Nursing home wastewater surveillance for early warning of SARS-CoV-2-positive occupants-Insights from a pilot project at 8 facilities.

BACKGROUND: Wastewater surveillance for SARS-CoV-2 has been used widely in the United States for indication of community incidence during the COVID-19 pandemic, but less is known about the feasibility of its use on a building level in nursing homes to provide early warning and prevent transmission. METHODS: A pilot study was conducted at 8 Department of Veterans Affairs nursing homes across the United States to examine operational feasibility. Wastewater from the participating facilities was sampled daily during the week for 6 months (January 11, 2021-July 2, 2021) and analyzed for SARS-CoV-2 genetic material. Wastewater results were compared to new SARS-CoV-2 infections in nursing home residents and employees to determine if wastewater surveillance could provide early warning of a COVID-19-positive occupant. RESULTS: All 8 nursing homes had wastewater samples positive for SARS-CoV-2 and COVID-19-positive occupants. The sensitivity of wastewater surveillance for early warning of COVID-19-positive residents was 60% (3/5) and for COVID-19-positive employees was 46% (13/28). CONCLUSIONS: Wastewater surveillance may provide additional information for reinforcing infection control practices and lead to preventing transmission in a setting with high-risk residents. The low sensitivity for early warning in this real-world pilot highlights limitations and insights for applicability in buildings.

Factors That Affect Legionella Positivity in Healthcare Building Water Systems from a Large, National Environmental Surveillance Initiative.

Legionella growth in healthcare building water systems can result in legionellosis, making water management programs (WMPs) important for patient safety. However, knowledge is limited on Legionella prevalence in healthcare buildings. A dataset of quarterly water testing in Veterans Health Administration (VHA) healthcare buildings was used to examine national environmental Legionella prevalence from 2015 to 2018. Bayesian hierarchical logistic regression modeling assessed factors influencing Legionella positivity. The master dataset included 201,146 water samples from 814 buildings at 168 VHA campuses. Overall Legionella positivity over the 4 years decreased from 7.2 to 5.1%, with the odds of a Legionella-positive sample being 0.94 (0.90-0.97) times the odds of a positive sample in the previous quarter for the 16 quarters of the 4 year period. Positivity varied considerably more at the medical center campus level compared to regional levels or to the building level where controls are typically applied. We found higher odds of Legionella detection in older buildings (OR 0.92 [0.86-0.98] for each more recent decade of construction), in taller buildings (OR 1.20 [1.13-1.27] for each additional floor), in hot water samples (O.R. 1.21 [1.16-1.27]), and in samples with lower residual biocide concentrations. This comprehensive healthcare building review showed reduced Legionella detection in the VHA healthcare system over time. Insights into factors associated with Legionella positivity provide information for healthcare systems implementing WMPs and for organizations setting standards and regulations.

Implementation of Legionella Prevention Policy in Health Care Facilities: The United States Veterans Health Administration Experience.

CONTEXT: The Veterans Health Administration requires implementation of Legionella prevention policy in potable water systems at Department of Veterans Affairs (VA) medical facilities across the United States and territories. PROGRAM: The Veterans Health Administration Central Office program offices with expertise in engineering and clinical aspects of Legionella prevention policy have provided joint, structured on-site assistance to VA medical facilities for consultation on policy implementation. Site visits included review of facility documentation and data, discussions with staff, touring of buildings, and development of recommendations. IMPLEMENTATION: Information obtained from on-site consultative assistance provided to VA medical facilities from December 2012 through January 2018 was reviewed to identify engineering and clinical challenges and lessons from implementation of Legionella prevention policy in VA health care buildings. Fifteen consultative site visits were conducted during this period regarding implementation of Legionella prevention and validation of effectiveness. EVALUATION: It was found that implementation of Legionella prevention policy in potable water systems was complex and practices varied for each building. Common implementation challenges included capability of applying engineering controls, water stagnation, and assessment of health care association of Legionella cases. Process challenges included routine verification of actions, methods for assessing environmental validation data, and documentation of requirements. It was found that consistent and data-driven implementation of policy is crucial for an effective program. DISCUSSION: Guidance and standards documents in the community for Legionella prevention in building water systems are often general in nature, but implementation requires specific decisions and routine assessments and modifications to optimize outcomes. This real-world review of challenges and lessons from a large health care system with a detailed primary Legionella prevention policy informs future development of guidance and policy, both within and external to VA, and can provide insight to other health care facilities planning to implement practices for water safety.