予防と感染制御のジャーナル オープンアクセス

抽象的な

Investigation of Methods of Cleaning Taps to Prevent Hospital- Associated Infections: An Environmental Survey Based Study

Masayoshi Hashimoto1,2, Satomi Asai2,3*, Kazuo Umezawa3,4, Ryosuke Tanitsu2, Miki Miyazawa2, Michiko Kobayashi2,5, Yuji Kawakami6, Yoshika Sekine7, Yuji Suzuki1, Hayato Miyachi3, Kenji Okami2,8

Background: Contamination around washbasins in hospital wards can cause nosocomial infections. Specifically, bacteria that adhere to taps may cause nosocomial infections by adhering to medical staff and patients using such taps. A previous environmental survey of washbasins in the emergency high care unit of Tokai university hospital identified Carbapenem Resistant Enterobacterales (CRE) in samples from washbasin taps.

Aims: This study investigated methods of cleaning taps using commonly used detergents and disinfectants to assess their effectiveness at removing hard scale and CRE.

Methods: We conducted a bacteriological survey around four washbasins in the high care unit of the advanced emergency and critical care center of Tokai university hospital in Kanagawa, Japan. The bacterial count was measured according to a semi-quantitative culture method. A microdilution method was used for susceptibility testing of the bacterial isolates. Different methods of cleaning taps were undertaken using various cleaning agents, including environmental-neutral detergent, citric acid, baking soda, cleanser, 80% ethanol, 0.1% sodium hypochlorite, and a phosphoric acid-based environmental detergent (space shot). The cleaning effect was assessed based on the agent’s effectiveness at removing hard scale from taps.

Results: Biofilms and scales were identified on taps, and several types of bacteria were cultured. Soft scales could be removed by cleaning taps with neutral detergent, cleanser, 80% ethanol, and 0.1% sodium hypochlorite; hard scales could not be removed by scraping them with clips and screwdrivers for 30 minutes, and multiple bacteria were recovered from taps after cleaning. However, a phosphoric acid-based strongly acidic environmental detergent was effective in removing hard scales. After cleaning with the environmental detergent, the bacterial count decreased, and no CRE or other pathogenic microorganisms were detected.

Conclusion: A phosphoric-acid based detergent was very effective in removing hard scales. Effective cleaning of the taps as part of the hygiene management of washbasins is important for hospital infection control.