The Transfer of Staphylococcus aureus from Contaminated Hospital Bedrails to Hands

Background:

Bedrails have been identified as one of the most frequently contaminated areas within the patient environment. They are also frequently handled or touched by both patients and staff so represent a likely reservoir for cross-infection. Previous studies have suggested different bed rail-finishes may influence the transfer of bacteria from bedrail to hands.

Objective:

To establish whether different finishes and coatings influence the transfer of Staphylococcus aureus from bedrails to fingertips.

Methods:

Six bed rails (A to F) currently in use within the UK NHS were selected for their different surface-finish or coating. Overnight cultures of Staphylococcus aureus were suspended in five model soils/body fluids (Tryptone Soya Broth with 5% Horse Serum (TSB+HS), Urine, Faeces, Blood and 0.6% Bovine Serum Albumin) and compared against a control (Ringers’ Solution). A 10ul aliquot of each bacterial suspension (~10⁵ cfu) was inoculated onto each rail and immediately touched by the fingertip of the index finger of a volunteer. Each experiment comprised ten replicate samples.

Results:

The surface-texture of each bedrail was examined by eye. Rails A, B and F were observed to have visibly rough surfaces while rails C, D and E were visibly smooth. When suspended in Ringers’ solution, significantly more bacteria were transferred from rail B (37%) than from rail C (21%), E (23%), and F (24%). With the exception of urine, the presence of body fluids affected bacterial transfer from all rails. In comparison to the control soil, the presence of faecal contamination significantly increased the transfer of S. aureus from rails C (44%), E (64%) and F (37%). In comparison to all soils tested, the presence of blood significantly increased the numbers of S. aureus transferred from all rails. The greatest transfer was from rail E (70%) and the lowest from rail B (50%). In contrast, all rails contaminated with either TSB+HS or urine showed an overall lower transfer of S. aureus to fingertips. Taking all results into consideration, bedrail B exhibited the highest transfer of S. aureus to fingertips, followed by rails D, E, A, C and F. Irrespective of surface roughness, the transfer of S. aureus from rail B was not significantly different to that from rail D. However, these two rails were made of the same material.

Conclusions:

Bedrails are likely to serve as reservoirs for bacteria and different rails, for example those smilar in type to rail B, may promote bacterial transfer. Such cross-infection may depend upon material-type rather than texture. The presence of blood posed the greatest risk for cross-infection. Although some protein-rich soils (e.g. TSB+HS) contributed to an overall lower transfer to fingertips, the presence of such soils may prolong the persistence of bacteria in the patient environment.