Recently the news stream has been filled with Coronavirus as hundreds of people lost their lives due to the spreading virus. The name was coined from the Latin corona and the Greek κορώνη (korṓnē, “garland, wreath”), meaning crown or halo.
It is inspired by the characteristic appearance of virions (this is the infective form of the virus) by electron microscopy, which has a fringe of large, bulbous surface projections creating an image reminiscent of a royal crown or at the solar corona. Also, the morphology is created by the viral spike (S) peplomers, which are proteins that populate the surface of the virus and determine host tropism.
Coronaviruses are viruses that cause diseases in mammals and birds. The virus causes respiratory infections that are typically mild, but in rare cases can be deadly. However, it can result in diarrhea in cows and pigs but affects the upper respiratory diseases in chickens. Unfortunately, there are no approved vaccines or antiviral drugs for prevention or treatments at the publication of this article.
Coronaviruses are viruses in the subfamily Orthocoronavirinae in the family Coronaviridae in the order Nidovirales. They are enveloped viruses with a positive-sense single-stranded RNA genome and with a nucleocapsid of helical symmetry. Besides, the genomic size of coronaviruses ranges from 26 to 32 kilobases, and the largest for an RNA virus.
Furthermore, proteins that add to the overall structure of all coronaviruses are the spike (S), membrane (M), and nucleocapsid (N). A defined receptor-binding domain on S mediates the attachment of the virus to its cellular receptor, angiotensin-converting enzyme 2 (ACE2), in the specific case of the SARS coronavirus.
Some coronaviruses, especially the members of Betacoronavirus subgroup A, have a shorter spike-like protein called hemagglutinin esterase (HE).
What are Human coronaviruses?
Human coronaviruses cause a large percentage of all common colds in human adults and children. The major symptoms include fever, swollen throat adenoids, in humans primarily in th winter and early spring seasons.
Coronaviruses can cause pneumonia, either direct viral pneumonia or secondary bacterial pneumonia, and they can cause bronchitis, either direct viral bronchitis or secondary bacterial bronchitis.
The human Coronavirus was first discovered in 2003, SARS-CoV, which causes severe acute respiratory syndrome (SARS), it has unique pathogenesis because it causes both upper and lower respiratory tract infections.
Seven strains of human coronaviruses
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.
Effects of Coronavirus
Coronaviruses mainly infect the upper respiratory and the gastrointestinal tract of mammals and birds. The viruses are the cause of some diseases in farm animals and domesticated pets, some of which be lethal and are a threat to the farming industry.
In chickens, the infectious bronchitis virus (IBV), caused by Coronavirus, targets the respiratory tract and the urogenital tract. The infection can spread to different organs throughout the chicken. Economically significant coronaviruses of farm animals include;
Porcine Coronavirus- a transmissible gastroenteritis coronavirus
Feline Coronavirus – they are 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.
There are two types of Coronavirus that infect ferret: ferret enteric Coronavirus causes a gastrointestinal syndrome known as epizootic catarrhal enteritis (ECE) and a more dangerous systemic version of the virus-like FIP in cats known in ferrets as ferret systemic coronavirus (FSC).
Two types of canine Coronavirus (CCoV), one that causes mild gastrointestinal disease, and one has been found to cause respiratory disease.
Mouse hepatitis virus (MHV) is a coronavirus that causes murine epidemic 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 harderian glands.
Swine acute diarrhea syndrome coronavirus, which is An HKU2-related bat coronavirus, causes diarrhea in pigs.
MHV had been the best-studied Coronavirus both in vivo and in vitro and molecular level before the discovery of SARS-CoV. Some strains of MHV cause progressive demyelinating encephalitis in mice, which has been used as a murine model for multiple sclerosis.
Also, significant research efforts have been focused on clarifying the viral pathogenesis of these animal coronaviruses, especially by virologists interested in veterinary and zoonotic diseases.
Effects on Coronavirus in domestic animals
• Infectious bronchitis virus (IBV) causes avian infectious bronchitis
• Porcine Coronavirus (transmissible gastroenteritis coronavirus of pigs, TGEV)
• Bovine Coronavirus (BCV), responsible for severe profuse enteritis in of young calves
• Feline Coronavirus (FCoV) causes mild enteritis in cats and acute Feline infectious peritonitis (other variants of the same virus).
• The two types of canine Coronavirus (CCoV) (one causing enteritis, the other found in respiratory diseases)
• Turkey coronavirus (TCV) causes enteritis in turkeys
• Ferret enteric Coronavirus causes epizootic catarrhal enteritis in ferrets
• Ferret systemic coronavirus causes FIP-like systemic syndrome in ferrets
• Pantropic Canine Coronavirus
• Rabbit enteric Coronavirus causes acute gastrointestinal disease and diarrhea in young European rabbits. Mortality rates are high
However, another new veterinary disease, porcine epidemic diarrhea virus (PED or PEDV), has emerged around the world. Its economic importance is as yet unclear but shows high mortality in piglets.
How to prevent Coronavirus
Currently, there is no definite way of preventing viruses, but there are some practical steps you can take to avoid getting infected.
Keep your traveling plans: if you are planning to visit China soon, especially the Wuhan city, it is advisable to wait until the virus is contained or eradicated. According to WHO “On 31 December 2019, WHO was alerted to several cases of pneumonia in Wuhan City, Hubei Province of China.”
Stop eating meats from animals that are prone to have Coronavirus. However, if you must eat, cook it properly, steer clear of medium or rare cooked meats. Also, do not eat bat or snake soup or any form of meals prepared with bats, snakes and any animals that eat bats.
Wash your hands as often as you can; avoid using your hands to touch your eyes, nose, and mouth. If you must, then wash them before and after use.
If you are sick, please stay at home; do not take any of the symptoms for granted.
For the sake of your loved ones, stay off the grid; be alert. Watch what you eat, touch, and where you go. Also, protect your pets by restricting their movements for now, until there are proven solutions for eradicating the virus.