Persistent contamination of heater-cooler units for extracorporeal circulation cured by chlorhexidine-alcohol in water tanks

J Hosp Infect. 2018 Jul;99(3):290-294. doi: 10.1016/j.jhin.2018.01.005. Epub 2018 Jan 11.


Recently, surgical site infections due to non-tuberculous mycobacteria (NTM) have been linked to heater-cooler unit contamination. The European Centre for Disease Prevention and Control and manufacturers now recommend the use of hydrogen peroxide in filtered water to fill heater-cooler unit tanks. After implementation of these measures in our hospital, heater-cooler units became heavily contaminated by opportunistic waterborne pathogens such as Pseudomonas aeruginosa and Stenotrophomonas maltophilia. No NTM were detected but fast-growing resistant bacteria could impair their detection. The efficiency of hydrogen peroxide and chlorhexidine-alcohol was compared in situ. Chlorhexidine-alcohol treatment stopped waterborne pathogen contamination and NTM were not cultured whereas their detection efficiency was probably improved.

Keywords: Chlorhexidine–alcohol; Heater–cooler units; Non-tuberculous mycobacteria; Pseudomonas aeruginosa; Stenotrophomonas maltophilia.

MeSH terms

  • Alcohols / pharmacology*
  • Bacteria / drug effects
  • Bacteria / isolation & purification*
  • Chlorhexidine / pharmacology*
  • Cross Infection / prevention & control
  • Disinfectants / pharmacology*
  • Disinfection / methods*
  • Equipment and Supplies / microbiology*
  • Extracorporeal Circulation / methods
  • Hospitals
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Water Microbiology*


  • Alcohols
  • Disinfectants
  • Hydrogen Peroxide
  • Chlorhexidine