{"doc_desc":{"title":"Water\u2013Vapor treatment of Shower Systems in healthcare facilities: An effective protocol to contain the risk of exposure to Legionella of at-risk patients"},"study_desc":{"title_statement":{"idno":"10.16909-dataset-62","title":"Water\u2013Vapor treatment of Shower Systems in healthcare facilities: An effective protocol to contain the risk of exposure to Legionella of at-risk patients","translated_title":"\u00c9valuation d'un dispositif de m\u00e9lange vapeur-eau pour \u00e9liminer et contr\u00f4ler les biofilms et le tartre dans les syst\u00e8mes de douche"},"authoring_entity":[{"name":"Helene Niculita-Hirzel","affiliation":"Unisant\u00e9, University Center for Primary Care and Public Health &  University of Lausanne, Lausanne, Switzerland"}],"production_statement":{"producers":[{"name":"Alexis Marette","abbr":"","affiliation":"Gjosa","role":""}],"copyright":"This dataset is available under the CC-BY licence : https:\/\/creativecommons.org\/licenses\/by\/4.0\/","funding_agencies":[{"name":"Innosuisse","abbr":"","role":""}],"grant_no":"61963.1 INNO-EE"},"distribution_statement":{"contact":[{"name":"Group Microbiomes and Health","affiliation":"Unisant\u00e9, University Center for Primary Care and Public Health &  University of Lausanne, Lausanne, Switzerland","email":"mebs@unisante.ch","uri":""}]},"version_statement":{"version_date":"2026-01-01"},"study_info":{"keywords":[{"keyword":"Legionella","vocab":"","uri":""},{"keyword":"Legionnaires' disease","vocab":"","uri":""},{"keyword":"healthcare facilities","vocab":"","uri":""},{"keyword":"shower systems","vocab":"","uri":""},{"keyword":"built-environment microbiome","vocab":"","uri":""}],"abstract":"Legionnaires' disease (LD) causes severe pneumonia with 5-15 percent (%) fatality rates in hospitalized patients, with rising incidence across Europe, North America and Japan. While established disinfection protocols exist for building pipes, no large-scale solution addresses shower systems themselves, where point-of-use filters remain impractical for widespread implementation. We assessed an effective protocol to contain Legionella proliferation from terminal water outlets in healthcare facilities, nursing homes, and high-risk residences.\n\t\tWe evaluated an innovative water-vapor protocol consisting of sequential water flushing followed by high-pressure vapor at 120\u2103. Biofilms were grown under controlled conditions across five settings\u2014one healthcare facility, one nursing home, and three private residences\u2014targeting biofilms aged 5-104 weeks during peak LD season. Efficacy was assessed through scanning electron microscopy, flow cytometry, 16S rRNA sequencing, and functional pathway analysis (PICRUSt2), comparing results with conventional thermal disinfection (65\u2103, 10 minutes) and untreated controls.","coll_dates":[{"start":"2022\/06\/21","end":"2022\/09\/21","cycle":""}],"nation":[{"name":"Switzerland","abbreviation":"CHE"},{"name":"France","abbreviation":"FR"}],"geog_coverage":"Lausanne, Nods, Nidau and Pr\u00eales (Switzerland)\nSt-Etienne (France)","universe":"healthcare facilities, nursing homes, and residences of patients at high-risk of contracting Legionellosis","data_kind":"--"},"method":{"data_collection":{"data_collectors":[{"name":"Unisante Microbiomes et Sant\u00e9","abbr":"","role":"","affiliation":""}],"sampling_procedure":"Shower systems were installed in replicate across 5 different settings\u2014In the healthcare facility in Lausanne (University hospital of Lausanne, Switzerland) and in the nursing home in St-Etienne (France) shower units were installed in triplicate for each treatment condition (no treatment, water-vapor treatment, or conventional thermal disinfection) and for each biofilm age targeted for sampling. In the domestic settings, three residential setting located in Nods, Nidau and Pr\u00eales (Switzerland) were selected based on the presence of at least two independent shower cabins per building, allowing for paired comparisons between treated and untreated conditions. The frequency of use was controlled to ensure biofilm grow. At 5 weeks, 32 weeks, 52 weeks and 104 weeks, paired biofilms were either directly extracted or subjected to a single treatment either water-vapor treatment or thermal disinfection (10 min at 65\u2103) prior to extraction. To assess the effects of repeated weakly water-vapor treatments, biofilms aged 32 weeks were treated once per week for four consecutive weeks, one sample was extracted after each treatment,      \n\t\t\tThe efficacy of the treatment in removing biofilm from hoses was visualized by scanning electron microscopy on 1 cm sections cut from both extremities and the center of each hose. These pieces were fixed in 2.5% Glutaraldehyde \/ Cacodylate buffer (0.1 M, pH 7.2), dehydrated with increasing concentration of ethanol and carbon-coated by thermal evaporation. Biofilms from the remaining hose sections were extracted following previously validated protocol. Total cell counts were determined by flow cytometry using SYBR green and PicoGreen-stained aliquots, and metal concentration by inductively coupled plasma mass spectrometry (ICP-MS Thermo iCAP TQ) following previously published protocol. Microbiome community composition was assessed by 16S rRNA gene amplicon sequencing targeting the V3-V4 regions, using the Illumina MiSeq plateform, when sufficient DNA was available. SEM and ICP-MS analysis were performed by the Forensic Toxicology and Chemistry Unit (UTCF) at CHUV, and sequencing by Microsynth (Switzerland).","coll_mode":["Other [oth]"],"sources":[{"name":"","origin":"","characteristics":""}],"coll_situation":"Study design\nShower systems were installed in replicate across 5 different settings. In the healthcare facility Lausanne (University hospital of Lausanne, Switzerland) and in the nursing home in St-Etienne (France) shower units were installed in triplicate for each treatment condition (no treatment, water-vapor treatment, or conventional thermal disinfection) and for each biofilm age targeted for sampling. In the domestic settings, three residential setting located in Nods, Nidau and Pr\u00eales (Switzerland) were selected based on the presence of at least two independent shower cabins per setting, allowing for paired comparisons between treated and untreated conditions. The frequency of use was controlled to ensure biofilm grow. At 5 weeks, 32 weeks, 52 weeks and 104 weeks, paired biofilms were either directly extracted or subjected to a single treatment either water-vapor treatment or thermal disinfection prior to extraction. To assess the effects of repeated weakly water-vapor treatments, biofilms aged 32 weeks were treated once per week for four consecutive weeks, one sample was extracted after each treatment.      \nThe efficacy of the treatment in removing biofilm from hoses was visualized by scanning electron microscopy on 1x1 cm2 sections cut from both extremities and the center of each hose. These pieces were fixed in 2.5% Glutaraldehyde \/ 0.1 M Cacodylate buffer pH 7.2, dehydrated with increasing concentration of ethanol and carbon-coated by thermal evaporation. Biofilms from the remaining hose sections were extracted following previously validated protocol11. Total and viable cell counts were determined by flow cytometry passing SYBR green and PicoGreen-stained aliquots on a CYTOFLEX S2 (Beckman Coulter, US), and metal concentration by inductively coupled plasma mass spectrometry (ICP-MS Thermo iCAP TQ) following previously published protocol11,12. Microbiome community composition was assessed by 16S rRNA gene amplicon sequencing targeting the V3-V4 regions, using the Illumina MiSeq plateform, when sufficient DNA was available. ICP-MS analysis was performed by the Forensic Toxicology and Chemistry Unit (UTCF) at CHUV, and sequencing by Microsynth (Switzerland). Detailed protocol is provided in Annex 1."}},"data_access":{"dataset_availability":{"access_place":"Unisant\u00e9 Data repository","access_place_url":"https:\/\/doi.org\/10.16909\/62","status":"This dataset is available under the CC-BY licence : https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},"dataset_use":{"contact":[{"name":"Documentation and data unit (UDD)","affiliation":"Unisant\u00e9, University Center for Primary Care and Public Health &  University of Lausanne, Lausanne, Switzerland","email":" udd.data@unisante.ch","uri":"https:\/\/www.unisante.ch\/fr\/formation-recherche\/bibliotheque"}],"cit_req":"You, T., Parmar, P., Niculita-Hirzel, H.Water. Vapor treatment of Shower Systems in healthcare facilities: An effective protocol to contain the risk of exposure to Legionella of at-risk patients. Center for Primary Care and Public Health (Unisant\u00e9), University of Lausanne, Switzerland. Version 1.0 of the licensed dataset (08\/2025), provided by the Unisant\u00e9 Research Data Repository. DOI:https:\/\/doi.org\/10.16909\/dataset\/62","disclaimer":"The user of the data acknowledges that the original collector of the data, the authorized distributor of the data, and the relevant funding agency bear no responsibility for use of the data or for interpretations or inferences based upon such uses."}}},"schematype":"survey"}