Dr. Kamlesh Jha, Additional Professor, Department of Physiology, All India Institute of Medical Sciences, Patna, India
First of all what do you mean by virus? Viruses are very minute particles or organisms that have been placed in between the living and non-living things in the universe. Cell is called the smallest unit for unit of life and consists of almost everything required for its livelihood right from energy source (mitochondria) to synthetic and reproductive mechanisms within them. Unlike cell, viruses are having only genetic material (RNA or DNA) covered by nucleocapsid cap. They therefor require some living cell for their proliferation outside which they exists simply as a non-living material. In a layman language we can say that these miniature particles are living when it is outside a biological system and multiplying when enters in any biological system like human body human cell or any other living cell but becomes a non- living material outside it.
Corona viruses are one of the family of viruses also called Coronaviriadae which is basically an enveloped Virus with a single stranded RNA genome. It is one of the largest RNA viruses. Unlike the common believe the coronaviruses are well-known since long. It was first discovered in 1930 and are well known as agent responsible for many of the respiratory condition especially common cold.
One very interesting property of most of the viruses are that it can frequently change its genetic structure and virulence. The most recent coronavirus epidemics secondary to the spread of so called Noble coronavirus or COVID-19 is basically a genetic variant of the same coronavirus which has been discovered almost hundred years ago.
Why these viruses are so dangerous in causing infections and why it is difficult to treat viral condition:
as I just discussed these viruses take the help of our cellular structures and our genetic materials for its g proliferation. Therefore it is very easy for them to change its form frequently. Many viruses are having segmented genetic materials and due to its permutation combination they frequently change their genetic structures and because of that before we recognise it change its form and therefore difficult to treat. Secondly because these viruses are taking help of our own cell structure our genetic materials sometimes they acquire our immunity for its own protection and because of that if we try to kill the viruses we have to harm our own cells inadvertently due to collateral damage. so in layman terms most of the viruses that have been discovered so far are difficult to treat and very few antiviral agents are there that can effectively kill viruses without harming our own cells.
How the virus acts
The virus gets attached to the host cell with its spike protein to the complement host cell receptors present in the most of the cells that are specific for certain viral spikes. This determines the viral specificity to specific host species. That is why some virus affects a particular species but spare some other species. The by birth immunity of certain species from certain specific virus is called innate immunity. For example the virus affecting plants like Tobaco mosaic Virus ( TMV) doesn’t affect human or animal species. Some other viruses are although found in some perticular animal species as asymptomatic agent but due to accidental contact (eg. Raw eating the animal or bite from the animal) transmits it to human host. A common example is Rabies virus.
The Novel Corona Virus (COVID-19) is a virus very similar to one found in wild bats which as such or after some transformation got passed to human. The most problematic issue in this case is its ability to cross transmission from person to person and its very high contagious nature.
Is it serious?
There are 3 factors which determines the seriousness of an infective condition-
- The agent: It is the infective organism, its virulence, its nature, resistance to various environmental factors and its sensitivity to various therapeutic agents.
- The host: The primary host which is the natural reservoir of the infective agent, the secondary host the ability to cross infection etc.
- The environment: This is another important factor which determines the persistence of the agent in a particular environment, its cross infectivity and possible measures that can contain the condition.
In case of Corona infection The primary host is possibly bat but the as the agent has now acquired the capability of cross transmission among secondary host, the host factor became very grave to contain. The environment factor is one of a very sensitive parameter in most viral infection. Though the COVID 19 is a new agent and not much is known about it, preliminary research outcomes show that the virus is quite sensitive to the environmental temperature, humidity, disinfectants etc.
What a common man should be doing
As this is highly infectious the best way to avoid transmission is to take care of our own hygiene, frequent hand washing, using mask, and physical distancing or social distancing are till date proven best measures to avoid cross transmission .of this viral condition.
The possible symptoms and when to contact doctors:
The common symptoms which acts as a warning sign for possible CORONA infection are usually-
- Dry persistent cough
- Fever- usually high grade
- Breathlessness
A definite history of travel or social contact with COVID positive subject
All coughs are not to be feared of Corona related as most of the common flue conditions are associated with fever and cough, thus unnecessary fear psychosis in the community should be avoided. But if someone is having dry cough with fever and breathlessness he or she must visit a medical facility and get advice from the experts or get tested for the for the possible corona infection.
What is quarantine and why is it required?
Basically any infective agent requires some time for itself to get acquainted inside your body and then start multiplying and so for the disease signs to appear. when we contract some infection it is not that we immediately become symptomatic but a lag period exists between contracting the infection and showing the symptoms of the disease. This period is called incubation period. Now different infectious diseases are having different incubation periods and unless and until the incubation period passes we cannot know whether we have been infected or not. In case of Corona virus the incubation period is 2 to 14 days, that means someone who have come in the contact of a Corona virus patient will become symptomatic on any day between 2nd to 14 th day after contracting infection. So if we keep the person isolated for a period of 14 days then if he had ever contacted the infection he will start showing the symptoms. if someone doesn’t show any symptom after 14th day then probably he/she did not contracted the disease. That is why this concept of isolation or quarantine has come out for the infectious diseases. As mentioned earlier, the duration of isolation or querantine depends upon the incubation period of the infectious disease but the person may be infective even when he is not showing any symptom. The period between infection and appearance of symptom is also called the window period when the patients are infective but asymptomatic. This is the most dangerous period from social perspectives as the person may be a potential carrier of the disease. This is the reason, querantine of all the contacts of the known cases are being practiced.
Treatment or management of the person suffering from Corona infection
as per the available data most of the patient suffering from Corona viral infection show features of mild upper or lower respiratory tract infection and they recover without any treatment or symptomatic management approach. The only important landmark in the management is the isolation or qurantine of the subject with symptomatic treatment. In some 5- 10% cases we may require an escalated approach of management when the person for the patient suffering from the disorder slips into a deeper pathological status. if a person is immune-compromised or is suffering from any pre-existing systemic disorder like diabetes, hypertension and chronic illnesses of respiratory system then these viral infection dominant over his immune system and the immune system of the body get defeated in essence and the virus takes Upper Hand, it starts damaging the respiratory passage especially the lower respiratory tract. Sometimes the main function of lungs that is, oxygenation of blood get impaired and is not able to completely full-fill the oxygen need of our body.Iin that condition we need to support our body by giving adequate oxygen some may require assisted ventilation too. Besides, the infection is attempted to be controlled by anti-infective agents. The novel corona virus is a new strain of the coronavirus so there is no well-known antiviral or any anti-infective agents that is having a proven efficacy but in the case of emergency many drugs including many antiviral agents have been tried all across world on this viral situation and they have shown some efficacy over it. The commonly recommended medicines especially the anti-infective agents for the containment of Corona infection are usually the selected antiviral agents, hydroxyl choloroquine and some antihelminthic agents. Though scientist are not yet very sure about the efficacy of all the agents on the coronavirus but they are using it in a desperate attempt to contain the condition because there is not enough time to do research and prove its efficacy and then use it. It is not at all advisable to common man to use the agents as a self-medicating tools. All the agents are very toxic and they have their own Side Effects so they are being used by the experts only when they feel that there is a need to use otherwise all these drugs to be avoided especially as a prophylactic agents.
Prognosis
If someone contract the Corona infection or tests positive for it does that mean he or she is going to die? No differently not! Because as it has been mentioned most of the Corona infections are asymptomatic or Mild infections. Most of the positive cases recover completely without any active intervention ot at the most by simple symptomatic management approaches. Becoming Karana positive is not stigma at all and simple precaution, quarantine and supportive therapy itself is sufficient to cure most of the patients and is not a matter of fear psychosis. Immunity to Corona infection is not yet well known although as per the standard teaching most of the infections when we contract it produces some immunity in our body for the disorder for certain time period. The period is variable and it maybe lifelong or it may be very short duration depending upon the infective agent and host factors. As Corona new virus it is not yet known, once getting the infected and getting cured after wards whether we become immune to it or are we still under risk of re-infection. Thus it is safer to assume that one is always under risk even if he/she recovered from an active corona infection recently. They should follow all the precautions including hygiene, social distancing etc like any other fellow of the society.
What is the role of immunity booster foods and Agents for prevention of Corona infection?
Recently, after the outbreak of Corona pandemic, a lot of propaganda is being made regarding the immunity boosters, herbal products and other tit bits acclaimed to be the immunity booster and protective from Corona infection. Most of the social media platforms are flooded with such types of messages. Here one important things that everyone should keep in their mind is that immunity is not such a thing that could be boosted in minutes or hours. It is a composite feature of an individual that is determined by his or her genetic makeup, long term life style, environmental factors etc. But, one thing that matters most is his way of living, dietary pattern, presence or absence of various risk factors like smoking, alcohol related habits, stress or presence or absence of chronic illnesses etc. changing life style and dietary pattern towards a healthier one will definitely improve the immunity profile but not a very short term manner. Herbals are also good in the same manner but definitely not in a manner as magical remedies acclaimed in the most of the social media platforms.
