Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acure Respiratory Syndrome (SARS-CoV). A novel coronavirus (nCoV) is a new strain that has not been proviously identified in humans.
Coronaviruses are a family of viruses that cause disease in animals. Detailed investigations found that SARS-CoV was transmitted from civet cats to human and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans.
The new coronavirus, officially called Covid-19 currently has fatality rate between 0.7 per cent to 3.4 per cent. This is much lower than fatality rates for Mers (30 per cent) and SARS (10 per cent), but still a significant threat. However, the new coronavirus (Covid-19) is spreading fast. The bulk cases and fatalities have been confined to China, but the virus is spreading internationally.
The source of the coronavirus is believed to be a "wet market" in Wuhan which sell both dead and live animals including fish and birds. Such markets pose a heightened risk of viruses, jumping from animals to humans because hygiene standards are difficult to maintain if live animals are being kept and butchered on site. Typically, they are also densely packed.
The animal source of the latest outbreak has not yet been identified, but the original host is thought to be bats. Bats were not sold at the Wuhan market but may have infected live chickens or other animals sold there.
Bats are host to a wide range of zoonotic viruses including Ebola, HIV and rabies.
Scientist in China believe that Covid-19 has mutated into two strains, one more aggressive than the other, which could make developing a vaccine more complicated.
It is impossible to say which way the disease will go but, on its current trajectory, it is likely to spread to more countries, affecting many more people. The number of cases is beginning to decrease in China but is increasing in the rest of the world.
Initial common symptoms of Covid-19 include fever, dry cough, tiredness and a general feeling of being unwell. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death. Symptoms are thought to appear between 2 and 10 days later after contracting the virus, but it may be up to 24 days
The virus is spread via droplets when a person coughs or sneezes. The droplets land on surfaces and are picked up on the hands of others and spread further. People catch the virus when they tough their infected hands to their mouth, nose or eyes. Standard recommendations to prevent infection include regular hand washing, covering mouth and nose when coughing and sneezing, thoroughly cooking meat and eggs. Avoid close contact with anyone showing symptoms or respiratory illness such as coughing and sneezing.
Various crazy conspiracy theories have been circulating that the virus somehow escaped from a Chinese lab, either by accident or design. However, that is categorically untrue and scientists studying its genetic code have linked it to bats. It probably then jumped to another animal, which passed it on to humans.
The 1918 Spanish Influenza or the H1N1 virus remains the most devastating flu pandemic in the modern history. The disease swept around the globe and is estimated to have caused between 50 to 100 million deaths. A version of the same virus was also behind the 2009 swine flu outbreak, thought to have killed as many as 575,400 people.
Other major influenza outbreaks include Asian flu in 1957, which led to roughly 2 million deaths, and Hong Kong flu which killed 1 million people 11 years later.
But coronavirus outbreaks have so far been far smaller. Sars eventually spread to 27 countries in total, infecting around 8000 people and killing 700
