The death toll of China’s mysterious new virus outbreak has climbed to 17 people, with over 500 infections reported so far. The city of Wuhan, where the outbreak first appeared, is now under quarantine but the disease has already spread to nearby countries like South Korea, Japan, and Thailand, as well as Washington State in the US. Scientists are grappling to find out more about the disease so that it may be prevented – so far, we know it’s a new kind of coronavirus, temporarily named 2019-nCoV. Now, researchers think they know where it came from.
China has taken swift action to prevent the spread of the virus due to fears of a repeat of the 2002-2003 SARS epidemic, which led to 774 deaths across 37 different countries. Like the new respiratory virus, SARS belongs to a group of viruses known as the coronaviruses. Coronaviruses can jump from animals to humans, and the SARS outbreak was eventually linked to horseshoe bats living in Yunnan Province in southwest China.
With this in mind, researchers at Wuhan University have been looking for an animal source of the new virus. They performed a genetic analysis of the virus and looked for similarities with genetic information from other kinds of viruses and potential host species. They concluded that the virus likely formed from an unknown coronavirus combining with another coronavirus usually found in bats. The resulting virus can attach itself to receptors on the cells of host animals, making it an infectious disease.
But while bats are partly to blame, a more slippery critter has been harboring the virus. The first reported cases of 2019-nCoV were linked to workers at a market in Wuhan that sells various different animals for food, including wild animals like snakes. The team thinks that snakes acted as a reservoir for the virus and transmitted it to humans. Now, it is being passed from human to human. The findings are reported in the Journal of Medical Virology.
The researchers note that there is a lack of treatments and effective vaccines against coronaviruses – some vaccines have been developed but so far only tested on animals. So, keeping 2019-nCoV under control is essential to prevent further spread. Officials in Wuhan, which is home to more than 11 million people, are attempting to quarantine the city, cutting off public transport. The move has been controversial as Wuhan is a huge city and the quarantine coincides with Chinese New Year on January 25, a time when much travel takes place within the country. Meanwhile, experts are questioning how effective the quarantine will actually be now the virus has already spread across the border. The nearby city of Huanggang, home to 7 million people, has also gone into lockdown today to try to control the disease's spread.
“As there is no effective therapeutics or vaccines, the best way to deal with severe infections of CoVs is to control the source of infection, early diagnosis, reporting, isolation, supportive treatments, and timely publishing epidemic information to avoid unnecessary panic,” the researchers write. “For individuals, good personal hygiene, fitted mask, ventilation and avoiding crowded places will help to prevent CoVs infection.”
The team notes the importance of finding new ways to target coronaviruses as they spread could be enhanced by environmental changes in the coming decades.
“Along with the changes of climate and ecology and the increased interaction of human and animals, new CoV outbreaks seem unavoidable in the future, and effective therapies and vaccines against CoVs must be developed as soon as possible,” they note.