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.
Adenoviruses are relatively large DNA viruses—as opposed to many other viruses that replicate using RNA—that commonly cause colds and respiratory infections in humans. They’re also responsible for a variety of illnesses in cattle, dogs, horses, pigs, and other animals, but scientists thought the viruses and their ailments couldn’t jump between species.
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).