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New virus jumps from monkey to humans.
by Science Now:
It started with a single monkey coming down with pneumonia at the California National Primate Research Center in Davis. Within weeks, 19 monkeys were dead and three humans were sick. Now, a new report confirms that the Davis outbreak was the first known case of an adenovirus jumping from monkeys to humans. The upside: the virus may one day be harnessed as a tool for gene therapy.
Then, on 14 May 2009, a healthy adult male titi monkey—a small, reddish-brown species that calls much of South America home—came down with a cough at the Davis primate center and soon became lethargic and wouldn’t eat. Staff members gave the animal intravenous fluids and antibiotics, but its condition worsened, and after 5 days staff members euthanized him. Four weeks later, another titi monkey came down with the same symptoms. Then another. And another. Within 2 months, 23 of the 65-strong population had become sick, and 19 eventually died. A team led by infectious diseases researcher Charles Chiu of the University of California, San Francisco, analyzed lung tissue samples from the dead monkeys and identified a never-before-seen adenovirus, which they named titi monkey adenovirus (TMAdV).
Neither the lab worker nor her family members sought medical attention, and all recovered within 4 weeks, after which it was too late for researchers to swab for traces of the adenoviruses directly. Instead, they examined the patients’ blood for antibodies and compared them with those found in the infected monkeys.
After testing the other monkeys at the primate center, which houses hundreds of enclosures, the researchers found one healthy rhesus macaque with TMAdV antibodies. That suggests the disease might have arisen in the macaques and somehow passed to lab workers or the titi monkeys via shared medical equipment or some other contact between the two species, the researchers report today in PLoS Pathogens.
Although the virus didn’t prove deadly, or even all that serious, to the humans it infected, the new findings suggest there may be more pathogens than previously thought with species-jumping potential. “Now we need to broaden our focus in looking at monkeys’ and other animals’ adenoviruses,” Chiu says. “We’ve only touched the tip of the iceberg.”
TMAdV’s rarity in humans could make it a potentially powerful tool as a viral vehicle for delivering gene therapy, Chiu adds. Researchers already use custom adenoviruses stitched with beneficial snippets of DNA to treat diseases; for instance, the cancer-fighting virus Gendicine introduces genes that code for the tumor-suppressing protein p53. The problem is that many people have antibodies to these viruses and their immune responses can make such treatments dangerous or even deadly. That problem likely wouldn’t occur with an engineered version of TMAdV because nobody has antibodies to it. Chiu has a patent pending for using TMAdV as a gene-therapy vehicle.
The discovery is remarkable in a sense that it gives scientists clues on the genetic makeup of a virus to be capable of mutating from monkey to human (mammal to mammal). One redditor noted:
This is amazing, and will definitely be important to identifying the types of mutations necessary to change host specificity in this important virus family. It won’t be long until they identify the amino acid change (or changes) that occurred to allow the virus to infect the researchers. I know a lot of people not familiar with the field are worried about this, but much more good than harm will come from the infections. They are lucky this happened.
Lucky indeed, spread the word