Although not a long flight, we have just travelled to Sanya and back last weekend, which was just over an hour flight, with my 16m month old daughter and I am 31 weeks pregnant. We figured that it is no different being stuck on a plane full of people than my husband going to work with a rooms full of people everyday, not knowing where they have been or who they have interacted with. Many on the flight did wear masks, and once the plane landed China's health authority boarded and temperature checked every individual, which meant we were stuck on the flight for an extra hour. But, it was reassuring to know that China (and HK for that matter) take it seriously. In the end, they did locate one person who had abnormal temperature and quarantined the 3 rows behind and after that individual. Thankfully we were in the first row so were able to leave after this, and were told we would be contacted if the relevant person was infected (which we weren't). Was a little scary initially, but we still believed it was no different from every day interaction with people in HK. You come into contact with so many people in our day to day lives (work, school, playgroups etc) and you don't know who they have been in contact with. We also figure, the swine flu could continue to be a threat for months to come, we don't want to be house bound or HK bound for that length of time.