COVID-19: Scientific Facts, Expert Knowledge and Just How Deadly is It?
There is much more to learn about the transmissibility, severity, and other features associated with COVID-19, and investigations are on-going. However, that doesn’t mean that there are no solid and proven knowledge about the virus.
Here is a summary of current knowledge relating to coronavirus and COVID-19:
How contagious is COVID-19?
Respiratory viruses like these can travel through air, enveloped in tiny droplets that are produced when a sick person breathes, talks, coughs or sneezes. According to the Centers for Disease Control (CDC), transmission between close contacts can occur, as coronaviruses can travel about 1.8m from the infected person.
This is much lower than the highly contagious pathogens such as measles, chickenpox and tuberculosis which can travel 30m through the air. It’s unknown how long SARS-CoV2 survives on surfaces, so it is currently unclear if touching contaminated surfaces followed by touching your mouth, nose, or possibly eyes can transmit the virus.
How easily a virus spreads person-to-person can vary, primarily depending on the characteristics of the virus. The basic reproduction number (R0) is a central concept in infectious disease epidemiology, indicating the risk of an infectious agent with respect to an epidemic spread. Early estimates by WHO suggest the R0 for SARS-CoV2 is 1.4 to 2.5, producing roughly two secondary cases for each initial infection. In comparison, scientists estimated the initial basic R0 for the SARS epidemic and influenza to be 2-4, while measles has an R0 of 12-18.
While basic R0 is an estimate based on an idealised scenario i.e. without effective containment measures, the effective reproduction number however, depends on the population’s current susceptibility. Susceptibility is multifactorial – nutritional status, compromised immune systems, the environment, including demographics, socioeconomic and climatic factors, all play a role.
Even in the absence of a vaccine, human behaviour and the environment itself can change the likelihood of the spread.
Our March issue answers most of your questions about the COVID-19 pandemic.Since heading out to newsstands and bookstores is currently a big no, check out our posts and articles on our website: https://www.unreservedmedia.com/how-to-prevent-and-control-epidemics/https://www.unreservedmedia.com/unreserved-exclusive-an-experts-opinion-on-what-exactly-is-a-coronavirus/Alternatively, get your digital copy here: https://www.magzter.com/MY/UNRESERVED-Sdn-Bhd/UNRESERVED/Lifestyle/
Posted by UNRESERVED Media on Wednesday, 25 March 2020
Hospitals can isolate infected people or they can choose to stay home. A further decrease also often occurs as an outbreak matures and many people become immune because of previous exposure, reducing the number of susceptible hosts.
Hand washing and social distancing can also reduce transmission rates. Effective public health measures, isolating people infected and the methodical tracking by global health authorities during SARS in 2003, brought the effective R0 to about 0.5, enough to stop the outbreak.
How deadly is the COVID-19 virus?
Based on current data, WHO reported 82% would develop mild symptoms, 15% develop severe symptoms and 3% become critically ill. The proportion dying from the disease, known as the case fatality ratio in COVID-19, has been difficult to estimate. Preliminary studies estimated a case fatality ratio of 1–2%, which is lower than that for SARS (9.6%) but higher than the influenza virus. MERS has been known to cause severe illness in infected individuals with 34.4% fatality ratio.
The major difference between coronaviruses that cause a common cold and those that cause a severe illness is that the former primarily infects the upper respiratory tract (the nose and throat), whereas the latter thrives in the lower respiratory tract (the lungs) and can lead to pneumonia.
Clinically, experts report three major patterns of the clinical course of a COVID-19 infection: mild illness with upper respiratory tract presenting symptoms, non-life-threatening pneumonia, and severe pneumonia with Acute Respiratory Distress Syndrome (ARDS) that begins with mild symptoms for seven to eight days and then progresses to rapid deterioration, requiring advanced life support.
However, the complete clinical picture is still not fully clear. China’s National Health Commission (NHC) indicated that 80% of deaths were among patients 60 and above, while 75% had pre-existing conditions such diabetes, pulmonary disease, and other chronic conditions.
How is COVID-19 managed and how long will it take to develop a vaccine?
Non-pharmaceutical interventions remain central for management of COVID-19 because there are no licensed vaccines or coronavirus antivirals. Currently, treatment relies on the basics – keeping the patient’s body going, including breathing support, until the immune system can fight off the virus. As it is a virus, antibiotics can’t be used as a means of prevention or treatment. During hospitalisation, antibiotics may be given because bacterial co-infection may have developed.
A vaccine could prevent infections and stop the spread of COVID-19. But vaccines take time to develop. Although vaccines against respiratory illnesses are recommended, they do not provide protection against the new COVID-19. Coronaviruses are part of a large family of RNA (ribonucleic acid) viruses, and they generally have very high mutation rates compared to DNA viruses, undermining the effort to develop effective treatment regimens quickly. According to WHO, researchers studying the genome of the new COVID-19 have discovered the proteins that are crucial for infection. There are currently four vaccine candidates in development. Perhaps in three months there might be human trials, but it could still take months or even years after initial trials to conduct extensive testing that can prove a vaccine is safe and effective.
Why we shouldn’t panic?
Based on current evidence, experts believe that COVID-19 causes a mild and self-limiting disease in most people who are infected, with severe disease more likely amongst older people or those with comorbidities.
Over the coming days, weeks, months and even years, there is much to learn about the biology of this new SARS-CoV-2 virus, including better estimates of case fatality, reproduction rates, and a finer understanding of the epidemiology of infected cases.
This is an exceprt from UNRESERVED’s March Issue from the article Rumours + Reality.
