Europe News Desk!!! Scientists have identified a new mutation in the avian influenza virus H5N1, which recently infected a person in Chile and may be at risk of spreading to humans. According to the European Center for Disease Control (ECDC), the risk of human-to-human transmission remains low, but the new changes being observed are worrying. This also suggests that the potential risk of human transmission is increasing. Last month, Chile’s Ministry of Health confirmed that a 53-year-old man had tested positive for the H5N1 virus. The man was said to be in a serious but stable condition with severe pneumonia. The New York Times reported that according to officials at the US Centers for Disease Control and Prevention, the virus sample taken from the man contained two genetic mutations that are indicative of an adaptation to mammals.
In experimental animal studies the mutations, both of which are in what is known as the PB2 gene, have previously been shown to help the virus replicate better in mammalian cells. The risk to the public remains low, health officials said, adding that there have been no additional human cases linked to the Chilean man who remains hospitalized. Importantly, The New York Times reported, the samples did not contain other key genetic changes that scientists believe would be necessary for H5N1 to spread efficiently among humans, including mutations that would stabilize the virus. And will help it bind more strongly to human cells. Bird flu expert Richard J. “We think there are three major categories of changes that have changed H5 from a bird virus to a human virus,” Webby said. The sequence in the Chilean man is one of those classes of changes, but we also know that of those three sets of changes, it’s the easiest for the virus to do.
Globally, since 2004, there have been 874 human cases of human infection with avian influenza A (H5N1) in 23 countries, including 458 deaths (case-fatality rate: 52.4 percent), the ECDC said. To date, human-to-human transmission has not been detected. In a report published this week, the agency said there is high uncertainty in its assessment of the risk due to increased transmission of H5N1, including its spread in the Americas and animals. The PB2 gene was recently identified in mink in Spain. The Telegraph reported that H5N1 spread from wild birds to thousands of farmed animals—within weeks, more than four percent had died from hemorrhagic pneumonia. Altogether 50,000 mink were killed. Experts noted that an increase in mammalian transmission could pose a greater risk to humans. Last month, a woman in China was hospitalized with H5N1, while a young girl died earlier this month. The report said that during the sequencing of cases from Cambodia it was found that the virus had mutations that allowed it to infect humans, but there was no indication that the pathogen was able to better spread between people. changed for
–IANS
World News Desk!!
KC/SGK