J Prev Med Hyg. 2021 Sep 15;62(3):E751-E758. doi: 10.15167/2421-4248/jpmh2021.62.3.1944. eCollection 2021 Sep.
Legionella contamination of a cold-water supplying system in a German university hospital - assessment of the superheat and flush method for disinfection.
Journal of preventive medicine and hygiene
Matthias Unterberg, Tim Rahmel, Thomas Kissinger, Christian Petermichl, Michael Bosmanns, Martin Niebius, Christina Schulze, Hans-Peter Jochum, Nina Parohl, Michael Adamzik, Hartmuth Nowak
Affiliations
Affiliations
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Knappschaftskrankenhaus Bochum, Bochum, Germany.
- Nursing Service Management, University Hospital Knappschaftskrankenhaus Bochum, Bochum, Germany.
- Department of Hygiene, University Hospital Knappschaftskrankenhaus Bochum, Bochum, Germany.
- Management, University Hospital Knappschaftskrankenhaus Bochum, Bochum, Germany.
- HyKoMed GmbH, Lünen, Germany.
PMID: 34909504
PMCID: PMC8639127 DOI: 10.15167/2421-4248/jpmh2021.62.3.1944
Abstract
INTRODUCTION: In case of a contamination of water-supplying systems in hospitals with legionella, usually chemical disinfection measures are used for remediation. Unfortunately, it is reported, that these methods may not be sustainable, have an impact on water quality, and can even fail. As an alternative, the superheat and flush method does not need any special equipment, can be initiated in a short lead of time and does not affect the water quality. However, evidence on this disinfection measurement against legionella is lacking. We therefore investigated and report on the effectiveness and long-term results of the superheat and flush disinfection method.
METHODS: During routine periodical examinations, a rising count of legionella was detected in the cold-water supplying system at a German university hospital. Adapted to an analysis of risks, effort and benefit, the superheat and flush procedure was applied twice within 6 months.
RESULTS: While 33 out of 70 samples had a higher legionella count than the legal threshold of 100 CFU/100 mL (CFU - Colony Forming Units) before the first disinfection was carried out, this number could be reduced to 1 out of 202 samples after the first intervention. Additionally, in contrast to previously published studies, the effect was long-lasting, as no relevant limit exceedance occurred during the following observation period of more than two years.
CONCLUSION: The superheat and flush disinfection can provide an economic and highly effective measure in case of legionella contamination and should be shortlisted for an eradication attempt of affected water-supplying systems in hospitals.
©2021 Pacini Editore SRL, Pisa, Italy.
Keywords: Hospital-acquired Legionnaires’; Legionella; Superheat and flush; Water-supplying system; disease
Conflict of interest statement
Conflict of interest statement The authors declare no conflict of interest.
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