Coronavirus/ COVID-19: Signs, Symptoms, Diagnosis, Clinical Classifications,Treatment and Prevention

Coronaviruses (CoV) are a large family of RNA viruses which are important viral pathogens in animals and humans and which can cause respiratory and gastrointestinal tract infections. The disease ranges from the common cold to more serious diseases, such as Middle Eastern respiratory syndrome (MERS-CoV) and severe acute respiratory syndrome (SARS-CoV)

A novel coronavirus (nCoV) is a new strain that has not been already identified in humans. In late 2019, a new coronavirus, called acute severe respiratory syndrome coronavirus 2 (SARSCoV-2) because there is a similarity with (SARS-CoV) and this disease has been called Coronavirus Disease 2019 (COVID-19) while Organization (WHO) has declared a pandemic of COVID-19. Coronavirus (COVID-19) has been prevalent so far and is more aggressive than SARS-CoV

Definition of Coronavirus/ COVID-19

COVID-19 is a new highly infectious disease that primarily affects the lung alveoli, which primarily damages the lungs of critically ill patients and leads to severe respiratory failure
• Disease: coronavirus Disease 2019 (COVID-19)
• Virus: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Coronavirus/ COVID-19 Structure

Coronaviruses have an envelope that encloses the RNA genome consisting of all viral components and is coated with structural proteins, forming a complex known as nucleocapsid, so that the nucleocapsid protein encapsulates the viral genome and can be used as an antigen diagnostic

The spike protein is found on the surface of the virus as one of the main antigenic proteins of the virus that binds to a receptor, so the virus and the membrane of the host cell merge causing the viral genome to enter the cell

The stick-shaped tips emanate from the envelope and form the shape of a crown, so "crown" means "crown". So it's called "coronavirus"

Origin of the Coronavirus/ COVID-19

Understanding the origin of the virus can also aid in the development of treatment and vaccine

Many coronaviruses that infect humans can be found in bats, which are natural reservoirs of coronavirus, but it is currently unclear whether the virus passed directly from bats to humans or if there is an intermediate mammalian host while

There is a theory that bats are the original host of the new coronavirus (85% homology between the new coronavirus and a coronavirus in bats) and that the transmission from bats to humans occurred after a mutation through an intermediate host (pangolins ). A virus that is regularly transmitted from an animal to a human being is called a zoonotic virus

Transmission routes of COVID-19 Disease

Direct contact transmission

The virus is transmitted through respiratory droplets generated when the virus carrier coughs, sneezes or  talking, where after inhaling drops persons are exposed to infection

Indirect contact transmission

The droplets containing the virus are on the surface of the object, which may be touched by the hand. The virus may get passed to the mucosa of mouth, nose and eyes,  the person becomes infected

Aerosol transmission

There is no evidence that COVID-19 disease can still be transmitted through aerosol yet 

Mother to child transmission

The pregnant woman does not transmit the virus to the fetus, but transmits it after birth, is not transferred during breastfeeding. The virus is transmitted by the respiratory drops of the mother carrying the virus or by infected people and there is a high risk that babies will die

Coronavirus/COVID-19 Signs and Symptoms

Common signs of infection include respiratory symptoms that can appear 2 to 14 days after exposure:

• Fever 
• Dry cough
• Fatigue
• Shortness of breath and difficulty breathing

Other signs

• Sore throat
• Runny nose
• Nasal congestion
• Chills
• Aches

Rare signs

• Nausea, vomiting, Diarrhea

What can COVID-19 cause?

Severe cases refer to patients with unstable vital signs and rapid progression of infection with dysfunction of organic systems that require mechanical ventilation and intensive care support treatment, causing acute respiratory failure, septic shock, renal failure, metabolic acidosis. irreversible and bleeding disorders and this leads to death

What to do if you feel you have coronavirus?

If you experience any of these symptoms and find that you are a covid-19 carrier, don't go to the doctor's office. You should immediately call your family doctor or health care services and explain your health and offer guidance on the next steps, the doctor can perform tests to rule out the development of infections

In the event that they are positive with mild symptoms, the doctor may suggest isolating themselves with continuous monitoring to prevent the spread of the infection

Coronavirus/ COVID-19 Diagnosis and Clinical Classifications

The diagnostic criteria follow the protocols for the diagnosis and treatment of COVID-2019. An established case is based on:

• Epidemiological history (including group broadcasting)
• Clinical manifestations (signs and symptoms)
• Laboratory tests (rRT-PCR), rapid test kits (anti-SARS-CoV-2)
• CT Scanning

Laboratory Test for COVID-19

COVID-19 can be identified by real-time reverse transcriptional polymerase chain reaction (rRT-PCR), analysis of respiratory samples from nasopharyngeal and oropharyngeal swabs (sputum and throat swabs) and from lower respiratory tract samples whenever it could be possible. In addition, serum samples must be collected at the beginning of the symptoms

COVID-19 poses several diagnostic challenges due to a long incubation period (14 days) which includes a prolonged interval (approximately 5 days) of viral clearance before the onset of symptoms. However, considering the possibility of false negatives in the detection of nucleic acid, isolation and continuous testing of multiple samples should be performed in such cases

COVID-19 Rapid Test kit

Test kits are one of the main quick ways to diagnose whether a patient has coronavirus for suspected qualitative detection of coronavirus IgM and IgG antibodies in people suspected of being infected with COVID-19. In just 10 minutes, the rapid serological test uses a drop of blood to determine whether an individual has antibodies (Anti-SARS-CoV-2) to combat COVID-19. This helps diagnose patients early on in the disease and facilitates their rapid treatment

CT Scanning 

Since coronavirus primarily targets the lungs and consequently leads to severe respiratory failure, there are multiple radiological organizations that claim that CT should not be considered the primary diagnostic / screening tool for COVID-19. However, thoracic imaging is of great value in the diagnosis of COVID-19

Daily monitoring of the therapeutic efficacy of thoracic CT scans is recommended for critically immobile patients and also for patients with COVID-19 on the day of hospitalization. If ideal therapeutic efficacy is not achieved, it can be performed again after 2-3 days. Different features of CT are observed depending on the severity of the disease, which can aid in the layering of COVID-19 and in assessing patient discharge

Suspected cases of characteristic manifestations in CT scans can be treated as confirmed cases

• COVID-19 in the initial phase often presents small irregular shadows or opacity of the frosted glass (lung infiltrates) located in the pulmonary periphery, in the subpleural area and both lower lobes

• In severe cases, lung consolidations and even "bleaching" of the lungs are observed. Pleural effusions are rare

Clinical classifications

Mild Cases

• Clinical symptoms are mild
• Absence  pneumonia manifestations in imaging

Moderate Cases

• Fever and respiratory tract symptoms
• Pneumonia manifestations can be seen in imaging

Severe Cases

• Respiratory rate ≥ 30 breaths / min
• Oxygen saturation ≤ 93% at a rest 
• Arterial partial pressure of oxygen (PaO2)/oxygen concentration (FiO2) ≤ 300 mmHg

Critical Cases

Requires monitoring and treatment in intensive care (mechanical ventilation):

• Occurrence of respiratory failure (failure of other organs)
• Septic shock

The critical cases are divided into initial, intermediate and late phases, according to:

• Oxygenation index
• The compliance of the respiratory system

Serious and critically ill patients present various degrees of dysfunction, in particular respiratory failure, dyskinesia and cognitive decline, both in the acute and recovery phases

Coronavirus/ COVID-19 Therapy

Currently, there are no specific vaccines or antiviral treatments against COVID-19. The development of a new vaccine against a new disease can take time and go through phases such as preclinical and clinical development, the administration of a vaccine in a program such as An expanded immunization program is the end result of years of discovery and development. . Therefore, patients generally receive supportive care to relieve symptoms

Coronavirus/ COVID-19 Prevention

The basic principles for reducing the risk of coronavirus transmission (COVID-19) include:

• Avoid going to an epidemic area and crowded places
• If you have to go out and buy food, for example, put the distance between you and the others. This is what is known as the social distance (2 m) to stop the virus from spreading
• Avoid "close contact" with sick people who have symptoms similar to pneumonia or common cold, such as cough or runny nose, such as approximately 1.8 m (6 feet) "or within the room or area of cure "of people with coronavirus
• Do not touch the eyes, nose or mouth / (zone T) with the unwashed hand
• Wash your hands often with soap and water for at least 30 seconds, you can also use a hand sanitizer that contains at least 60% alcohol
• When you cough or sneeze, cover your nose and mouth with a disposable tissue, put the used tissue in the basket
• If you have no tissue, cough or sneeze in the elbow, not in the hands
• Stay home if you are sick and contact your family doctor
• Wear a mask only if you are sick or take care of someone who is sick
• Clean and disinfect surfaces

How effective is self-isolation?

Self-isolation and early diagnosis remain the best way to prevent the spread of the infection. You should stay at home and, if possible, do not leave for any reason to limit social contact in the absence of treatment (COVID-19 Cure) and vaccination, because there are people with mild or no symptoms who could spread COVID-19