A never-before-seen virus detected in the Chinese city of Wuhan has claimed more than approx 170 lives and infected almost 2,000 Chinese citizens with a pneumonia-like illness, according to China’s National Health Commission.
The virus was first described to the World Health Organization (WHO) on Dec. 31 and has been under research since. Chinese scientists have connected the disease to a family of viruses known as coronaviruses, which involve the deadly Severe Acute Respiratory Syndrome Coronavirus (SARS) and the Middle East respiratory syndrome (MERS).
What is Coronavirus?
Coronaviruses are a family of enveloped, single-stranded, positive-strand RNA viruses classified within the Nidovirales order. The genomic RNA is 27–32 kb in size, polyadenylated and capped.
This coronavirus family comprise pathogens of various animal species which includes rats, mice, chickens, swine, turkeys, dogs, rabbits, cats, cattle, horses, a Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and humans, including the recently confined.
Coronaviruses provoke acute and chronic respiratory, Central Nervous System (CNS) and enteric diseases in many species of animals, including humans. Patients may present with a dry cough, fever, dyspnea, hypoxemia, and headache.
Typical laboratory findings are lymphopenia and moderately elevated aminotransferase levels. Death may occur from progressive respiratory failure because of alveolar damage. SARS appears to be caused by an obscure infectious agent that is spread from human to human.
Where did the Coronavirus come from?
The virus seems to have originated in the Huanan Seafood Wholesale Market in Wuhan, a Chinese city about 650 miles south of Beijing, which has a population of more than approx 11 million people.
The market sells sea-fish, as well as a panoply of meat from other animals, including snakes and bats. Health experts believe it may have originated in bats and then transferred to humans, possibly through another animal species.
The World Health Organization (WHO) was warned to several cases of pneumonia in Wuhan at the end of December. Chinese officials confirmed they had identified a new virus a week late.
What are the types of Coronavirus?
Common types include:
- NL63 (alpha coronavirus)
- 229E (alpha coronavirus)
- HKU1 (beta coronavirus)
- OC43 (beta coronavirus)
Existence of coronavirus:
Coronavirus in Humans:
There were two prototype human coronaviruses, OC43 and 229E, both etiologic factors of the common cold. There had long been considering the association of human coronaviruses with more dangerous human diseases such as multiple sclerosis, an enteric disease in newborns or hepatitis.
Though, none of these early associations had been proved. The recently identified SARS-CoV, which was confirmed to cause a Severe Acute Respiratory Syndrome was the first instance of serious illness in humans caused by a coronavirus.
The World Health Organization (WHO) had registered 2353 cases by April 4, 2003. About 4 percent of sufferers with SARS have died. The SARS epidemic rose in Asia, with the majority of cases happening in China and the Asia–Pacific region.
“The plague has spread from Asia to other continents through foreign travel. The WHO has built a network of international labs to facilitate the identification of the causative agent of SARS”.
Coronavirus in Animals:
Coronavirus in chickens:
Infectious Bronchitis Virus (IBV), a coronavirus of the chicken (Gallus gallus), is one of the foremost causes of economic loss within the poultry industry, affecting the performance of both meat-type and egg-laying birds.
The virus replicates not only in the epithelium of upper and lower respiratory tract tissues, but also in many tissues along the alimentary tract and elsewhere e.g. kidney, oviduct, and testes. It can be detected in both respiratory and faecal material. There is increasing evidence that IBV can infect species of bird other than the chicken.
Interestingly breeds of chicken vary to the severity of infection with IBV, which may be related to the immune response. Probably the major reason for the high profile of IBV is the existence of a very large number of serotypes.
Both live and inactivated IB vaccines are used extensively, the latter requiring priming by the former. Their effectiveness is diminished by poor cross-protection. The nature of the protective immune response to IBV is poorly understood. What is known is that the surface spike protein, indeed the amino-terminal S1 half, is sufficient to induce good protective immunity.
There is increasing evidence that only a few amino acid differences amongst S proteins are sufficient to have a detrimental impact on cross-protection. Experimental vector IB vaccines and genetically manipulated IBVs – with heterologous spike protein genes have produced promising results, including in the context of Ovo vaccination.
Coronavirus in cats:
The coronavirus in cats is transmitted through oral contact with the infected faeces or airborne contaminants. It is common in young cats and also cats with a weak immune system.
Coronavirus causes feline infectious peritonitis. Coronavirus in Cats is of two types wet and dry. In most cases, the infection fades-off with time as the cats develop antibodies against it.
Coronavirus in dogs:
Coronavirus in dogs is an infectious intestinal disease that affects dogs all around the world. It affects the small intestine and lymph nodes. The coronavirus symptoms can be seen in the form of vomiting and diarrhea.
It affects the worst in puppies with serious complications, protracted diarrhea, and dehydration. It also causes severe enteritis in puppies. Coronavirus in dogs remains asymptomatic in adult dogs and does not require any treatment.
Coronavirus in the dog is presented with severe symptoms such as enteritis, respiratory problems, or blood, they may need antibiotics. There is a vaccine for coronavirus in dogs to prevent the disease.
Coronavirus in bats:
The existence of coronaviruses in bats is unknown until the recent discovery of bat-SARS-CoV in Chinese horseshoe bats and a novel group 1 coronavirus in other bat species.
Among 309 bats of 13 species captured from 20 different locations in rural areas of Hong Kong over 16 months, coronaviruses were amplified from anal swabs of 37 (12%) bats by RT-PCR. Phylogenetic analysis of RNA-dependent-RNA-polymerase (pol) and helicase genes revealed six novel coronaviruses from six different bat species, in addition to the two previously described coronaviruses.
Among the six novel coronaviruses, four were group 1 coronaviruses (bat-CoV HKU2 from Chinese horseshoe bat, bat-CoV HKU6 from Rickett’s big-footed bat, bat-CoV HKU7 from greater bent-winged bat and bat-CoV HKU8 from lesser bent-winged bat) and two were group 2 coronaviruses (bat-CoV HKU4 from lesser bamboo bats and bat-CoV HKU5 from Japanese pipistrelles). An astonishing diversity of coronaviruses was observed in bats.