Guidelines

Description

The United States has lagged behind our European counterparts in producing engineering and water treatment standards designed to protect building occupants from the risk of Legionellosis in water systems. The earliest U.S. guidance document — Approaches to Prevention and Control of Legionella Infection in Allegheny County Health Care Facilities — was produced in 1993 by the Allegheny County Health Department (ACHD), Pittsburgh, Pennsylvania. Numerous hospitals were experiencing outbreaks of Legionnaires' disease and the Centers for Disease Control & Prevention (CDC) approach of postponing environmental monitoring until after cases had occurred was deemed inadequate.

 

In Our Opinion

A more proactive approach was needed and the ACHD guideline filled that void by recommending that healthcare facilities culture their water systems before cases of Legionnaires' disease were diagnosed in their hospitals. Drs. Victor L. Yu and Janet E. Stout were instrumental in its development.

Description

Guidelines for the Prevention of Healthcare-associated Pneumonia describes the approach to prevention of healthcare acquired Legionnaires' disease. This document states that environmental culturing of the hospital water system can be performed as part of a comprehensive strategy to prevent Legionnaires' disease in transplant patients.

 

For facilities with hemopoietic stem-cell- and/or solid-organ transplantation programs, periodic culturing for legionellae in water samples from the transplant unit(s) can be performed as part of a comprehensive strategy to prevent Legionnaires' disease in transplant recipients.

Description

Outbreaks of healthcare-associated Legionnaires' disease in Maryland raised questions about the need for further public health guidelines to reduce the risk of legionella infections associated with water systems. Maryland Department of Health and Mental Hygiene (DHMH), formed a Scientific Working Group to review scientific and technical data and gather information from experts on the current status of prevention and management of water system-related legionella bacteria. This report summarizes the key findings and recommendations of the Scientific Working Group.

 

Report Recommendation - Water distribution systems within acute care hospitals (i.e., all building plumbing systems that distribute water for human contact) should be routinely cultured, with the time schedule determined by risk assessment for each institution. The periodicity and interpretation of environmental testing should be determined as part of an overall risk assessment process. Such a risk assessment process should consider both institutional risk factors and remediation efforts.

 

In Our Opinion

The State of Maryland Working Group recognized the need for a more proactive approach (beyond CDC recommendations) to the prevention of healthcare-acquired Legionnaires' disease. Like the Allegheny County Health Department Guidelines, the Maryland report recommends pre-emptive culturing for Legionella to identify whether Legionella colonization of the hospital hot water system is a problem before a patient becomes infected.

Description

The state of New York issued guidelines to underscore the importance of preventing healthcare-associated Legionnaires' disease. The first edition of the New York State Department of Health (NYSDOH) guidance was issued in 1999, and updated in 2005.

 

All healthcare facilities are required to conduct surveillance for Legionella infections and to ensure proper maintenance of potable water systems and cooling towers. Culturing for Legionella spp. in potable water samples from HSCT (bone marrow) or solid organ transplant units shall be performed at least quarterly as part of a comprehensive strategy to prevent Legionnaires' disease. Culture is the gold standard for environmental testing for Legionella. The laboratory chosen for culturing should be proficient in culturing environmental samples for Legionella. PCR and DFA methods are not useful for environmental sampling.

 

In Our Opinion

New York, like Pennsylvania and Maryland, saw increasing numbers of cases of healthcare-acquired Legionnaires' disease. National guidance from CDC does not recommend environmental testing for Legionella - a critical step in determining risk for Legionnaires' disease in hospitals. This gap is addressed in the New York State Department of Health Guideline.

Description

The Joint Commission produced guidance for management of utility water systems in the Environment of Care Hospital Accreditation Program in 2008. The [organization] manages risks associated with its utility systems.

 

The guidance that the addresses the risk of Legionella in hospital water systems by requiring "The organization identifies and implements processes to minimize pathogenic biological agents in cooling towers, domestic hot/cold water systems, and other aerosolizing water systems."

 

In Our Opinion

While a step in the right direction, the Joint Commission Environment of Care Standard provides no specific guidance on how the risk of healthcare-acquired Legionnaires' disease is to be mitigated. We are aware that Joint Commission inspectors are inquiring as to whether the institution has a plan, so hospitals should have a Legionella risk management plan in place.

Description

Published in 2000, the purpose of the ASHRAE guideline was to provide information and guidance to reduce Legionella contamination in building water systems. This guideline provides specific environmental and operational guidelines that assist managers and operators in the safe operation of building water systems and is intended to reduce the risk of building-associated Legionellosis.

 

In Our Opinion

Guideline 12-2000 has much to offer in details of systems operation and background information on Legionnaires' disease. However, much of the information on remediation will, if followed, not reduce the risk of Legionellosis.

 

We have written on the lack of evidence-based and validated recommendations in the guideline Preventing Legionellosis (Stout ASHRAE Journal 2007). The guideline does note that environmental testing for Legionella can be performed to evaluate the efficacy of treatment methods and should be performed if there is suspicion of cases of Legionnaires' disease.

Description

The Centers for Disease Control and Prevention (CDC), the Infectious Disease Society of America (IDSA) and the American Society of Blood and Transplantation (ASBT) provide recommendations for prevention of Legionnaires' disease in a document titled Guidelines for Preventing Opportunistic Infections Among Hematopoietic Stem Cell Tranplant (HSCT) Recipients. They recommend an environmental investigation to determine the likely environmental source of Legionella after cases of hospital-acquired Legionnaires' disease has been identified either in a person in an inpatient HSCT unit or in a person who has visited an outpatient HSCT center.

 

In Our Opinion

It is encouraging that the guideline notes that these patients are at much higher risk for disease and death from Legionellosis, and periodic routine culturing for legionellae in water samples from the transplant units' potable water supply may (should) be part of an overall prevention strategy in such unit. We are equally concerned about other waterborne pathogens such as Pseudomonas, Stenotrophomonas and Acinetobacter. There is growing evidence that Aspirgillus infections can be acquired from exposure to water. Considering that the air in HSCT unit is purified through HEPA filters, shouldn't patients be equally protected from tap water?