COVID-19 is a type of coronavirus. This is a family of viruses which cause respiratory infections. Coronaviruses originate in animals and, in some cases, the virus can jump to humans. Some strands of coronaviruses, such as the common cold, only lead to mild symptoms. Others cause more severe effects and, in the worst case, can prove fatal.
Previous pandemics of coronaviruses include Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS). COVID-19 is often compared to swine flu (H1N1) which was an influenza virus rather than a coronavirus.
The seven known coronaviruses which affect humans are divided into four sub-groups: alpha, beta, gamma and delta. The four common strands are 229E, NL63 (both alpha), OC43 and HKU1 (both beta). The three rarer strands are:
- SARS-CoV (beta): caused SARS
- MERS-CoV (beta): caused MERS
- SARS-CoV-2: the virus that causes COVID-19
The name ‘coronavirus’ derives from the shape of the virus when viewed beneath a microscope. It resembles a crown; corona in Latin.
What is COVID-19?
COVID-19 is also termed SARS-CoV-2 due to its structural resemblance to SARS. This novel coronavirus first emerged in the Chinese city of Wuhan in December 2019 and was initially believed to be a strain of pneumonia. It was later confirmed to be a new coronavirus that had originated from animals in a live food market.
China shared the genetic sequence of what later became known as COVID-19 on 12 January 2020. The following day, the first case of the novel coronavirus outside of China was reported in Thailand. The WHO declared COVID-19 a pandemic on 11 March 2020, exactly one month after the novel coronavirus received its official name.
Over 5.6 million cases have been confirmed worldwide across 216 countries. Over 348,000 deaths have been reported in total. Over 2.3 million infected persons have made a full recovery.
How does COVID-19 spread?
All coronaviruses are extremely contagious and COVID-19 is no exception. As a respiratory infection, a person infected with COVID-19 can transmit the virus to another person via droplets formed from coughing, sneezing and breathing. Those droplets may land on surfaces such as tables, doorknobs and appliances and lead to contamination.
The bacteria can linger for under four hours on copper, less than 24 hours on cardboard, and up to 72 hours on plastic and stainless steel. Household detergents kill the virus. Regular hand washing and vigilance around surfaces can help curb the spread of infection.
Some coronaviruses are airborne and particles can linger in the air for many hours. Researchers are currently assessing exactly how long COVID-19 remains airborne for. Wearing personal protective equipment (PPE) can protect against this.
A person infected with coronavirus may notice symptoms within two days, or as late as 14 days. This is why social distancing and practising good hygiene is essential to prevent the spread of COVID-19.
How is COVID-19 Cured?
As COVID-19 is a type of virus, it is not possible to treat it with antibiotics. Research is underway to create a vaccine however scientists advise that this is won’t be available until late 2021 at the earliest.
Researchers are using previous evidence from MERS and SARS to speed up the development of the vaccine. But, the vaccine will need to clear clinical trials before scientists can begin the distribution.