From someone who has worked extensively on flu virus in ferrets...and many other microbiological diseases:
1) Piggies do not catch human cold viruses. The viruses responsible for human colds are generally rhinovirus which cannot jump to other animals..
2) However, Human FLU viruses CAN theoretically jump the species gap - (swine and bird flu jumped to us from their respective hosts). Human flu has, in an experimental situation at high doses, been shown to infect piggies. Flu is distinguished from a cold by a temperature and general malaise such that you ache/can;t move and are physically bed bound for a few days.
3) Antibacterial gel kills bacteria NOT viruses (uness it also contains a viricidal chemical). Virkon kills viruses.
Anyone with a respiratory virus infection can then get a secondary bacterial infection in the lungs - manifested by coughing up yellow/gree goo - in which case you need to go to the doctor to get some antibioitics. If the goo is clear/white then it is just a feature of the flu/respiratory virus infection. Antibioitics ONLY kill bacteria, not viruses
If you are feeling poorly and cannot know if you have a cold virus or mild flu virus then it is best to keep away from your piggies. Because if they get exposed to flu, then even if it doesn;t cause clinical symptoms in them (which is unlikely) it can weaken their immune systems and make secondary bacterial respiratory infections a problem.
If you have to go near your piggesi then make sure you don;t hold them close to your face and wash your hands with a viricidal scrub such as virkon
In the major human flu pandemics, the fatalities were mainly caused by secondary bacterial pneumonia in the elderly or immunocompromised individuals.....not the flu virus itself.
I hope this helps clear up the misconceptions posted on this thread