Updated: Jul 7, 2021
The coronavirus or COVID19 is an acute and very infectious disease of the respiratory system.
It was first discovered in residents of Wuhan City; China in December 2019.
The disease has since escalated and on 11th March 2020 The World health Organisation (WHO) declared COVID 19 a pandemic.
The disease is caused by The novel coronavirus severe acute respiratory syndrome coronavirus 2(SARS-CoV-2). The SARS-CoV-2 virus needs another cell to survive. The virus uses the spike proteins on its surface to bind to and eventually gets enveloped into the human cell where it replicates.The virus cells are then released to invade more cells.
Most people experience mild symptoms of the flu type.
The major symptoms include :
fever, aching of muscles and joints, headache, loss of taste or smell, cough ,nausea vomiting and diarrhoea.
Some people may not develop any symptoms(asymptomatic).
Patients are most infectious in the first week of illness.
In mild illness the body's immune response helps to control the infection followed by healing.
In severe disease however the immune response is excessive causing organ damage which has been the reason for many hospitalisations and unfortunately death in some.
The diagram below was adopted from BMJ 2020 ;371:m3862 Virology Transmission and pathogenesis of SARS-CoV-2 and shows the timeline of the progressive disease .
Should be stressed the majority of people get mild disease or remain asymptomatic.
SARS-CoV-2 is mainly spread through the air by droplet infection, for example through sneezing/coughing and even speaking hence the advice to wear face masks and keeping a distance of at least two meters from other people.
Direct contact is also known to transmit SARS-CoV-2 therefore regular hand washing or use of antiseptic gel or solution is important particularly after making contact with a person or surfaces likely to have been contaminated.
If you develop any symptoms of Covid 19 infection the advice is to straight away isolate yourself from the public and arrange to get a COVID 19 test.
You should also inform your contacts from 48hours before your symptoms so that they can take appropriate action depending on the local protocols.
Guidelines are continuously changing depending on the status of cases, new virus variants and vaccination status in the country or local area.