THE Wuhan virus is a coronavirus that emer-ged in Wuhan, China. The official name has not been decided yet; it is now known as novel coronavirus (2019-nCoV). This virus has, within weeks, spread to more than a dozen countries and killed at least 54 people in China.
What is a coronavirus? It is a virus with a distinct pedal-shaped projection on the corona. The virus is common in birds and mammals.
In rare cases, it can be transmitted to humans, a process known as zoonosis. The Wuhan virus is the seventh coronavirus that can infect humans, affecting the respiratory system.
Some of the infections are mild while others such as the Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) that were first isolated in 2003 and 2012, respectively, are much more dangerous.
Mammals and birds are the natural hosts (reservoirs) of coronaviruses. They carry the viruses in the respiratory and gastrointestinal tracts without showing signs of infection.
Often, these viruses have an intermediate host before they can infect humans. We know that the natural and intermediate hosts of SARS-CoV are bats and civet cats, while the ones for MERS-CoV are bats and camels.
So far, we do not know the animal host(s) of the Wuhan coronavirus. Recent studies based on genome sequencing indicate the possible involvement of bats in the transmission of the coronavirus.
The Wuhan virus shares 80 per cent of its genes with the SARS virus and 96 per cent with bat coronaviruses. Since the virus was first detected from wet markets in Wuhan that sell various animals, identifying the creatures could help control its spread.
Wet markets in China and certain parts of the world put people and live and dead animals — dogs, chickens, pigs, snakes, civets, bats, and more — in constant close contact. These places are hotspots for a novel virus to jump from an animal to human beings.
It seems that the virus can be transmitted from human to human. However, it is still not clear how often this process occurs. It is also not clear how deadly the virus is to humans. Some of the early cases in China are of concern, but there are more mild cases turning up.
The latest report from China indicates that they are seeing positive cases in humans without obvious clinical signs. Hence, it seems the Wuhan virus is not as deadly as SARS-CoV, which killed 11 per cent of the people that got infected.
However, a recent study by Chinese scientists demonstrates
that the virus can infect and hijack cells the same way as SARS did.
It is difficult to determine the actual confirmed cases in humans since detection kits are limited in supply. It is very likely that thousands may have got infected primarily in China and exported the disease abroad.
The latest report also indicates that the majority of the fatal cases involve elderly people with underlying problems.
However, Chinese authorities have confirmed that health workers were also infected with the virus.
So far, one doctor has succumbed to the illness. Since the situation is rapidly evolving it is too early to gauge the destructive potential of the new virus.
No vaccine is available against the virus. Antibiotics will not work since the disease is caused by a virus. What we can do is take precautions commonly practised to prevent respiratory flu-like illness.
Drink plenty of water, stay healthy and practise good personal hygiene by washing or disinfecting your hands regularly, especially after touching surface or fomites.
Wear a surgical mask and avoid being in close contact with people who are from infected areas.
The writer is professor of immunology and infectious diseases and dean, Faculty of Veterinary Medicine, Universiti Putra Malaysia