2019 Novel Coronavirus (2019-nCoV) Update: Uncoating the Virus

Jan. 31, 2020

UPDATE: The previous nomenclature of 2019-nCoV has been replaced with the official name of the virus, SARS-CoV-2, and the disease that the virus causes, COVID-19.

Should You Be Worried about the Novel Coronavirus Outbreak?

Outbreaks of new (novel) virus infections among people are always public health concerns. Public health officials, scientists, researchers, media and the public should take this current COVID-19 outbreak seriously and monitor it closely. According to the Centers for Disease Control and Prevention (CDC), the risk to individuals is dependent on exposure. To date, some people will have an increased risk of infection, for example healthcare workers caring for COVID-19 patients and other close contacts, as well as immunocompromised individuals. For the general American public, who are unlikely to be exposed to this virus, the immediate health risk from COVID-19 is considered low at this time.

It’s understandable that some may be overwhelmed, or even frightened, by news about the outbreak. What can one do about these worries and concerns? One of the most important things that can be done is to monitor reputable sources like the CDC, WHO, and other expert agencies and people. 

The rapid dissemination of information, including misinformation, during an outbreak is a relatively recent development. Facebook, Twitter, Instagram and Snapchat were still years away from being founded in 2002, when severe acute respiratory syndrome (SARS) rattled southern China, infecting more than 8,000 people and killing nearly 800, including 44 Canadians. In today’s age of social media, there is a plethora of sites from which anyone can obtain information, and many of them are not credible or vetted by medical or scientific experts. A misinformed tweet, post, or photo can easily convince someone to disregard proper hygiene or create shock value about the risk of contracting an illness.

It might be worthwhile to tune out social media or other non-reputable sources if it creates panic. I always tell my students, friends and family members that “microbes don’t read the book” with regards to our understanding them. The microbes don’t read or listen to social media either. Try to stay informed, and listen to experts and sources that do offer facts but not sensationalism.

When I was working on my PhD dissertation regarding MRSA adaptation, I immersed myself in Social Representation Theory (SRT). SRT offers a new approach for studying how the media and citizens construct societal and political issues colouring our age, or some specific time period (e.g. climate change, health stigmas like tuberculosis, etc.). We rarely want to admit that we are all influenced by media (especially social media) with respect to fear. It literally can create its own reproduction rate of spread among the general public, as well as those in charge or experts. We are all human. And, in the age of Facebook, Twitter, and other media outlets we all participate in being vectors to spread these dangerous and fear-invoking story lines.

CDC Recommendations

While the immediate risk of this new virus to the American public is believed to be low at this time, everyone can do their part to help us respond to this emerging public health threat: The top US public health officials report that the COVID-19 outbreak that began in Wuhan, China is not a threat to the average American citizen. Nevertheless, it is important to understand this new human pathogen (in this case, the virus is named SARS-CoV-2 and the disease it causes is called COVID-19), and this article will cover coronavirus basics and what scientists have learned about the virus so far.

Coronaviruses Categorization: What Are Coronaviruses?



Coronaviruses are everywhere. They are the second leading cause of the common cold (after rhinoviruses) and until recent decades, rarely caused any disease more serious than a common cold in humans.

The first coronavirus was isolated in 1937. Some cause illness in people and others circulate among other animals, including camels, cats and bats. Since its discovery, related coronaviruses have been found to infect cattle, pigs, horses, turkeys, cats, dogs, rats, and mice. The first human coronavirus was cultured in the 1960s from nasal cavities of people with the common cold. 

The 4 major categories of coronavirus are known by the Greek letters alpha, beta, delta and gamma. Only alpha and beta coronaviruses are known to infect humans . These viruses spread through the air and are responsible for about 10-30 percent of colds worldwide. Long known to cause upper respiratory infections, coronaviruses were not felt to significantly cause pneumonia until relatively recently. Seven human coronaviruses (HCoVs) have now been identified: HCoV-229E, HCoV-OC43, HCoV-NL63, HCoV-HKU1, SARS-CoV (which causes severe acute respiratory syndrome), MERS-CoV (Middle East respiratory syndrome), and now SARS-CoV-2. All but 2019-nCoV appear to be established human pathogens with worldwide distribution, causing upper and lower respiratory tract infections, especially in children. Typically, HCoV infection follows a seasonal pattern similar to that of influenza, although Hong Kong researchers found that HCoV-NL63 infections mainly occurred in early summer and autumn. While there aren’t many coronaviruses that cause lower respiratory disease in humans, they can have serious consequences for those they infect. 
 
Coronaviruses are zoonotic, meaning they can be transmitted between animals and people, but most infect only their specific animal host. Rarely, animal coronaviruses can evolve to infect and spread among people. This was the case with Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). SARS killed nearly 10% of the 8,096 people who fell ill in 29 countries. A total of 774 people died, according to the World Health Organization. MERS is even more deadly, claiming more than 30% of people it infects. Unlike SARS, outbreaks of MERS are still occuring, NIAID Director Anthony Fauci says. Since 2012, MERS has caused 2,494 confirmed cases in 27 countries and killed 858 people. SARS-CoV and MERS-CoV generally spread between people who were in close contact, which resulted in many fatalities of healthcare workers.

These viruses spread similar to the flu virus, and past MERS-CoV and SARS-CoV outbreaks have been complex, requiring comprehensive public health responses. The rapid public health responses to these outbreaks were able to quickly determine that the SARS-CoV genome sequence is different from all other known coronaviruses and that it was first transmitted from civet cats to humans, though bats were determined to be the reservoir. Scientists also quickly found that MERS-CoV spread from dromedary camels to humans. Therefore, it’s important to briefly discuss coronavirus genetics.

Coronavirus Genetics 

Coronaviruses, so named because they look like halos (known as coronas) when viewed under the electron microscope, are a large family of RNA viruses. The typical generic coronavirus genome is a single strand of RNA, 32 kilobases long, and is the largest known RNA virus genome. Coronaviruses have the highest known frequency of recombination of any positive-strand RNA virus, promiscuously combining genetic information from different sources when a host is infected with multiple coronaviruses. In other words, these viruses mutate and change at a high rate, which can create havoc for both diagnostic detection as well as therapy (and vaccine) regimens.
 
Coronaviruses have an unusual replication process, which involves a 2-step replication mechanism. Many RNA virus genomes contain a single open reading frame (ORF) which is then translated as a single polyprotein that is then catalytically cleaved into smaller functional viral proteins, but coronaviruses can contain up to 10 separate ORFs. Most ribosomes translate the biggest one of these ORFs, called replicase, which alone is twice the size of many other RNA viral genomes. The replicase gene encodes a series of enzymes that use the rest of the genome as a template to produce a set of smaller, overlapping messenger RNA molecules, which are then translated into the structural proteins -- the building blocks of new viral particles. For a detailed, complete description of coronavirus replication and pathogenesis, see the 2016 publication by Fehr and Perlman.
Diagram of coronavirus virion structure showing spikes that form a "crown" like the solar corona, hence the name.

Lessons from Past Coronavirus Outbreaks

As a public health and medical laboratory scientist, I have experienced numerous “new” and reemerging microbial outbreaks spanning 3 decades. Over the coming days, weeks, months and even years, we will learn more about the biology of this new SARS-CoV-2 virus, including better estimates of case fatality, reproduction rates, and other important data. More cases are likely to be identified in the coming days, including more cases in the United States. Given what has occurred previously with MERS-CoV and SARS-CoV, it’s likely to spread from person-to-person, including within the United States. Seek out reputable sources for new information and follow CDC guidelines and recommended health precautions (e.g. hand washing, updated vaccinations, and travel alerts). This is a rapidly evolving situation, and information will be updated as it becomes available.

This article was compiled from a variety of sources by the author, with the bulk of information from the CDC and WHO (and their connected sources). This is an emerging, rapidly changing situation, and CDC will provide updated information as it becomes available, in addition to updated guidance.

Coronavirus Resources:

ASM Coronavirus Resource Page

CDC 2019 Novel Coronavirus (2019-CoV) Situation Summary

World Health Organization Novel Coronavirus (2019-CoV) Website

Frequently Asked Questions about coronaviruses from the CDC.

Dr. Rohde interview on Fox 7 news regarding #nCoV outbreak
 
Dr. Rohde Linkedin Blog article about coronavirus 

The above represent the views of the author and does not necessarily reflect the opinion of the American Society for Microbiology.

Author: Rodney Rohde

Rodney Rohde
Dr. Rodney Rohde, Ph.D., is the Associate Director of the Translational Health Research Initiative at Texas State University.