Acetic acid as a decontamination method for ICU sink drains colonized by carbapenemase-producing Enterobacteriaceae and its effect on CPE infections

Background: Carbapenemase-producing Enterobacteriaceae (CPE) are emerging pathogens representing a major concern for public health. In Belgium, the OXA-48 carbapenemase resistance gene is identified most frequently. Sink drains in intensive care units (ICUs) are known to be colonized by Gram-negative bacilli. A correlation between environmental contamination and CPE infections in ICUs has been established. A long-term CPE epidemic in a local ICU proved difficult to control. Methods and results: A variety of CPE strains, all carrying the OXA-48 resistance gene, were isolated from almost all sinks in patient rooms in the ICU. Decontamination of the sinks with 250 mL 25% acetic acid three times weekly was implemented. Sink drain colonization was followed up for six months thereafter. Both the number of CPE-colonized sinks and the number of patients colonized or infected with CPE decreased drastically, to the extent that the epidemic was considered to be eradicated. In-vitro growth of all isolates was inhibited by a concentration of acetic acid equal to or smaller than that used for decontamination. Epidemiological analysis demonstrated a positive and significant relationship between contaminated sinks and CPE acquisition of patients admitted to ICU rooms, indicating the importance of contaminated sinks as the environmental reservoir of the epidemic. Conclusion: Decontamination of sink drains with acetic acid is a valuable alternative to other methods, such as heated sinks and water-free care, especially when other options are not feasible in the short term. Acetic acid is cheap, widely available, effective and manageable from a safety and technical point of view. (C) 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.