Stephen Chen

The coronavirus that causes Covid-19 might have been quietly spreading among humans for years or even decades before the sudden outbreak that sparked a global health crisis, according to an investigation by some of the world’s top virus researchers. Researchers from the United States, Britain and Australia looked at piles of data released by scientists around the world for clues about the virus’s evolutionary past, and found it might have made the jump from animal to humans long before the first detection in the central China city of Wuhan. Though there could be other possibilities, the scientists said the coronavirus carried a unique mutation that was not found in suspected animal hosts, bu

The new coronavirus is more sensitive to alcohol than Sars or Mers and can be killed almost completely by ethanol concentrations as low as 30%, according to a joint study by scientists from Germany and Switzerland. Though many spirits such as whisky or gin have an alcohol content higher than that, scientists do not recommend using them as a disinfectant unless in desperate situations – and they stressed that people should not regard drinking as a way to prevent or cure Covid-19, the disease caused by the coronavirus. Stephanie Pfaender, the lead scientist of the study, said on Wednesday that their experiment was conducted in a laboratory setting, therefore “one cannot directly translate thes

People with blood type A may be more vulnerable to infection by the new coronavirus, while those with type O seem more resistant, according to a preliminary study of patients in China who contracted the disease known as Covid-19. Medical researchers in China took blood group patterns of more than 2,000 patients infected with the virus in two Chinese cities, Wuhan and Shenzhen, and compared them to local healthy populations. They found that blood type A patients showed a higher rate of infection and they tended to develop more severe symptoms. While the researchers said the study was preliminary and more work was needed, they urged governments and medical facilities to consider blood type dif

Scientists who infected monkeys with the coronavirus that causes Covid-19 have found those that recovered developed effective immunity from the disease. Scientists around the world have been racing to develop a vaccine and the first clinical trials could be held in China and the US within a month. But a number of cases, where people who had tested negative for the disease and were discharged from hospital only to give a positive result a few days later, have cast doubt on the process. If it turns out that these patients had been reinfected by the same virus, then vaccines will not prove effective. But the monkey experiment carried out by a team from the Chinese Academy of Medical Sciences ma

Three separate studies suggest China’s quarantine measures to limit the spread of the coronavirus may have changed its genetic course, potentially making it more “insidious” and harder to detect. Clinical researchers in Wuhan, the central Chinese city where the new virus strain was first reported in December, say that locking down millions of people may have caused mutations in the genetic make-up of the coronavirus that resulted in milder symptoms of the illness, or no symptoms at all in the early stage of infection. Authorities locked down Wuhan – home to 11 million people – on January 23, confining residents to their homes, halting transport and closing public areas.  The drastic measures

A study suggesting fine droplets carrying the new coronavirus could linger in the air for at least 30 minutes and travel up to 15 feet has been retracted five days after its publication. The research on so-called aerosol transmission, by a group of government researchers from the central Chinese province of Hunan, was based on a reconstruction of how the infectious disease Covid-19 spread on a bus on January 22 during the peak Lunar New Year travel season. Hu Shixiong, the lead author of the study who works for the Hunan Provincial Center for Diseases Control and Prevention, said security camera footage demonstrated how the disease spread from an initial carrier of the virus to passengers as

China has less than a month to prevent businesses from leaving the country in droves because of the coronavirus epidemic, according to the latest estimate by government scientists. Labor-intensive and high-tech manufacturing industries could be among the first to leave if Beijing failed to contain the spread of the virus by the end of the month, the experts said in a report published on Monday in the Bulletin of the Chinese Academy of Sciences. Professor Wang Shouyang, chief forecast scientist at the government research body and a co-author of the report, used a mathematical model to predict the impact of the epidemic on the global value chain. The risk of China losing jobs not only existed

The new coronavirus has an HIV-like mutation that means its ability to bind with human cells could be up to 1,000 times as strong as the Sars virus, according to new research by scientists in China and Europe. The discovery could help to explain not only how the infection has spread but also where it came from and how best to fight it. Scientists showed that the virus that causes Sars (severe acute respiratory syndrome) entered the human body by binding with a receptor protein called ACE2 on a cell membrane.  Some early studies suggested that the new coronavirus, which shares about 80% of the genetic structure of Sars, might follow a similar path. But the ACE2 protein does not exist in larg

Chinese factories are producing thousands of tons of a “green zombie fungus” to help fight the swarms of locusts in East Africa. Metarhizium is a genus of fungi with nearly 50 species – some genetically modified – that is used as a biological insecticide. Its roots drill through the insects’ hard exoskeleton and gradually poisons them. In China, it was named lu jiang jun, which means “green zombie fungus,” because it gradually turns its victims into a green mossy lump. There are now dozens of factories across the country dedicated to producing its spores and, despite the curbs introduced to stop the spread of the coronavirus that causes Covid-19, many of them have resumed operations and are

On January 22, four days before the Lunar New Year, a village in southeastern China held a banquet. Some 3,000 people, or half the village’s population, showed up.  It was a blast. Then the villagers found out that one family among them had returned from the central city of Wuhan and brought with it a new strain of coronavirus that has killed at least 1,100 people worldwide since it was first reported in December. The banquet took place two days after the Chinese government declared the coronavirus outbreak a national emergency, and authorities at all levels were tracking and restricting the movements of people from Wuhan. The family slipped through all measures of screening and, according