Changing symptoms of the coronavirus which can be a grave matter of concern

by Meghashree Das

The coronavirus is a virus which causes the common cold, as well as SARS. When infected with this virus, you are more susceptible to getting SARS. Learn what the danger symptoms of the coronavirus are here!

The Symptoms of Coronavirus Disease by Daniel J. Clark, PhD., Senior Science Writer for Agriculture and Animal Sciences at truenorthvet@truenorthvet.com on Wednesday, November 13th 2018

How are the symptoms different in animals and people?

Coronaviruses can cause common colds in people as well as SARS in animals and humans. Coronaviruses are double-stranded RNA viruses, and therefore can survive the harsh environment of the stomach to infect the body. The lack of an outer coat surrounds and protects the inner core of the virus, which is where the viral genome is replicated. The viral genome encodes for proteins used to bind to host receptors, which allows a virus entry into cells. Inside host cells, a number of things contribute to viral replication: new proteins made by host cell, viruses bind to their receptors inside the cell which allows them to survive inside cells for long periods of time and replicate.

The cycle continues when host cells replicate their DNA in a process called transcription. The new DNA codes for proteins, and these proteins attach to structural elements in the cell called ribosomes. Ribosomes can then translate the viral mRNA into viral proteins. When these new viral particles are released into the environment, they enter a host cell and replicate more new viruses. The newly-infected host often experiences flu-like symptoms such as fever, runny nose, sore throat, and muscle aches. After sufficient replication of the virus within a host cell, cells of that individual become infected and may start dying off due to apoptosis (involuntary suicide) or necrosis (cell death) as the virus exits the cell through a process called cytoplasmic release. The dying and infected cells can release virus into the environment and infect other cells nearby, which begins a chain reaction of more infections.

How can the symptoms be highly contagious?

Coronaviruses are known to cause the common cold as well as SARS (severe acute respiratory syndrome). The coronavirus has the ability to infect many types of animals, including pigs, horses, ferrets, cats, dogs, and people. The virus is known to spread from person-to-person through close contact with saliva (through sharing food or drinks) or by touching an infected surface with your hands. Coronaviruses can be spread through air when droplets from an infected person’s coughs or sneezes are suspended in airborne water droplets in the air. The coronavirus is a highly contagious virus that can spread beyond direct contact with an infected individual. The most common symptoms of coronavirus are fever, runny nose, sore throat, muscle aches, and headache; however, some coronaviruses have been known to cause pneumonia and bronchitis in humans. Infection with the coronavirus usually causes mild symptoms and people often recover in one to two weeks without treatment; however, some coronaviruses can be fatal if not treated.

How have the symptoms being targeted from day one?

The virus behind Severe Acute Respiratory Syndrome (SARS) is a member of the Coronavirus genus called SARS-CoV. This coronavirus can also cause a mild form of respiratory disease called acute respiratory syndrome (ARS). As of March 23, 2003, the WHO has defined the following as symptoms: shortness of breath; cough; fever; nausea or vomiting; diarrhea or abdominal pain; rash (of unknown cause); and headache. SARS has been caused by two groups of members in the Coronavirus genus: Simian hepatitis virus and Rous sarcoma virus. The first group is transmitted through direct contact with an infected animal (in this case, a macaque) while the second group is spread by direct contact with an infected person or animal.

SARS has an incubation period of 3 to 7 days. Human-to-human transmission takes place through the airborne route or by direct contact with body fluids. The virus is spread by droplets suspended in the air that come from coughing or sneezing. It is easily spread between people in closed spaces such as airplanes and offices since people are trapped together in a small space for long periods of time. The virus can also be spread through physical contact when there is an exchange of bodily fluids such as touching contaminated surfaces, touching other people, or kissing someone who is infected with the virus. This can happen if there are no disinfectants available to sanitize the environment and hands are contaminated with fluids from an infected individual.

How can the virus spread fast?

The virus is spread through the respiratory tract and into the bloodstream where it is then transported to internal organs. The virus targets epithelial cells in the respiratory tract and there is a pattern of damage as the cells move further into the respiratory system; in the initial stages, damage is seen in cells lining bronchial passages, followed by infection throughout large airways and small airways. Since there are different cell types that are affected by SARS coronavirus, it suggests that this virus can mutate when infecting different host species. The symptoms of SARS include fever and an overall feeling of being unwell. The symptoms progress to include nausea, vomiting, and diarrhea. The skin may become red with raised welts (known as exanthema). The eyes may also be affected causing conjunctivitis and sore throat. Pulmonary symptoms are the most common, which include cough and shortness of breath. Symptoms will begin to appear after 5 days and the health of the infected person will rapidly deteriorate after 10 days unless treated.

The coronavirus is responsible for causing at least four different diseases in people: Infectious Bronchitis, acute respiratory syndrome (SARS), Middle Eastern Respiratory Syndrome (MERS), and Severe Acute Respiratory Syndrome (SARS). These diseases are caused by different types of coronaviruses. Infectious Bronchitis virus uses the receptor ACE2 to enter an animal’s cells; this is the same receptor that SARS Coronavirus uses. ARES Coronaviruses and MERS-CoV (Middle East Respiratory Syndrome Coronavirus) work by binding to a protein called dipeptidyl peptidase 4 (DPPIV). All coronaviruses that infect humans use a protein on the surface of our cells called nectin-4 to enter our cells and cause infection.