By Omotosho Faithfulness (Medickristitofunmi97@gmail.com)
The outbreak of a new type of coronavirus in the city of Wuhan, capital of central Hubei province in china has raised a lot of public health concerns across the world. Government of different countries are trying to ensure their citizens are informed on what to do to prevent themselves and others around them. But how do we separate the facts from the myths? What do we know about coronavirus?
What are Coronaviruses?
Coronaviruses belongs to a large family of viruses that causes illness that range from the common cold to severe respiratory diseases. They were first identified in the 1960s and were named ‘corona’ because of their crown-like shape. This virus consists of a non-segmented, positive sense RNA genome of approximately 30kb and four main structural proteins: the spike (S), membrane (M), envelope (E), and nucleocapsid (N) proteins (Fehr and Perlman, 2015). This genome has a 5’ cap structure along with a 3’ poly(A) tail that allows it to acts as a mRNA for translation of its replicase protein using the host cell’s translation machinery.
Coronavirus Life Cycle
The life cycle of coronavirus occurs in four stages: Attachment and entry; Replicase protein expression; RNA replication and transcription; Assembly. Once the virus enters into the system of the host, it attaches itself to the host cell by S protein-receptor interaction. Following receptor binding, the virus gains access into host cell’s cytosol where the replicase protein expression creates a suitable environment for the virus’s RNA replication and transcription. The newly synthesized RNA and viral structural proteins are assembled to form matured virions within the host cell. These matured virions are then transported to the surface of the host cell in vesicles where they are released into the extracellular environment by exocytosis to infect neighboring cells. It has been shown that some structural proteins that were not involved in the assembly process transits to the cell surface where they mediate cell-cell fusion between the infected cells and adjacent uninfected cells. This leads to the formation of big, multinucleated cells that allows the virus to spread within an infected organism without detection or neutralization by virus specific antibodies.
Coronaviruses are zoonotic viruses because they are transmitted between animals and humans, causing a variety of diseases. Most of the disease caused by these group of viruses in humans include the 2019-nCoV Acute Respiratory Diseases caused by 2019-nCoV, Middle East Respiratory Syndrome caused by MERS-CoV, Severe Acute Respiratory Syndrome caused by coronavirus SARS-CoV. The other human coronavirus causing diseases include 229E, NL63, OC43 and HKU1 (Centers for Disease control and Prevention, 2020).
The SARS-CoV outbreak occurred between 2002- 2003 in Guangdong province of China, with approximately 8098 reported cases and 774 deaths. Although cases of outbreak from anywhere in the world were no longer reported in 2004. The MERS-CoV outbreak which was responsible for the series of highly pathogenic respiratory tract infection in Saudi Arabia occurred in 2012. In August 2014, the European Center for Disease Prevention and Control reported 333 deaths from a total of 855 reported cases. MERS-CoV is still monitored globally to better understand the risk of the virus, how it spreads, and how to prevent infection.
The Novel Coronavirus (2019-nCoV)
Years after the SARS-CoV (2003) and MERS-CoV (2012) epidemic outbreak in the Guangdong province, China and Middle East respectively, a novel Coronavirus has begun to cause series of Pneumonia like symptoms among the population in Wuhan, capital of central Hubei province, China. This epidemic outbreak was reported to the World Health Organisation (WHO) in December, 2019. Since little is known about this virus, the coronavirus was given the name 2019-nCoV. In the interim, the WHO recommends that the name of the disease causing the outbreak should be 2019-nCoV Acute Respiratory Disease as a final name of this infectious disease would be provided by the International Classification of Diseases (ICD). The final decision on the official name of the virus will be made by the International Committee on Taxonomy of Viruses (WHO 2019-nCoV situation report, 2020).
|A patient infected by nCoV receiving treatment at the intensive care unit of Zhongnan Hospital of Wuhan University in Wuhan in central China’s Hubei Province on January 24, 2020 (Source – China’s Xinhua News Agency)|
According to the WHO situation report on Novel Coronavirus (2019-nCoV), as at 29th January, 2020, a total number of 6065 cases have being confirmed globally. In china, 5,997 cases have been confirmed and 132 death recorded. Outside of china, 15 countries have been affected with a total of 68 confirmed cases. The World Health Organisation risk assessment established that China is at a very high risk of 2019-nCoV transmission, while at the regional and global level there is a high risk with the 2019-nCoV transmission.
The situation report on 30th January, 2020, confirmed cases of 2019-nCoV acute respiratory disease in Finland, India and Philippines; which all had a travel history to Wuhan City. Globally, 7,818 cases have been confirmed with a total of 170 deaths recorded in China. Outside of china, 18 countries have been affected and 82 cases has been confirmed but no death reported. This shows that there is a high probability rate of 2019-nCoV transmission and high number of death that would be recorded in China if effective diagnostic approaches are not developed.
|Graphical distribution of nCoV cases globally as of 5th February, 2020 (Source: European Centre for Disease Prevention and Control)|
Currently, the WHO is working with specialists to analyze the full genomic sequence of 2019-nCoV, and they are also working on laboratory detection approaches and diagnostic strategies to improve surveillance, early detection and track of spread of 2019-nCoV acute respiratory disease. To date, human- to- human transmission outside of China has been limited, and public health efforts are targeted at limiting further transmission in countries with imported cases which depends critically on the ability to detect the pathogen.
On 30th January, 2020, the World Health organization (WHO) declared 2019-nCoV Acute Respiratory Diseases as a public health emergency of international concern due to the global outbreak of the diseases outside of China.
According to the situation report released by the World Health Organisation on 4th February, no new countries have reported cases of 2019-nCoV. But globally, 20,630 cases have been confirmed. Out of these confirmed cases, 20,471 were from China, and 159 cases from outside of China. Of the 20,471 cases from China, 2,788 cases were regarded as severe and 425 deaths has been recorded. While outside of China, only one death has been recorded from the 159 confirmed cases.
Based on available data, the likelihood of transmission of 2019-nCoV is through contact with a symptomatic infected person. Therefore, the World Health Organization has recommended ways by which we can prevent ourselves and others from contracting the virus. This includes hand hygiene, respiratory hygiene and safe food practices.
There are some myths about Coronavirus, most especially the 2019-nCoV
- When most people hear coronavirus, they assume that it is a new type of virus. Coronavirus is not a new TYPE of virus but a Virus that belongs to the family Coronaviridae (bigger family of virus). 2019-nCoV is a type of Coronavirus.
- It is believed that Coronavirus diseases can be treated with Antibiotics. Viral infections cannot be treated with antibiotics because antibiotics are meant for bacterial infections. Therefore, 2019-nCoV cannot be treated with antibiotics although people infected with 2019-nCoV can be given antibiotics in case of a bacterial co-infection.
- Some believe that only a certain group of people can get infected by Coronavirus. This is not true as people of all ages can get infected by any type of coronavirus. Older people and those with an underlying illness are more susceptible to 2019-nCoV or any type of coronavirus.
- Since coronaviruses are zoonotic, there are concerns that household pets might be infected by coronavirus. Although there is no evidence to prove this but it is recommended that everyone protect themselves through hand hygiene to prevent the transmission of common bacteria such as E. coli from pets to humans.
Other myths about 2019-nCoV can be found on the World Health Organisation website at the 2019-nCoV myths busters section (link: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/myth-busters).
Regardless of these myths, the World Health Organization has recommended ways by which we can prevent ourselves and others from contracting the virus. This includes hand hygiene, respiratory hygiene and safe food practices.