“This is not a question for an expert on etiquette!” I expostulated. “It’s a question for an Infectious Disease specialist!”
The trigger for that objection: A query to Social Qs, the New York Times etiquette column on “awkward situations.” The writer describes a group of 10 close friends who meet regularly for dinner; one, who is immuno-suppressed, asks that another member who is getting over the flu and still on antibiotics keep 12 feet away and avoid touching anything she may eat. The reader asks: “Shouldn’t one of them have declined the invitation? But which?”
The columnist responds that no, no one needed to bow out, and that this distance-setting arrangement seems a good compromise, adding, “I hope the person with the flu called her doctor to make sure she was no longer contagious — for everyone’s sake.”
Surely you can understand my frustration. Fine, the flu patient could call her doctor, but what about the rest of us, hungry for more general knowledge on contagion for our own social gatherings? Why not answer the obvious questions? Like: Is 12 feet really far enough to avoid flu germs? Are you still contagious when you’re finishing a course of antibiotics?
Oddly, the day after I read that column, a similar situation played out at my house: One friend was getting over a respiratory infection, still coughing, and another friend regretfully said she could not stay and chat at the dining table, for fear of carrying a germ to an immuno-compromised loved one.
That did it. I called CommonHealth’s go-to guy on infectious disease questions of public interest, Dr. Ben Kruskal, chief of infectious diseases at Harvard Vanguard Medical Associates, and shared my annoyance. Actually, he gently corrected me, this is an issue of both medical science and etiquette. Our conversation, lightly edited:
Dr. Kruskal: You need to have the facts and then you can figure out the etiquette in light of them.
First, when it come to infectious disease transmission, we know a fair amount, but there’s a lot that is still argued over. So let’s take flu as a good example. We know that there are multiple mechanisms by which flu is transmitted, or by which you could postulate reasonably that it might be transmitted:
• Physical contact: You’ve got germs on your hands, you touch somebody else’s hands or face. Or indirect contact — you touch your face, and then touch the doorknob. A few minutes later, someone else touches the doorknob and then their face.
And there are two different mechanisms of airborne transmission:
• Respiratory droplets, which fall to the ground pretty quickly after they leave your mouth and nose. People argue about the distance they can travel — some people say three feet, some say six feet. Six is a very conservative estimate.
• And then there’s what’s called true airborne transmission (technically, droplet nuclei), which is the mechanism by which TB, measles and chicken pox are all transmitted. And that’s the kind that can go much longer distances and can linger in the air for a long time afterward.
So which is flu?
Flu looks like it’s probably mostly droplets, with some contact, and then there’s a lot of debate in the medical literature about whether there’s some component of airborne transmission or not. If it’s there, it’s probably not huge — we’re arguing whether it’s .1 percent or 1 percent or 5 percent, but it’s probably not more than that.
What else should we know? Continue reading