Coronavirus disease, its composition, testing method, and management:

Coronavirus disease, its composition, testing method, and management:

Coronaviruses are important human and animal pathogens. During epidemics, they are

the cause of up to one-third of community-acquired upper respiratory tract infections in adults and perhaps also play a role in severe respiratory infections in both broods and adults. In addition, it is possible that coronaviruses can cause diarrhea in infants.

WHY CORONA VIRUS IS KNOWN AS COVID- 19:

A novel coronavirus was recognized as the cause of a cluster of pneumonia cases in Wuhan at the end of 2019. It later spread throughout China and elsewhere, becoming a global health emergency. The World Health Organization (WHO) designated the disease COVID-19, in February 2020 which stands for coronavirus disease 2019.

VIROLOGY:

Coronaviruses are categorized as a family within the order Nidoviridales, viruses that replicate using a set of mRNA. The coronavirus subfamily is further classified into genera that are alpha, beta and gamma. The human coronaviruses are in two of these genera:

α coronaviruses
β coronaviruses

Viral composition:

Corona viruses are enveloped, medium-sized, positive-stranded RNA viruses whose name derives from their crown-like appearance in the electron microscope.

These viruses have viral RNA genomes, with a length of 27 to 32 kb. The host-derived membrane is covered with glycoprotein spikes that surround the genome, which is enclosed in a nucleocapsid that is helical in its relaxed form but it adopts a roughly spherical shape in the virus particle.
Viral RNA replication occurs in the host cytoplasm by a unique mechanism. In this mechanism RNA polymerase binds to a leader sequence and then it detaches .After this it reattaches at multiple locations, allowing for the production of a set of mRNA molecules with common 3' ends.
The spike (S) protein projects over the viral envelope and forms the spikes in the coronavirus crown. It is heavily glycosylated, most likely forms a homotrimer, and mediates receptor binding then blend with the host cell membrane. The major antigens are on the S proteins that stimulate neutralizing antibody, as well as major targets of cytotoxic lymphocytes
The membrane protein has a short N-terminal domain. It projects on the external surface of the envelope and spans the envelope three times, leaving a long end inside the envelope. The M protein plays a significant role in viral assembly.
The nucleocapsid protein links with the RNA genome to form the nucleocapsid. It might be involved in the regulation of viral RNA synthesis and may interrelate with M protein during the budding of the virus.
The envelope protein leaves its end inside the envelope and then also spans the envelope. Its function is not known, though, the E protein along with M and N are essential for proper assembly and release of the virus.

Testing for coronavirus:

· Polymerase chain reaction is used to detect the viral DNA

· In testing the single standard RNA is converted into its complementary DNA with the help of reverse transcriptase and then amplified. This is completed by producing new DNA strands from deoxynucleoside triphosphates using DNA polymerase

Management:

· People are managed with supportive care that comprises of fluid therapy, oxygen support. Those who suspect they carry the virus wear a simple, clean face mask.

· Extracorporeal membrane oxygenation has been used to report the issue of respiratory failure. But its benefits are quiet under consideration.

· Healthy life style and diet have been suggested to improve immunity. Supportive treatment might be helpful in those with mild symptoms at an early stage.