Detecting Covid-19 disease in people

In 2019, the Centers for Disease Control and Prevention (CDC) started monitoring the outbreak of a new coronavirus, SARS-CoV-2, which causes the respiratory illness now known as COVID-19. Authorities first identified the virus in Wuhan, China.

Since then, the virus has spread to other countries, both in and outside Asia, leading the World Health Organization (WHO) to declare this as a pandemic.

Pathogenesis

Studies in both organ cultures and human volunteers show that coronaviruses are extremely fastidious and grow only in differentiated respiratory epithelial cells. Infected cells become vacuolated, show damaged cilia, and may form syncytia. Cell damage triggers the production of inflammatory mediators, which increase nasal secretion and cause local inflammation and swelling. These responses in turn stimulate sneezing, obstruct the airway, and raise the temperature of the mucosa.

What causes coronaviruses?

Coronaviruses are zoonotic. This means they first develop in animals before developing in humans.

For the virus to pass from animal to humans, a person has to come into close contact with an animal that carries the infection.

Once the virus develops in people, respiratory droplets can spread coronaviruses from person to person. This is a technical name for the wet stuff that moves through the air when you cough or sneeze.

The viral material hangs out in these droplets and we can breathe it into the respiratory tract (your windpipe and lungs), where the virus can then lead to an infection.

The researchers haven’t definitively linked 2019 coronavirus to a specific animal.

But researchers believe that the virus may have been passed from bats to another animal — either snakes or pangolins — and then transmitted to humans. This transmission likely occurred in the open food market in Wuhan, China.

Coronaviruses can also spread in the following ways:

1. Touching or shaking hands with a person who has the virus can pass the virus between individuals.
2. Making contact with a surface or object that has the virus and then touching the nose, eyes, or mouth.
   Some animal coronaviruses, such as feline coronavirus (FCoV), may spread through contact with feces. However, it is unclear whether this also applies to human coronaviruses.

What are the symptoms?

According to the WHO, the most common symptoms of Covid-19 are fever, tiredness and a dry cough. Some patients may also have a runny nose, sore throat, nasal congestion and aches and pains or diarrhoea. About 80% of people who get Covid-19 experience a mild case – about as serious as a regular cold – and recover without needing any special treatment. Whereas, about one in six people, the WHO says, become seriously ill.

In UK, the National health Service (NHS) has identified the specific symptoms. What are these specific symptoms ? These specific symptoms are either:

• a high temperature – you feel hot to touch on your chest or back
• a new continuous cough – this means you’ve started coughing repeatedly

Diagnosis

The most useful method for laboratory diagnosis is to collect paired sera (from the acute and convalescent phases of the disease) and to test by ELISA for a rise in antibodies against OC43 and 229E.Direct hybridization and polymerase chain reaction tests for viral nucleic acid have been developed and, particularly with the latter, are the most sensitive assays currently available for detecting virus.

Complications

The most serious complication of COVID-19 is a type of pneumonia that we have called it as 2019 novel coronavirus-infected pneumonia (NCIP).

About 4.3 percent of these people who were admitted to the ICU died from this type of pneumonia.

So far, NCIP is the only complication specifically linked to the 2019 coronavirus. But researchers have seen the following complications in people who have developed a coronavirus:

1. acute respiratory distress syndrome (ARDS)
2. irregular heartbeat (arrhythmia)
3. cardiovascular shock
4. severe muscle pain (myalgia)
5. fatigue
6. heart damage or heart attack