversely related to the number of referral laboratories, thus affecting the length of time for diagnosis. Clinical and analytical validation is important for all commercial instruments, including RT-PCR before its widespread use. The risks of false positives and negatives will aggravate efforts to prevent the spread of this disease. Based on this background, researchers from the Department of Internal Medicine, Faculty of Medicine, RSUD Dr. Soetomo, Institute of Tropical Disease, Universitas Airlangga have published its research in an international journal, International Journal of Pharmaceutical Research, which focuses on observing various serological and molecular test modalities for COVID-19.

An important conclusion that can be drawn based on this study is on specific diagnosis of COVID-19, through molecular examination using airway samples collected from swabbed throat, sputum, endotracheal aspiration, and bronchoalveolar lavage. The virus can also be detected in the stool and blood in severe cases, while the definitive diagnosis of COVID-19 is by rRT-PCR examination using samples from the lower airway. This method was chosen because it is specific, easy, and quantitative, but it is prone to contamination and takes a long time. Another way is through serological examination which detects the presence of antigens and antibodies in the form of IgM, IgG, or total antibodies. Molecular examination is the main modality in diagnosing COVID-19. This method was later developed by experts, despite the challenges from the virus rapid mutation. The accuracy of the molecular examination depends on the quality of the specimens being examined, so the CDC allows for several alternative specimens provided that the examination must be carried out within 24 hours.

Furthermore, the choice of PCR tool should also be considered. The John Hopkins Center for Health Safety tried to compare the sensitivity and specificity of various primers used in several countries. Sensitivity can be seen from how small the Limit of Detection is(LoD). Indonesia uses a tool that targets the Orf1ab (RdRp) gene and E- gene. Molecular rapid test is a simple (less than 1 hour) rapid test, which includes a cartridge-based test with a selection of instruments instrumental in expanding the diagnostic range of SARS -CoV-2. Examination of specific antibodies to SARS-CoV-2 using a patient’s blood sample is a fast, easy, and sensitive diagnostic test for COVID-19. Moreover, several studies conducted testing and validation on several antigens using the Enzyme-linked Immunosorbent Assay (ELISA) method, and the Immunofluorescence Assay.(IFA) used to detect antibodies by detecting fluorescent signals. Antigen testing is another type of rapid test that detects the presence of proteins (antigens) expressed by the COVID-19 virus from airway samples.

Various countries have shown great efforts to diagnose SARS-CoV-2, and the role of diagnostic testing is very important in dealing with large-scale infectious diseases, such as COVID-19. It is very important to pay attention to the type of examination, the tools needed, and the time of the examination to get optimal results. Indonesia has succeeded in producing its own RT-PCR and rapid test kits. This RT-PCR kit is named NUSANTARA TRFIC-19. The target genes used by the Indonesian kit are the RdRp gene and N-gene. Validation tests were carried out using imported Asian virus strains and local virus strains obtained from Indonesian Health Research and Development Agency.

The conclusion of this study, it is very important to have a fast and accurate diagnostic tool. The RT-PCR method is the gold standard in diagnosing COVID-19. Serological examination must also consider the detection target, both antigen, total antibody, IgM, and IgG. The time of collection and the type of specimen examined also need to be considered in all examinations. The validation of the modalities we use is essential to achieve accurate results.

Author: Muhammad Miftahussurur, dr., M.Kes., Sp.PD-KGEH., Ph.D

Details of this research can be viewed in our article in the International Journal of Pharmaceutical Research. Here is the link:

http://www.ijpronline.com/ViewArticleDetail.aspx?ID=17327

Berita Terkait

UNAIR News

UNAIR News

Media komunikasi dan informasi seputar kampus Universitas Airlangga (Unair).