Cleaning Soiled Hands: Will Alcohol based sanitizers rub soap away? A randomized blind trial on elementary school students
By SPANDAN SENGUPTA, Kolkata, India
ACKNOWLEDGMENTS: Mrs. Manjuli Mukherjee, Class teacher & Biology teacher at St James’ School; Ms. Amrita Nandy, Asst. Manager in Quality Assurance Dept., Apollo Gleneagles Hospitals, Kolkata; Ms. Shilpi Aurora Kundu, Regional Manager, Schülke India Ltd
Hand-washing is a vaccine. Effective hand-washing is one of the easiest ways to prevent diseases especially in children. We conducted a simple trial on primary school children to determine whether washing hands with water alone, or soap and water, or an alcohol-based sanitizer was effective in removal of germs that were contaminated at the end of classes and after visiting the restroom. We used a novel, easy to use technique using a "Glo Germ" kit to observe the presence or absence of germs in specific areas of both hands after each of the three methods of hand-washing. We found that hand-washing with water was virtually ineffective in removal of germs as 93% of them showed presence of germs. Soap and water was effective in removal of germs in 80% of children and the alcohol-based sanitizer was also effective in 80% of children. We also found that fingers and palm had maximum residual germ load after washing with water only, while nails and fingers were the most resistant areas for germ removal after both soap and water or the alcohol-sanitizer method. Our study further reiterates the benefits of washing hands with soap and that washing with water only is not very effective in removal of germs. Alcohol based sanitizers are also effective in removal of germs when used properly. This message needs to be spread amongst school authorities and children.
Hand-washing is like a vaccine and it involves very simple and effective steps and yet has the potential to reduce the spread of very common diarrheic and respiratory illness.1 In short, hand-washing helps you to stay healthy. Regular hand-washing, particularly before and after certain activities, is one of the best ways to remove germs, avoid getting sick, and prevent the spread of germs to others.2
The Center for Disease Control and Prevention recommends that hand-washing should be carried out at the following times:
1. Food preparation: before, during and after
2. Prior to eating food
3. Caring of the sick: before and after
4. Treatment of wounds: before and after
5. After using toilet
6. After handling the diapers or cleaning a child who has used the toilet
7. After coughing, sneezing or blowing nose
8. After touching or caring animals, animal waste or handling pets
9. After disposing garbage3
To be effective, hands need to be washed and cleaned the proper way. Yet again, The Center for Disease Control and Prevention provides the five easy steps of how best to do hand-washing.
1. Wet hands with clean running water and apply soap.
2. Lather hands by rubbing them together with the soap. Ensure that the backs of hands, in between fingers, and under side nails are taken care of.
3. Scrub hands for at least 20 seconds. It has been suggested that singing “Happy Birthday to you” twice is a good timer!
4. Rinse hands well under clean, running water.
5. Dry hands with the help of a clean towel or air-dry them.4
However, there remains confusion as to which is the best technique of hand-washing. There has been considerable debate in the scientific community on the effectiveness of soap and water versus the use of alcohol based hand sanitizers. Many believe that washing hands with soap and water is the best way to reduce the number of germs on them in most situations.5
However, if soap and water are not available, then the use of an alcohol-based hand sanitizer can quickly reduce the number of germs on hands in some situations. It should be noted that sanitizers do not eliminate all types of germs and certain harmful chemicals. Hand sanitizers are also not as effective when used on visibly dirty or greasy hands. Hand sanitizers should be applied to the palm of the hand and the hands should be rubbed together ensuring that the sanitizer is well spread over all surfaces of hands and fingers until the hands are dry. 6
The next round of challenge is in figuring out whether the hand-washing technique is actually serving its purpose or not. The most scientific method would be to do a microbiological assay of the hands after hand-washing. This is a tedious and a very expensive process. There is an easy and practical way to figure out the effectiveness of hand-washing by using Glo Germ Kit TM . The Glo Germ™ Kit contains a bottle of liquid or gel and a ultra-violet lamp. The liquid or gel and the powder contain the plastic simulated germs, and the lamp illuminates them to test the effectiveness of the hand-washing technique.7 Prior to hand-washing, Glo Germ™ Liquid is rubbed to the hands like a lotion. After the appropriate hand-washing technique the ultraviolet light is shone to the various areas of the hand to reveal the presence or absence of the germs.
The aim of the study was to determine the effectiveness of hand-washing technique with soap and water or using an alcohol based hand sanitizer over hand-washing with running water only. We also tried to determine whether hand-washing with soap and water was as effective as hand-washing with an alcohol based hand sanitizer. The other thing that we tried to find was the area of the hand that had the greatest germ burden.
Our study is based on some guidelines on an online resource website.8 In our study, there were 60 volunteers. All of them were students from the primary section of St James’ School, Kolkata. Permission was obtained from the school authorities prior to embarking on this project. The study was conducted after the end of the third class since morning and when all the students would go to use the restrooms prior to their meal break. Upon their return from the rest room, all the students were explained the five steps involved in hand-washing. They were asked to come in one by one according to their roll number and were subsequently allocated randomly to any of the three groups by a method of easy randomization using the sealed envelope technique.
(1) Hand washing with water only – Group W
(2) Hand washing with non-antibacterial soap – Group S
(3) Hand washing with alcohol based solution – Group A
As they come out of the restroom and before they wash their hands, a few drops o “Glo Germ” (registered trademark of Schülke India) were applied to each student's hands. They were then asked to rub both their hands as though they were applying lotion onto their hands. Children were then asked to wash their hands according to their group allocation.
Students in Group W washed their hands on running tap water, rubbed their hands and finally dried them on a clean disposable paper towel.
Group S students followed all the five steps of hand washing using soap and water, as had been explained earlier and also dried their hands with the disposable paper towel.
Students allocated to Group A washed their hands with water only, dried their hands on the paper towel and then applied the hand sanitizer in the way explained till the hands become dry. The hand sanitizer that we used was liquid, with an alcohol content of 75%.
After their hands were dry ultraviolet light was shone on the hands and directed to different areas of both hands. The researcher who shone the ultraviolet light and recorded the areas which showed white marks, revealing the presence of germs.
My classmate and my class teacher did not know which group the individual children were allocated to. This ensured that the observers were blinded to group allocation. While observing, we also took care that the ambient light in that area was low. When the ultraviolet light was shone, the areas where germs were visible as white marks were noted. (Figure 1, 2, 3)
The areas observed were – (Figure 4)
3. Back of hand
4. Between fingers
The results were recorded in a data table.
We analyzed the data by looking at the number of areas of both hands that glowed when the UV light was shone on the hands of children. We recorded the areas that actually showed presence of germs and the areas that did not show the presence of germs. We then found out the percentage of areas that either showed or did not show the presence of germs after washing hands using the three techniques that were studied. The median percentage and the average percentage of the presence or absence of germs were calculated for the three groups.
From the analysis it is evident that hand-washing with water only was ineffective in removal of germs. Most of the areas showed the presence of germs after washing hands with water only (Median – 93%, Average – 93%). Hand-washing with soap and water was far more effective in removal of germs than with just water alone (Median – 20%, Average – 24%). Hand-washing with an alcohol based sanitizer showed nearly similar results as hand-washing with soap and water, but better than hand-washing with water only (Median – 20%, Average – 22%). The results are shown in Table 1.
We also found that fingers and palm had maximum load of germs (100% each) when they were washed with water only, while nails (33%) and fingers (28%) had more germs showing when washed with soap and water. In case of alcohol-based sanitizer method of washing hands, nails (30%) and fingers (25%) showed presence of germs. These have been shown in Graph 1.
After hand-washing with soap and water least amount of germs were found at the back of the hand (18%) while in the alcohol sanitizer group least germs were found at the back of the hand and palm (both 18%). The results are shown in Graph 2.
It is evident from this study that washing hands with water only is completely ineffective in the removal of germs. Washing hands with soap and water is effective and washing hands with an alcohol-based sanitizer is as effective as soap and water in the removal of germs.
It has been seen that using soap to wash hands is more effective than using water alone. This is mainly because the surfactants in soap lift soil and microbes from skin. It has also been found that people tend to scrub hands more thoroughly when using soap. This also ensures further removal of germs.9
It has also been observed that alcohol-based hand sanitizers can inactivate many types of microbes very effectively when used correctly. However, people may not use an adequate volume of sanitizers and they may wipe them off before it has dried. Soap and water has been found to be more effective than hand sanitizers against certain kinds of germs.9
It has been shown that hand sanitizers may work well against certain types of germs especially on slightly soiled hands. When hands are heavily soiled or greasy, hand sanitizers may not work well. It is recommended to wash hands with soap and water in such circumstances. 9
The alcohol-based sanitizers to be effective should contain adequate amount of alcohol. Ideally it should contain a minimum of 60% alcohol - typically listed as ethyl alcohol.10
In our study we found that in some children there was evidence of germs in those who washed hands with soap and water or with alcohol as well. This could possibly mean that the techniques of hand washing were not implemented properly. More efforts in this regard will be needed to ensure greater compliance to the steps of hand-washing, that adequate time is spent, and that the volume of alcohol-based sanitizer used is appropriate.
We tried to find the presence or absence of germs by using Glo Germ lotion and then shining ultraviolet on the hands. This technique has been described to be reasonably reliable. However this technique does not actually tell us what the microbes were and their potential to cause diseases. The way to determine that would be conducting a microbiological assay of the hands.
It is now well understood that the key to reduce diseases caused by germs in the community is not by giving medicines but by undertaking measures to improve personal and general hygiene. Hand-washing has been described to be the most effective tool in reducing disease incidence in the self as well as in the spread of disease to others. Washing hands with soap and water is the most effective and recommended way to remove germs. In certain situations where soap and water is not available alcohol based sanitizers may be as effective in the removal of germs. We can possibly add value to what is already known by spreading the message amongst children using social media, carrying out projects and making a contribution in improving hygiene and health.
1. http://www.cdc.gov/handwashing/. (accessed Aug 15, 2016).
2. http://www.cdc.gov/handwashing/when-how- handwashing.html. (accessed September 1, 2016).
3. http://www.cdc.gov/handwashing/when-how- handwashing.html. (accessed September 1, 2016).
4. http://globalhandwashing.org/about-handwashing/promote- handwashing/. (accessed September 1, 2016).
5. https://en.wikipedia.org/wiki/Hand_sanitizer. (accessed August 16, 2016).
6. http://www.glogerm.com. (accessed September 1, 2016).
7. http://www.sciencebuddies.org/science-fair-projects/project_ideas/MicroBio_p018.shtml from=Blog#summary. (accessed August 19, 2016).
8. http://www.who.int/gpsc/5may/tools/who_guidelines- handhygiene_summary.pdf. (accessed August 15, 2016).
9. http://www.cdc.gov/handwashing/show-me- the-science- hand- sanitizer.html (accessed September 1, 2016)
10. http://www.berkeleywellness.com/self-care/over- counter- products/article/6-things- know-about- hand-sanitizers.(accessed September 1, 2016)
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