Searching For The Right Hand-Scrubbing Message Researchers tried various slogans to encourage travelers to lather up after using rest stop toilets, from the disgusting — "Soap it off or eat it later" — to the educational — "Water doesn't kill germs, soap does." Hygiene expert Val Curtis reports on the most effective messages.
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Searching For The Right Hand-Scrubbing Message

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Searching For The Right Hand-Scrubbing Message

Searching For The Right Hand-Scrubbing Message

Searching For The Right Hand-Scrubbing Message

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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Researchers tried various slogans to encourage travelers to lather up after using rest stop toilets, from the disgusting — "Soap it off or eat it later" — to the educational — "Water doesn't kill germs, soap does." Hygiene expert Val Curtis reports on the most effective messages.

JOE PALCA, host:

If you walk into a public restroom and don't find soap, what do you do? Do you quick rinse with water and push the door open using a paper towel on the handle? Or do you just take a free pass and head straight for the door rather than touch that dirty faucet? Come on, let - be honest. This is an important question. A recent study in England showed that only two-thirds of women washed their hands after using the toilet. And it's even worst for men. Only one-third of guys wash up after a trip to the loo.

Is there any way to get more people to lather up? Well, there's a project some scientists in the UK are working on using different messages to sway potential hand-washers into actually pumping some soap into their hands and washing. But it's not so simple to get people to change their ways and men and women respond very differently to these messages. So, how do you figure out what's best?

Well, my next guest is here to talk about that. Val Curtis is director of the Hygiene Centre at the London School of Hygiene & Tropical Medicine, part of the University of London, and she joins us by phone from London.

Thanks for joining us on SCIENCE FRIDAY, Dr. Curtis.

Dr. VAL CURTIS, (Director, Hygiene Centre, London School of Hygiene & Tropical Medicine): Good afternoon, good evening.

(Soundbite of laughter)

PALCA: Good afternoon and evening, yes. We have that time zone thing. And I gather this research you were doing appeared in the journal - American Journal of Public Health.

Dr. CURTIS: Indeed, indeed. (Unintelligible) time, yeah.

PALCA: Okay. So, we've set the stage. Okay. So, before we actually go onto how do you get people to wash their hands, I think it'd be interesting just briefly you say why you should wash your hands.

Dr. CURTIS: Well, most of the work that we've been doing has been, in fact, in developing countries. And in developing countries, something in the order of two million children a year die of diarrheal diseases. In fact - I mean, it's quite shocking. That's probably more people than die of malaria or HIV or measles or put together, and it's something of a forgotten disease.

But, in fact, hand washing with soap is probably the most cost effective intervention for preventing death from diarrheal diseases, also from respiratory infections. And also, as you know, hand washing is probably one of the most effective ways of preventing the flu that are going around now, the pandemic flu like the AH1N1 and swine flu.

PALCA: Dr. Curtis, I'm going to have to stop you there, right? We'll talk lots more about this when we come back after a short break.

(Soundbite of music)

This is Science Friday from NPR News.

From NPR News, this is Science Friday. I'm Joe Palca.

We're talking this hour about hand washing and how to get people to do it, with my guest, Val Curtis. She is the director of the Hygiene Centre at the London School of Hygiene & Tropical Medicine, part of the University of London.

And just before the break, we might not heard, but you were saying that H1N1 can be transmitted from hand-to-hand contacts. So if you sneeze on your hand and you don't wash and you shake somebody else's hand, they can get it if they touch their face or their mouth or something like that. So that's one point.

But I just want to make one thing clear, because it's always sort of bothered me. I understand you were saying that washing after using the toilet is important for controlling diarrheal diseases. But I may have been the only one that was so dumb that didn't realize this. But the idea is that there's bad bacteria in your feces that you cannot - if you get them on your hands, you can just keep re-infecting yourself and that's how this bacteria - these diarrheal diseases keep propagating. And do I have that right?

Dr. CURTIS: Not quite right. And obviously, diarrheal diseases are caused by bugs that are most lying in your stomach. And they want - they - it would be an evolutionarily dead end if they just lived in you, so they want to get to another person. So they are very good at getting out.

So they - so whenever you go to the toilet, it's almost impossible not to get some fickle material on your hand. And then, you contaminate other surfaces, you contaminate other people when you shake - whether you shake their hands, for example, or when you prepare food, for example. So it's a superhighway, basically. Hands are a superhighway for the bacteria and viruses that cause diarrheal disease to pass from person to person.

PALCA: So, okay. So I was wrong. It's not so much re-infecting yourself, it's for getting…


PALCA: …other people involved.

Dr. CURTIS: No, no. So it's getting other - it's infecting other people, absolutely. If you're a mom, for example, preparing food for your child and you don't wash your hand after going to the loo, then you're going to pass on the infection.

PALCA: Right. So, this is a little hard, I think, for people to believe, because we just talked about a sort of an icky subject which is getting, you know, fecal material on your hands and then preparing food. I mean, why would anybody do that?

(Soundbite of laughter)

Dr. CURTIS: Well, it's not very well known, but feces contain, perhaps - for every gram of feces, there's more bugs in there than there are people on the planet - in the order of billions of bacteria. So it only takes a very, very tiny amount to get smeared on your hands - I mean, for example, toilet paper is pretty transparent to bacteria. They get through it very easily. Just slightly dampen it and you've got a smear of bacteria on your hand.

And it's - that seems to be the main root by which the diarrheal diseases get passed. Our analysis suggests that you could cut half of all the diarrheas, of all the tummy bug infections that we get both in developed countries and in developing countries - if you could have washed their hands with soap regularly, particularly after you enter a toilet.

PALCA: Right. Okay. So, what were some of the techniques that you found were effective? And, I mean, these are people that have access to clean water and soap. So you have, at least, that going for you.

Dr. CURTIS: Yeah.

PALCA: I suppose there are some places in the world where that's not so available. How do you get people in a developed country with lots of detergents around to wash their hands?

Dr. CURTIS: Yeah. I mean, it's - you would think it would be as simple as just telling people, hey, guys, you're going to make yourself another people sick if you don't wash your hands with soap. But it's not as simple as that. I mean, you think about it. The people who understand most about germs are people like doctors, and they're quite famous for not being very good at washing their hands with soap.

So what you have to do is find some other ways to nudge people into hand washing. It's a deeply habitual habit, something that you probably learned in childhood and you've always done the same thing - either/or with washing with soap or not washing with soap or with other - as most people unfortunately don't - don't do it.

So, you got to use something a little bit more powerful to shock people and get them into changing their hands with soap - washing their hands with soap - to change their behavior. So, it takes a lot of effort.

Well, we had a lot of hypotheses about the sort of things that might work. We thought that - disgust, for example. You just mentioned talking about how yucky it is to have pooh on your hands, might work quite well. We thought that people are a bit ashamed if they feel that other people see that they're not washing hands with soap, and then might wash their hands. So those are some of the ideas that we tried to see if we could change people's hand washing.

So, we flashed up different messages, based on some of those ideas, on electronic display boards on the outside of the entrance to some public toilets on a - in a motorway service station in London. And we had over 200,000 people go through.

And we were able to count how many people were going through and count how many people were actually using the soap dispensers, and then calculate which messages were working best to get people to change their hand-washing behavior.


Ms. CURTIS: Well, in fact, the one that came out strongest for both the male and - for the ladies and the gents, was - is the person next to you washing hands with soap? I mean, if you think about it, obviously somebody who've seen that message goes into the toilet, knows that other people have seen that message, knows that other people will be looking to see if you're washing your hands…

That increased hand washing with soap by about 12 percent in the population as a whole. But after that, we found that women and men were actually reacting quite differently, so message is based on, for example, disgust. For example, don't take the loo with you, or soap it off or eat it later, worked quite well for men. They didn't work quite as well for women.

Women tended to react better and wash their hands more when they were reminded. So for example, water doesn't kill germs, soap does, was one message - was a message that worked better for women, for example. And also trying to scramble up the reminder so that we used a message that looked a bit like wash your hands with soap, but the letters are all mixed up, and that really worked quite well for women but not for men. So still slightly puzzling findings for us.

PALCA: Yeah. Yeah. Well, it's - yeah. Well, if you have questions about hand washing and maybe your experiences about what convinced you to wash your hands or why you don't, give us a call. Our number is 800-989-8255. That's 800-989-TALK.

And let's take a call now. Let's go to - let's see. That would be Carl in Oakland, California. Carl, have I got you there?

CARL (Caller): Yeah, right here. Just a comment on - and that's the biggest thing that would help me would be if bathrooms were better maintained. And I've got a really good example. I was in a bathroom at a school recently, and there was a poster up encouraging us to wash our hands, but the faucet for the wash basin was busted. I mean, there's a mixed message there…

PALCA: Yeah, yeah. Carl, interesting point. Is it access to facilities or is it people not using facilities they have access to?

Ms. CURTIS: Well, it's both, obviously. It's very hard to wash your hands if the faucet isn't working. There's not much you can do about that. But also if toilets are poorly maintained, people often feel, oh, this is so dirty and contaminated already that I don't want to risk getting dirty anymore. So people tend to rush out of the toilet without washing their hands. So if the toilet smells bad, for example, it discourages hand washing.

And also, often paper towels have been taken out of public toilets in favor of those air blowers because obviously it's much more convenient for the manager of the facilities to not have to provide the towels and not have to clean up the messy old towels afterwards. But it does seem to discourage hand washing as well because people don't like the air blow so much and doesn't find it so effective.

PALCA: Yeah. And the towels are better, do you think?

Ms. CURTIS: Well, the paper towels are good in the sense that they - if you had any residual bacteria left on your hands and your hands are still wet, when you then dry your hands off with the towels, it helps to just strip off some more of the bacteria that are left on your hands.

PALCA: Okay.

Ms. CURTIS: But I think the reason - I mean, the reason they're good really is people like to use them. And the - I mean, the most important message is it's not how you wash your hands and how you dry your hands afterwards, it's just that you do it. You do it and you do it with soap, and people are great at finding excuses why they're not going to wash their hands with soap. But really, we just have to do it, not find any excuses.

PALCA: Okay. Let's take another call now from Don in Kinston, North Carolina. Welcome to SCIENCE FRIDAY. You're on the air.

DON (Caller): Hi. I've been wanting to tell somebody about this for a long time. I was in a restaurant in Jacksonville, North Carolina. The two side-by-side restrooms were there, and when people came out, they couldn't wash their hands on the inside but the sink was out there in the dining room proper, so everybody knew who washed their hands and who didn't.

PALCA: That's a great example of social peer pressure, I would think.

Ms. CURTIS: That is an excellent - if people - if that was adopted globally, you would probably find that rates of hand washing with soap would go up dramatically.

In fact, in Ghana we tried the same thing in public toilets. We put hand wash stands outside public toilets with a big message about hand washing. And we found that that was quite an effective way because all the people queuing up to use the toilet were watching who was coming out and washing hands and who wasn't.

PALCA: Yeah. Yeah. Don, that's a great story. Thanks for sharing that.

DON: Yeah. Almost everybody washed their hands.

(Soundbite of laughter)

Ms. CURTIS: Yeah. I bet they did.

PALCA: Thanks. You were talking about just do it. But there's a question I - I mean, how important is soap in this equation because I always figured, you know, sometimes you bang the soap dispenser and nothing comes out, but you're still better off to get some of that water stream and maybe a paper towel to strip off the bacteria.

Ms. CURTIS: Yeah. Yeah. Well, we recently sent out a lot of our students into London to go and touch buses and touch museum surfaces. And then we randomized them into groups as to who could wash - who would wash with soap, who would just wash with water and who wouldn't wash at all. And 40 percent of people who didn't wash at all had bugs. It went down to about 23 percent if you wash with water, but it went down to eight percent if you wash with soap. So hand washing - so that soap really makes a massive difference.

It basically - the germs adhere to the dirt on your hands and the soap chemically attaches to the dirt, and then water attaches to other end of the soap molecules and pulls the soap molecule off your hands and it pulls the dirt with the bacteria attached to it off your hands. So soap is, so is by far the most important part of the equation. Washing without - you really have to rub your hands very, very hard, scrub them away and use very hot water if you're going to get the same amount of bacteria off your hands as if you were just using soap. By far the easiest thing to do.

PALCA: And what about anti-bacterial wipes?

Ms. CURTIS: They're equally effective at killing bacteria on your hands. There are circumstances in which antibacterial wipes/gels are much more convenient to use. And then, you know, if you're on the go, for example, and you have a gel in your bag, and you feel you've got contaminated, then using a gel is just as effective as hand washing. But I mean, most - for most of us, hand washing with soap is much the easiest thing to do. And particularly in developing countries, asking people to use antibacterial gels is a little bit out of reach for most people.

PALCA: Yup. Let's take another call now, and go this time to Marlina(ph) in Wenatchee - did I say that right - Washington? You're on the air.

MARLINA (Caller): Yes. Thank you. I'm so glad you're bringing this topic on SCIENCE FRIDAY. I have so often been really frustrated and concerned by people not washing their hands. And being a mom with small children, there were lots of times when you would be with other moms with their small children in social situations. And the only way I could find to tactfully produce hand washing would be to ask the children, you know: Oh, did you wash your hands? When they came back from the rest room, for instance. And oh, they'd take their head, no. Oh, well, let me go take you.

And at other times, sometimes just directly asking the moms: Oh, did you guys wash your hands, and it's, oh, it's just - I'm looking for a positive way to socially interact instead of just, you know, when you point blank ask someone it has this sort of shame producing…

PALCA: Maybe you should make up some…

(Soundbite of laughter)

PALCA: Maybe you should make up some placards, Marlina. But lets…

(Soundbite of laughter)

MARLINA: So I thought I'd ask your guest if she had any…

PALCA: Good question.

MARLINA: …socially influencing ways, you know, when you're in those social situations…

PALCA: Okay.

MARLINA: …where you could say something…

PALCA: All right. Right.

MARLINA: …and have a more positive interaction.

PALCA: Marlina, let us hear the answer. Thanks very much.

Dr. CURTIS: Yes. Well, it would be great if we had the magic tool that would get everybody washing their hands. We wouldn't be having to do this experiment if we knew already what it was that was going to work best. But I think the experiment that we did gives you some clue. And I think it's quite important to give the impression that everybody is washing their hands. So rather than saying, oh, isn't it terrible how few people wash their hands, you want to say, oh - you want to bring up in a conversation how fantastic you've noticed that people really, perhaps, since swine flu has come along, everybody seems to be washing their hands.

So you're giving the impression that that's what is the norm. And then people who don't do the norm start to feel embarrassed and feel that they should do what everyone else is doing. So that might work.

We've often found that kids are fantastic ambassadors for hand washing to take home. So if you do take those kids to the toilet and then you say to them, well, you could, you know, you could tell your mommy about hand washing as well. And the messages then can find their way home as well. And then eventually, moms can - I mean, one of the things that we tried in a school in Uganda, it seemed to work rather well, was a message was taken home by the mums. And their mums will asked would say please help teach children to wash their hands with soap. So you could give a little card out to your mum saying, we're trying to teach our kids to wash hands with soap. Would you teach your kids to wash hands with soap at home?

PALCA: Dr. Curtis, can you…

Dr. CURTIS: And that's quite clever because what happens is the mother teach the kids, but at the same time the mums then start to learn that that's what they should be doing as well, so in fact the whole family turns into a hand-washing family. So you could try that maybe.

PALCA: I'm Joe Palca. And this is SCIENCE FRIDAY from NPR News.

You know, there's a question that - there was a study that came out earlier this week about the so-called - what they called them super-spreaders, people in hospitals who actually were hospital workers who seem to be transmitting disease from patient to patient inside of hospitals. It's just unbelievable that this would happen in a health care setting.

Dr. CURTIS: I don't know about unbelievable. I mean, we all carry bugs with us all the time. Some of us carry pathogenic bugs. Many of us carry the bugs that can cause disease, but actually aren't sick. And so it's not any different for the health care workers. They may very well be carrying those bugs. And they may have picked them up because they work in the hospitals or maybe they just picked them up from the community. So it's possible both in hospitals and in the community that there are just a small proportion of people amongst us who are spreading the bugs to everyone else.

PALCA: Okay. Val, I'm sorry, we have to stop you there. We run out of time. Thanks for joining us today.

Dr. CURTIS: My pleasure.

PALCA: Val Curtis is director of the Hygiene Center at the London School of Hygiene and Tropical Medicine, part of the University of London.

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