Mobile phone technology and hospitalized patients: a cross-sectional surveillance study of bacterial colonization, and patient opinions and behaviours

Authors


Corresponding author: R. R. Brady, Department of Surgery, Western General Hospital, Crewe Rd, Edinburgh, Scotland EH4 2XU, UK
E-mail: richardbrady@btinternet.com

Abstract

Clin Microbiol Infect 2011; 17: 830–835

Abstract

Healthcare workers’ mobile phones provide a reservoir of bacteria known to cause nosocomial infections. UK National Health Service restrictions on the utilization of mobile phones within hospitals have been relaxed; however, utilization of these devices by inpatients and the risk of cross-contamination are currently unknown. Here, we examine demographics and characteristics of mobile phone utilization by inpatients and phone surface microbial contamination. One hundred and two out of 145 (70.3%) inpatients who completed a questionnaire detailing their opinions and utilization of mobile phones, also provided their mobile phones for bacteriological analysis and comparative bacteriological swabs from their nasal cavities; 92.4% of patients support utilization of mobile phones by inpatients; indeed, 24.5% of patients stated that mobile phones were vital to their inpatient stay. Patients in younger age categories were more likely to possess a mobile phone both inside and outside hospital (p <0.01) but there was no gender association. Eighty-six out of 102 (84.3%) patients’ mobile phone swabs were positive for microbial contamination. Twelve (11.8%) phones grew bacteria known to cause nosocomial infection. Seven (6.9%) phones and 32 (31.4%) nasal swabs demonstrated Staphylococcus aureus contamination. MSSA/MRSA contamination of phones was associated with concomitant nasal colonization. Patient utilization of mobile phones in the clinical setting is popular and common; however, we recommend that patients are educated by clear guidelines and advice on inpatient mobile phone etiquette, power charging safety, regular cleaning of phones and hand hygiene, and advised not to share phones or related equipment with other inpatients in order to prevent transmission of bacteria.

Introduction

A number of studies have consistently reported that 5–21% of healthcare workers’ mobile phones provide a reservoir of bacteria known to cause nosocomial infections [1–7]. Despite this knowledge, there exists a paucity of advice provided to either healthcare workers (HCWs) or inpatients on the use or decontamination of mobile phones in hospitals.

Previously, concerns regarding mobile phone electromagnetic interference (EMI) with the function of medical equipment led to UK National Health Service (NHS) restrictions on their utilization in the clinical arena [8]. Further concerns regarding patient confidentiality, data storage, privacy and noise disruption have also been raised (reviewed in Ref. [2]). However, since January 2009, restrictions on the use of mobile phones by medical staff and patients have been removed in the UK [9]. This was principally due to the absence of supportive evidence to demonstrate risks [10,11], advances in handset technology, the reality that many HCWs and patients were using the devices irrespective of restrictions and putative patient psychological advances in avoiding isolation from contacts [12,13].

In view of the withdrawal of previous restrictions, and likely increase in patient utilization of mobile communication technology, the investigators wished to characterize inpatient utilization of mobile phones and assess whether recent changes in policy had implications for infection prevention and control policies aimed at reducing healthcare-associated infections.

In addition, previous studies have reported co-contamination of methicillin-resistant Staphylococcus aureus (MRSA) on HCWs’ hands and their mobile phones [5,6] and that previously decolonized hands of HCWs can become contaminated by bacteria from the device [4]. Given that mobile phones are in close contact with the user’s face during use, we wished to evaluate if patients’ mobile phones were associated with personal nasal Staphylococcus aureus colonization status.

Materials and Methods

Without prior notification, on five sampling events, consecutive inpatients on surgical/urological wards of the Western General Hospital, Edinburgh, were asked to participate in the study. After agreement, written consent was obtained, and patients provided details of their demographics and opinions and utilization of mobile phones by completion of a questionnaire.

The following exclusion criteria were applied: those who were not mentally capable of consenting, those who had already previously been sampled on a different sampling occasion, and those <16 years of age.

Following completion of the questionnaire, patients were asked to give their mobile phones to the investigators. The investigators used a moist sterile swab (dipped in sterile saline) to sample the phones’ keypad areas in a uniform fashion. In addition, a separate sterile swab was also used to sample both anterior nares in a uniform fashion. Swabs were marked with a unique but anonymous identifier code to link questionnaire responses to bacteriological samples. Following sampling, swabs were immediately sealed and transported within 24 h to the Department of Laboratory Medicine at the Royal Infirmary of Edinburgh for further analysis.

Phone swabs were inoculated onto two blood agar plates (Columbia agar containing horse blood; Oxoid, Basingstoke, UK) and incubated, one aerobically and one anaerobically, at 37°C for 48 h. Plates were examined daily and any microorganisms present were identified using standard laboratory procedures. Selected organisms were identified by Vitek 2 using GPI, GNI or ANC cards (Biomerieux, Marcy L’Etoile, France) or the yeast Auxacolor 2 kit (BioRad, Hercules, CA, USA).

Nasal swabs were inoculated onto mannitol salt agar (Oxoid) and incubated at 37°C for 48 h. Plates were examined daily and suspect colonies were subcultured onto blood agar. Isolates were confirmed as S. aureus using the Microscreen Staph Latex kit (Microgen, Camberley, UK). Methicillin susceptibility was determined using an oxacillin strip (Mast Diagnostics, Bootle, UK) against a 0.5 MacFarland inoculum on Mueller–Hinton agar (Oxoid). MRSA-positive isolates were stored for further sensitivity testing, phage typing and genotyping at the Scottish MRSA reference laboratory (Glasgow, UK).

Questionnaire responses were transferred to a Microsoft Excel worksheet and statistical analysis was performed at the Epidemiology and Statistics Core, Wellcome Trust Clinical Research Facility, University of Edinburgh, Edinburgh.

Differences in proportions were examined using a binomial test for the comparison of proportions while associations in categorical data were examined using chi-square and chi-square test for trend (presented as Fishers exact test as appropriate due to small samples).

Ethical approval and permissions for the above studies were obtained from the Lothian Regional Ethics Committee (10-S1102-36) and Lothian NHS Research and Development Office.

Results

General demographics

One hundred and seventy-five inpatients were approached for inclusion in the study, of whom, 145 (82.9%) agreed to participate (29 refused; one patient was unable to communicate). One hundred and two (70.3%) patients who completed questionnaires also provided a mobile phone for bacteriological sampling and underwent nasal sampling.

Demographics of study population and possession of mobile phone

Twenty-seven (18.6%) patients did not own a mobile phone. Ninety-eight (67.6%) patients owned one mobile phone, 16 (11.0 %) patients owned two mobile phones and four patients (2.8%) owned three or more mobile phones. One hundred and two (86.4%) of those patients who owned a phone brought it into hospital.

Of those responding to the questionnaire, 59% (86/145) were men; 73.3% (63/86) of the male patients and 66.1% (39/59) of the female patients provided mobile phones for analysis (p 0.359, 95% CI for difference in proportions (−8.1%, 27.4%)). There was evidence of an association between age-group and provision of a mobile phone (p <0.001), with a linear trend suggesting that as age-group increases the proportion providing a phone decreases (p <0.001). There was no evidence of an association between duration of stay and provision of a mobile phone (p 0.375).

Opinions and problems experienced with inpatient mobile phone utilization

Sixteen (11.0%) respondents stated that they had experienced problems with noise from other patients’ mobile phone use during their inpatient stay (p 0.15). Seven (4.8%) stated that they had experienced a loss of privacy due to other patients’ use of mobile phones (p 1.00). Neither of the above responses was associated with whether or not the respondent provided a mobile phone.

A majority of respondents (92.4%) supported the lifting of restrictions on inpatient use of mobile phones; 93.8% of respondents supported the use of mobile phones by medical staff. However, only 24.1% supported a suggestion that the NHS should routinely supply patients with a mobile communication device for their use during their admission to hospital.

Of those that provided a phone, only one patient stated that future restrictions on mobile phone utilization in hospital would improve their inpatient experience, while 39 (38.2%) patients felt that it would make no difference and 62 (60.8%) said that it would negatively effect their inpatient experience. Indeed, 30 (29.4%) patients stated that the ability to use a mobile phone as an inpatient was useful, 40 (39.2%) that it was important and 25 (24.5%) that it was vital; the remainder stated that it made no difference (seven patients; 6.9%).

Few mobile users complained of difficulties with phone utilization as an inpatient (n = 13), with only six (5.9%) patients having experienced problems with network coverage, one stating that they had experienced problems with inadequate privacy to make calls and six (5.9%) stating problems with availability of power charging for their device.

Seventy-two (70.6%) patients charged their phone using their own charger plugged into the hospital ward/bedside power sockets/points. Twenty-seven (26.5%) stated that they or their relatives had charged their phone prior to admission but three (3.0%) stated that they had borrowed a fellow patient’s charger during this inpatient stay to charge their own phone.

Characteristics of mobile phone utilization by patients

Eighteen (17.6%) of the mobile phones sampled were owned by the participant for <6 months, 22 (21.6%) for 6–12 months, 41 (40.2%) for 12 months to 5 years and 21 (20.6%) for >5 years. Five (4.9%) respondents regularly shared the use of their mobile phone with another individual outside of hospital. Whilst no patient admitted to having shared their phone with another patient during the index inpatient stay, 50 (49.0%) stated that if asked, they would be happy to share their phone with another patient.

The impact of hospital stay on the daily frequency of mobile phone utilization is recorded in Table 1. Seventeen (16.7%) patients reduced their frequency of utilization, 41 (40.2%) did not change and 44 (43.1%) increased their frequency of utilization (Table 1).

Table 1.   A cross-tabulation of phone use in hospital and outside hospital
Daily use outside hospital (times per day)Daily use within hospital (times per day)Total
<112–45–910+
  1. Those on the diagonal show no change in usage pattern (n = 41) while those above the diagonal use the phone more in hospital (n = 44) and those below the diagonal use the phone less in hospital (n = 17).

<1811153 37
12451 12
2–411134221
5–91 46314
10+  351018
Total1216401915102

There was no evidence of an association between gender and mobile phone usage either during (p 0.097) or outside the hospital stay (p 0.482). However, there was evidence of a linear association between age (<60 vs. 60+) and frequency of daily utilization both within (p <0.001) and outside (p <0.001) hospital.

Cross-contamination and cleaning

One hundred and two (70.3%) respondents were aware that phones could carry harmful bacteria, but no patient had received advice or information regarding mobile phone utilization during their hospital admission.

When asked about cleaning of their phone, 52 (50.9%) of those presenting phones stated that they had never cleaned their phone outside hospital. Seven (6.9%) stated that they cleaned their phone yearly, 12 (11.8%) monthly, 18 (17.6%) weekly and 13 (12.7%) daily. The most common methods for cleaning were alcohol/antibacterial wipes (21 patients), damp cloths (17 patients), or wiping with dry cloth (12 patients). Only 11 (10.8%) patients providing a phone in hospital had cleaned their phones since their admission.

Bacteriological analysis of mobile phone keypads

Table 2 shows the number of mobile phones from which we isolated bacterial or fungal organisms during subsequent analysis of bacteriological swabs. Seventeen (16.6%) phones demonstrated no microbial growth, 66 (64.7%) grew one bacterial species, 12 (11.8%) grew two species and seven (6.9%) grew three or more. The most common group of bacteria isolated was coagulase-negative staphylococci, identified from 78 (76.5%) mobile phones.

Table 2.   Organisms identified from mobile phone analysis
Microbial speciesNo. of phones (total = 102)
  1. VRE, vancomycin-resistant enterococci; spp., species.

  2. aPathogenic.

Coagulase negative staphylococci78
Staphylococcus aureus (MSSA/MRSA)7a
Corynebacterium (jeikeium, pseudodiptheriticum, amycolatum)5
Streptococcus spp. (constellatus, parasanguinis)3
Sphingomonas paucimobilis3
Enterococcus faecium (not VRE)2a
Rhizobium radiobacter2
Acinetobacter ursingii1a
Enterobacter cloacae1a
Moraxella spp.1
Micrococcus spp.1
Burkholderia cepacia1a
Dermacoccus nishinomiyaensis1
Kocuria kristinae1
Lactococcus garvieae1
Gemella morbillorum1
Bacillus spp.1
Unidentified Gram-positive bacillus1
Unidentified alpha-haemolytic streptococcus1
Candida albicans1

However, 12 (11.8%) mobile phones demonstrated growth of pathogenic bacterial species (i.e. bacteria likely to cause infection in a variety of situations, such as skin wounds and urinary catheters) (see Table 2). There was no evidence of a difference in gender (men, 11.1%; women, 10.3%; p 1.0; 95% CI for difference (−11.4%, 13.1%) using Fishers exact test) or age (<60, 12.5%; ≥60, 9.3%; p 0.601; 95% CI for difference (−8.9%, 15.4%)) of those who had these bacterial genera isolated from their mobile phone swabs.

Mobile phone as a marker of personal S. aureus colonization status

Thirty-two (31.4%) of the nose swabs grew S. aureus. There was no evidence of a difference in the proportion of men and women with nasal S. aureus (male, 34.9%; female, 25.6%; p 0.314; 95% CI for difference (−8.8%, 27.3%)) or between those under 60 years old and those who were older than 60 (<60, 37.5%; ≥60, 25.9%; p 0.208; 95% CI for difference (−6.4, 29.6%)).

Six out of 32 (18.75%) patients with nasal colonization also demonstrated concurrent mobile phone S. aureus contamination (positive predictive value = 85.71; sensitivity = 18.7; specificity = 98.57), including five (17.9%) of those with nasal methicillin-sensitive S. aureus (MSSA) (n = 28) and one (25%) of the four patients with nasal methicillin-resistant S. aureus (MRSA) (N = 4).

Six out of seven (85.7%) patients with mobile phones demonstrating S. aureus had concurrent nasal S. aureus, including five out of six (83.3%) of the total number of phones with MSSA and the one patient with a phone that grew MRSA.

Subsequent genotype/phage testing of MRSA isolates was undertaken and demonstrated that 75% nasal MRSA isolates were EMRSA-15 (all with different PFGE patterns). Analysis from the patient with both phone and nasal MRSA isolates demonstrated both isolates as EMRSA-16 with identical PFGE patterns.

Discussion

This is the first study to characterize inpatient utilization of mobile communication devices in an unrestricted clinical environment. The study reveals that mobile phone utilization is viewed as important or vital by a majority of those possessing them, and restrictions viewed as detrimental to the inpatient experience. However, a small proportion of patients did admit to experiencing difficulties with noise or problems with privacy due to patients’ use of mobile phones. These issues could pose difficulties in responding to increasing numbers of patients utilizing mobile phones at increased frequency.

Tarzi et al. [14] investigated the impact of hospitalization and MRSA isolation on the psychological functioning of older adults undergoing rehabilitation and found that depressive and anxious symptoms amongst the isolated group were significantly higher; they concluded that amongst older adult inpatients, isolation has a negative impact on mood. A systematic review of 16 studies by Abad et al. [15] showed that contact isolation led to higher depression scores, anxiety and anger amongst patients. Patient safety is also negatively affected, leading to an eight-fold increase in adverse events related to supportive care failures.

Whilst there is limited research on this aspect of the use of mobile phones by hospitalized patients, the psychological sequelae of relief from isolation have been documented. One study investigating mobile phone utilization in the setting of a young person’s unit demonstrated that it was helpful for patients to be able to use mobile phones to avoid isolation and ease boredom [13]. Therefore, this study confirms that provision of mobile communication devices is popular and can add positively to the inpatient experience. However, given our demographic findings of mobile phone possession in hospital, further study of this area would be required in order to assess whether provision of mobile communication devices to the elderly would be practicable and effective at alleviating psychological problems associated with isolation.

This study confirms a compelling body of research evidence demonstrating that mobile phones in the clinical environment provide a mobile reservoir for bacteria known to cause nosocomial infections [1–7]. However, despite this, there remains an absence of clear advice from healthcare providers to mobile phone users (whether HCW or inpatient) on cleaning or decontamination of mobile phones, before, during or after admission to hospital. In addition, whilst a majority of patients are aware that mobile phones can harbour bacteria, a minority of patients actually attempt decontamination of their phones. The majority of those that do attempt such measures utilize methodologies that would be considered ineffective at surface bacterial decontamination. This situation is presumably sustained by both lack of knowledge and paucity of patient education surrounding these issues.

Importantly, we found that no patient in our study had shared a phone during their inpatient stay. Whilst this would appear to minimize the risk of cross-contamination, many stated that they would share their phone if asked. Inpatients should therefore be given advice to avoid sharing mobile phones with other inpatients in order to mitigate the potential risk of cross-contamination. The same advice might be applied to mobile phone chargers, where there was evidence of sharing between patients.

To our knowledge, no phone charging device had been confirmed as safe for use in a hospital environment, despite which, they were often plugged into the hospital power supply. In our setting, this is a short distance from the patient’s own oxygen supply. The health and safety implications of this practice are highlighted by cases in the literature of second-degree burns resulting from explosions and sparks caused by mobile phones being answered whilst charging, particularly when in close proximity to supplementary oxygen [16,17].

Previous pilot studies have compared nasal MRSA colonization and mobile phone contamination in a HCW cohort. However, the low levels of MRSA colonization were inadequate for statistical analysis (<2%) [1,18]. Here, we analysed co-contamination by attempting to detect all S. aureus subtypes/strains, as there is an estimated 20–30% carrier rate in the general UK population [19]. Thirty-two (31.3%) of our patient cohort had MSSA/MRSA isolated from their nasal swabs, which is slightly higher than other contemporary studies, especially as in our setting, patients were routinely screened for MRSA pre-admission. The higher rate noted here may be a reflection of the nature of emergency admissions, local colonization levels or transient colonization, which occurred within the healthcare environment. Additionally, it is important to note that as all MRSA isolates in this study had different PFGE patterns, the evidence provided here would suggest that there was no transmission from one patient to another. Measures such as alcohol-based disinfection of their hands by HCWs just before patient contact and regular use by patients of hand disinfection during hospitalization are therefore key to the prevention of such bacterial transmission.

Whilst our study did demonstrate an association between nasal colonization with S. aureus and the presence of S. aureus on a patient’s mobile phone, the sensitivity/specificity of mobile phone S. aureus contamination status as a surrogate marker of nasal colonization was low. In this study, nasal sampling was also limited to those who provided a mobile phone. We were therefore unable to establish if there was a relationship between those who own a mobile phone and those who were positive for nasal S. aureus or indeed if hand contamination by S. aureus was also related to mobile phone use. Further research in the form of a case control study would be required to evaluate this relationship. This is especially important with regards to the demographics of possession, as whilst the elderly are a sub-population of general surgery patients at higher risk of MRSA colonization/ infection [20], they were also the group least likely to provide a phone, and thus a nasal swab for assessment. This potentially introduces bias within this sample population towards an underestimate of positivity. A specific study looking at mobile phone bacterial contamination in young vs. elderly patient populations may be of relevance to hospital-specific policy decisions.

In conclusion, inpatient mobile phone utilization is popular, common, valued and provides benefit to the inpatient experience. However, phones are a repository for bacteria associated with nosocomial infection and our data confirm that there is an association between personal nasal colonization with S. aureus and the presence of S. aureus on a patient’s mobile phone but the sensitivity/specificity of using mobile phones as a surrogate marker of nasal colonization was low. Importantly, this study has identified for the first time the risks of cross-contamination, fire and electrical safety in the ward environment, which require urgent address. Specifically, we recommend that patients are educated by clear guidelines and advice on inpatient mobile phone etiquette, power charging safety, regular cleaning of phones and hand hygiene and are advised not to share phones or related equipment with other inpatients in order to prevent transmission of bacteria.

Acknowledgements

The authors would like to thank the nursing staff and ward managers of the colorectal and urology wards of the Western General Hospital. In addition, for assistance with sample collection, the authors would like to thank Sharon La Bronte and Janathan Danial and in addition, the Department of Laboratory Medicine (Medical Microbiology), Lothian University Division, for provision of study funding. For assistance with further MRSA characterization the authors would also like to thank Dr Giles Edwards (MRSA Reference Laboratory, Glasgow).

Funding

Microbiology Research Fund, Lothian University Hospitals Division.

Transparency Declaration

RB, AH, AV, MR, CR, PK, HP and AP are employees of the healthcare organization in which sampling took place. There was no outside influence on the performance, analysis or write-up of the study.

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