Correspondence

Cellphones As Reservoirs of Nosocomial Pathogens

Sir,

Cellphones are increasingly used by the health care personnels for communication. When put in the vibratory mode, these can be used even in noise restricted areas such as ICU’s, post operative wards, OT’s etc. However, cellphones which are seldom cleaned and often touched during or after the examination of patients without handwashing , can harbour various potential pathogens and become an exogenous source of nosocomial infections among hospitalized patients.

We sought to address this issue, by screening the cellphones of doctors for microbial pathogens and also to assess the usefulness of simple cleaning with 70% isopropyl alcohol for their decontamination.

After obtaining the institutional ethical committee’s (IEC’s) approval, a total of 84 cellphones belonging to doctors at the PSG hospitals and about 60 cellphones belonging to doctors working in the pre and para clinical departments of PSG Institute of Medical Sciences and Research, Coimbatore, were screened for bacterial isolates. Sterile swabs moistened with trypticase soy broth were used to swab the front, back and the sides of the cellphones and were subjected to culture and sensitivity. After consulting the local cell phone dealers regarding safety of use, decontamination was done by cleaning with 70% isopropyl alcohol.1 After allowing it to dry for 10 mins, repeat swabs were taken for culture and sensitivity.

Except for the 12 new cellphones, all the others (91.6%) were found to be contaminated 76 (90.4%) owned by clinical doctors and 56(93.3%) owned by non clinical doctors. The difference was not statistically significant (P >0.05). Single bacterial type was recovered in 49 cellphones. Two and more than two bacterial types were isolated from 67 and 16 cellphones respectively. The contaminating pathogens were coagulase negative staphylococcus (108) Bacillus spp (46), Staphylococcus aureus (33) and others amounting to 229 bacterial isolates (Table 1).

Eighty nine (67.4%) of those contaminated cellphones, grew normal skin and oral flora. Most organisms are killed within hours due to drying but bacteria like Staphylococcus aureus and Acinetobacter are resistant to drying and can survive for weeks and multiply rapidly in warm environment.2 These were the predominant nosocomial pathogens isolated in our study.

Twenty eight out of 84(33.3%) and 15 out of 60 (25%) cellphones of clinicians and non clinicians grew bacteria that cause nosocomial infection. S aureus could colonise as normal commensal flora but Methicillin resistant staphyloccus aureus (MRSA) are associated more often cause nosocomial infections, spread mainly by contact and are a major concern. Four (2.7%) MRSA’s were isolated only from the cellphones of clinicians who perform surgeries or handle acutely ill patients and may act as a source of MRSA transmission to patients. The incidence of MRSA among post operative wound infections was found to be 25.4%. The genetic relatedness between isolates found on the mobiles and from patients was not performed.

Acinetobacter spp with a potential for drug resistance were isolated from 7 (4.8%) cell phones of 3 clinicians and 3 microbiologists. Studies have shown that 30% of nosocomial infection in the ICUs, are associated with Acinetobacter spp. Similar study at the Soroka university medical centre, Israel, identified multidrug resistant Acinetobacter baumannii in the hands, cellphones of the health care workers and patients admitted to the ICU. Following this study, the use of cellphones in patient-care areas has been banned in that hospital.2

One each of Pseudomonas, E coli and E faecalis were isolated from the cellphones of 2 physiologists working on amphibians, and a pharmacologist. None of these isolates were found to be resistant.

Since restriction or even prohibition of cellphones may prove impractical, strategies for preventing nosocomial transmission in this context are needed. Sterilizing - cellphone chargers, are now being marketed which can charge and sterilize, at the same time. These are expensive and not readily available. Simple cleaning of the cellphones with 70% isopropyl alcohol could disinfect 129 out of the 132 cellphones found contaminated in our study. In the remaining three cellphones there was a gross reduction in the number of organisms, to a visible 2-5 colonies. Regular hand washing would reduce the risk associated with the reservoir potential of cellphones

Acknowledgement

We express our heartfelt thanks to all the doctors of PSG Institute of Medical Sciences and Research and PSG hospitals for their kind cooperation.

J Jayalakshmi* , B Appalaraju**, S Usha***

*Associate Professor; **Professor and Head; ***III MBBS Student, Dept of Microbiology, PSG Institute of Medical Sciences and Research, Coimbatore-4.

Received : 27.6.2007; Revised : 20.2.2008; Accepted : 31.3.2008

References

1. Singh D, Kaur H, Gardner WG, Treen LB. Bacterial contamination of hospital pagers. Infect Control Hosp Epidemiol 2002;23:274-6.

2. Borer A, Gilad J, Smolyakov R, et al. Cell phones and Acinetobacter transmission. Emerg Infect Dis 2005;11:
1160-1.