A type of bird flu that has killed millions of chickens is becoming more infectious to mammals and scientists fear it could cause the next worldwide pandemic in
humans.
The avian flu has forced authorities to slaughter millions of chickens and other fowl in Asia to stem outbreaks in recent years. Thousands more have been killed in the US and elsewhere.
Already the flu has passed from birds to humans in Hong Kong, killing six of 18 people infected in 1997, and human cases have been reported since then in Vietnam and Thailand.
Now China-based researchers studying the H5N1 strain of the flu report that it has been changing over the years to become more dangerous to mammals. Their research, based on tests in mice, is reported in Monday's issue of Proceedings of the National Academy of Sciences.
"Our results demonstrate that while circulating in domestic ducks, H5N1 viruses gradually acquired the characteristics that make them lethal in mice," reported the team, led by Chen Hualan of the Animal Influenza Laboratory of the Chinese Ministry of Agriculture.
Human infections from bird flu remain rare, but the World Health Organization (WHO) considers it a potential major threat.
Two possibilities exist for the bird virus becoming a serious danger to people.
Viruses constantly mutate, and this one could accumulate enough genetic changes to become good at passing between humans. So far human cases have derived from birds, and no evidence has arisen of the bird flu being passed from person to person.
Even more worrisome, the experts say, would be sudden change that could be caused should the flu combine with a human flu in someone's body. The two viruses could swap genes and create a potent hybrid as deadly as the bird strain and as contagious as a regular human strain.
Klaus Stohr, head of the WHO's global influenza program, noted the new study confirms that the virus is evolving fairly rapidly, and viruses that are pathogenic for chickens are more apt to be transmitted to humans because humans are in contact with chickens.
The tests in mice act as a magnifying glass to help understand how dangerous the virus might be for humans, Stohr said. While seeing no cause for panic, Stohr observed that the virus' ability to infect humans raises the possibility of a new pandemic of dangerous flu.
The new Chinese analysis looked at samples of the H5N1 virus collected from ducks between 1991 to 2002. The researchers tested the effect of the viruses in mice and found that the samples collected between 1999 to 2000 were less dangerous than those from 2001 to 2002. How the viruses evolved with increasing lethality is not clear, but it may have occurred in farms where pigs and ducks live in close proximity
SEEKING CHANGE: A hospital worker said she did not vote in previous elections, but ‘now I can see that maybe my vote can change the system and the country’ Voting closed yesterday across the Solomon Islands in the south Pacific nation’s first general election since the government switched diplomatic allegiance from Taiwan to Beijing and struck a secret security pact that has raised fears of the Chinese navy gaining a foothold in the region. The Solomon Islands’ closer relationship with China and a troubled domestic economy weighed on voters’ minds as they cast their ballots. As many as 420,000 registered voters had their say across 50 national seats. For the first time, the national vote also coincided with elections for eight of the 10 local governments. Esther Maeluma cast her vote in the
Nearly half of China’s major cities are suffering “moderate to severe” levels of subsidence, putting millions of people at risk of flooding, especially as sea levels rise, according to a study of nationwide satellite data released yesterday. The authors of the paper, published by the journal Science, found that 45 percent of China’s urban land was sinking faster than 3mm per year, with 16 percent at more than 10mm per year, driven not only by declining water tables, but also the sheer weight of the built environment. With China’s urban population already in excess of 900 million people, “even a small portion
UNSETTLING IMAGES: The scene took place in front of TV crews covering the Trump trial, with a CNN anchor calling it an ‘emotional and unbelievably disturbing moment’ A man who doused himself in an accelerant and set himself on fire outside the courthouse where former US president Donald Trump is on trial has died, police said yesterday. The New York City Police Department (NYPD) said the man was declared dead by staff at an area hospital. The man was in Collect Pond Park at about 1:30pm on Friday when he took out pamphlets espousing conspiracy theories, tossed them around, then doused himself in an accelerant and set himself on fire, officials and witnesses said. A large number of police officers were nearby when it happened. Some officers and bystanders rushed
HYPOCRISY? The Chinese Ministry of Foreign Affairs yesterday asked whether Biden was talking about China or the US when he used the word ‘xenophobic’ US President Joe Biden on Wednesday called for a hike in steel tariffs on China, accusing Beijing of cheating as he spoke at a campaign event in Pennsylvania. Biden accused China of xenophobia, too, in a speech to union members in Pittsburgh. “They’re not competing, they’re cheating. They’re cheating and we’ve seen the damage here in America,” Biden said. Chinese steel companies “don’t need to worry about making a profit because the Chinese government is subsidizing them so heavily,” he said. Biden said he had called for the US Trade Representative to triple the tariff rates for Chinese steel and aluminum if Beijing was