Efficacy of chlorine dioxide disinfection to non-fermentative Gram-negative bacilli and non-tuberculous mycobacteria in a hospital water system

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• 作者：M.-S. Hsu^a ; M.-Y. Wu^b ; Y.-T. Huang^a ; C.-H. Liao^a ; ^c ; ^{liaochunhsing@gmail.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Chlorine dioxide ; Non-fermentative Gram-negative bacilli ; Non-tuberculous mycobacteria ; Water disinfection
• 刊名：Journal of Hospital Infection
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：93
• 期：1
• 页码：22-28
• 全文大小：271 K

文摘

Chlorinated tap water in hospitals often contains low levels of non-fermentative Gram-negative bacilli (NFGNB) and non-tuberculous mycobacteria (NTM). Measures are needed to ensure a safe water supply in hospitals to prevent nosocomial infections from these waterborne pathogens.

Aim

To evaluate the efficacy of ClO₂ treatment of a hospital water system on the levels of NFGNB and NTM in the water.

Methods

Our institution is a 1000-bed medical centre with two main buildings (B1 and B2). B1 has three intensive care units (ICUs) and transplant wards and polyethylene water pipes. B2 (control) has no ICUs and galvanized water pipes. A ClO₂ generating unit was installed in the water system of B1 in April 2012 and water samples were collected in B1 and B2 before and eight times after installation. All samples were cultured for NFGNB and NTM.

Findings

The ClO₂ concentration was significantly lower in the hot water than in the cold water (P < 0.001). After 40 weeks of ClO₂ use, the overall NFGNB colonies decreased significantly (hot water: 160 ± 143 vs 2 ± 4 cfu/mL, P < 0.001; cold water: 108 ± 138 vs 3 ± 7 cfu/mL, P < 0.001). Highly prevalent nosocomial NFGNB, such as Pseudomonas spp. and Stenotrophomonas spp., were undetected three months after ClO₂ disinfection; Sphingomonas spp. persisted but had lower colony counts. NTM was present in 25% (three out of 12) of sampling locations initially, but was not detected at two weeks after ClO₂ disinfection. The ICUs had no overall change in the number of NFGNB nosocomial infections after the intervention.

Conclusion

Addition of a ClO₂ disinfection unit to our hospital water system reduced the numbers of NTM and NFGNB in the hot and cold water systems.