Coronaviruses are the group of viruses causing diseases in mammals, including humans, and birds. In human beings, it caused respiratory infections which are typically milds but in some rare cases, it may be lethal. In other mammals like pigs and cows, it caused diarrhea, while in birds and chickens it can cause upper respiratory diseases. Till the last update of this articles, there is no many vaccines or antiviral drugs for the prevention of this viruses, and therefore, the only way to be safe from this virus in prevention which includes like the use of mask while going outside and so on.
|Electron micrograph of coronavirus virions
Coronaviruses are believed to cause a significant percentage of all common colds in human adults and children. Coronaviruses cause colds with major symptoms, e.g. fever, throat swollen adenoids, in humans primarily in the winter and early spring seasons. Coronaviruses can cause pneumonia, either direct viral pneumonia or secondary bacterial pneumonia and they can also cause bronchitis, either direct viral bronchitis or secondary bacterial bronchitis. The much-publicized human coronavirus discovered in 2003, SARS-CoV which causes severe acute respiratory syndrome (SARS), has unique pathogenesis because it causes both upper and lower respiratory tract infections.
There are seven strains of human coronaviruses:
Human 229E (HCoV-229E)
Human coronavirus OC43 (HCoV-OC43)
Human coronavirus NL63 (HCoV-NL63, New Haven coronavirus)
Human coronavirus HKU1
Middle East respiratory syndrome coronavirus (MERS-CoV), previously known as novel coronavirus 2012 and HCoV-EMC.
Novel coronavirus (2019-nCoV) also known as Wuhan pneumonia or Wuhan coronavirus (‘Novel’ in this case means newly discovered, or newly originated and is a placeholder name.)
The coronaviruses HCoV-229E, -NL63, -OC43, and -HKU1 continually circulate in the human population and cause respiratory infections in adults and children worldwide.
Coronaviruses were discovered in the 1960s; the earliest ones discovered were infectious bronchitis virus in chickens and two viruses from the nasal cavities of human patients with the common cold that were subsequently named human coronavirus 229E and human coronavirus OC43. Other members of this family have since been identified, including SARS-CoV in 2003, HCoV NL63 in 2004, HKU1 in 2005, MERS-CoV in 2012, and 2019-nCoV in 2019; most of these have been involved in serious respiratory tract infections.
On 31 December 2019, a novel strain of coronavirus, officially designated as 2019-nCoV by the World Health Organization, was reported in Wuhan, China, as responsible for the 2019–20 Wuhan coronavirus outbreak. By 24 January 2020, 25 deaths have been reported and 547 confirmed cases. The Wuhan strain has been identified as a new strain of Betacoronavirus from group 2B with an ~70% genetic similarity to the SARS-CoV. The virus was suspected to have originated in snakes, but many leading researchers disagree with this conclusion.
Coronaviruses primarily infect the upper respiratory and gastrointestinal tract of mammals and birds. They also cause a range of diseases in farm animals and domesticated pets, some of which can be serious and are a threat to the farming industry. In chickens, the infectious bronchitis virus (IBV), a coronavirus, targets not only the respiratory tract but also the urogenital tract. The virus can spread to different organs throughout the chicken. Economically significant coronaviruses of farm animals include porcine coronavirus (transmissible gastroenteritis coronavirus, TGE) and bovine coronavirus, which both result in diarrhea in young animals. Feline coronavirus: two forms, feline enteric coronavirus is a pathogen of minor clinical significance, but spontaneous mutation of this virus can result in feline infectious peritonitis (FIP), a disease associated with high mortality. Similarly, there are two types of coronavirus that infect ferrets: ferret enteric coronavirus causes a gastrointestinal syndrome known as epizootic catarrhal enteritis (ECE) and a more lethal systemic version of the virus (like FIP in cats) known in ferrets as ferret systemic coronavirus (FSC). There are two types of canine coronavirus (CCoV), one that causes mild gastrointestinal disease and one that has been found to cause respiratory disease. Mouse hepatitis virus (MHV) is a coronavirus that causes an epidemic murine illness with high mortality, especially among colonies of laboratory mice. Sialodacryoadenitis virus (SDAV) is a highly infectious coronavirus of laboratory rats, which can be transmitted between individuals by direct contact and indirectly by aerosol. Acute infections have high morbidity and tropism for the salivary, lachrymal and hardarian glands.
A HKU2-related bat coronavirus called swine acute diarrhea syndrome coronavirus (SADS-CoV) causes diarrhea in pigs.
Prior to the discovery of SARS-CoV, MHV had been the best-studied coronavirus both in vivo and in vitro as well as at the molecular level. Some strains of MHV cause progressive demyelinating encephalitis in mice which has been used as a murine model for multiple sclerosis. Significant research efforts have been focused on elucidating the viral pathogenesis of these animal coronaviruses, especially by virologists interested in veterinary and zoonotic diseases.