{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:03:54Z","timestamp":1753891434927,"version":"3.41.2"},"reference-count":29,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,6,15]],"date-time":"2023-06-15T00:00:00Z","timestamp":1686787200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>The \u201cLeTriWa study\u201d on community-acquired cases of Legionnaires\u2019 disease (LD) found that most cases likely acquired their infection at home (AHALD). However, which sources confer the infection is largely unknown. We therefore analyzed the data set from the LeTriWa study to find out if individual sources were associated with AHALD and if specific behavioral habits may increase or lower the risk for AHALD.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>During the study we had used two comparison groups: (i) controls matched for age group and hospital (\u201ccontrols\u201d), (ii) household members of cases with AHALD (\u201cAHALD-HHM\u201d). We inquired about exposure to water sources, such as showering or wearing dentures, as well as behavioral factors and habits related to oral hygiene. We took standardized household bathroom water and biofilm samples of both cases with AHALD and controls, and in addition from households of cases with AHALD only samples from suspect residential (non-)drinking water sources. We first conducted bivariate analyses for infection sources and behaviors, followed by multivariable analyses.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>There were 124 cases with AHALD, 217 controls and 59 AHALD-HHM. In bivariate analyses using controls for comparison, wearing dentures was the only variable significantly positively associated (odds ratio (OR) = 1.7, 95% confidence interval (CI) = 1.1\u20132.7, <jats:italic>p<\/jats:italic>-value = 0.02). Behavioral factors such as showering, letting water run before use and not being alcohol abstinent were significantly negatively associated, smoking was significantly positively associated. In a multivariable analysis, we identified good oral hygiene as a preventive factor for both denture wearers (OR = 0.33, 95% CI = 0.13\u20130.83, <jats:italic>p<\/jats:italic>-value = 0.02) and non-denture wearers (OR = 0.32, 95% CI = 0.10\u20131.04, <jats:italic>p<\/jats:italic>-value = 0.06). Analyses of comparisons with AHALD-HHM showed similar effects but lacked statistical power. We identified <jats:italic>Legionella<\/jats:italic> in 16 residential (non-)drinking water sources, one of which was a PCR-positive scratch sample of dentures.<\/jats:p><\/jats:sec><jats:sec><jats:title>Discussion<\/jats:title><jats:p>Wearing (inadequately cleaned) dentures or poor oral hygiene might confer an increased risk for AHALD, and oral hygiene may prevent AHALD. The hypothesis that <jats:italic>Legionella<\/jats:italic> in oral biofilm or dental plaque may be the cause of cases with AHALD should be examined further. If confirmed this may open new and simple avenues for the prevention of LD.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fmicb.2023.1199572","type":"journal-article","created":{"date-parts":[[2023,6,15]],"date-time":"2023-06-15T05:31:31Z","timestamp":1686807091000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Could oral hygiene prevent cases of at-home-acquired Legionnaires\u2019 disease? \u2013 Results of a comprehensive case\u2013control study on infection sources, risk, and protective behaviors"],"prefix":"10.3389","volume":"14","author":[{"given":"Ann-Sophie","family":"Lehfeld","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Franziska","family":"Reber","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marina M.","family":"Lewandowsky","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Heiko J.","family":"Jahn","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian","family":"L\u00fcck","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Markus","family":"Petzold","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Benedikt","family":"Schaefer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anna-Rachel","family":"Germelmann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katrin","family":"Lorenz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Udo","family":"Buchholz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2023,6,15]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"191","DOI":"10.1067\/moe.2002.123493","article-title":"Effect of professional oral health care on the elderly living in nursing homes","volume":"94","author":"Adachi","year":"2002","journal-title":"Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod."},{"key":"ref2","doi-asserted-by":"publisher","first-page":"2924","DOI":"10.1001\/jama.1990.03440210074036","article-title":"Association of shower use with Legionnaires' disease. Possible role of amoebae","volume":"263","author":"Breiman","year":"1990","journal-title":"JAMA"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"3","DOI":"10.25646\/9144.2","article-title":"Epidemiologie der Legion\u00e4rskrankheit in Deutschland \u2013 Entwicklungen in den Jahren 2010 bis 2020","volume":"42","author":"Brodhun","year":"2021","journal-title":"Epid. Bull."},{"key":"ref4","doi-asserted-by":"publisher","first-page":"e0241724","DOI":"10.1371\/journal.pone.0241724","article-title":"Source attribution of community-acquired cases of Legionnaires' disease-results from the German LeTriWa study; Berlin, 2016\u20132019","volume":"15","author":"Buchholz","year":"2020","journal-title":"PLoS One"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1789","DOI":"10.1001\/archinte.158.16.1789","article-title":"The AUDIT alcohol consumption questions (AUDIT-C): an effective brief screening test for problem drinking. Ambulatory care quality improvement project (ACQUIP). Alcohol use disorders identification test","volume":"158","author":"Bush","year":"1998","journal-title":"Arch. Intern. Med."},{"key":"ref6","doi-asserted-by":"publisher","first-page":"e30","DOI":"10.1016\/j.ijid.2010.09.007","article-title":"Progress in the surveillance and control of Legionella infection in France, 1998\u20132008","volume":"15","author":"Campese","year":"2011","journal-title":"Int. J. Infect. Dis."},{"key":"ref7","doi-asserted-by":"publisher","first-page":"1167","DOI":"10.3201\/eid2107.141130","article-title":"Results from the national Legionella outbreak detection program, the Netherlands, 2002\u20132012","volume":"21","author":"Den Boer","year":"2015","journal-title":"Emerg. Infect. Dis."},{"key":"ref8","doi-asserted-by":"publisher","first-page":"566","DOI":"10.1016\/j.puhe.2006.03.009","article-title":"Risk factors for sporadic community-acquired Legionnaires' disease. A 3-year national case-control study","volume":"120","author":"Den Boer","year":"2006","journal-title":"Public Health"},{"year":"2004","key":"ref9"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"173","DOI":"10.1007\/s00408-011-9297-0","article-title":"Association between pneumonia and oral care in nursing home residents","volume":"189","author":"El-Solh","year":"2011","journal-title":"Lung"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"175","DOI":"10.1016\/j.job.2021.02.003","article-title":"Correlation between the relative abundance of oral bacteria and Candida albicans in denture and dental plaques","volume":"63","author":"Fujinami","year":"2021","journal-title":"J. Oral Biosci."},{"key":"ref12","doi-asserted-by":"publisher","first-page":"591","DOI":"10.1093\/alcalc\/37.6.591","article-title":"Audit-3 and audit-4: effectiveness of two short forms of the alcohol use disorders identification test","volume":"37","author":"Gual","year":"2002","journal-title":"Alcohol Alcohol."},{"key":"ref13","doi-asserted-by":"publisher","first-page":"1673","DOI":"10.1007\/s10096-011-1492-7","article-title":"Legionella pneumophila urinary antigen subtyping using monoclonal antibodies as a tool for epidemiological investigations","volume":"31","author":"Helbig","year":"2012","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"ref14","doi-asserted-by":"publisher","first-page":"28S","DOI":"10.1177\/0022034514552493","article-title":"Denture wearing during sleep doubles the risk of pneumonia in the very elderly","volume":"94","author":"Iinuma","year":"2015","journal-title":"J. Dent. Res."},{"key":"ref15","doi-asserted-by":"publisher","first-page":"1016","DOI":"10.1177\/154405910808701104","article-title":"Pyrosequencing analysis of the oral microflora of healthy adults","volume":"87","author":"Keijser","year":"2008","journal-title":"J. Dent. Res."},{"key":"ref16","doi-asserted-by":"publisher","first-page":"3","DOI":"10.25646\/10170","article-title":"Infektionsquellensuche bei ambulant erworbenen F\u00e4llen von Legion\u00e4rskrankheit \u2013 Ergebnisse der LeTriWa-Studie; Berlin, 2016\u20132020 \u2013 Teil 2 (Ergebnisse und Diskussion)","volume":"28","author":"Lehfeld","year":"2022","journal-title":"Epid. Bull."},{"key":"ref17","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1086\/426023","article-title":"Modifiable risk factors for nursing home-acquired pneumonia","volume":"40","author":"Quagliarello","year":"2005","journal-title":"Clin. Infect. Dis."},{"key":"ref18","doi-asserted-by":"publisher","first-page":"50","DOI":"10.1902\/jop.2001.72.1.50","article-title":"Potential associations between chronic respiratory disease and periodontal disease: analysis of national health and nutrition examination survey III","volume":"72","author":"Scannapieco","year":"2001","journal-title":"J. Periodontol."},{"key":"ref19","doi-asserted-by":"publisher","first-page":"155","DOI":"10.1159\/000510191","article-title":"Biofilms on restorative materials","volume":"29","author":"Schmalz","year":"2021","journal-title":"Monogr. Oral Sci."},{"key":"ref20","doi-asserted-by":"publisher","first-page":"101644","DOI":"10.1016\/j.jebdp.2021.101644","article-title":"Cleaning of removable dental prostheses \u2013 a systematic review","volume":"21","author":"Schmutzler","year":"2021","journal-title":"J. Evid. Based Dent. Pract."},{"key":"ref21","doi-asserted-by":"publisher","first-page":"291","DOI":"10.1186\/1471-2334-13-291","article-title":"Legionnaires' disease case-finding algorithm, attack rates, and risk factors during a residential outbreak among older adults: an environmental and cohort study","volume":"13","author":"Silk","year":"2013","journal-title":"BMC Infect. Dis."},{"key":"ref22","doi-asserted-by":"publisher","first-page":"2109","DOI":"10.1111\/jgs.14260","article-title":"Oral care and mortality in older adults with pneumonia in hospitals or nursing homes: systematic review and meta-analysis","volume":"64","author":"Sjogren","year":"2016","journal-title":"J. Am. Geriatr. Soc."},{"key":"ref23","doi-asserted-by":"publisher","first-page":"9576","DOI":"10.1038\/s41598-020-66312-2","article-title":"Association between oral health and incidence of pneumonia: a population-based cohort study from Korea","volume":"10","author":"Son","year":"2020","journal-title":"Sci. Rep."},{"key":"ref24","doi-asserted-by":"publisher","first-page":"596","DOI":"10.7326\/0003-4819-90-4-596","article-title":"Sporadic community-acquired Legionnaires' disease in the United States. A case-control study","volume":"90","author":"Storch","year":"1979","journal-title":"Ann. Intern. Med."},{"key":"ref25","doi-asserted-by":"publisher","first-page":"1685","DOI":"10.1001\/archinte.1996.00440140115011","article-title":"Risk factors for domestic acquisition of Legionnaires disease. Ohio Legionnaires disease group","volume":"156","author":"Straus","year":"1996","journal-title":"Arch. Intern. Med."},{"key":"ref26","doi-asserted-by":"publisher","first-page":"387","DOI":"10.7416\/ai.2018.2238","article-title":"Presence of Legionella spp. in human dental plaque","volume":"30","author":"Tesauro","year":"2018","journal-title":"Ann. Ig."},{"volume-title":"Management of Legionella in water systems","year":"2019","key":"ref27"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"209","DOI":"10.1111\/j.1600-051x.1984.tb02211.x","article-title":"Plaque and systemic disease: a reappraisal of the focal infection concept","volume":"11","author":"Thoden van Velzen","year":"1984","journal-title":"J. Clin. Periodontol."},{"key":"ref29","doi-asserted-by":"publisher","first-page":"515","DOI":"10.1016\/s0140-6736(05)75550-1","article-title":"Oral care and pneumonia. 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