Recently, there has been much discussion regarding the topic of coronavirus. The word “coronavirus” has been frequently used to refer to the respiratory disease that broke out in January in Hubei, China. However, coronavirus precisely refers to a family of viruses including Severe Acute Respiratory Syndrome (SARS-CoV) and Middle East Respiratory Syndrome (MERS-CoV) that are commonly found on animals such as camels, cattle, and bats.
The World Health Organization declared this virus outbreak in China as a Public Health Emergency of International Concern on January 30, 2020, and officially named the disease COVID-19 on February 11, 2020. COVID-19 is only the disease name and not the scientific name of the virus, which is currently called 2019-nCoV as a placeholder (e.g. the disease SARS is caused by the virus SARS-CoV). Humans have very limited knowledge of this novel coronavirus, but researchers continue to identify new information such as the biological structure, transmissions, and symptoms of 2019-nCoV, with the hope of finding a possible vaccine or cure.
Coronaviruses are single-stranded RNA viruses with long genomes that can go up to 32 kbp (kilo-base pair). 2019-nCoV is classified as a Betacoronavirus, a genus of the coronavirus family, originating from bats, which do not transmit the virus directly. It is most closely related to the two viruses bat-SL-CoVZXC21 and bat-SL-CoVZC45, which can be found on Chinese rufous horseshoe bats. The virus traces back to lineage B of Betacoronaviruses, the same lineage as SARS, and both ZXC21 and ZC45 are SARS-like CoVs.
In addition, genomic analysis of the early cases of 2019-nCoV in China shows that the virus has limited genomic variation since all sequences have over 99% similarity. The close association to SARS and other bat coronaviruses and the limited variation of the virus itself means a greater chance of having vaccines for the viruses based on previous research on the Betacoronaviruses group. Despite the consistency in China, more variations of the virus have been found in confirmed cases in the U.S., which provide clues to the source of animal-to-person transmission.
Despite 2019-nCoV’s intermediate host between bats and humans is yet to be determined, person-to-person transmission is now the main concern. This is because the virus attacks cilia cells and mucous cells in the respiratory system, which is why it is most easily transmitted via respiratory droplets from coughs or sneezes, and such transmissions can be partially prevented by wearing a face mask. The mucous membrane is also located on the eye, the nose, and the mouth, so one of the best ways to limit transmission is to frequently wash both hands and refrain from touching any parts of the face.
People infected are believed to be the most contagious when they show severe symptoms, but there is a possibility of person-to-person transmission from someone not demonstrating any symptoms. The suggested quarantine period for anyone with the possibility of getting infected is 14 days, which is also the estimated incubation period of the virus.
As of March 1, 2020, the total number of confirmed cases worldwide has exceeded 88,948 people with a death toll of at least 3,043, surpassing SARS in 2003 in cases but greatly lower in death rate. However, in general, COVID-19 spreads far more quickly than SARS but is not as severe and fatal. Many of the people who died from the virus were elders with a relatively weaker immune system or those who already had an existing illness.
Symptoms of COVID-19 usually resemble those of pneumonia. The virus starts with attacking the cilia and mucous cells in the lungs. The immune system, alerted by the invasion, goes off trying to kill the viruses, but also kills the body’s own healthy cells at the same time, destroying the lungs. The interaction between the virus and immune system ultimately scratches the lungs and creates symptoms such coughs, fevers, and breathing difficulties, which are documented in a study of the first 99 cases of the 2019 novel coronavirus pneumonia in Wuhan, China by professor Nanshan Chen, MD, et al. published on The Lancet on January 30, 2020.
Based on the special lung features created by COVID-19, a new diagnostic method of taking chest X-rays was used starting on February 12, 2020, increasing the efficiency of confirming cases greatly. This also increases the efficiency of finding people who were in contact with confirmed patients to put them under medical observation.
With more scientists diligently investigating this new coronavirus, we hope that a vaccine could be developed and that the spread will cease before long. We hope that everyone at Concord Academy will take care of themselves by washing their hands frequently, especially before eating, sneezing into their sleeves, and preventing hand and face contact.