The UN Food and Agriculture Organization is calling for strict bio-security measures for pigs for any evidence of respiratory illness. However, it is not calling for the slaughter of the animals. The announcement follows the discovery of the A-H1N1 virus in pigs in Canada, which apparently was transmitted to the animal by a person.

If there are signs of respiratory illness, there should be a restriction on the movement of pigs, good and people on those farms or facilities until a diagnosis of the illness is made. Joseph Domenech, the FAO's chief veterinary officer, says the human-to-animal transmission of the flu virus does not come as a surprise.

"So, what does it mean? It means that the virus, which is a new virus?can infect pigs. But this unique case is showing that it's not very pathogenic. (causing infectious disease) and maybe not also as contagious as the other influenza viruses in swine. In Canada, the herd is showing about 10 percent of animals having clinical signs only with very mild signs. And after two or three days, all have recovered," he says.

However, precautions should be taken and surveillance increased to see whether the A-H1N1 virus spreads to other farms and then back to people. He says that could affect the epidemiology (health factors) of the human pandemic.

Farms with infected pigs would basically be placed under quarantine. "Then you stop having (the) possibility to have spread the virus from the farm to other farms. It means concretely, first of all, you have to prevent people from entering or going out of the farm without any control and for the goods as well," he says.

The FAO adds that "persons who work directly with swine should not go to work if they have any signs of respiratory disease, fever or any influenza-like illness. Again, the FAO stress "there is absolutely no need to slaughter animals in view of preventing circulation of the A-H1N1 virus."