I'm a PostDoc in a large research lab. Unfortunately we have a very small, and very crowded office. Most of our grad students only show up infrequently. Because of the space and noise issues, it's often easier to work from home or the library if you're not doing labwork.
One particular student, Mary, works from home most of the time but has a tendency to turn up when she's sick. It's like clockwork. I'm not sure if it's because she's trying to show how hardcore she is, or whether she's just wants company when she's feeling miserable.
Mary invariably infects everyone. I don't know how. I mean, I understand that there is transmission of bodily fluids involved, but managing to infect all 12+ coworkers pretty much simultaneously is an impressive achievement and somewhat ironic given our field of expertise.
The PostDocs have fairly intensive workloads with 60+ hr weeks not unusual. Since there really isn't anyone to cover our individual projects if we get sick, it's not unusual for us to come in if sick. But we huddle in our little cubies and use so much alcohol-based hand rub you could get high off the fumes. Occasions where we've actually managed to pass something onto somone else are negligible.
Last time Mary was sick, the entire office (including visiting officials) became ill, an international meeting had to be postponed, and I got a secondary infection for which I've just finished my second course of antibiotics. My eustachian tubes are still not happy, and I'm a little bit ragey.
How can I politely ask Mary to not come in sick, particularly when there are double standards for post-docs. Is there a tactful way of pointing out that since her hygiene is clearly lacking, additional quarantine standards apply to her?