It's time for another burning question. Today, we're going to talk about that awful smell your co-worker left in the bathroom... and whether or not it poses a risk to your health.
I have an embarrassing public health question. If I go into a public bathroom stall and the person who used it before me left smelly gassy air behind like they might have diarrhoea, or vomiting can I get sick (flu? Virus?) from only smelling their emissions? Should I move quickly to another stall or am I OK as long as I wash my hands and use a seat cover like usual?
I got the flu soon after being in the next stall to a woman with terrible intestinal distress a few years ago and always wondered if I got sick from airborne contaminants.
Inquiring mind (during this bad flu season) wants to know?
Troubled in Toilet-ville
First of all, Troubled in Toilet-ville, I am delighted that you've given yourself a nickname, although somewhat less delighted that I will now have to refer to you as TIT. Maybe TITV? Can we go with TITV?
Anyway. About that cloud of smelly gassy air. It's a well known fact that smells themselves don't make people sick. Or at least, that's well known in modern times. Only a century or two ago there was a theory that smells cause diseases, which makes sense in that stinky air does tend to accompany germ-riddled sources of disease, like faeces or decomposing corpses.
In that line of thinking, you could protect yourself from getting sick by sniffing some perfume or vinegar while you navigate the sewage-strewn streets.
But times have changed. We know that the flu is caused by a virus, for example, and it spreads mainly through droplets from coughs and sneezes. Other diarrhoea-causing "stomach bugs" are likewise caused by germs, like norovirus and the bacterium Clostridium difficile to name a few.
But you're not writing from Victorian London, TITV. You know that illness is caused by germs, and you want to know if there could be enough of them in the air to get you sick. So I called up Dr. Lisa Maragakis, the senior director of infection prevention at Johns Hopkins.
"It's not a silly question," she says. (Phew.) "It's actually an active area of investigation in infection prevention."
Diarrhoea-causing bacteria and viruses are known to spread through droplets that get launched into the air and either land on you directly or settle on a surface that you later touch. But there is some evidence suggesting that they can also spread through tiny droplets that stay airborne for a little while.
One extreme example comes from the SARS outbreak that spread through a Hong Kong apartment complex in 2003. Faulty plumbing and ventilation combined to spread aerosolised bacteria from bathroom to bathroom. This is not how your typical flu virus gets to you, and the flu isn't nearly as contagious as SARS. But this story does show that airborne transmission is possible.
That said, your risk of catching the flu from a cloud of aerosolised faecal matter is probably a lot less than your chance of catching it by touching a handrail or a doorknob or standing next to someone at the bus stop who just up and sneezes on you. On the bright side, Maragakis says, somebody who has actual influenza bad enough that it's giving them explosive diarrhoea is more likely to be holed up at home than heading out into the world to contaminate public bathrooms.
Meanwhile, there are plenty of reasons somebody could have diarrhoea — or as she politely puts it, "GI distress" — that aren't infectious.
Your chances of catching the flu this way are pretty small, TITV. But I made sure Dr. Maragakis gave us the bottom line: how much should you actually worry if somebody's got the splatters in the stall next door? She says: "If there's a chance you can exit the bathroom, or be on the other side of the bathroom, that's what I would do."