In December 2019, a group of people that all visited the Wuhan seafood market developed an infection with pneumonia-like symptoms. After extensive testing and genomic sequencing, researchers determined that the causative agent behind this new disease was a new type of coronavirus. Most coronaviruses are relatively nonpathogenic and are responsible for predominantly respiratory infections, such as the common cold. However, there have been a few other instances of epidemic diseases caused by a coronavirus. These infections, known as severe acute respiratory syndrome coronavirus (SARs) and Middle East respiratory syndrome coronavirus (MERS), were considered to be an epidemic and could be quite dangerous if transmitted to an individual that was immunocompromised. In fact, SARS had a fatality rate of 10%, making it a concern for public health officials. While the new coronavirus is not the same virus as SARS or MERS, it is important to understand the mechanisms of these previous viruses to gain an idea of how the new coronavirus might be contained and treated.
Even though the coronavirus has just been identified, researchers have already discovered multiple different aspects to the disease which might be useful when containing the spread of the disease. For example, researchers now know the bat is the primary reservoir for the coronavirus. However, the bat is most likely not the vector for this disease, as it originated in a seafood market. Researchers believe that this coronavirus was most likely spread through a mammal, as SERS and MERS were originally spread through a civet cat and a camel, respectively. Transmission, however, is not limited to human-animal, as healthcare workers in hospitals where patients of the coronavirus were treated also become infected, indicating that human-human transmission was possible. Researchers believe that this virus most likely is transmitted through direct contact, namely droplet transmission. Thus, when considering methods for infection control, it is useful to adopt good handwashing techniques and proper procedures for sneezing or coughing. The estimated R0 value for the virus is around 1.3 to 2.5. According to a news article written by Ewen Calloway and David Cyranoski, any R0 value above one warrants the use of countermeasures to control the spread of the infection. This means that even though the disease can only be spread through direct transmission, it is still important to partake in infection control protocols, such as quarantining and early identification, to prevent the virus from becoming an epidemic. They also know that the virus is a large, enveloped, positive-strand RNA virus, which is useful to know when formulating a possible antiviral medication to treat the infection.
A few questions have arisen surrounding the virality of the virus. One of these questions is if the virus can be asymptomatic. The answer to this question seems to be yes, as a study conducted amongst a Chinese family found that one of the children, who was infected with the virus, did not show any signs of the disease, which include fever, difficulty breathing, cough, and lesions on the lungs. However, these signs are usually not fatal, as the coronavirus has a mortality rate of 3%, meaning that for every 100 people infected, only three die. As stated above, the people at the greatest risk of developing serious complications after becoming infected are immunocompromised people. If the infection is commonly asymptomatic, this could present many problems for infection control procedures. The coronavirus has a relatively long incubation period of 2 to 11 days, which is long enough for a person to accidentally transmit the virus to someone or spread it to a new, unaffected area.
Elena Heath's MCRO Blog 