Nosocomial infections pose a serious threat in paediatric wards where patients are particularly susceptible. As with other environmental surfaces, prior studies have suggested that mobile phones may serve as a reservoir for pathogenic bacteria. Given the difference in bacterial epidemiology, it is of interest to evaluate the type of bacteria found on the mobile phones of health-care workers in a paediatric ward.
Forty mobile phones were sampled over a 3-month period. These were taken from medical students (n = 18), resident medical officers (n = 10), registrars (n = 8) and consultants (n = 4). Self-reported frequency of mobile phone use averaged at once every 70.5 ± 57.0 (standard deviation) min. Out of these, 27 had phone covers, and the most common location our participants carried their phones was in their pockets (n = 28), followed by their hand bags (n = 10) and belt pouches (n = 2). Four reported cleaning their phones in the past 48 h, and 10 cleaned them regularly. None of our subjects cleaned their phones with alcohol wipes.
Table 1 illustrates the bacterial organisms isolated from the samples. Out of 40 samples taken from mobile phones, 38 (95%) were contaminated with bacteria (Table 1). Twenty (50%) had one bacterial species, 17 (42.5%) had two and only 1 (2.5%) had three. The types of microorganisms isolated from mobile phones and dominant hands were similar.
|n (%)||n (%)|
|Coagulase-negative Staphylococci||36 (90)||31 (77.5)|
|Bacillus spp.||3 (7.5)||4 (10)|
|Diphtheroid spp.||8 (20)||16 (40)|
|Non-haemolytic Streptococcus||7 (17.5)||8 (20)|
|Alpha-haemolytic Streptococcus||1 (2.5)||1 (2.5)|
|Coliforms||1 (2.5)||2 (5)|
|Methicillin-sensitive Straphylococcus aureus||1 (2.5)||1 (2.5)|
|Enterococcus||0 (0)||1 (2.5)|
|Acinetobacter||0 (0)||1 (2.5)|
Those with >100 colonies were categorised as having ‘heavy growth’, and logistic regression was performed to explore the relationship between heavy growth and phone user characteristics. We found that medical students had greater odds of having heavy growth (odds ratio (OR) = 4.05, confidence interval (CI) 1.02–16.015, P value = 0.046). When frequency of use was taken into account, the strength of the association remained similar and approached significance (OR = 3.76, CI 0.93–15.17, P value = 0.063). Seniority, presence of a phone cover, phone location and phone cleaning showed no significant associations with the level of growth (data not shown).
In this pilot study, the use of mobile phones by staff in the paediatric ward demonstrated a high contamination rate, mostly with skin flora. Currently, there are no evidence-based guidelines for the use of mobile phones in hospitals. This pilot study adds to the growing body of evidence that suggests that phones act as a vector for pathogenic organisms.[2, 4] Given that mobile phones are now an integral part of most hospitals, guidelines for decontamination of mobile phones should be developed.
We believe that our study is the first to suggest that there may be greater contamination of mobile phones used by medical students. This was not fully explained by the inclusion of phone use frequency in the model. Given the widespread use of mobile phones, these findings should be confirmed by a larger study.