Introduction:
The novel coronavirus (nCov) was named COVID-19, was caused by SARS Cov- 2 (severe acute respiratory syndrome) with a significant outbreak of pneumonia (respiratory illness) globally. The first case was reported in Wuhuan City, China. After significant studies, the bat was thought to be the reservoir of this highly contagious COVID-19 virus transmitted among humans. They are categorized into four different types:
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Gamma coronavirus.
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Delta coronavirus.
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Beta coronavirus.
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Alpha coronavirus.
Gamma and delta coronavirus affect birds, whereas beta and alpha coronavirus affect humans.
Symptoms of COVID-19
In mild-to-moderate cases, the following symptoms are seen:
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Fever.
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Dry cough.
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Loss of smell (anosmia) or taste.
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Fatigue.
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Muscle and headaches.
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Diarrhea.
The majority of groups are symptomless or with mild symptoms and usually recover without hospitalization. However, medical attention is required for people with serious illnesses, such as:
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Breathing difficulties.
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Chest pain.
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Loss of speech.
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Confusion.
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Irritation of the eyes.
It takes approximately 5 to 6 days to recognize the symptoms once an individual is infected. However, some individuals take up to 14 days.
How Does the Virus Transmission From One Person to Another?
The virus is highly contagious and spreads from one person to another through infected nasal droplets and saliva (while sneezing, breathing and coughing). These droplets are inhaled into the healthy lung through the eyes, nose, or mouth. Close contact with an infected person has a higher incidence of transmission. It's considered to be an airborne disease (short-range airborne transmission). Although, detailed evidence is still under research.
What Is the Classification of Covid-19?
Classification of COVID-19 based on severity:
Mild COVID-19:
- Mild flu-like symptoms such as fever, cough, sore throat, fatigue, body aches, loss of taste or smell.
- Individuals with mild COVID-19 generally have no or minimal respiratory distress and can manage their symptoms at home without hospitalization. Recovery typically occurs within a couple of weeks with appropriate self-care.
Moderate COVID-19:
- More pronounced symptoms including persistent fever, cough, shortness of breath, chest pain or tightness, fatigue.
- Moderate cases may cause significant discomfort and difficulty in performing daily activities. Some individuals may require medical care, supplemental oxygen, or hospitalization. The recovery time can vary but usually takes a few weeks.
Severe COVID-19:
- Severe respiratory distress, high fever, severe cough, shortness of breath, chest pain, confusion, bluish lips/face.
- Severe cases can lead to pneumonia, acute respiratory distress syndrome (ARDS), organ failure, or other life-threatening complications. Hospitalization in intensive care units (ICUs) and immediate medical attention are often required. The recovery period for severe cases can be prolonged, with some individuals experiencing long-term effects.
Does a Symptomless Infected Person Transmit the Virus?
There are possibilities of spreading COVID-19 to others, but the data is still under debate.
The individuals who have a higher risk of contracting COVID-19 are:
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Blood pressure.
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Heart disease.
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Respiratory problems.
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Pregnant women.
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Autoimmune disease (immunocompromised).
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Senior citizens (above 65 years of age).
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Physically challenged people.
Which Tests Were Used for COVID-19?
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RT- PCR (Reverse Transcription Polymerase Chain Reaction): It is the golden standard for testing COVID-19. However, some errors do get reported due to improper testing kits. False positive & negative results were noted at the early stage of testing where there was a limited number of viruses in the collected sample.
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Swab Test: Upper respiratory tract samples were collected from the nose (nasopharyngeal swab), throat, or saliva swab. Lower respiratory tract specimens were collected from critical care patients who were under ventilation support.
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Sputum Test: If a patient presents symptoms of cough, a sputum sample is collected and initiated for a COVID-19 test.
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At-Home Tests: They are available, but only with the doctor's advice.
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Chest X-ray: In the initial days of infection, the virus penetrated the respiratory system (lung) and affected the airways by submerging them with debris and fluids, resulting in the collapsing of lungs. Hence, chest X-ray is considered to be a basic guideline for investigations.
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Chest CT (Computed Tomography) Scan: This helps in staging (early, progressive, peak, late stage) and scoring of disease. The degree of lung lobe involvement is measured by CT severity scores as listed below:
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0 % (0 points).
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1 to 25 % (1 point).
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26 to 50 % (2 points).
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51 to 75 %(3 points).
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76 to 100 % (4 points).
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The results range from 0 to 25 (0 - no involvement of the lung, 20 and above - maximum involvement) by summing up five lobes of the lung and distinguishing the patients based on the severity of the disease (mild, moderate, severe). Despite all, it is considered to be a more sensitive test with drawbacks of misleading it with other infections like SARS (severe acute respiratory syndrome) and seasonal flu.
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Lung Ultrasound: Lund ultrasound is a well-defined diagnostic method to point out the disease in correlation with the image of CT ( computed tomography). During testing, the location, age, past medical history, recent contact with affected individuals, and onset and duration of symptoms are recorded for better diagnosis and to figure out the appropriate candidates with more risk of virus exposure.
Treatment and Medications for COVID-19
The appropriate treatment at an earlier stage (within a few days after the first symptom) decreases the chance of hospitalization and death rate. According to the FDA (U.S Food and Drug Administration), antivirals are used to treat mild-to-moderate patients with treatment guidelines. The antivirals include:
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Remdesivir (administered intravenously after the 7th day of symptom).
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Molnupiravir (administered orally within the 5th day of symptom).
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Nirmatrelvir and Ritonavir (administered orally within the 5th day of symptom).
The symptomatic treatment involves:
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Acetaminophen (Tylenol).
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Ibuprofen.
The hospitalized patients have different guidelines based on their illness to reduce hyperactive immune cells, which leads to COVID-19 complications such as septic shock and cardiopulmonary arrest.
What Is the At-Home Treatment for COVID-19?
The mild-to-moderate symptoms usually recover within a few weeks. For a speedy recovery,
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Take a significant amount of rest.
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Drink water to avoid dehydration.
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If there is a persistent cough, it is advised to have honey along with medicine prescribed by your doctor to get rid of all the cough.
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Monitor the oxygen levels with help of a pulse oximeter. If it's below 95, contact the general practitioner for advice, whereas for pregnant patients immediate hospitalization is required.
Immediate hospitalization is required under these conditions:
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Severe breathlessness.
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Cough with blood.
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Rashes under the skin and more prone to bleeding.
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Low urine output (Oliguria).
What Are the Treatment Option for Severe Cases of Covid-19?
- Hospitalization for close monitoring and immediate medical intervention if needed.
- Oxygen therapy to ensure adequate oxygen levels in the blood.
- Administration of antiviral medications, such as remdesivir, to inhibit viral replication.
- Use of anti-inflammatory drugs, like corticosteroids (e.g., dexamethasone), to reduce excessive immune responses and inflammation.
- Blood thinners to prevent blood clots, which can be a complication of severe COVID-19.
- Supportive care, including fluid management, symptom management, and treatment of complications such as pneumonia or organ failure.
- Rehabilitation and follow-up care to address physical and psychological complications during recovery.
What Are the Types of Vaccines Used for COVID-19?
The dosage for the primary vaccine has been laid down specifically by the United States. Immunocompromised patients have specific guidelines for COVID-19 vaccines.
Types of Vaccines:
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Pfizer- BioNTech and Moderna.
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Novavax.
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Johnson and Johnson's Janssen.
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Covishield (viral vector vaccine based on the adenovirus).
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Covaxin - is an indigenous COVID-19 vaccine developed by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR) and the National Institute of Virology (NIV). It is an inactivated vaccine.
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Sputnik V - Sputnik V is a Russian COVID-19 vaccine developed by the Gamaleya Research Institute of Epidemiology and Microbiology. It is a viral vector vaccine based on the adenovirus.
Common Side Effects:
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Pain, swelling and redness at the injected site.
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Tiredness.
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Headache.
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Chills.
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Muscle and joint pain.
Considerations:
Avoid using counteracting drugs such as aspirin, acetaminophen, or ibuprofen.
Which Preventive Measures Can Be Taken?
Coronavirus can survive in the air for several hours and on land for 14 days or more. To prevent infection, the following measures can be taken:
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Get vaccination, followed by a booster dosage.
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Maintain a social distance of at least 6 feet from others: both affected and unaffected.
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Avoid crowded areas and close contact with others.
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Wear a mask with maximum coverage of the nose and mouth in poorly ventilated areas.
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Wash your hands frequently and for at least 20 seconds.
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Use alcohol-based hand sanitizer to free yourself from germs.
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Don't touch your face unless your hands are clean.
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Cover your mouth and nose with a tissue while coughing or sneezing and dispose of them immediately and clean your hands regularly.
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Isolate from others when testing positive for COVID-19.
Conclusion:
The spread of coronavirus across the world is difficult to predict. The health, humanity, and socioeconomic status adopted by countries determine the speed and strength of the recovery. To assess the likelihood of future epidemics, both in-vitro and in-vivo studies should be carried out using appropriate animal models. Currently, there are no approved treatments or vaccinations for SARS-CoV, MERS-CoV, or SARS-CoV-2. However, the rapid development of effective therapeutic agents for COVID-19 will be made possible by advancements in the design of antiviral medications and vaccines against multiple other developing diseases.