People who have travelled to flu- affected countries should wear a face mask for seven days regardless of whether they displayed symptoms, a local microbiologist said after it emerged that the influenza (A)H1N1 virus had jumped the species barrier to infect pigs in Canada.
University of Hong Kong microbiologist Ho Pak-leung said that meant the virus - known as swine flu - might have mutated, and everyone should step up preventive measures to avoid its further spread. It was not unusual for people to infect pigs; it had happened in the 1968 H3N2 flu pandemic, he said.
But since the incubation period could last for seven days, and infected people might show no symptoms, Dr Ho said all travellers - especially pig-farm workers - flying to Hong Kong from affected countries should wear a mask for seven days starting from when they boarded the plane.
Farm workers should be extra-cautious when making contact with pigs, but nobody should be afraid of eating pork, he said: 'As long as the pork is thoroughly cooked, the risk is very small.' The focus in combating the swine flu pandemic should not be on reducing pork consumption but on containing the disease by wearing masks, he said.
Dr Ho said surgical masks would protect wearers from catching the virus through droplets. He does not recommend wearing the N95 or N99 masks as they make it difficult to breathe normally after one or two hours of use.
Simon Cheng Ka-shing of the Hong Kong Pig Development Association said workers in all local pig farms had been reminded to wear masks whenever they came into contact with the animals.