At the beginning of 2020, the latest virus started to make headlines worldwide because of its incredible transmission speed. Its roots were traced back to the food market in Wuhan, China, in December 2019. From there, they have entered countries as distant as the United States and the Philippines. The virus has been blamed for hundreds of thousands of deaths caused by millions of infections worldwide—one of the most impacted countries in the U.S.
Coronaviruses are a virus gene that can cause Middle East Respiratory Syndrome (MERS) and Extreme Acute Respiratory Syndrome (SARS). The cause of an outbreak of disease that originated in China was established as a new coronavirus in 2019. The virus is also referred to as coronavirus 2 (SARS-CoV-2). The infection it causes is called Coronavirus Disease 2019 (COVID-19).
Coronaviruses are typically a broad family of zoonotic viruses, causing diseases ranging from severe respiratory diseases to common colds. These viruses can be transmitted by zoonotic means from animals to humans. Many coronaviruses are thought to be circulating in various animal species that have not yet infected humans. The most recent one to leap human infection is COVID-19.
The World Health Organization (WHO) declared a pandemic of COVID-19 in March 2020. The epidemic is monitored by the Centers for Disease Control and Prevention (CDC) and WHO. These organizations updated the outbreak on their websites. Since then, recommendations to prevent and cure the disease have been made by these organizations.
After two to 14 days of exposure, signs, and coronavirus disease symptoms, 2019 (COVID-19) may appear. This period is called the incubation period after exposure and before having symptoms. Signs and symptoms that are typical can include fever, cough, and tiredness. The disease’s early symptoms include shortness of breath, muscle aches, chills, sore throat, runny nose, headache, and chest pain. Both children and adults will experience these symptoms. However, some people may have no symptoms at all.
In general, older people have a higher risk of getting the disease than youngsters. People who have existing medical conditions also have a higher risk of being diagnosed with COVID 19. These conditions include heart diseases, cancer, diabetes, obesity, and kidney diseases. One should seek medical attention if experiencing trouble breathing, chest pain, confusion, and blue lips or face.
The virus can quickly spread among people. The virus can infect people within two meters. It spreads by respiratory droplets released by someone who has been infected. The infected person may be coughing, sneezing, or even speaking. Besides, the virus can also be spread by touching a surface with the virus on it and then touching your eyes, nose, or mouth.
To prevent getting the disease, one should avoid large events and mass gatherings. Avoiding contact is also an effective way. It is even better to stay indoors all the time to prevent social interaction. Moreover, washing hands often will also prevent the virus from infecting. Do not travel to other countries for safety.
While COVID-19 has already seen some similarities to recent coronavirus outbreaks, there are differences, and when we deal with this one, we will learn much more. As reported in 17 countries, SARS cases totaled 8,098, with a fatality rate of 11 percent, with most cases occurring in southern mainland China and Hong Kong. The fatality rate was strongly dependent on the patient’s age, with those who were less likely to die under 24 (one percent) and those over 65 more likely to die (55 percent).
As of 2020, MERS cases totaling more than 2,500 have been registered in 21 countries and resulted in around 860 deaths, according to the World Health Organization (WHO), as those with mild symptoms are most likely undiagnosed. The fatality rate could be much lower. In the United States, only two cases have been confirmed, both in May 2014, and both patients have recently traveled to Saudi Arabia. In the Arabian Peninsula, most cases have occurred. The way the virus is transmitted from camels to humans is still unknown. Outside of hospitals, its distribution is rare. Therefore, its risk to the world population is currently considered to be relatively low.
An international panel of experts conducted a systematic evaluation and benchmarking of health protection and response capabilities across 195 countries. The project’s goal was to resolve risks from outbreaks of infectious diseases that could contribute to international epidemics and pandemics and quantify each nation’s response capabilities. The GHS Index was hoped to result in quantifiable improvements in national health security and enhance global preparedness.
Phylogenetic research indicates that SARS-CoV-2 originated in animals, possibly bats, and was transmitted to other animals before crossing into humans at the wet market of Huanan in Wuhan City. There is some evidence that pangolin, a form of nocturnal anteater illegally imported for its meat, may have been the intermediate vector. This animal has a very similar coronavirus similar to SARS-CoV-2 but differs in a critical region that determines the range of host and viral infectivity.
SARS-CoV-2 isn’t the first coronavirus to cause human outbreaks of respiratory infection. Six others, all suspected of coming from animals, have so far been identified. 10-15% of common colds are caused by the four coronaviruses that are now endemic to humans, sometimes peaking between December and April in temperate climates. NL63 and 229E may have come from bats; OC43 and HKU1 seem to have emerged from rodents. Both of these cause mild symptoms, while OC43 is ancestral to the bovine co-operative.
Two non-endemic coronaviruses have caused severe illnesses. SARS-CoV, which first appeared in China in November 2002 and came to the attention of the WHO in Viet Nam early in 2003, was initially recognized. The epidemic was mostly over by July, and the last cases were registered in April 2004 in China. This virus was responsible for a flu-like disease, Extreme Acute Respiratory Syndrome (SARS), while diarrhea was prevalent. It could progress to pneumonia and respiratory failure in two weeks, requiring intensive care for 25% of people infected. A total of 8098 cases were reported, and 774 fatalities were reported. SARS-CoV appears to have originated in horseshoe bats and may have been transmitted to humans through palm civet cats, marketed for their meat in China.
The second severe infection due to a coronavirus was Middle Eastern Respiratory Syndrome (MERS). In 2012, the MERS-CoV virus was first reported as the cause of a fatal illness in Saudi Arabia. In 27 countries, it has spread. MERS is still prevalent, unlike SARS, and 2494 infections were registered as of November 2019, of which 858 proved fatal. Like SARS, MERS causes symptoms ranging from mild to extreme pneumonia, acute respiratory distress syndrome, septic shock, and multi-organ failure to generate a flu-like illness. Through dromedary camels, which tend to be a reservoir in some Middle East nations, MERS-CoV is thought to have entered humans. It is not clear about the source species, but bats are the most likely.
SARS-CoV-2 is equivalent to either SARS-CoV or MERS-CoV wild bat virus, strongly suggesting a novel human coronavirus. For the coronavirus spike protein, the structure which binds the virus to the target receptor and mediates cell entry, six amino acids are required: SARS-CoV-2 shares only one of these with SARS-CoV. This spike protein has a high affinity for the human host receptor (and many other species, including pigs, primates, and cats), the angiotensin-converting enzyme 2 (ACE2). Viral infectivity is defined by a specific subunit of the spike protein, and the second crucial structural difference from SARS-CoV is the host selection. It may have been a mutation of this phenotype during human infection that led to the rapid spread of COVID-19 in humans. There is currently no evidence that the essential features of COVID-19 have been affected by any of the mutations found since the SARS-CoV-2 virus appeared in humans.