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OJHAS Vol. 10, Issue 2:
(Apr-Jun 2011) |
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| Potential of Mobile Phones to Serve as a Reservoir in Spread of Nosocomial
Pathogens |
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Sham S. Bhat, Sundeep Hegde K, Shailaja Salian,
Department
of Pedodontics and Preventive Dentistry, Yenepoya Dental College, Yenepoya
University, Mangalore, Karnataka, India |
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Address for Correspondence |
Department of Pedodontics
and Preventive Dentistry,
Yenepoya Dental College,
Yenepoya University,
Mangalore- 575018,
Karnataka, India.
E-mail:
viceprincipalydc@yenepoya.edu |
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Bhat SS, Hegde SK, Salian S.
Potential of Mobile Phones to Serve as a Reservoir in Spread of Nosocomial
Pathogens. Online J Health Allied Scs.
2011;10(2):14 |
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Submitted: June 20,
2011; Accepted: Jul 16, 2011; Published: Jul 30, 2011 |
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| Abstract: |
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Objective:
The use of cellular telephones by medical personnel and the associated
nosocomial transmission of pathogens have not been thoroughly examined.
The objective of this study was to determine the incidence of bacterial
colonisation on mobile phones of Healthcare workers (HCWs) and its accompanying
resistance to commonly used antimicrobials in a medical and dental hospital
in India. Method:
A total of 204 mobile phones of HCWs from medical and dental departments
were screened. A sterile swab moistened with sterile saline was rotated
over the external surface of the phone. Swabs were cultured on 5% sheep
blood agar and MacConkey agar plates. Plates were incubated aerobically
at 37°C for 24 hours. All isolates were tested for antimicrobial susceptibility.
A questionnaire was used for data collection on mobile phone use in
hospital. Result:
99% of the phones demonstrated evidence of bacterial contamination.
64.8% of medical samples showed growth of pathogenic micro-organisms
and 37.9% showed growth of Multi drug resistant bacteria. 59.37% of
dental samples showed growth of pathogenic micro-organisms and 43.75%
showed growth of Multi drug resistant bacteria. Pathogens isolated included Methicillin-resistant
Staphylococcus aureus, Methicillin-sensitive Staphylococcus aureus,
Escherichia coli, Klebsiella pneumoniae, Acinetobacter,
Enterococcus faecalis, and Pseudomonas aeruginosa. According to
the questionnaire 40% admitted to using their phones between examination
of patients. Only 6% used disinfectants to wipe their phones. Conclusion:
This study reveals that mobile phones are commonly used by HCWs, even
during patient contact and may serve as a potential vehicle for the
spread of nosocomial pathogens.
Key Words:
Mobile phones; Bacterial Contamination; Nosocomial Infection
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Despite overall
progress, hospital acquired infections are a problem in both developed
and developing countries. It significantly increases the patients’
length of stay in hospital resulting in higher hospital costs. Such
infections can be prevented by health care workers taking proper precautions
when caring for patients. Source of infection may be exogenous such
as from the air, medical equipment, hands of surgeons and other staff
or endogenous such as the skin flora in the operative site, or rarely
from blood used in the surgery.1 The hands of healthcare
workers play an important role in transmission of nosocomial pathogens.
With recent
advances in the source of information, mobile phone use has become indispensible
in hospitals.2 The use of cell phones often occurs in hospital
halls, laboratories, and/or intensive care units when dealing with severe
illnesses. The Telecom and Regulatory Authority of India (TRAI, 2009-10)
reported that the share of mobile phone users in India stood at 584.32
million as compared to 391.76 million a year before. The growth was
49.15% year-on-year.3 Mobile phones may transmit more than
just information in today’s busy hospitals. They may also be involved
in the transmission of infections in the healthcare systems. Mobile
phones are used in close contact with the body and, as for most non-medical
electronic equipment, there are no cleaning guidelines available that
meet hospital standards, and the hygiene risk involved in using mobile
phones or has not yet been determined.
Thus, in this
study, we investigated bacterial contamination of the mobile phones
of the healthcare workers employed in a medical and dental institution
in Mangalore, INDIA and its resistance to commonly used antimicrobials.
A total of 204 mobile
phones of HCWs from medical and dental hospital i.e. 12 each from Department
of Paediatrics, General Medicine, Orthopaedics, Obstetrics-Gynaecology,
Dermatology, ENT, Ophthalmology, General Surgery, Anaesthiology, Pedodontics,
Orthodontics, Oral Medicine, Oral Surgery, Community Dentistry, Endodontics,
Periodontics and Prosthodontics were included in this study.
A questionnaire was used for data collection on use of mobile phones
in hospitals by personnel. Their profession, duration of their profession,
whether they used their phones between patients, usage of phones with
gloved hands and whether routine cleaning of phones was done were recorded.
The samples
were collected aseptically using swabs moistened with sterile saline.
Samples were collected by rotating the swabs over the mouthpiece, earpiece,
keypad and external cover of the mobile phones and were streaked on
5% sheep blood agar and MacConkey agar plates, and were incubated at
37°C
for 24 hours. Plates were observed for growth. Isolates were identified
by colony morphology, gram staining and standard biochemical reaction.4
Gram positive catalase positive cocci were tested for mannitol utilisation
and for production of coagulase enzyme. Gram positive catalase neagative
cocci were identified by bile esculin agar, oxidase and other biochemical
tests including production of indole, utilisation of citrate, production
of enzyme urease and triple sugar ion agar. The isolates were further
subjected to antibiotic sensitivity testing by Kirby-Bauer disc diffusion
method on Mueller-Hinton agar according to Clinical Laboratory Standards
Institute antibiotic disc susceptibility testing guidelines.5
Out of the
204 phones screened in this study, 201 showed bacterial growth. Only
2 medical and 1 dental sample showed no growth. Polymicrobial growth
was detected in 17 (17.7%) of dental samples and 42 (38.8 %) of medical
samples (Figure 1). A higher percentage of mobile phones from departments
of Periodontics, Endodontics and Oral Medicine were contaminated (Figure
2). The most commonly isolated organism was Coagulase-negative Staphylococci
(CNS) (44). However, bacteria that might be associated with hospital
infection were isolated in 154 samples including Pseudomonas aeruginosa
(43), Escherichia coli (34),
Methicillin- sensitive Staphylococcus aureus (29), Klebsiella
pneumonia (16). Metihcillin-resistant Staphylococcus aureus
is one of the most frequently isolated bacteria in hospital infections
and was isolated in 10 samples. Pathogens isolated also included Acinetobacter spps, Enterococcus
spp, Enterobacter spp and Diptheroids.
(Table 1 shows the frequency of distribution of pathogens.)
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Figure
1: Extent of Mobile Phone Contamination in Medical and Dental Hospital |
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Figure
2: Percentage of Bacterial Contamination of Mobile Phones of Healthcare
Workers in Various Departments |
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Table
1: Distribution of Bacterial Growth in Medical and Dental Departments |
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Organism
isolated |
Medical personnel
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% |
Dental personnel
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% |
All personnel
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Staphylococcus
aureus (MRSA) |
4 |
40 |
6 |
60 |
10 |
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Staphylococcus
aureus (MSSA) |
17 |
58.62
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12 |
41.38 |
29 |
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Escherichia
coli |
16 |
47.06 |
18 |
52.94 |
34 |
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Klebsiella
pneumoniae |
11 |
68.75 |
5 |
31.25 |
16 |
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Pseudomonas
aeruginosa |
27 |
62.79 |
16 |
37.21 |
43 |
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Acinetobacter
spp |
6 |
50 |
6 |
50 |
12 |
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Enterococcus
spp |
6 |
60 |
4 |
40 |
10 |
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Enterobacter
spp |
1 |
100 |
0 |
0 |
1 |
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Citrobacter
spp |
0 |
0 |
1 |
100 |
1 |
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Proteus |
0 |
0 |
1 |
100 |
1 |
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Diptheroids
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0 |
0 |
1 |
100 |
1 |
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Coagulase-negative
Staphylococci (CNS) |
23 |
52.27 |
21 |
47.73 |
44 |
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Figure
3: Microbiological Profile of Multi Drug Resistant Bacteria from Mobile
Phones |
Among medical
samples, 64.8% were pathogenic and 37.9% showed growth of multiple drug
resistant bacteria. 59.37% of dental samples showed growth of pathogenic
micro-organisms and 43.75% showed growth of multiple drug resistant
bacteria (Figure 3). According to the questionnaire, 99% of HCWs used
cellphones in the hospital. 40% of HCW’s admitted to using their mobile
phones while attending to patients. Only 6 % of HCWs sometimes used
an alcohol based disinfectant to wipe their mobile phones. Almost all
the HCWs do not wash their hands after using their phones and before
attending to patients.(96%). 36% of HCWs do not believe that cell phones
can act as vector for spread of nosocomial infections from one patient
to another and it can have harmful colonization. Most of them share
cell phones with colleagues (90%) and at home (98%).
In the world
over, maintaining hygiene standards is a prerequisite for healthy living.
It is not uncommon however to observe shift in hygiene practices that
deviate from normal standards of hygiene in both the developing and
the developed world. Medical personnel use their cellular telephones
excessively while in the hospital. The threat of contamination with
potential pathogens is a valid concern. We found that one third of the
cellular telephones that belonged to HCWs harboured varied and potentially
pathogenic microorganisms. Several reports have documented the contamination
of mobile phones among HCWs ( Borer et al, 2005 ; Brady et al, 2006;
Goldblatt et al, 2007; Jayalakshmi et al, 2008; Karabay et al, 2007).6-10 However, so far no study has determined the contamination
of mobile phones in different departments in a hospital environment.
Overall, the bacterial contamination was higher in the dental departments
as compared to the medical departments. This may be attributed to the
fact that air contamination occurs in a dental clinic setup due to dissemination
of bacterial aerosols when high speed dental equipment is used.11
Ultrasonic scaling which is most commonly performed in the department
of Periodontics is one of the most air-contaminant dental treatment
procedures.12
The purpose
of the study was to determine the presence of aerobic bacteria, so cultivation
of anaerobic bacteria and fungi was not done. Simultaneous cultures
from the hands of HCWs or environmental surfaces were not carried out;
this is a limitation of the study.
If the same
phones are used both outside and inside of hospitals, our results indicate
that, these contaminated phones can play a potential role in the spread
of hospital infection bacteria in the community. HCWs should be aware
that their cellular telephones may carry potentially pathogenic bacteria
that may affect not only patients, but also their loved ones at home.
MRSA is one
of the most frequently isolated bacteria in hospital infections and
was isolated in 10 samples and is a cause for concern. This represents
an additional route for cross-transmission of MRSA. MRSA isolates are
often resistant to multiple commonly used antimicrobial agents. Recent
estimates by the Centers for Disease Control and Prevention indicate
that more than 125,000 hospitalizations because of MRSA occurred in
the United States between 1999 and 2000, a rate of 3.95 cases per 1,000
hospital discharges.13 MRSA infections usually develop in
hospitalized patients, but recent reports emphasize the emergence of
serious community-acquired MRSA infections.14,15
Most organisms die within hours due to dehydration but bacteria such
as S. aureus and Acinetobacter
are resistant to drying and survive for weeks and multiply rapidly in
a warm environment.16-19
Our phones
are ideal breeding sites for these microbes as they are kept warm and
snug in our pockets and handbags. Also, there are no guidelines for
the care, cleaning and restriction of mobile phones in our health care
settings. Hence, in a country like ours, mobile phones of HCWs play
an important role in transmission of infection to patients, which can
increase the burden of heath care. Simple measures such as increasing
hand hygiene and regular decontamination of mobile phones with alcohol
disinfectant wipes may reduce the risk of cross contamination caused
by these devices. One study reported the use of 70 % isopropyl alcohol
as an effective disinfectant.9 Another study reported that
restricted use of mobile phones during working hours along with proper
hand hygiene practices enabled mobile phones to remain free of
contamination ( Goldblatt et al, 2007 ).8
In summary,
since restrictions on the use of mobile phones by Healthcare workers
in hospitals is not a practical solution, we suggest that Healthcare
workers should practice increased adherence to infection control precautions
such as hand washing after each use of the telephone. In addition, they
should be informed that these devices may be a source for transmission
of hospital-acquired infections. Further studies for the possible methods
of decontamination of mobile phones, such as using alcohol and/or disinfection
tissues, should be conducted in hospitals.
The authors
thank all the participants for their kind cooperation and would like
to acknowledge Dr. Sunil Rao, Head of Dept; Dept of Microbiology and
Dr. Rouchelle Charmaine Tellis, Assistant Prof, Dept of Microbiology,
Yenepoya Medical College for microbiological assistance.
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A practical guide, 2nd edition: World Health Organization, Department of Communicable Disease,
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P, Rani U, Chawla K, Mukhopodhyay C, Barry I. Do mobiles carry pathogens.
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- Pina-Vaz I,
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