This is not about swine flu, this is about The Flu, all strains.
If you have a fever, swollen glands, or other very obvious signs that you are unwell:
Do not come to work because "it's boring at home" or "everyone is just being paranoid". Do not come to work.
Do not spread it around.
You are not limited to the following two options:
1. Freak out, believe media sensationalism.
2. Ignore illness and spread it liberally.
There is a happy middle ground between paranoia and wantonly germing up your workplace. Just because you stay home and choose not to spread your illness, it does not mean you've bought in to media-induced paranoia.
Swine flu or not, the flu is always particularly dangerous for certain people. Everyone you work with seems healthy, right? It's okay for them to get the flu. Everyone is just paranoid.
Actually, there can be some health concerns your coworkers have that are not obvious to you that put them at higher risk for flu complications. Do you want to put them in danger just to show off how not paranoid you are? Just to keep from being bored at home? How about their relatives? Might your coworkers have children? Elderly relatives that live with them or that they see often? Might they have pregnant wives or friends? If you pass the flu to your coworker, you could be endangering these people in their lives, particulary if you happen to catch a strain for which it hasn't yet been possible to vaccinate everyone at high risk.
You don't have to prove that you're not giving into sensationalism and you're so cool and non-paranoid, and you don't have to give in to sensationalism either. This should be your approach every year: if you get the flu or obvious signs of illness such as fever or swollen glands, please do your coworkers and the at-risk people in their lives a favor and stop the spread. Your workplace can go on without you while you get better.