Did you ever think bath basins might be a reservoir for infection?

Research Abstract with Commentary

Patients’ Bath Basins as Potential Sources of Infection: A Multicenter Sampling Study

Background. Nosocomial infections are a marked burden on the US health care system and are linked to a high number of patient deaths.
Objective. To identify and quantify bacteria in patients' bath basins and evaluate the basins as a possible reservoir for bacterial colonization and a risk factor for subsequent hospital-acquired infection.
Methods. In a prospective study at 3 acute care hospitals, 92 bath basins, including basins from 3 intensive care units, were evaluated. Sterile culture sponges were used to obtain samples from the basins. The culture sponges were sent to an outside laboratory, and qualitative and quantitative microbial tests were conducted and the results reported.
Results. Some form of bacteria grew in 98% of the samples (90 sponges), either by plating or on enrichment (95% confidence interval, 92%-99.7%). The organisms with the highest positive rates of growth on enrichment were enterococci (54%), gram-negative organisms (32%), Staphylococcus aureus (23%), vancomycin-resistant enterococci (13%), methicillin-resistant S aureus (8%), Pseudomonas aeruginosa (5%), Candida albicans (3%), and Escherichia coli (2%). Mean plate counts, in colony-forming units, were 10 187 for gram-negative organisms, 99 for E coli, 30 for P aeruginosa, 86 for S aureus, 207 for enterococci, and 31 for vancomycin-resistant enterococci.
Conclusions. Bath basins are a reservoir for bacteria and may be a source of transmission of hospital-acquired infections. Increased awareness of bath basins as a possible source of transmission of hospital-acquired infections is needed, particularly for high-risk patients.

Johnson, D., Lineweaver, L., & Maze, L. M. (2009). Patients’ bath basins as potential sources of infection: A multicenter sampling study. American Journal of Critical Care, 18, 31-40.

Commentary by Dana N. Rutledge, RN, PhD, Nursing Research Facilitator

In this eye-opening study, researchers address an area of common concern to nursing: infection control. They break the myth that a “dry” bath basin cannot harbor bacteria. New knowledge has shown that the development of biofilm (multiple colonies of microorganisms attached to a surface) can be present on multiple surfaces (including contaminated items or unwashed hands).

Johnson and colleagues (2009) sampled bath basins used at least twice for whole-body bathing of patients hospitalized for 48+ hours that had not been “cleaned” with any substance (probably just rinsed out with the washcloth). All basins were disposable and were found in the upright position, many times with articles in them (e.g., incontinence supplies). They were swabbed (cultured) at least 2 hours after patient bathing.

Findings showed that age, gender, and length of stay did not affect the findings of bacterial presence in the 98% of bath basins. Of concern is that 8% harbored methicillin-resistant Staphylococcus aureas (MRSA) and 13% harbored vancomycin-resistant enterococci (VRE), both of which are difficult organisms to eradicate, and the subject of much infection control work. The patients from which the 92 basins were taken all had been screened on admission for MRSA and VRE, and had been found to be negative indicating their presence in the hospital environment.

Study authors discuss how bathing can release skin flora into bath water, and how this water can be a potential contaminant to patients, particularly for mucosal introduction. Nurses should consider bath basins as a potential source of bacterial spread. Potential methods to decrease the likelihood that bath basins will be reservoirs are listed here:
Use disposable bath packages and products
Use disposable cleansing cloths to eliminate reuse of a washcloth to cover all parts of the body
Potential benefits include prevention of urinary tract infections and less skin damage from drying soap and water baths.