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 Table of Contents  
Year : 2018  |  Volume : 6  |  Issue : 1  |  Page : 19-22

Effectiveness of isopropyl alcohol and ultraviolet-based sanitiser on decontamination of mobile phones used by dental personnel

1 Department of Public Health Dentistry, Ragas Dental College, Chennai, Tamil Nadu, India
2 Department of Microbiology, Ragas Dental College, Chennai, Tamil Nadu, India
3 Department of Periodontics, Ragas Dental College, Chennai, Tamil Nadu, India

Date of Web Publication6-Aug-2018

Correspondence Address:
Dr. Srikanthan Sriram
Old No 8/3C, New No 25, Arunachalam Nagar, Sevilimedu, Kanchipuram, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jpsic.jpsic_4_18

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Introduction: Mobile phones have become an inevitable mode of communication. Dental office and the dental operators along with their mobile phones are exposed to numerous pathogens as a part of their profession, leading to nosocomial infection. This study aimed at assessing the effectiveness of isopropyl alcohol and a customised ultraviolet-based (UV) sanitiser in decontamination of mobile phones.
Methods: A cross-sectional study was carried out on 30 touch screen mobile phones belonging to dental professionals in a college setting. Swabs were collected along the screen, camera lens and on/off buttons of mobile phones. Swabs were streaked onto nutrient agar and incubated at 37°C for 24 h for the assessment of microbial load before and after the disinfection procedures. The disinfection process was performed using 70% isopropyl alcohol and an UV-based sanitiser. Mann—Whitney U-test was used to compare the values between the two groups. Wilcoxon signed-ranks test was used to compare values within each group
Results: There was a statistically significant reduction in the mean number of colonies (P = 0.001) after decontamination by the two groups (isopropyl alcohol and UV-based sanitiser) indicating that both agents were effective in disinfection.
Conclusion: The study concluded that the percentage reduction in microbial load of the mobile phones was better with isopropyl alcohol compared to UV-based sanitiser. It is recommended that mobile phones in the dental setup be regularly decontaminated and dentists must adhere to strict infection control protocols specifically in relation to hand hygiene.

Keywords: Decontamination, isopropyl alcohol, mobile phones, ultraviolet-based sanitiser

How to cite this article:
Sriram S, Madan Kumar PD, Swaminathan R, Venkatesh R, Menaka V. Effectiveness of isopropyl alcohol and ultraviolet-based sanitiser on decontamination of mobile phones used by dental personnel. J Patient Saf Infect Control 2018;6:19-22

How to cite this URL:
Sriram S, Madan Kumar PD, Swaminathan R, Venkatesh R, Menaka V. Effectiveness of isopropyl alcohol and ultraviolet-based sanitiser on decontamination of mobile phones used by dental personnel. J Patient Saf Infect Control [serial online] 2018 [cited 2023 Mar 30];6:19-22. Available from: https://www.jpsiconline.com/text.asp?2018/6/1/19/238600

  Introduction Top

Communication technology is a fast-growing arena, and among them, mobile phones occupy an important position. Mobile phones now are becoming a baby in everyone's hands and thus have established themselves as one of the indispensable accessories of our professional and personal life inevitably. However, in spite of having all the advantages, mobile phones have certain drawbacks, when healthcare setups are considered.[1]

According to the report by Cellular Operators Association of India, the total number of mobile phone users as of April 2017 is 934.58 million.[2] If dentistry is concerned in particular, India now has >70,000 registered dentists, and it has been assumed that almost every dentist has a private cellular telephone (mobile phone), which highlights its importance in the medical/dental field.[3]

Mobile phones have become indispensable in hospitals and can be put in silent mode in Intensive Care Units, post-operative wards, operation theatres and even in dental clinics. However, the key fact is that these phones are seldom cleaned by healthcare professionals and are frequently being contacted during or after patient examination and handling of specimens without proper aseptic measures such as proper handwashing, wearing personal protective equipment and sterilisation of dental instruments. Being small and compact, these mobile phones take up the role of reservoirs of infection, leading to the occurrence of various nosocomial infections. Certain studies have shown that mobile phones were dirtier and contained more microbes than a toilet seat or the bottom of a shoe.[4]

Dental clinics deal with bacterial aerosols generated by high-speed dental handpieces which settle over a long distance. Particularly, aerosols and spatter produced during dental procedures are a potential source for various diseases.[5] Since mobile phones have established themselves as an unavoidable means of communication, dentists make or receive phone calls in clinical setup which has become a routine practice nowadays. It leads to the dental professionals being at a greater risk for acquiring and spreading infections.[6]

If disinfection of mobile phones is taken into consideration, there are a few common methods. Antibacterial wipes which are simple and time-saving have the disadvantage that they could corrode the protective coating on the glass screen. Rubbing the phone with a lint-free cloth dipped in 70% isopropyl alcohol is one of the most commonly used methods and certain studies have proved that this method is very much effective.[7] A newer and innovative method of disinfection of mobile phones is by use of ultraviolet (UV) radiation. However, there is a dearth in the literature regarding the effectiveness of disinfection of mobile phones by UV radiation.[8]

Hence, the aim of this study was to compare the effectiveness of 70% isopropyl alcohol and UV-based mobile sanitiser on decontamination of mobile phones used by dental personnel. The objective of this study was to assess the microbial load on the mobile phones used by dental personnel and their disinfection by aforementioned two methods.

  Methods Top

This cross-sectional study was conducted for a period of 3 months at a Dental College and Hospital in Chennai, India. Dental personnel who were involved actively in patient care and who voluntarily consented were included in the study. Before commencing the study, ethical clearance was obtained from the Institutional Review Board, and informed consent was obtained from all the participants. Mobile phones of students (undergraduate and post-graduate) and faculties which satisfied the inclusion criteria and exclusion criteria were selected. Touch screen mobile phones of dental personnel and mobile phones of those dental personnel who voluntarily gave their consent for the study were included in the study. Mobile phones which were <3 months old and those keypad mobile phones without camera facility were excluded from the study.

Two different sanitising methods were used — (i) Disinfection using 70% isopropyl alcohol and (ii) Disinfection using a UV-based sanitiser. Commercially, available isopropyl alcohol was obtained, and it was diluted with water to make it up to 70%. Laminar airflow chamber equipped with UV lamps (TUV/15W/G15 T8) was used. A total of 30 mobile phones were surveyed. The participants were asked about the disinfection practices they follow, how frequently they cleaned their phones, the cleaning agent used, the time interval from the last cleaning of their mobile phones and washing hands before and after using their phones. A sterile cotton swab was moistened with sterile normal saline, and it was rolled over three areas of the mobile phone (screen, on/off button and camera lens) that has been used at least for 3 months. A new pair of gloves was used when sampling each mobile phone to avoid cross-contamination.

One group of 15 phones were cleaned with 70% isopropyl alcohol wipes and allowed to dry for 10 min. Then, repeat swabs were taken. The other group of 15 phones was kept in the laminar airflow chamber equipped with UV light for 15 min. Then, repeat swabs were taken. The samples were transported within 30 min to the nearby microbiological laboratory for culture and assessment of microbial load.

Swabs were streaked onto nutrient agar for the assessment of microbial load and incubated at 37°C for 24 h. Culture results were measured as mean number of colonies. The difference in microbial load between pre- and post-treatment and also between the two disinfection procedures were assessed. The difference in microbial load by the two disinfection procedures was also assessed in terms of percentage.

The data collected was compiled using MS-Office Excel and was subjected to Statistical analysis using IBM Corp. SPSS Statistics for Windows, version 20.0 (Armonk, NY, USA) Statistical significance was set at P < 0.05. Descriptive and inferential statistics were used to analyse the data. Mann—Whitney U-test was used to analyse values before and after intervention between groups. Wilcoxon signed-ranks test was used to compare the values within the group.

  Results Top

A total of 30 mobile phones were divided into two intervention groups (isopropyl alcohol and UV-based sanitiser). Of the three surfaces from which swabs were taken, there was maximum microbial contamination in the screen in both the groups (mean number of colonies — 16.13 and 16.40).

There was a statistically significant reduction in the mean number of colonies (P = 0.001) after decontamination within the two groups (isopropyl alcohol and VU-based sanitiser) indicating that both agents were effective in disinfection. However, there was no statistically significant reduction in the mean number of colonies between the two intervention groups (P = 0.884, 0.183) [Table 1]. The reduction in microbial load in the mobile phones post-intervention in terms of percentage was 79.89% in the isopropyl alcohol group and 71% in the UV-based sanitiser group.
Table 1: Distribution of mean number of colonies in pre- and post-evaluation interventions

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  Discussion Top

There is a massive rise in incidence of a lot of diseases such as AIDS, tuberculosis and hepatitis. This has made it mandatory that healthcare professionals are bound to follow infection control protocols and guidelines. The possibility of transmission of infections by various electronic devices has been previously reported.[9] Very few studies have reported transmission of infection among healthcare workers. There is a dearth in literature regarding the transmission of various infections among dental professionals. Studies have shown that healthcare workers' mobile phones were contaminated with nosocomial pathogens.[10],[11] The comparison of various disinfecting agents in reducing the microbial load in mobile phones of dental healthcare workers has not been assessed.

All the mobile phones surveyed in our study were contaminated with microorganisms. The participants were lacked knowledge of cleaning mobile phones and basic infection control measures. It was evident from our study that decontamination of mobile phones by 70% isopropyl alcohol for 10 min and UV-based sanitiser for 15 min, significantly reduced the total number of colonies.[10],[12] The percentage decrease in microbial load of the mobile phones was found to be better with isopropyl alcohol when compared to UV-based sanitiser. The effectiveness of alcohol and UV radiation in cleaning mobile phones has been previously reported.[8] This study did not report any chaotic events that occurred during the decontamination procedures. Moreover, most of the electronic devices including the mobile phones carry ingress protection rating which certifies them as resistant to dust and water which is also applicable for various decontamination procedures.[13] However, there are no proper guidelines available on the decontamination procedures, and the fact that use of cleaning aids on mobile phones has been forbidden by some of the manufacturers.

It is obvious from the results of this study that there is an absolute lack of knowledge among dental healthcare professional regarding the basic infection control guidelines and protocols. Thus, training the dental healthcare professionals regarding infection control procedures and disinfection methods is of paramount importance. Routine decontamination of mobile phones and other electronic equipment with isopropyl alcohol reduces the risk of cross-contamination. A widely used, easier method for disinfecting mobile phones is by 70% isopropyl alcohol which acts by causing membrane damage and rapid denaturation of the proteins, interfering with the metabolism of the microorganism causing cell lysis.[14] An innovative method in disinfection of mobile phones is the UV-based sanitiser. It uses the mechanism of UV radiation which destroys the nucleic acids and breaks apart the germ DNA. UV light reacts with bacterial DNA to cause the formation of pyrimidine dimers, thus inactivating the bacteria. Once the DNA of the microorganisms are broken, they are unable to replicate/reproduce and eventually they die.[15] Reduction in microbial colonisation on the mobile phones used by the dental healthcare professionals can be insisted through proper staff education regarding the use of gloves during a procedure, handwashing and the use of disinfecting agents on mobile phones.

Dental gloves lead to protection of the dental professional from being infected by patients. The use of mobile phones by the dental health professionals with gloved hands, which has become common nowadays, leads to increased tendency of developing nosocomial infections. Use of gloves along with proper handwashing is a must for the dental health professionals to stay free of infection.[16] Thus, the reinforcement on awareness on the infection control guidelines among dental healthcare professionals is a must if they are to stay free of infection.

Dental health professionals need to set standards for their patients by adopting and adhering to stringent infection control protocols. Dental students in particular, are at a greater risk of exposure to various harmful pathogens while they are involved in direct patient care during their training. Thus, the dental institutions need to take up the responsibility of laying the foundation for healthier and safer patient practice in oral healthcare by adopting rigorous training for the students in the area of infection control. There is an obvious need for studies regarding the assessment of infection control training among dental students. The education and the knowledge that the students gain in their dental curriculum is really important, and it should help them adhere to adequate strategies in infection control. Importance of infection control practices should be stressed among students even before they are involved in direct patient care. This aspect will them develop dental health behaviour which in turn will have a positive impact on the patients. The establishment of a new clinical protocol regarding infection control will be effective in disseminating the current information and practices to follow dental health personnel.[7]

  Conclusion Top

On the whole, systematic decontamination of mobile phones is effective in reducing the microbial load. Guidelines and regulations regarding mobile phones in healthcare setups such as hospitals need to be reassessed. Studies regarding the adherence of healthcare professionals to stringent infection control protocols are needed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Jayalakshmi J, Appalaraju B, Usha S. Cellphones as reservoirs of nosocomial pathogens. J Assoc Physicians India 2008;56:388-9.  Back to cited text no. 1
Telecomtalk.info. Indian Mobile Subscriber Base Reaches 934.58 Million at the End of April 2017: COAI. Vol. 102. 2017. p. 1. Available from: https://www.telecomtalk.info/indian-mobile-subscriber-base-reaches-934-58-million-april2017-coai/163906/. [Last accessed on 2017 Aug 12].  Back to cited text no. 2
Walia SS, Manchanda A, Narang RS, Anup N, Singh B, Kahlon SS, et al. Cellular telephone as reservoir of bacterial contamination: Myth or fact. J Clin Diagn Res 2014;8:50-3.  Back to cited text no. 3
Abbas I, Parthasarathi Reddy P, Anjum S, Monica M, Rao Y. Cell phones: A mechanical vector for bacterial pathogens. Indian J Dent Sci 2013;5:24-7.  Back to cited text no. 4
Harrel SK, Molinari J. Aerosols and splatter in dentistry: A brief review of the literature and infection control implications. J Am Dent Assoc 2004;135:429-37.  Back to cited text no. 5
Prasad P, Bhat M, Fouad Al-Bayati SA. Is cellular phone a source of infection? — A hospital based study among dentists in Ajman and Sharjah, UAE. J Dent Sci 2013;1:1-6.  Back to cited text no. 6
Singh S, Acharya S, Bhat M, Rao SK, Pentapati KC. Mobile phone hygiene: Potential risks posed by use in the clinics of an Indian dental school. J Dent Educ 2010;74:1153-8.  Back to cited text no. 7
Nowakowicz-Dębek B, Wlazło L, Krukowski H, Pawlak H, Trawińska B. Reduction of microbial contamination of mobile phones using ultraviolet UV radiation and ozone. Afr J Microbiol Res 2013;7:5541-5.  Back to cited text no. 8
Ulger F, Esen S, Dilek A, Yanik K, Gunaydin M, Leblebicioglu H, et al. Are we aware how contaminated our mobile phones with nosocomial pathogens? Ann Clin Microbiol Antimicrob 2009;8:7.  Back to cited text no. 9
Borer A, Gilad J, Smolyakov R, Eskira S, Peled N, Porat N, et al. Cell phones and acinetobacter transmission. Emerg Infect Dis 2005;11:1160-1.  Back to cited text no. 10
Brady RR, Wasson A, Stirling I, McAllister C, Damani NN. Is your phone bugged? The incidence of bacteria known to cause nosocomial infection on healthcare workers' mobile phones. J Hosp Infect 2006;62:123-5.  Back to cited text no. 11
Brady RR, Verran J, Damani NN, Gibb AP. Review of mobile communication devices as potential reservoirs of nosocomial pathogens. J Hosp Infect 2009;71:295-300.  Back to cited text no. 12
Corrosion Pedia. Ingress Protection (IP). Vol. 102. 2018. p. 1. Available from http://www.corrosionpedia.com/definition/2838/ingress-protection-ip. [Last accessed on 2017 Aug 18].  Back to cited text no. 13
McDonnell G, Russell AD. Antiseptics and disinfectants: Activity, action, and resistance. Clin Microbiol Rev 1999;12:147-79.  Back to cited text no. 14
Vatansever F, Ferraresi C, de Sousa MV, Yin R, Rineh A, Sharma SK, et al. Can biowarfare agents be defeated with light? Virulence 2013;4:796-825.  Back to cited text no. 15
Larson EL. APIC guideline for handwashing and hand antisepsis in health care settings. Am J Infect Control 1995;23:251-69.  Back to cited text no. 16


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