സെന്റ് ജോൺസ് എച്ച്.എസ്.എസ്. ഉണ്ടൻകോട്/അക്ഷരവൃക്ഷം/World in the fear of corona virus

World in the fear of corona virus

In December 2019,a pneumonia outbreak was reported in wuhan, china .On 31 December 2019,the outbreak was traced to a novel strain of corona virus. Which was given the interim name 2019-n cov by the World Health Organization later renamed SARS-ncov -2 by the International Committee of Taxonamy of viruses some researchers have suggested the human seafood Whole sale Market may not be the orginal source of viral transmission to humans.
As of 17April 2020,there have been at least 143,844 confirmed deaths and more than 2,153,620 confirmed cases in the corona virus pneumonia pendamic. The wuhan strain has been identified as a new strain of Beta corona virus from group 2B with approximately 70% genetic similarity to the SARS-cov .The virus has a 96% similarity to a Bat corona virus,so it is widely suspected to originate from bats as well.
Corona virus are a group of related viruses that causes diseases in mammals and birds. In humans, corona viruses cause respiratory tract infections that can range from mild to lethal. Mild illness include some cases of the common cold, while more lethal varieties can cause SARS , MERS, and COVID-19 symptoms in other spices vary in chickens,they cause an upper respiratory tract diseases, while in cows and pigs they cause diarrhea. There are not yet to be vaccines or antiviral drugs to prevent or treat human corona virus infection.
Corona virus constitute the sub family Orthocoronavirinae, in the family coronaviridae,order Nidoviraless and realm Riboviria. They are enveloped viruses with a positive-sense single- strainded RNA genomic and a nucleocapsid of helical symmetry. The genome size of corona viruses ranges from opprozimately 26 to 32 Kilobases ,one of the largest among RNA viruses . They have characteristic club-shaped spikes that project from their surfaces, which in electron micrographs create an image reminiscent of the solar corona from which their name derives

Discovery

                  Corona virus were first discovered in the 1930s when an acute respiratory infection of domesticated chickens was shown to be caused by infections bronchitis virus. In the 1940s, two more animal corona virus. mouse hepatitis virus and transmissible gastroenteritis virus were isolated .
                            Human corona virus were discovered in the 1960s. The earliest ones studied  were from human patients with the common  cold. Which were later named human corona virus  229E and human corona virus oc43.They were first imaged by scottish  virologist  June Almedia at St. Thomas Hospital in London other human corona virus have since been identified, including SARS-COV in 2003.HCOV  NL63 in 2004, AHKUI  in 2005  MERS -Cov in 2012, and SARS -Cov-2 in 2019 Most of these have involved serious respiratory tract  infections.

Etymology

                  The name 'corona virus' is derived from Latin  corona meaning 'crown' or 'wreath', itself a borrowing from  Greek, garland ,wreath.The name was first used in 1968 by an informal group of virologist in the journal Nature of to designate the new family of  viruses . The name refers  to the characteristics  appearance of versions by  electrons microscopy, which have a fringe of large bulbous surface projections creating an image reminiscent of a crown or of a solar corona. This morphology is created by the viral spike peplomers, which are proteins on the surface of the virus.

Structure

                      Corona virus are large pleomorphic spherical particles with bulbous surface projections. The average diameter of the virus particles is around 120nm.The diameter of the envelope of the virus ~80nm and the spikes are ~20nm long. The envelope  of the virus in electron dense shells.
                               The viral envelope consists of a lipid bilayar where the membrane,envelope and spike structural proteins are anchored A subset of corona virus also have a shorter spike like surface protein called  hemagglutinin esterase .
                               
                                 Inside the envelope,there is a nuclecapsid ,which is formed from multiple copies of the nucleocapsid protein which are bound to the positive-sense single -stranded RNA genome  in  a  continous  beads  -on a string type conformation.

Genome

                   Corona virus contain a positive sense ,single -stranded  RNA genome size for corona virus ranges from 26.4 to 31.7 kilobases. The genome size is one of the largest among  RNA viruses the genome has a 5' methylated cap and a 3' polyadenylated tail.
                              The genome organization for a corona virus is 5'-leader -UTR - replicase / transcriptase spike (5)-envelope (E)-membrane (M)  nucleocapsid   (N) -UTR- poly  (A)  tail .The open reading frames 'a and 'b. which  occupy the first two -third of the genome, encode  the replicase / transcriptase  polyprotein . The replicase  /  transcriptase  polyprotein self  cleaves to form  non structural proteins.
                             The later reading frames encode the four major structural proteins spike envelope membrane and  nucleocapsid  Inter spread between these reading frames are the reading frames. for the accessory proteins The number of accessory proteins and their functions is unique depending on the specific corona virus.

Life cycle

Entry

             Infection begins when the viral spike (S) glycoprotein attaches to its complementary host cell receptor after attachment , a protease  of the host cell cleaves and activates the receptor-attached spike protein Depending on the host cell protease available , cleavage and activation allows the virus to enter the host cell by endocytosis or direct fusion of the viral envelope with the host membrane.
                                    On entry into the host cell the virus particle is uncoated ,and its genome enters the cell cytoplasm . The corona virus RNA genome has a 5' methylated cap and a3' polydenlyated  tail. Which allows the RNA to attach to the host cells Ribosome for translation. The host Ribosome translates the initial overlapping open reading frame of the virus genome and forms a long polyprotein has in own proteases which cleave the polyprotein into multiple non structural proteins.

Replication

                             A number of non structural proteins coalesce to form a multi-protein  replicase  transcriptase  complex. The main replicase  transcriptase  protein is the RNA-  dependent RNA polymerase. It is directly involved in the replication and transcription of  RNA from an  RNA  strand . The other non structural  proteins in the complex assist in the replication and transcription process. The exoribonuclease non structural protein, For instance provides extra fidelity to replication by providing a proofreading function which the RNA dependent RNA polymerase lacks.
                                   One of the main functions of the complex is to replicate the viral genome. RdRp directly mediates the synthesis of negative sense genomic  RNA from the positive sense genomic RNA  . This is followed by the replication of  positive sense  genomic  RNA  from the negative sense genomic RNA . The other importance function of the complex is to transcribe the viral genome . RdRp directly mediates the synthesis of negative sense sub genomic RNA molecules from the positive sense genomic RNA . This is followed by the transcription of these negative sense sub genomic RNA molecule to their corresponding positive sense Mrnas.

Transmission

                      The interaction of the corona virus spike protein with its complement host cell

receptor is central in determining host cell receptor is central in determining the tissue tropism, infectively, and spices range of the virus. The SARS corona virus , For example , infections human cells attaching to the angiotensin – converting enzyme 2 receptor

Symptoms

              Corona virus vary significantly in risk factor some can kill more than 30% of these infected , such as MERS -Cov , and some are relatively harmless , such as a common cold corona virus can cause cold with major symptoms such as fever , and a sore throat from swollen adenoids corona virus can cause pneumonia (direct viral pneumonia or secondary bacterial pneumonia) and bronchitis . The human corona virus discovered in 2003,SARS -cov , which causes severe acute respiratory syndrome has a unique pathogenisis because it causes both upper and lower respiratory tract infections .
                               Six species of human corona virus are known , with one species sub divided into two different strains , making seven strains of human corona virus altogether four of these corona virus continually circulate in the human population and produce the generally mild symptoms of the common cold in adults and children world wide corona virus cause about 15% of common colds . The majority of colds are caused by rhino viruses . The four mild corona viruses have a seasonal incidence occuring  in the winter months in temperate climates . There is no preference towards a particular season in tropical climates.

Treatment

                            There is currently no vaccine or treatment for  covid -19  symptoms of a corona virus usually go away on their own . If symptoms feel worse than a common cold, contact your doctor  he or she may  prescribe  pain or fever medication . The FDA is currently advising people to be cautious of websites and stores selling products that claim to prevent treat or cure covid -19 . Additionally , do not take any form of chloroquine unless it has been prescribed for you by your family doctor and purchased from a legitimate source . As with a cold or the flu, drink fluids and get plenty of rest . If you are having trouble , breathing , seek immediate  medical care

Prevention

Clean your hands often use soap and water or an alcohol – based hand rub.
Maintain a safe distance from anyone who is coughing or sneezing .
Don't touch your eyes , nose and mouth.
Cover your nose and mouth with your bent elbow or a tissue when you cough or sneeze.
Stay home if you feel unwell.
If you have a fever , a cough and difficulty breathing , seek medical attention , call in advance.
Follow in directions of your local health authority

The pandemic will bring about a new era of international cooperation,even,or especially between rivals like the U S and china. Nations will start diverting resources away from defence and towards measures for reducing climate change and poverty and improving health care and education.
It's the time for us to join our hands and do whatever our government is asking. Because the death toll is raising tremendously . But if we work altogether we will reach the heights According to Abraham Lincoln, 'The best way to predict your future is to create it' We could change this crisis and make a good future by joining the battle against the corona virus.
In December 2019,a pneumonia outbreak was reported in wuhan, china .On 31 December 2019,the outbreak was traced to a novel strain of corona virus. Which was given the interim name 2019-n cov by the World Health Organization later renamed SARS-ncov -2 by the International Committee of Taxonamy of viruses some researchers have suggested the human seafood Whole sale Market may not be the orginal source of viral transmission to humans.
As of 17April 2020,there have been at least 143,844 confirmed deaths and more than 2,153,620 confirmed cases in the corona virus pneumonia pendamic. The wuhan strain has been identified as a new strain of Beta corona virus from group 2B with approximately 70% genetic similarity to the SARS-cov .The virus has a 96% similarity to a Bat corona virus,so it is widely suspected to originate from bats as well.
Corona virus are a group of related viruses that causes diseases in mammals and birds. In humans, corona viruses cause respiratory tract infections that can range from mild to lethal. Mild illness include some cases of the common cold, while more lethal varieties can cause SARS , MERS, and COVID-19 symptoms in other spices vary in chickens,they cause an upper respiratory tract diseases, while in cows and pigs they cause diarrhea. There are not yet to be vaccines or antiviral drugs to prevent or treat human corona virus infection.
Corona virus constitute the sub family Orthocoronavirinae, in the family coronaviridae,order Nidoviraless and realm Riboviria. They are enveloped viruses with a positive-sense single- strainded RNA genomic and a nucleocapsid of helical symmetry. The genome size of corona viruses ranges from opprozimately 26 to 32 Kilobases ,one of the largest among RNA viruses . They have characteristic club-shaped spikes that project from their surfaces, which in electron micrographs create an image reminiscent of the solar corona from which their name derives