Public health and healthcare-associated risk of electric, warm-water bidet toilets

J Hosp Infect. 2017 Nov;97(3):296-300. doi: 10.1016/j.jhin.2017.07.021. Epub 2017 Jul 26.


Background: In recent years, installation of bidet toilets within hospitals in Japan has raised concerns regarding potential for cross-contamination by antimicrobial-resistant bacteria from patients who are hospitalized over an extended period.

Aim: To investigate the distribution of antimicrobial-resistant bacteria recovered from bidet toilets at a university-affiliated hospital in Japan.

Methods: All 292 electric bidet toilets at a university hospital were sampled for contamination. Swabs for culture were used to sample water-jet nozzles and toilet seats.

Findings: Of the 292 toilet seats sampled, warm-water nozzles of 254 (86.9%) were found to be contaminated by one or more of the following organisms: Staphylococcus aureus, Streptococcus spp., Enterococcus spp., Enterobacteriaceae and non-Enterobacteriaceae Gram-negative bacteria. S. aureus was recovered from one water-jet nozzle and nine toilet seats; of these, meticillin-resistant S. aureus was recovered from the water-jet nozzle and from one toilet seat. Both the water-jet nozzle and seat of the same toilet were contaminated with a CTX-M-9 group extended-spectrum β-lactamase-producing Escherichia coli. Of the Gram-negative isolates recovered from samples, the organism with the highest frequency of isolation was Stenotrophomonas maltophilia, which was recovered from 39 bidet toilets.

Conclusion: Warm-water nozzles of bidet toilets are contaminated with a wide range of bacteria, making them a potential vehicle for cross-infection. In the hospital setting, shared use of bidet toilets must consider the clinical background of patients. Based on these findings, these devices must be part of the risk management programme, and steps should be included for monitoring and disinfection.

Keywords: Antimicrobial-resistant bacteria; Bacterial contamination; Bidet toilet.

MeSH terms

  • Cross Infection / epidemiology
  • Cross-Sectional Studies
  • Environmental Microbiology*
  • Gram-Negative Bacteria / classification
  • Gram-Negative Bacteria / isolation & purification*
  • Gram-Positive Bacteria / classification
  • Gram-Positive Bacteria / isolation & purification*
  • Hospitals, University*
  • Humans
  • Japan
  • Risk Assessment
  • Toilet Facilities*