Title: Bacterial contamination of cell phones of medical
students at King Abdulaziz University, Jeddah, Saudi Arabia
Author: Shadi Zakai Abdullah Mashat Abdulmalik
Abumohssin Ahmad Samarkandi Basim Almaghrabi Hesham
Barradah Asif Jiman-Fatani
Reference: JMAU 88
To appear in:
Received date: 3-8-2015
Revised date: 22-12-2015
Accepted date: 28-12-2015
Please cite this article as: Zakai S, Mashat A, Abumohssin A, Samarkandi A,
Almaghrabi B, Barradah H, Jiman-Fatani A, Bacterial contamination of cell phones
of medical students at King Abdulaziz University, Jeddah, Saudi Arabia, J. Microsc.
Ultrastruct. (2016), http://dx.doi.org/10.1016/j.jmau.2015.12.004
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Bacterial contamination of cell phones of medical
students at King Abdulaziz University, Jeddah, Saudi
Shadi Zakai1, Abdullah Mashat2, Abdulmalik Abumohssin2, Ahmad
Samarkandi2, Basim Almaghrabi2, Hesham Barradah2 and Asif Jiman-Fatani1,3
1Department of Medical Microbiology and Parasitology, Faculty of Medicine, King
2 Medical Students, Faculty of Medicine, King Abdulaziz University.
3 Clinical and Molecular Microbiology Laboratory, King Abdulaziz University
Telephone: 00966-12-6400000 Ex: 21080
Address: Department of Medical Microbiology and Parasitology
Faculty of Medicine
King Abdulaziz University
PO Box: 80205
Number of Figures: 2
Number of References: 23
Number of Authors: 7
Arabic title page: Cannot provide
Arabic abstract: Cannot provide
The authors disclose that this article has not been presented in any
Disclosure of benefit: The authors have no conflict of interests and
the work was not supported by any drug company.
The authors declare that this work has been approved by the Unit of
Biomedical Ethics at the Faculty of medicine, King Abdulaziz
Page 2 of 13
Bacterial contamination of cell phones of medical
students at King Abdulaziz University, Jeddah, Saudi
Cell phones are commonly used in healthcare setting for quick communication within
hospitals. Concerns have been increased about the use of these devices in hospitals, as
they can be used everywhere even in toilets. Therefore, they can be vehicles for
transmitting pathogens to patients. This study aimed to examine the presence of
pathogenic bacteria on the surfaces of cell phones that are used frequently by medical
students at pre-clinical years. This cross-sectional study identified both pathogenic
and non-pathogenic bacteria from cell phones of 105 medical students at King
Abdulaziz University, using standard microbiological methods. Out of 105 cell
phones screened, 101 (96.2%) were contaminated with bacteria. Normal floras
belonging to Coagulase-Negative Staphylococci (CoNS), were the most abundant
isolates (68%). Seventeen (16.2%) cell phones were found to harbor Staphylococcus
aureus. Gram positive bacilli were isolated from 20 (19%) samples. Viridans
streptococci and Pantoea species were also isolated but at lower levels. Our findings
indicate that cell phones can act as reservoirs of both pathogenic and non-pathogenic
organisms. Therefore, full guidelines about the restriction of the cell phone use in the
clinical environments, hand hygiene and frequent decontamination of mobile devices
are recommended to be applied at early stages in medical schools; to limit the risk of
cross-contamination and healthcare-associated infections caused by cell phones.
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Cell phones have become one of essential devices used for communication in daily
life. The various purposes of their use make them commonly used in almost
everywhere. Medical students and healthcare workers use these phones for quick
communication within hospital settings. Evidence showed that many medical
conditions have been controlled after the innovations of mobile communications (1,
2). These conditions include diabetes (3) and asthma (4), and an increased rates of
vaccinations by travelers reminded by short message service (SMS) (5). However,
one of the most common concerns regarding its heavy use is that they can act as a
vehicle for transmitting pathogenic bacteria and other microorganisms (6, 7).
Contamination can spread from outside surfaces to more than 80% of exposed hands
(8).Moreover, a previous study reported that more than 90% of mobile phones of the
healthcare workers are contaminated with microorganisms and over 14% of them
carry pathogenic bacteria that commonly cause nosocomial infections (9).
People rarely disinfect mobile phones and it is cumbersome to clean. As a result,
these devices have the potential for contamination with various bacterial agents (10).
Many researchers have studied cell phone contamination among health care workers
and in the community. However, little work has been reported in our region on
bacterial contamination on cell phones used by medical students. So the present study
aimed to investigate the presence of pathogenic bacteria on cell phones that are
frequently used almost all the time by medical students at pre-clinical years.
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Materials and methods
This cross-sectional study was performed during a period of two months from April to
June 2015, at the department of medical microbiology and parasitology, faculty of
medicine, King Abdulaziz University (KAU), Jeddah, Saudi Arabia. A total number
of 105 samples were collected from cell phones of 105 volunteers from medical
students at pre-clinical years at King Abdulaziz University, Jeddah, Saudi Arabia. The
examined samples were collected from mobile phones of second and third-year
medical students who were asked to complete a written questionnaire for data
collection. The questionnaire included variables such as the use of mobile phones in
toilets, the use of disinfectants to clean the surface of the cell phone, and the use of
mobile phone at work. Also, a written informed consent was signed by the students
prior to sample collection. The study was approved by the Unit of Biomedical Ethics
at the Faculty of medicine, KAU.
Samples were obtained from cell phones of all participants using sterile cotton swabs.
Prior to sample collection, swabs were moistened in sterile water and were rotated
over the front screen and the back of the cell phones. All swabs were immediately
inoculated into Amies transport media (Amies®, Copan, Italy) and processed within
one hour. Swabs were then inoculated onto fresh brain-heart infusion (BHI) broth and
incubated overnight at 37°C with aeration at 190 rpm. A subsequent culture was
carried out on blood and MacConkey agar plates, and incubated aerobically at 37°C
for 18 hours.
Bacterial identification and antibiotic susceptibility:
Single colonies grown on both blood and MacConkey agar plates were tested using
standard microbiological methods. Briefly, single colonies were tested using colonial
morphology, Gram stain, and catalase test. A slide coagulase test (Microgen Staph,
Page 5 of 13
Microgen Bioproducts Ltd, Camberley, UK) was used to differentiate Staphylococcus
aureus from other coagulase-negative staphylococci (CoNS).
Further antimicrobial susceptibility tests were carried out for Staphylococcus aureus
isolates to test their methicillin susceptibility, using 1 µg oxacillin and 30 µg cefoxitin
(Oxoid Limited, Hampshire, UK) placed on Muller-Hinton agar. The zones of
inhibitions were measured and interpreted according to the Clinical and Laboratory
Standards Institute (CLSI) (12).
Statistical data analysis was carried out using SPSS version 16.0 (SPSS Inc., Chicago,
IL, USA). Using one-way ANOVA test, the means of all bacterial isolates were
compared to determine the significant abundance of each organism. Grouping of
results was based on variables included in the questionnaire, and the type of
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Results and discussion:
In this study, 105 volunteers from medical students at pre-clinical years at the Faculty
of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia were involved. From
each volunteer, one sample was obtained from the surface of their cell phones
(n=105). Sixty two (59%) participants use cell phones in toilets, whereas the
remaining 43 (41%) participants do not use cell phones in toilets. The questionnaire
also revealed that all participants (100%) use their cell phones at work at least once a
day, and 71 (67.6%) cell phones had never been cleaned by their holders (Figure 1).
The percentage of bacterial contamination of the tested cell phones was 96.2%, in
which the most abundant bacterial isolates found were normal floras belonging to
Coagulase-Negative Staphylococci (CoNS), which counted more than 68% of the
total tested samples. Staphylococcus aureus was isolated from 17 (16.2%) samples.
Gram positive bacilli were isolated from 20 (19%) samples. Viridans streptococci and
Pantoea species were also isolated but at lower levels (Figure 2).
Although most cell phones tested were contaminated with one or more
microorganism, contamination with S. aureus was found in 17 cell phones. This
number represents a high percentage of contamination with this pathogenic organism
that is commonly found in toilets (11). Nevertheless, according to our statistical data
analysis, there was no statistical correlation between the use of cell phones in toilets
and the presence of S. aureus (p=0.085). Evidence from previous studies revealed that
about 20% of cell phones belong to doctors and nurses are contaminated with
pathogenic bacteria (13-15). Given the fact that medical students will be directly
exposed to healthcare setting, mobile devices belonging to this group may act as
transmission vehicles of infections to patients if these devices are not cautiously used.
The concern about cell phones contamination in medical settings is increased due to
the possibility of cross-contamination of these devices that act as an environmental
reservoir and sources of bacterial cross-contamination, particularly in the most
sensitive clinical areas such as operation theatres, intensive care units and burn units
(7, 16). A crucial part of patient safety is the reduction of the bio-transfer potential of
Page 7 of 13
these objects, especially to susceptible patients (17). Thus, it is suggested to involve
medical students at early stages to training programs in patient safety, to increase their
awareness about infection transmission, prevention and control in medical
environments before they are exposed to clinical work.
Two-third of the cell phones examined in our study have never been decontaminated.
This rate is slightly less than previously reported studies, which show that 80 – 92%
of staff, have never decontaminate their cell phones (9, 14, 18). One of the most
recommended methods of decontamination is cleaning the cell phone with 70%
alcohol, which showed a significant decrease in the amount of bacterial contaminants
(7, 13-15, 18-20).
Education of medical students can be a part of healthcare staff educational programs
in infection control, which may help in increasing awareness of transmission of
pathogenic organisms from colonized areas of healthy individuals to susceptible
patients. Continuous visual reminders such as leaflets and posters about cell phone
restrictions and hand hygiene can be included in good infection control practice
methods. Although hand hygiene is one of the basic infection control measures, many
authors strongly recommend further focus on this issue, providing more evidence
about its importance in this context (7, 9, 14, 19-23).
The ability of pathogens found in cell phones to survive on the surface, the survival
time and the risk of transmitting these pathogens to patients should be examined.
Therefore, more studies are required to guarantee that they are aligned with the
guidelines on infection control; in order to decrease the potential of transmitting
pathogenic organisms found in cell phones.
Page 8 of 13
Cell phones are commonly used in almost everywhere in the community and in
healthcare environments. Our findings indicate that these phones used by medical
students can act as transmission vehicles for both pathogenic and non-pathogenic
organisms. Therefore, it is suggested to offer training programs at early stages in
medical schools on guidelines about the restriction of the cell phone use in the clinical
environments, increasing awareness of hand hygiene and frequent decontamination of
mobile devices, in order to decrease the risk of cross-contamination caused by these
devices in clinical settings. Additionally, more studies are required to assess the
efficacy of the above strategies in decreasing bacterial contamination and limiting
infection transmission caused by the use of cell phones.
Page 9 of 13
Figure 1: Behavioral distribution of cell phone usage among medical students at
Figure 2: Percentages of bacterial isolates found in cell phones of medical
Page 10 of 13
The authors would like to thank Dr. Hani Shukri, Supervisor of the Clinical and
Molecular Microbiology Laboratory at King Abdulaziz University Hospital for his
kind assistance in samples processing and bacterial identification. Also, the authors
thank Dr. Mahmoud Abdulkhaleq from the Faculty of Pharmacology at KAU and Mr.
Hani Yousif from the Department of Medical Microbiology and Parasitology at KAU
for their valuable supports during the practical work.
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