Aerosolization of C. difficile after flushing toilets: the role of toilet lids | Hacker News Reader

Aerosolization of C. difficile after flushing toilets: the role of toilet lids

journalofhospitalinfection.com

87 pointsbookofjoe103 comments

Full-on Baader-Meinhof here, seeing this posted while I am at home/in the hospital (for two days about a week ago) for the second week because of a C. diff infection I got from an antibiotics treatment for the tonsillitis prior.

I do know for a fact that I never want to feel this sick again. If that requires me to keep the toilet lid closed whenever flushing for all eternity, I'll gladly do so - and I think you should, too. (I was actually advised to do that and flush 'carefully'/slowly, with the lid down, by my doctors, and took care to comply.)

> flush 'carefully'/slowly

How does one flush "carefully/slowly"? The speed you press the handle doesn't change the pressure of the flush - at most it might extend it and waste water, by keeping the flapper open longer than necessary.

Instead press the handle rapidly and briefly to save water and still have a proper flush.

Extend it, use more water, and get fewer aerosols into the air. That's the point of his post.

If you have C. diff. and don't want to spread it, it's probably worth it to spend (not waste, spend) the extra water for a slower flush if your toilet will work that way.

That's .... not what will happen.

Instead you'll get the exact same regular violent flush, and then water will pour into the tank extending the time that water can aerosolsize, and worse, pushing any existing aerosols farther out into the room.

So basically that's the opposite of what you should do, if that's your goal.

Instead, reduce the flush time.

Try it: hold down the flush lever and time how long it takes before you can smell the water.

> hold down the flush lever

That's not what's being suggested. Slowly open the valve by slowly pressing the lever to let some water in before the valve pop all of the way open.

I don't understand what goal that will accomplish. You might wash the walls of the toilet slightly, but that's not where the bacteria are, they would be in the center, in the bulk of the material.

Plus toilets are designed to prevent you from doing that, they try very hard to be either fully closed, or fully open.

And, even if you succeeded, by releasing some water in advance, you reduce the pressure of the flush, which would elongate it, instead of rapidly removing the material, and time with water flowing = amount of aerosol.

This plan seems counterproductive.

I suspect you're used to much more modern toilets than the person you're replying to. Toilets from at least a decade ago in the USA don't feel like they're designed to try very hard to do anything contrary to the direct mechanical effect of you pushing down a lever.

Many (most?) toilets around where I live do let you exert "analog" control over the flushing process, at least when initiating it. On the one in my apartment, If I begin to press the flush button very gently, water will start flowing in at a very reduced rate (and carrying material with it down the drain without causing a splash), compared to when just pushing down the button without any consideration.

My parents taught me to always close the lid before flushing because of the generic "germs" argument. I taught it to my kids. Takes 2 seconds.

This is nonsense. C diff in hospital settings is not a reason to close the lid when you flush in your home. The lid on a hospital toilet is designed to close a lot more than the lid on your home toilet. The amount that your home toilet lid can "reduce germs" is less than a factor of 2. There are basically no pathogens whose infectious innoculum is so close to dose of the average toilet plume that a factor of 2 makes any difference at all. Moreover, those are your germs. you are colonized with them already.

But what’s the harm in closing it?

It takes 2 seconds. Why spend 2 seconds doing something useless?

As established, it is not useless.

That is not, in fact, established. And the question was "what's the harm?"

https://news.ycombinator.com/item?id=31828469 indicates that there was a "mythbusters" that looked at whether germs would reach things like tooth brushes in the bathroom. So... maybe it is more plausible than you seem to be allowing? (I'm planning on watching that full episode later. Seems to be https://www.youtube.com/watch?v=1pFww_EaLiY.)

Edit: That must be the wrong episode. Will keep looking for it.

Depending on the toilet (and esp with "water saving toilets"), floating remains left behind for the next person to discover?

The problem is that many toilets seems to be designed so that the flowing water is supposed to create a vacuum pull effect in the piping dragging with it water and the heavier materials from a toilet.

However with a closed lid the lower air pressure within the bowl is going to create a suction effect in the other direction thus lowering the flushing effect, leaving heavier brown materials still within the toilet ready for the next customer to discover.

I've never seen a toilet lid that seals well enough to affect the flushing action.

Like I mentioned, I do suspect that "modern" low-water toilets are half the blame here (less water->less suction). Also cheap "soft-plastic" lids seem pretty sealing compared to older/more expensive hard lids that were usually load bearing with spacers holding them up slightly (probably to let in air?).

Actually tested this a bit after open/close lid arguments with my ex and this does happen, hospital toilets do usually seem sturdier than those you find in homes here though.

For what its worth, look into actual modern toilets. The first batch of low water use ones were somewhat lacking. Modern ones are typically better than the old high water use of a decade ago.

Is kind of like LED lights. First batches were garbage. Nowadays, they are better in basically every way compared to what they replaced.

> a factor of 2

So, half? Is there some benefit to blasting literal shit into the air I am missing?

Yes, you save, according to OP, 2 seconds, 4, since you then have to open the lid every time. Since it has no impact on your health, you should prefer to save the time.

There is literal shit everywhere all the time. There's shit inside of you, right now. The bacteria that comprise that shit are basically the same as the bacteria on your skin. Performing little rituals to reduce the amount of perceived shit in your life is a symptom of, and perhaps even a pathway to, crippling neurosis.

> crippling neurosis.

Well that escalated quickly.

You are ignoring the actual benefit of halving exposure with a couple of seconds of effort. Worrying about that kind of time is itself crippling neurosis.

I reject your analysis.

Yeah, at first scan I thought it was going to be some ironic comment. Which it was, just not intentionally

I am not ignoring that effect. I am dismissing it with two arguments. The first is that this extremely unlikely to ever be your largest exposure to a pathogen. The reason that it is important in a hospital is because they essentially autoclave these room to try to eradicate C Diff. The second reason is that even if it is your largest exposure to that pathogen, and that is enough to make you ill, it is almost certain that a dose of half of that size will also be sufficient to make you ill.

It is notable that there are no studies to the effect of "do people who close their toilet lids at home get sick less often". The scientific journalism of this "effect" is always about the quantity of germs, or conflating home and hospital settings, where again, the objective is literally zero C diff. It riles up the germophobes.

> It is notable that there are no studies to the effect of "do people who close their toilet lids at home get sick less often".

There are also no studies proving that people who jump out of an airplane with a parachute live longer than a control. I guess we should not trust our instinct in this case.

Using UV light to see the plume of a flush

https://www.youtube.com/watch?v=1Tg7i66GGMI

Search youtube for many other demonstrations.

I think you think that the only kind of study that confirm this hypothesis is some kind of RCT, where we give one group a placebo toilet flush, and the other I try to get infect with norovirus. The point of "https://www.bmj.com/content/363/bmj.k5094" which is more or less making the same tongue in cheek argument as you, is that there are limitations to what can be counted through an RCT.

I am, however, not talking about an RCT. I am talking about the conspicuous lack of observational study of the clinical phenomenonology of toilet plume, rather than some secondary observation about scary germs.

Epidemiologists must find ways to study illness without actually making people ill, but they still, for the most part, manage. Moreover, observational study is not, in any way, lacking, about what happens when you jump out of a plane with a parachute. It's not merely common sense, it has been observed to happen. Moreover, this is reflected pretty fucking well in the literature https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1478603/pdf/brj....

I am simply amazed that you cannot see adverse risk in certain activities without a study - observational, RCT, or otherwise - confirming it. I wonder how people 500 years ago lived with risk without the proliferation of studies that we have today. Maybe risk simply did not exist back then since no studies confirmed it?

>you cannot see adverse risk in certain activities without a study - observational, RCT, or otherwise - confirming it.

This is pretty far from my claim. I didn't say that I don't believe things without clinical evidence. I said that there is a conspicuous lack of clinical evidence for something which otherwise has so many claims surrounding it. Even a simple questionnaire would be publishable, if it showed an effect. Do you close your toilet lid? Have you had an illness in which you experienced vomiting or diarrhea in the last 6 months? How many people do you live with?

I think perhaps you assume that "you are with the experts" on this one. That most researchers consider the evidence presented in this article to be good evidence that there is a health benefit to closing the toilet lid of your toilet. I can assure you that most researchers do not consider this to be good evidence, exactly because it has no clinical endpoint. It might as well say "in mice".

Perhaps you believe that there is some common sense reason to think that toilet plume is a bad thing, but common sense largely fails to come to correct conclusions about germs. Which is the case that I have been making in this thread.

Is it a benefit to reduce exposure in a household, or even non-hospital setting? We're only just beginning to understand the gut biome, and too much historical advice that seemed sensible turned out to be problematic when understood better.

Halving a 0.00001% chance that you get some crazy infection from flushing the toilet is definitely neurotic. You're better off saving the 2 seconds and not thinking about it. "But it's still half!" Half of nothing is nothing.

> There are basically no pathogens whose infectious innoculum is so close to dose of the average toilet plume that a factor of 2 makes any difference at all. Moreover, those are your germs. you are colonized with them already.

That's only true if you're living alone. If someone else is living with you, then it's always good to try and avoid sharing germs, especially when they're sick.

> If someone else is living with you, then it's always good to try and avoid sharing germs

I feel like this is a ridiculous enough question that I don't expect a source-though if you do have one or know how this sort of thing would be studied I'd love to hear it--but is that always true? I certainly try to reduce my exposure when someone's noticeably sick, but I wouldn't be surprised if some degree of exposure turned out to be beneficial. I also wouldn't be surprised if it turned out to be harmful. I would be least surprised to find out that doing this simply doesn't make a measurable difference in most home environments.

When your loved one is emptying from both sides every other hour, you generally just want to avoid it for yourself.

Of course, but you said that it's always a good idea to avoid sharing germs. I'm specifically asking about the common scenario where no one is noticeably sick

Using UV light to see the plume of a flush

https://www.youtube.com/watch?v=1Tg7i66GGMI

Sorry, how is this relevant to the question being asked?

We know about the pathogens which are likely to make you sick from fecal-oral transmission. We have studied them pretty well because they are common. The most likely candidate for a pathogen that could be spread through toilet plumes is called norovirus, and it is extremely studied. We have so far not found any clinical evidence of infection through toilet plume from norovirus. This includes in cases where water jet toilets produce many times more aerosolization in public bathrooms where lids are not even an option.

What of droplet spread to exposed surfaces in the bathroom like... a toothbrush drying on the rack beside the sink?

Granted, the way to reduce that possibility is to keep the toothbrush in a cabinet.

If you read the article:

> 12-fold greater counts than when lidded

How did you source your “factor of 2” assertion?

The same article. Look at the data. for aerosols one hand width above the surface of the toilet, the numbers are a factor of two different lidded vs unlidded. The 12 times claim is only for samples collected at "seat height".

> when you flush in your home

I did not say "in my home". Everywhere.

I tend to agree, it also adds another pain in the ass step and is not as efficient. I want to finish my business (no pun intended) as quickly as possible and move on to the next thing, not have to do pointless additional steps that have specious benefits at best. Also I highly recommend a bidet, it has made cleaning very fast and efficient and more hygienic.

> I tend to agree, it also adds another pain in the ass step

I am not sure I want to know what your doing with the toilet lid, but it certainly is not what the article is talking about. SCNR ;)

Toilet seat tends to be hard plastic material. I have never found a toilet that was pleasant to sit on for more than a few minutes. There is padding but that doesn't help too much. Squat toilet is ideal but requires holding squat position for many minutes.

    > another pain in the ass step
    ...
    > finish my business (no pun intended)

So that first pun was intended, I presume? Well done!

I wonder why those fancy high-tech Japanese toilets haven't caught on over here ("here" == Germany, but I suspect the situation is very similar in most places that aren't Japan). From what I heard they are like a toilet with a builtin bidet.

Washlets are the shit. Highly recommended.

But how do you use the toilet brush at the same time? Even if you use the toilet brush before flushing, you have to clean the brush somehow...

Uh, I never put the toilet brush into "used" water. Yes, rinse it with a flush. That's a lot different than flushing dirty toilet water with the lid up.

I'm in my 40's and my entire life I've had between 0-2 minor illness every year. Mostly mild head colds. I wonder if I was to adopt a rigid routine of taking extra precautions (like closing toilet lids, more diligent hand washing, using paper towels on bathroom door handles, etc) if I would ever notice a change in that pattern.

Or, is the idea that these extra precautions potentially protect against a more serious illness that might actually concern me?

Either way, my current method of existing in the world seems to result in very few acute health issues, so it's hard to be motivated to change.

That's great but when you get to my age you need vaccination as the immune system starts to weaken the older you get.

You are not consciously aware for every foreign organism your body fights.

Does it even cost two full seconds? I put the lid down as I stand and turn to press the flush. Not only is it more sanity, but every time I drop something in the bathroom and have it bounce off the toilet lid I'm happy it's not in the bowl.

Interesting observations. Some obvious consequences:

Hospital visitors and staff should never use patient toilets, ever.

Patients should use their own toilets only.

Staff gets clean scrubs after any visit to a toilet, helping a patient or on their own behalf. Yeah, sterile workers (surgery, etc) have to scrub in again after a bathroom break.

Clean patient bathrooms, including toilets, often, especially if infectious disease is present.

Design facilities to minimize the need to share bathrooms.

"Employees must wash hands before returning to work."

For what it's worth, hospitals already try to do this stuff.

Some Japanese toilets have a system to create negative pressure so that no aerosols escape even when the lid is down.

AFAIK, shower heads are also problematic. I recall NHS conducted a study and they concluded many vulnerable patients get infected by aerosols during showering. Shower heads that are not cleaned periodically get very nasty biofilm buildup inside the head.

I think that as a consequence some NHS trusts switched to some showerheads that get cleaned and rotated periodically.

Legionnaires' disease can come from shower heads that are not cleaned/maintained.

How do you get germs in something that is only running municipal water in it?

There no (or very little)biological matter to feed on, no light to provide energy.

Hospitals make a big show of a few things. Any hospital I’ve been to is filthy in most departments as they slash and burn overheads like aides and cleaning staff.

Half the people at the Starbucks across the street from a hospital are in scrubs.

Completely tangential and anecdotal observation: modern commercial toilets with their "strong" pressurized flush and often no covering lid tend to launch water droplets everywhere when flushed. If you're flushing a visibly clean toilet this is maybe not such a relevant problem (although perhaps the journal of hospital infection is claiming otherwise here) but if you're prepping to use a soiled toilet this is pretty unsanitary and frustrating.

Obvious business idea: toilets that slide a containing partition before flushing. There's no need to use the seat for that, or to require the person to get up.

There might be easier mechanical ways to accomplish the same.

Until someone flushes while sitting and chops their nuts off.

Castrating reverse poopers may seem harsh, but it's necessary to limit their spread.

Are there really so many people who don’t want to have to get up after pooping that this is a business and needing powered toilets would be worth the trade-offs?

If it gets builders in the US to add an electrical outlet near toilets, I'll selfishly advocate for it. Then I could install a Japanese electric bidet much more easily :)

I have something slightly better, with less of a chance of unwanted castration: Just make the bowl an area of low pressure so particles are less likely to be flung out of it. You could have a fan pulling air through a tube from the bowl, and then running it through some filters.

I had this idea mostly for smell control - why remove all the air from the room instead of just dealing with smell where it is created?

I think that would be really difficult to keep clean.

> There might be easier mechanical ways to accomplish the same.

You could probably rig a chain that connected from the front of the lid to inside the tank that disabled flushing if it wasn't fully extended -- given the handle itself is connected to a chain.

Sure, and I guess that'd be fine for commercial applications. When you have a potential clog, though, you certainly want to be able to visibly verify the flush is working as expected before leaving.

Of course, that could be solved with a see-through toilet lid, but I can only imagine the absurdity of trying to pitch that to consumers.

I was thinking more that people here might be interested in rigging something up for their families just to tinker with the idea. Maybe to encourage habits for kids. But really just for the fun of making it.

Vacuum toilet like on planes? An extractor fan? I want an extractor fan anyway (well, my family does).

Edit: retrofit by sucking air through toilet cistern overflow pipe e.g. https://www.panfan.co.nz/ (great name) but heaps of similar (loofloo, odourvac, airaway, toiletfriend, expella, clo-vent, etcetera) but probably want a Japanese toilet with it inbuilt so designed to suck air from all around the rim, not just the downpipe? Disclaimer: first time I’ve heard of any of those products.

My dad was a dentist and thought it would be unseemly for patients to become aware of any emanations from his private bathroom. He had exhaust fans rigged up that he claimed could changeover the whole room in 2 minute. They were unnervingly loud but did the trick.

There are threads here debating the trade off between a) the marginal time gain from not shutting the lid pre flush and b) literally spraying less shit into the air.

Truthfully, from the bottom of my heart, I love hacker news

With all of the press that "COVID in sewage" got, I'm curious if this same mechanism could be a better explainer for spread of covid in some areas than others. Specifically, my hypothesis would be that places that typically have non fitted lids on toilettes are a large part of why some super spreader gatherings turn into super spreaders.

Would love if someone has thoughts/suggestions on how to disprove this general idea.

Why would this be necessary to explain spread when COVID is aerosolized on every exhale?

It would more explain lack of spread in other large gatherings.

Edit: As an example, it could also go a long way to explain why more teachers don't get covid from students. They don't typically have shared restrooms. Big caveat, I've not seen a reliable quantification of that spread.

Didn't they test this on mythbusters at some point?

Yes. I remember they found the bacteria did spread to toothbrushes in the room.

They also found it spread to toothbrushes in other rooms as well.

But it was much much more on the in-room brushes right? Just comparitively I mean. Guess imma have to watch that episode again.

How am I supposed to know if my poop is fully flushed? I'm just supposed to repeatedly open and close the lid to flush my toilet?

Eat more fiber maybe

Get a new toilet. The modern (good ones - not all are good), pretty much never fail to do a proper flush, and they hardly ever clog.

I got the TOTO CST743S, and it basically never fails or clogs - the handful of times a year that it does clog, you just wait 5 minutes, and then flush again and it's clear.

See, my mother was right to insist on closing the loo seat before flushing.

Meanwhile, "eating ass", anal sex, and other variations of such behavior have been on a steep rise for decades.

Sounds like the spouse/GF putting those plush lid covers there takes care of your health by the plush reducing air exchange.

The bidet would like to have a talk with you.

Bidets don't spray dirty water.

Just use composting toilets, avoids the whole issue, and better for the environment. AMA if this interests you.

I don't see that working in a hospital.

Why not? Installation is easy and inexpensive. Collecting the waste and topping up mulching material (wood chips etc) is done once a day. The waste goes to a compost pile that can eventually fertilize a hospital's vegetable garden.

Vegetable garden and human waste?

people like to argue about seat up/down, but it's really just everybody close the lid, please. easy.

There are no toilet lids in the main men's rooms where I work.

Are courtesy flushes safe?

I flush while still sitting on the bowl, problem solved I guess?

Plus, you're sticking it to Big Bidet.

I actually use a bidet which is why I don't have to stand up until ass and toilet water are both clean.

Someone sells toilet lids for a living. 25 cm is meaningless. But touching a toilet seat every time you go is very meaningful….

Are you insinuating that the researchers have undeclared conflicts of interest?

That was humor but, based on the shred of evidence they claim to have, their conclusion and recommendation are simply bullshit.

You are going to wash your hands anyway, touching the seat makes no difference.

Depends how long how you wash your hands and with what

Soap and water for at least 20 seconds. This is basic hygiene.

that 4/5 of the world’s population doesn’t practice. too bad for them I guess

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