Deadly virus transmitted from pigs to monkeys without contact

Scientists have found that the deadliest form of the ebola virus could be transmitted between species by air.

Though the fruit bat has long been considered a natural host for the infection, evidence is now showing that both wild and domestic pigs could host the most deadly form of the virus - ebola zaire.

The virus causes fatal haemorrhagic fevers in both humans and species of non-human primates.

Experiments by scientists from the Canadian Food Inspection Agency and the country's Public Health Agency has revealed that the virus can be transmitted from pigs to monkeys without any direct contact.

In the experiments, pigs carrying the virus were housed in pens with macaques with a wire barrier between the two. After eight days, some of the monkeys were showing clinical signs of typical ebola.

The scientists believe aerosol droplets produced from the respiratory tracts of the pigs were inhaled by the monkeys, causing infection.

"[Large droplets] can be absorbed in the airway and this is how the infection starts," said Dr Gary Kobinger from the National Microbiology Laboratory at the Public Health Agency of Canada. "This is what we think, because we saw a lot of evidence in the lungs of the non-human primates that the virus got in that way."

Dr Kobinger stressed that the virus is not, however, airborne.

"The reality is that they are contained and they remain local," he said.