The AIDS virus has been circulating among people for about 100 years, decades longer than scientists had thought, a new study suggests.
Genetic analysis pushes the estimated origin of HIV back to between 1884 and 1924, with a more focused estimate at 1908.
Previously, scientists had estimated the origin in about 1930.
AIDS wasn’t recognized formally until 1981 when it received the attention of public health officials in the US.
The new result is “not a monumental shift, but it means the virus was circulating under our radar even longer than we knew,” says Michael Worobey of the University of Arizona, one of the authors of the new work.
The results appeared in today’s issue of the journal Nature.
Researchers note that the newly calculated dates fall during the rise of cities in Africa and suggest urban development may have promoted HIV’s initial establishment and early spread.
Scientists say HIV descended from a chimpanzee virus that jumped to humans in Africa, probably when people butchered chimps. Many individuals were probably infected that way, but so few other people caught the virus that it failed to get a lasting foothold, researchers say.
But the growth of African cities may have changed that by putting lots of people close together and promoting prostitution, Worobey said.
“Cities are kind of ideal for a virus like HIV,” providing more chances for infected people to pass the virus to others, he said.
Perhaps a person infected with the AIDS virus in a rural area went to what is now Kinshasa, Congo, “and now you’ve got the spark arriving in the tinderbox,” Worobey said.
Key to the new work was the discovery of an HIV sample that had been taken from a woman in Kinshasa in 1960. It was only the second such sample to be found from before 1976; the other was from 1959, also from Kinshasa.
Researchers took advantage of the fact that HIV mutates rapidly.
So two strains from a common ancestor quickly become less and less alike in their genetic material over time. That allows scientists to “run the clock backward” by calculating how long it would take for various strains to become as different as they are observed to be.
That would indicate when they both sprang from their most recent common ancestor.
The new work used genetic data from the two old HIV samples plus more than 100 modern samples to create a family tree going back to these samples’ last common ancestor. Researchers obtained various answers under various approaches as to when that ancestor virus appeared, but the 1884-to-1924 bracket is probably the most reliable, Worobey said.
The new work is “clearly an improvement” over the previous estimate of around 1930, said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland.
AIR SUPPORT: The Ministry of National Defense thanked the US for the delivery, adding that it was an indicator of the White House’s commitment to the Taiwan Relations Act Deputy Minister of National Defense Po Horng-huei (柏鴻輝) and Representative to the US Alexander Yui on Friday attended a delivery ceremony for the first of Taiwan’s long-awaited 66 F-16C/D Block 70 jets at a Lockheed Martin Corp factory in Greenville, South Carolina. “We are so proud to be the global home of the F-16 and to support Taiwan’s air defense capabilities,” US Representative William Timmons wrote on X, alongside a photograph of Taiwanese and US officials at the event. The F-16C/D Block 70 jets Taiwan ordered have the same capabilities as aircraft that had been upgraded to F-16Vs. The batch of Lockheed Martin
GRIDLOCK: The National Fire Agency’s Special Search and Rescue team is on standby to travel to the countries to help out with the rescue effort A powerful earthquake rocked Myanmar and neighboring Thailand yesterday, killing at least three people in Bangkok and burying dozens when a high-rise building under construction collapsed. Footage shared on social media from Myanmar’s second-largest city showed widespread destruction, raising fears that many were trapped under the rubble or killed. The magnitude 7.7 earthquake, with an epicenter near Mandalay in Myanmar, struck at midday and was followed by a strong magnitude 6.4 aftershock. The extent of death, injury and destruction — especially in Myanmar, which is embroiled in a civil war and where information is tightly controlled at the best of times —
China's military today said it began joint army, navy and rocket force exercises around Taiwan to "serve as a stern warning and powerful deterrent against Taiwanese independence," calling President William Lai (賴清德) a "parasite." The exercises come after Lai called Beijing a "foreign hostile force" last month. More than 10 Chinese military ships approached close to Taiwan's 24 nautical mile (44.4km) contiguous zone this morning and Taiwan sent its own warships to respond, two senior Taiwanese officials said. Taiwan has not yet detected any live fire by the Chinese military so far, one of the officials said. The drills took place after US Secretary
THUGGISH BEHAVIOR: Encouraging people to report independence supporters is another intimidation tactic that threatens cross-strait peace, the state department said China setting up an online system for reporting “Taiwanese independence” advocates is an “irresponsible and reprehensible” act, a US government spokesperson said on Friday. “China’s call for private individuals to report on alleged ‘persecution or suppression’ by supposed ‘Taiwan independence henchmen and accomplices’ is irresponsible and reprehensible,” an unnamed US Department of State spokesperson told the Central News Agency in an e-mail. The move is part of Beijing’s “intimidation campaign” against Taiwan and its supporters, and is “threatening free speech around the world, destabilizing the Indo-Pacific region, and deliberately eroding the cross-strait status quo,” the spokesperson said. The Chinese Communist Party’s “threats
RSS