The effect of pulsed-xenon ultraviolet disinfection on surfaces contaminated with vancomycin-resistant Enterococci in a Japanese hospital.

INTRODUCTION: Recently, a worldwide outbreak of vancomycin-resistant Enterococci (VRE) was reported. However, due to the low incidence of VRE infection and colonization, VRE contamination of hospital environments has not been fully investigated in Japan. METHODS: Surfaces were swabbed, before and after manual cleaning and after pulsed xenon ultraviolet (PX-UV) disinfection, in five patient rooms that had been occupied by patients colonized with VRE. Difference in the number of VRE-positive samples and VRE colony forming units (CFUs), before and after disinfection, for each cleaning method was estimated. RESULTS: We detected VRE contamination in 22/60 (37%) and 14/60 (23%) samples collected before and after manual cleaning, respectively. In contrast, VRE contamination was not detected in the samples collected after PX-UV disinfection. In addition, 3/5 (60%) spray nozzles of electric warm-water bidet toilet seats were found to be contaminated with VRE before terminal cleaning. Manual cleaning caused a significant decrease in the number of VRE CFUs compared with that before cleaning (P = 0.031). PX-UV disinfection also caused a significant decrease in the number of VRE CFUs compared to that of manual cleaning (P < 0.001). CONCLUSION: We identified hot spots of severe contamination, such as private bathrooms in patient rooms and areas around the bed of patients using diapers and required assistance. VRE contamination persisted even after terminal disinfection; PX-UV disinfection in addition to terminal disinfection was effective at eliminating VRE contamination. These results can be useful in controlling the spread of VRE infections in Japanese hospitals.

Prospective study of bidet toilet use: Association of abnormal vaginal colonization and preterm birth in high-risk pregnant women.

AIM: This study aimed to evaluate the association of bidet toilet use with abnormal vaginal microbial colonization and preterm birth (PTB) in high-risk pregnancies. METHODS: This is a prospective cohort study of 208 women, who were admitted to a high-risk pregnancy unit, due to preterm labor, preterm premature rupture of the membrane, or short cervical length, in two tertiary hospitals from April 2015 to July 2017. Responses to a questionnaire about using bidet toilet and vaginal culture were obtained upon admission. Maternal baseline characteristics, vaginal culture results, and pregnancy and neonatal outcomes were compared between bidet toilet users and nonusers. RESULTS: Among the 204 subjects, 67 (32.8%) women were identified as bidet toilet users. Overall, bidet toilet use was associated with a higher rate of abnormal vaginal microbial colonization, compared to the nonusers (60.7% vs 44.2%, P = 0.036). Notably, Escherichia coli colonization rate was significantly higher in bidet toilet users than nonusers (13.1% vs 3.3%, P = 0.023). Bidet toilet users had a significantly higher rate of PTB before 37 weeks of gestation, compared to the nonusers (87.3% vs 73.0%, P = 0.040). CONCLUSION: Our study suggests that chronic use of a bidet toilet is associated with a higher rate of abnormal vaginal colonization by Gram-negative bacteria and PTB in high-risk pregnancies.

Relationship between bidet toilet use and haemorrhoids and urogenital infections: a 3-year follow-up web survey.

Given the growing use of electric bidet toilets in Japan and other countries, we assessed the relationship between bidet toilet use and haemorrhoids or urogenital infections. Data were collected using a web-based longitudinal survey. In total, 10 305 subjects randomly selected from panels of a Japanese website research company for the baseline survey in 2013 were asked about their frequency of bidet toilet use and receipt of a doctor's diagnosis or subjective symptom of haemorrhoids and urogenital infections. One- and three-year follow-up surveys were performed in 2014 and 2016, respectively, and information on newly diagnosed/experienced outcomes occurring during the follow-up period were collected. Cumulative incidence of haemorrhoids and urogenital infections was not significantly increased by habitual use of a bidet toilet. In men, more habitual users reported subjective symptoms of irritated skin around the anus, which were newly experienced during follow-up than non-habitual users (adjusted risk ratio 1.36 (95% confidence interval 1.06-1.75)). Further studies are needed to confirm this relationship. Several of the outcomes were significantly more prevalent in habitual users, but these results were probably explained by reverse causation.

Survey of electric bidet toilet use among community dwelling Japanese people and correlates for an itch on the anus.

OBJECTIVES: We conducted a survey to investigate the use of bidet toilets among community dwelling Japanese people and explored the correlates for an itch on the anus. METHODS: A questionnaire-based survey was conducted among a convenience sample of individuals, who were derived from outpatients and employees of Kameda Medical Center, and students and employees of two technical colleges. RESULTS: A total of 4,963 respondents were evaluated in this study, 55 % of whom used bidet toilets either before or after defecation, and at least 30 % of bidet users washed the anus before defecation, partly to aid defecation. Men rather than women, and older people (aged ≥50 years) rather than younger people used bidets more actively. Logistic regression analysis showed that the correlates for an itch on the anus included male sex, younger age, washing the anus before defecation, warmer water for washing the anus after defecation, and the frequency of fecal leakage. CONCLUSIONS: Nearly, one-third of bidet toilet users washed the anus before defecation. An itch on the anus may be associated with the active use of bidets.

Severe circumferential rectal ulcer associated with electric bidet toilet use.

A 66-year-old man presented to the gastroenterology department with anal pain. For >10 years, he had used an electric bidet toilet while defecating for >5 min at a time, because of constipation. Two weeks prior to his visit, he became aware of discomfort in his anal area and had used an enema 1 week previously. He had persistent diarrhea and began to use the electric bidet toilet at the highest water pressure for long periods. As a result, his anal pain worsened. A colonoscopy revealed circumferential inflammation and ulceration extending from the anal canal to the lower rectum. Approximately half of the Japanese population washes their anuses before and after defecation. Cleaning the anus after defecation using a bidet contributes to hand hygiene and local comfort, and may be effective against constipation. However, excessive bidet use may cause rectal disorders, such as rectal mucosal prolapse syndrome and solitary rectal ulcers. Herein, we report a rare case of a patient with advanced rectal ulceration caused by electric bidet toilet usage.

Bidet-toilet Use as a Cause of Anterior Aphtoid Ulcer in the Anorectum.

Electric bidet toilets are automatic devices that deliver water jets to clean the anus. Although the use of bidets to clean the anus after defecation contributes to hand hygiene and local comfort, excessive use may cause anal pruritus and incontinence. However, no cases of anorectal aphtoid ulcers caused by bidet use have yet been reported in literature. A 61-year-old woman presented to our hospital with anal bleeding and pain. Anoscopy revealed an aphtoid ulcer in the anterior midline anorectum. She reported using a bidet toilet and washing her anus before and after defecation for one year. The frequency of washing was five times or more per day, the force of the water jet was strong, the thickness of the water was thin, and the duration of washing per use was 1 min or more. She responded well to the advice of stopping bidet use. At the follow-up, 5 weeks after discontinuing bidet use, she became asymptomatic, and the anoscope showed that the aphtoid ulcer had completely healed. The water jet of the bidet toilet seemed to be the causative factor for the anterior aphtoid ulcer in the anorectum.

The Effectiveness of Neutral Electrolyzed Water for Decontaminating the Spray Nozzles of Electric Tankless and Tank-Type Warm-Water Bidet Toilet Seats.

Electrolyzed water is a novel disinfectant that is widely used in the food industry. We conducted an experimental model-based study to determine the effectiveness of neutral electrolyzed water (NEW) for the daily nozzle cleaning of artificially contaminated tankless and tank-type bidet toilet seats. The toilet seats were designed to automatically self-clean the spray nozzles using tap water or NEW after each use or at specified intervals. The numbers of Pseudomonas aeruginosa and Escherichia coli microorganisms in the spray water were measured twice or thrice per week. A Kruskal-Wallis test was used to compare the bacterial count in the spray water of various cleaning (NEW) and control (tap water) conditions. The number of bacteria was significantly lower in NEW conditions with and without periodic nozzle cleaning functions than in tap water conditions for both tank-type and tankless bidet toilet seats. Microorganisms were detected only on the surface area around the opening for ejecting spray water and not in the internal piping at the spray nozzle tip. These findings demonstrate that NEW has superior decontamination efficacy over tap water when used as a cleaning agent for the spray nozzles of warm-water bidet toilet seats.

Effect of the Cleanliness of Spray Nozzle on the Concentration of Microorganisms in the Spray Water in Warm-Water Bidet Toilet Seats.

Bidet-toilets are widely used in households and public spaces in Japan. The effect of nozzle cleanliness on spray water quality of warm-water bidet toilet seats is unknown. We conducted a long-term experimental model-based study (2015-2016) and two survey-based studies (A: 2018-2019 and B: 2020-2021) at a university campus. Survey A measured the effect of nozzle cleansing on total viable count (TVC) and heterotrophic plate counts (HPCs) in spray water. Survey B measured the total organic carbon, residual chlorine concentration, TVC, and HPC of different fractions of sprayed water. We found no upstream migration of microbes from the nozzle to water tanks. While daily cleaning of the nozzle surface could reduce bacterial count in spray water, continuous discharge of water washed away bacterial contamination. Fecal indicator bacteria were in traces in spray water, indicating proper maintenance of these toilet seats.

A Retrospective Investigation on Electric Bidet Use as a Possible Cause of Anal Incontinence.

OBJECTIVES: The present study aimed to explore whether symptoms of anal incontinence (AI) in patients who used electric bidet toilets to clean the anus may improve after discontinuing bidet use. METHODS: Fifty-three patients with AI who habitually used the bidets before or after defecation and were examined between June 2019 and September 2020 were included in this retrospective study. Questionnaires on Likert-scaled items that assessed bidet use were administered at baseline. The sum of all points was regarded as the "bidet use score". The patients were instructed to discontinue bidets until subsequent examination. Incontinence severity was documented using the fecal incontinence severity index (FISI) score. RESULTS: Follow-up data were available for 49 patients (92%). Of those, 43 had fecal incontinence and 6 had only mucus discharge at baseline. The median duration between the baseline and follow-up was 4 weeks. The median FISI score was significantly reduced at the follow-up [baseline vs. follow-up: 15 (range: 3-43) vs. 10 (range: 0-43); P < 0.0001]. The incidence of fecal incontinence was significantly lower at the follow-up than at the baseline (59% vs. 88%, P = 0.003). A higher maximum squeeze pressure and the absence of associated factors that may cause AI (such as rectoanal intussusception and/or rectocele, mucosal prolapse, and previous anorectal surgery) were significantly associated with a reduction of at least 50% in the FISI scores at follow-up; however, this was not observed for the bidet use score. CONCLUSIONS: Our findings suggest that electric bidet use is a possible cause of AI.

Bidet Toilet Use May Cause Anal Symptoms and Nosocomial Infection.

Electric bidet toilets are widely used in Japan and are sanitary devices, that are integral to daily life. Approximately, half of the population washed the anus before or after defecation. Cleaning the anus after defecation using the bidets contributes to hand hygiene and local comfort, and it may be effective against constipation. However, excessive bidet use potentially causes anal pruritus and anal incontinence (AI). Physicians are advised to instruct patients with anal pruritus to avoid excessive cleaning of the anus and those with AI to discontinue bidet use. For the estimation of the inherent severity of AI, physicians should instruct a bidet user with AI to discontinue bidet use and assess the severity of AI later. Additionally, the nozzle surface and splay water of bidet toilets may be contaminated with fecal indicator bacteria, such as Escherichia coli and Pseudomonas aeruginosa, as well as antimicrobial-resistant bacteria, rendering them a potential vehicle for cross-infection. In the hospital setting, compromised patients must be cautious regarding the shared use of bidet toilets to prevent infection by antimicrobial-resistant bacteria. Specifically, they should be provided with bidet toilets exclusive for them or may need to be instructed to not use a bidet.