Novel Coronavirus: Epidemiology and Genomics

Novel Coronavirus belong to large family of viruses that are RNA in nature. They are zoonotic which means they are transmitted between animals and humans.

Novel Coronavirus: Epidemiology and GenomicsThere are several Novel Coronavirus that are present in animals but are not known to infect the humans. The two strains of coronavirus had been identified in the previous outbreaks. Severe acute respiratory syndrome (SARS-CoV) outbreak was reported in Guangdong province, China in November 2002. SARS-CoV was transmitted from civet cats to humans, infected at least 8096 people and caused 774 deaths. Middle East Respiratory Syndrome (MERS-CoV) was reported in June 2012 in Jeddah, Saudi Arabia. The mode of transmission was from dromedary camels to humans. This strain of coronavirus infected 2494 people and caused 858 deaths. A new strain of coronavirus has been named Novel Coronavirus (nCoV). This strain has not been previously identified in humans.

Symptoms

Coronavirus has mild to severe symptoms including fever, breathing problems, cough, pneumonia, respiratory tract infection, severe acute respiratory syndrome and kidney failure. People with weak immunity are vulnerable to severe symptoms which even causes death.

Epidemiology of Novel Coronavirus (nCoV)

In December 2019 several cases of viral pneumonia caused by unknown microbial agent were reported in Wuhan, China. Most of the patients were workers at or lived around the Hunan seafood market. Early symptoms included pneumonia, respiratory tract infection and some patients developed acute respiratory failure and other complications leading to organ failure. Immediate investigation started for the identification of disease. The epidemiological and clinical data collected from the patients for the development of diagnostic and treatment procedures. By January 2007 the causative agent was identified by the Chinese scientists from the throat swab sample of a patient in Wuhan. Afterwards it was named as 2019 novel corona virus by WHO. The human to human transmission of this virus has been confirmed. Till now approximately 30000 people have been infected including 722 deaths and the number is increasing day by day. This virus has a high mutation rate and people travelling from Wuhan has resulted in the expansion of novel coronavirus to other 24 countries.

Genomics of nCoV

Samples from the patients having history of exposure to Hunan seafood market subjected to genomic analysis, indicated that genome sequences of 2019-nCoV are extremely similar showing more than 99.98% sequence identity. 2019-nCoV showed close relationship (with 88% identity) to two bat-derived severe acute respiratory syndrome (SARS)-like coronaviruses. Data indicated bats as reservoirs for novel coronavirus.  

The phylogenetic analysis of the sequences showed that bat derived coronaviruses fell in the genus of Betacorona virus.  Bats also acted as the natural reservoir in the previously identified strains of coronaviruses SARS-CoV and MERS-CoV, with other animals as the intermediate host and humans as the terminal host. In case of novel coronavirus, the phylogenetic analysis suggests that bats might me the original host but have been transmitted to humans via intermediate host that can be unknown animals sold at Hunan seafood market. Researchers have suspected the link between endangered pangoiln (intermediate host) and spread of novel coronavirus at South China Agricultural University.

Measures against novel coronavirus

People infected with novel coronavirus are being kept in isolation in order to control the spread of infection. People are advised to limit their travel  from the affected areas. WHO has declared the global public health emergency due current situation. As the global health emergency continues, rapid access to the genome sequence of the novel coronavirus is being provided to biomedical community. The outbreak data would help in finding the ways to cure and prevention against novel viral pathogen.

By Aqsa Babar

BS(hons)Biotechnology Kinnaird College For Women Lahore