Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), generally known as 2019 novel coronavirus (2019-nCoV), may have been evolved from bats. A recent article published in the Nature Medicine journal used genomic data of novel coronavirus and predicted that the origin of coronavirus is natural and not laboratory-made.
Coronavirus has mainly four structural proteins, spike (S), membrane (M), envelope (E), nucleocapsid (N) proteins. Recent studies have suggested that spike proteins of the coronavirus first contact with Angiotensin converting enzyme 2 (ACE2) proteins of the cells. ACE2 may play a role in the regulation of cardiovascular function and renal function. Therefore, people with high blood pressure may be more vulnerable to coronavirus infection. Additionally, researchers have found that spike protein of 2019-nCoV is 10 to 20 times more efficient in binding with ACE2 on human cells compared to the SARS-like virus from 2002; thus, the coronavirus is more contagious than the earlier SARS-like viruses.
The test for coronavirus can be done in blood-based and swab-based methods. Polymerase chain reaction (PCR) and Enzyme-linked Immunosorbent Assay (ELISA) are the two molecular methods that can be used for the detection of the viral particles. PCR is a Deoxyribonucleic acid (DNA) amplification technique that is used regularly in the lab to increase the small amount of DNA into a large amount so that it can be analysed. The PCR technique in the combination of fluorescent dye gives real-time data about the amount of DNA present. However, for a virus like the coronavirus, single-stranded ribonucleic acid (RNA) has to be converted into DNA by using reverse transcriptase (RT) enzyme. Therefore, the technique is called RT-PCR. However, the RT-PCR method is more time consuming compared to the ELISA methods. In ELISA methods, the presence or absence of antibodies - Immunoglobulin M (IgM) and Immunoglobulin G (IgG) to coronavirus is detected. An antibody is a protein that is found in the blood; and is produced by the immune cells in response to foreign compounds like bacteria and viruses. The positive result of ELISA indicates that the patient has been infected with viral particles.
Viral infections can be prevented by using vaccines or by using antiviral drugs. In the current pandemic situation discovering new vaccines against coronavirus is not a suitable option, as it is a prolonged process. Favipiravir is a type of drug that blocks RNA-dependent RNA polymerase. Remdesivir is a 'nucleotide analogue' drug and has shown promise in the coronavirus treatment. Good results have been obtained for coronavirus infection from the lopinavir and ritonavir medications against HIV in Thailand and Japan. Apart from these medicines, some of the drugs help the immune system by increasing the production of interferons. Interferons cease the production of proteins and turning on the RNA-terminating enzymes in the infected cells to stop the spreading of viruses. Alpha 2B is an interferon stimulating drug that had been used in China for the treatment of coronavirus.
Bangladesh is a densely populated country, and at present, in a vulnerable situation for viral spreading. Personal hygiene and public awareness are the most effective ways of surviving viral infection until effective and approved medication against coronavirus are available.
The writer is an Assistant Professor at the Department of Biochemistry and Microbiology, North South University, Bangladesh.