- How the virus kills
Covid-19, officially named the novel coronavirus (nCOV-2019), is believed to be originated from Wuhan, a new strain and world knew little about it at first place. Its spread was exponential. Hence, WHO declared it an ‘epidemic’ which means a widespread occurrence of an infectious disease in a community at a particular time, which witnesses a larger number of infected cases than the expected number. In a couple of weeks, its status changed to pandemic, which derived from the Greek word that means “everyone” – a serious infectious disease that could spread to multiple continents, like cholera that engulfed the lives of one million people in the 1850s. That is where we stand today with respect to covid-19 as this menace has reached to over 199 countries across the globe, and exterminated around 185,000 so far while infected another over 2.6 million and count is still on. Presently, many of us argue that there are many other diseases and reasons that cause more deaths than covid-19. They come up with vague arguments as they might be oblivious of the fact that covid-19 is highly contagious unlike others and is spreading exponentially across the globe. So far, there is no vaccine or drugs available to prevent its spread. Therefore, Harvard scientists have already suspected that 40 to 70 percent of human beings across the globe are likely to get this monstrous virus. Isn’t it alarming?
In addition to that, many of us need to know that how these microscopic organisms work and attack the human body. A virus is an infectious agent that remains inactive without a host but when it gets its desired host in a cell, it hacks the machinery of a cell and generates its own copies through the process of replication in which a huge number of viruses infect other cells. Similarly, coronaviruses are large groups of viruses whose host is the lungs and are known to cause respiratory infections ranging from the common cold and influenza to MERS and SARS. At this juncture, it’s pertinent to mention here that corona is a Latin word meaning crown, as the outer shape of the virus resembles a crown. It is originated from animals, transferred to human beings and now the carriers are human beings. It transmits from person to person through tiny droplets from nose or mouth owing to coughing and sneezing. These droplets land on different surfaces and objects and their viability is different on various surfaces and objects, from few hours to days; it may be caught by others through touching these surfaces and breathing in droplets. According to the US National Institute of Health, covid-19 can also remain infectious in droplets in the air for hours. Pretty scary! That’s why many, despite taking appropriate measures, are being infected. Hence, it’s the need of the hour to maintain a distance of at least one meter away from others to actualize the purpose of physical distancing.
Remember, it’s not only about you, you might survive the virus, but someone who receives it from you might not recuperate. Hence, physical distancing, quarantine and other measures in the light of guidelines issued by present government are mandatory.
As the covid-19 outbreak continues, medical experts and scientists are in full swing to learn about its level of damage to the human body, particularly lungs. New findings are being shared at regular intervals. First, throat cell linings, airways and lungs are infected as virus multiplies there copiously to generate copies to infect more cells. Symptoms at this stage are not certain. Slight fever, body ache and may be headache is owing to the immune system responding to the infection. It means that the body has identified the invader and signals to the rest of the body to respond by releasing cytokines which are the chemical messengers to stimulate the immunes system against foreign attack and helpful to prevent damaging inflammatory events. These initial symptoms do not require specialized treatment because 80 percent can recover through bed rest, plenty of fluids, paracetamol and healthy diet. This stage lasts for seven days mostly.
Nevertheless, some might develop a more damaging form of covid-19 because of overreacting of the immune system that might cause inflammation. Hence, balance should be there as too much inflammation can lead to collateral damage to the body. This leads to pneumonia– an inflammation of lungs. At this stage, the wall of the air sacs in the lungs starts to get infected through which oxygen to red-blood cells in human body is provided, but in pneumonia the tiny sacs become thick and start to fill with water and this can eventually cause shortness of breath and difficulty in breathing. This is a critical stage as the wall gets thicker, transfer of oxygen gets harder, which ultimately leads towards severe illness. Some patients will require a ventilator for breathing at this juncture. This is where body starts to throw in the towel and there is an obvious chance that patient might die. If the immune system cannot supersede the virus then it will eventually spread to every nook and corner of the body. It can even disrupt kidneys to clean the blood.
According to Chinese experts, most of the patients who died had acute respiratory distress syndrome (ARDS) irrespective of age, because lungs become unable to provide enough oxygen to the body due to widespread inflammation. According to Lancet, healthy looking persons who are chain-smokers don’t have healthy lungs and are more vulnerable to a severe covid-19 attack.
The general public must be aware of the scourge of this deadly virus. It must be taken seriously as directed by Prime Minister Imran Khan in his recent telecast. Remember, it’s not only about you, you might survive the virus, but someone who receives it from you might not recuperate. Hence, physical distancing, quarantine and other measures in the light of guidelines issued by present government are mandatory. Let’s break this chain and help others!
The writer is a microbiologist who has worked on in-silico drug designing of anti-rheumatics.