(GIST OF YOJANA) COVID-19: The Novel Threat
COVID-19: The Novel Threat
- The World is experiencing one of the greatest pandemic in history. Every day, many more are being added to that. In today’s world we have good healthcare facilities, advanced knowledge in science and various treatment modalities, but still how come a tiny particle of a few nanometers has really shaken all the powerful nations? Let us start from the basics to understand it better.
What are Viruses?
- Viruses are on the borderline of living and dead beings. They are much tinier than bacteria. Their size ranges from 18 nm-400 nm, they do not grow on routine laboratory media. Because of this, specific laboratory diagnosis of viral infections is not easy. Viruses are host cell-dependent particles, they use host cell machinery to build their structure. That is why, specific antiviral drugs which don’t damage host cells are very limited. Mutations occur during every viral infection, either spontaneously or may be induced with chemicals or physical agents. A hybrid or recombinant virus will have new genes and new characteristics as well.
- All Coronaviruses are large (120-160 nm) enveloped RNA viruses which have a single stranded genome. The name “coronavirus” is derived from Latin corona, meaning “crown” or “wreath”. The virus possesses a club shaped or crown like peplomer spikes giving the appearance of solar corona. High rates of genetic mutations are shown by the corona viruses. Most of these infect animals and birds. Human infection is caused by only those which can adapt to human conditions. There are already known six corona viruses involved in human infections. Most of them are widespread, affecting people in most parts of the world and are known to produce mild upper respiratory tract infection and occasional diarrhea.
- In 2003 there was an outbreak of SARS-CoV (Severe Acute Respiratory Syndrome coronavirus). It originated from China and spread to around 29 countries causing 8098 cases and 774 deaths. The source was believed to be monkeys, raccoon dogs, cats and rodents.
- Another member of corona viruses, MERS-CoV (Middle East Respiratory Syndrome coronavirus) emerged in 2012. First reported from Saudi Arabia, MERS-CoV has affected more than 2143 cases and 750 deaths from 27 different countries. Here, the source was thought to be camels and bats.
- This is the latest terminology being used as per the WHO guidelines. It represents CoronaVirus Disease originated in 2019. Previously used names for COVID 19 are:
- 2019-nCoV acute respiratory disease
- Novel coronavirus pneumonia
- Wuhan pneumonia
- First case of this virus was identified in December 2019 from Wuhan, Hubei province of China. WHO declared the 2019-20 coronavirus outbreak, a Public Health Emergency of International Concern (PHEIC) on 30 January 2020 and a pandemic on 11 March 2020.
Challenges due to COVID 19:
- It is a novel virus, very little is known about it. That’s why currently the treatment being given is not very specific. Some antivirals, some anti-parasitic drugs are being tried. It is a highly contagious disease. The transmission rate of SARS-CoV-2 is higher than SARS-CoV and the reason could be genetic recombination.
- Asymptomatic carriers as well as convalescent individuals can transmit the virus. No age group is spared. The progression of the disease is very unpredictable. Mortality rates are very high in some parts of the world compared to others.
- There are two main routes of transmission of the COVID-19 virus: respiratory and contact. The virus is mainly spread by small droplets produced by coughing, sneezing or even talking to an infected person. These droplets may also be produced during breathing; however, since the virus is large (as compared to other viruses), they rapidly fall to the ground or surfaces and are not generally spread through the air, over large distances.
- People may also become infected by touching a contaminated surface and then their face. The virus can survive on surfaces for a few hours to a few days, depending upon the nature of the surface. It is most contagious during the first three days after onset of symptoms.
- Spread is possible before symptoms appear and in later stages of the disease as well. That makes it more dangerous. The time from exposure to onset of symptoms is typically around five days, but may range from two to fourteen days. There have been no reports of fecal−oral transmission of the COVID-19 virus.
- Common symptoms include fever, cough (mostly dry cough) and shortness of breath. Other symptoms may include fatigue, muscle pain, diarrhea, sore throat, loss of smell and abdominal pain. While the majority of cases result in mild symptoms (about 80%), some progress to viral pneumonia and multi-organ failure. Older people and people with other medical conditions (such as asthma, diabetes, hypertension or heart disease), are more vulnerable to becoming severely ill.
- Severity also depends on pollution levels in that area. Mortality rates vary in different age groups, highest being in 80+. Some survivors show permanent lung damage. Unfortunately coronavirus infections produce short and brief immunity, leaving a chance of reinfection.
- Early diagnosis proves beneficial in stopping further dissemination, as infected individuals are the only source of infection to others. Absence of specific symptoms makes the clinical diagnosis difficult. Laboratory testing is essential for confirmation.
- Real-time reverse transcriptase PCR (rRT-PCR) testing is the most useful test and currently the only reliable one. Blood antibody testing and viral antigen testing methods are being tried but are not specific.
- Currently, there is no uniform policy for treatment. Several drugs such as chloroquine, hydroxychloroquine, arbidol, redes vir, and favipiravir are undergoing clinical studies to test their efficacy and safety in the treatment. Right now, no vaccine is available for COVID-19. Major problem with vaccine production is the genetic alterations which the virus undergoes.
- In the initial phase of the disease where symptoms are mild, it can be treated by supportive therapy. In case of major lung damage, ventilator support might be required. Good immunity of individuals may prevent further complications.
- In a recent study, it was identified that monoclonal antibody (CR3022) binds with the spike RBD of SARSCoV-2, a structure essential for attachment of virus to the host cells. Monoclonal antibodies can be developed as a therapeutic candidate, alone or in combination with other neutralising antibodies for the prevention and treatment of COVID-19 infection. Further studies are going on.
- At this point of time, prevention is the best possible treatment.
Personal Preventive Measures in public places:
- Staying home.
- Covering mouth and nose with flexed elbow or tissue when coughing or sneezing.
- Disposal of used tissue immediately.
- Systematic washing of hands often with soap and water for at least 20 seconds OR using a hand sanitiser that contains at least 60% alcohol. Cover all surfaces of your hands and rub them together until they feel dry.
- Avoid touching your eyes, nose and mouth with unwashed hands.
- Cleaning frequently touched surfaces and objects.
Preventive Measures in Public Places:
- Keep about 6 feet distance with others.
- Wear a cloth face cover/mask. Do not use a facemask meant for a healthcare worker.
- Clean and disinfect frequently touched surfaces daily. This includes tables, doorknobs, lift handles, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets and sinks.
- To disinfect- Most common household disinfectants like bleach solution will work. Use disinfectants appropriate for the surface.
- Effective inactivation could be achieved within 1 minute using common disinfectants, such as 70% ethanol or sodium hypochlorite.
- There is no evidence about the survival of the COVID-19 virus in drinking-water or sewage, so any special treatment of water is not required.
- How far this pandemic of COVID 19 damages us is solely in our hands. If we follow personal and social behavioral discipline, then the damage can be minimised. But if we ignore it, then it will prove to be the most catastrophic event in the history of the globe. So let’s save ourselves and our globe.
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