Preventing Legionnaires' Disease: Frontline Tools for Environmental Health Practitioners - National Environmental ...
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
A D V A N C E M E N T O F T H E PRACTICE
D I R E C T F R O M C D C E N V I R O N M E N T A L H E A LT H S E R V I C E S
Preventing Legionnaires’
Disease: Frontline Tools
for Environmental Health
Benjamin CDR Jasen Elizabeth
Practitioners
Clopper, MPH Kunz, MPH Hannapel, MPH
such as decorative fountains, hot tubs, cool-
E d i t o r ’s N o t e : The National Environmental Health Association ing towers, and potable water systems;
(NEHA) strives to provide up-to-date and relevant information on • includes considerations for when Legio-
nella testing is appropriate;
environmental health and to build partnerships in the profession. In
• reviews recent and evolving Legionella
pursuit of these goals, NEHA features this column on environmental
testing methods; and
health services from the Centers for Disease Control and Prevention • suggests response activities according to
(CDC) in every issue of the Journal. routine Legionella testing results.
In these columns, authors from CDC’s Water, Food, and Environmental
Health Services Branch, as well as guest authors, will share insights and New Toolkit for Controlling
information about environmental health programs, trends, issues, and Legionella in Common Sources of
resources. The conclusions in these columns are those of the author(s) and
Exposure From the Centers for
Disease Control and Prevention
do not necessarily represent the official position of CDC. CDC created a series of six easy-to-use con-
Benjamin Clopper is a fellow with the Oak Ridge Institute for Science tent modules to summarize the updated
and Education (ORISE). CDR Jasen Kunz is an environmental health guidance. This toolkit aims to help environ-
subject matter expert for Legionnaires’ disease at CDC’s National Center mental health practitioners, building owners
for Environmental Health and the Water, Food, and Environmental Health and operators, and facility engineers:
Services Branch. Elizabeth Hannapel is an epidemiologist and Legionnaires’ • evaluate hazardous conditions quickly,
• implement Legionella control measures,
disease subject matter expert at CDC’s Division of Bacterial Disease within
• strengthen water management programs,
the National Center for Immunization and Respiratory Diseases. and
• support environmental assessments during
public health investigations.
E
nvironmental health practitioners now required in healthcare facilities nationwide The toolkit’s six content modules (Figure 1)
play a critical role in the preven- (Centers for Medicare & Medicaid Services, summarize Guideline 12-2020 updates across
tion, identification, and mitigation 2018; Veterans Health Administration, 2014). common sources of Legionella exposure: pota-
of Legionnaires’ disease outbreaks (Kunz & ble water systems, cooling towers, hot tubs,
Cooley, 2016). Over the last 20 years, Legion- Updated Guidance on Preventing decorative fountains, and other devices. Each
naires’ disease outbreaks have increased sig- Legionella in Water Systems content module includes essential information
nificantly and the Centers for Disease Control and Devices from Guideline 12-2020 regarding the design,
and Prevention (CDC) continues to learn about ASHRAE recently released expanded and operation, maintenance, and controls specific
the disease and how to prevent it (Association updated guidelines (Guideline 12-2020) to to the corresponding source of exposure. Mod-
of State and Territorial Health Officials, 2019; help prevent Legionnaires’ disease (ASHRAE, ule recommendations are anchored to four key
CDC, 2019). For example, CDC investigations 2020). These guidelines support water man- factors that affect the ability of Legionella to
show almost all (9 in 10) Legionnaires’ disease agement programs and significantly expand grow in water: sediment and biofilm, tempera-
outbreaks were caused by problems prevent- previous guidance. ture, water age, and disinfectant residuals. The
able with more effective building water man- The ASHRAE Guideline 12-2020: importance of these four factors is highlighted
agement. Water management programs have • provides design, operation, and control in a quick-reference table of Legionella control
become an important industry standard and are parameters for various devices and systems, measures for each respective device or system
32 Volume 83 • Number 8
Snapshot of Legionnaires’
FIGURE 1 Disease (LD)
Content Modules From the Centers for Disease Control and
Prevention for the ASHRAE Guideline 12-2020 • LD is caused by inhalation of aero-
sols that contain Legionella bacteria.
• Nearly 1 in 10 cases is fatal (Shah et
al., 2019).
• The Centers for Disease Control and
Protection (CDC) reported 9,933
cases in 2018—an increase of al-
most 900% since 2000 (CDC, 2019).
Potable Water Systems Cooling Towers Hot Tubs • Of all waterborne outbreaks reported
through CDC’s National Outbreak
Reporting System in 2017, 61%
implicated Legionella bacteria
(CDC, 2018).
field experience during outbreak responses
and to better align with Guideline 12-2020.
Decorative Fountains Other Devices Testing Public health officials can use LEAF to gain
a thorough understanding of a facility’s water
systems and assist facility management with
using environmental control measures to
minimize the risk of Legionnaires’ disease.
TABLE 1 It can also be used along with epidemiologic
Legionella Control Measures for Hot Tubs and Whirlpool Spas information to determine whether to conduct
Legionella environmental sampling and to
develop a sampling plan.
Water Control Measure Recommendation*
Parameter A key revision to LEAF includes an
expanded cooling tower appendix refined
Sediment and Cleaning frequency Vigorously scrub all surfaces each time tub is drained.
biofilm over the course of multiple CDC-led field
investigations. During an outbreak involving
Temperature Control limits Hot tubs operate within Legionella’s favorable growth range
(77–113 °F). Additional measures are required to control cooling towers, rapid identification and envi-
Legionella. Water should not exceed 104 °F for health and ronmental assessment are essential to limit
safety reasons. the number of people exposed. The updated
Age Bather load, frequency Water replacement frequency (days) = LEAF supports CDC procedures developed
of use (spa volume/3)/average number of users per day** in 2019 for identifying cooling towers during
Disinfectant Control limits pH: Free chlorine: Bromine: an outbreak investigation (Figure 2).
residual 7.2–7.8** 3–10 ppm** 4–8 ppm** By sharing knowledge and developing easy-
*See the Managing Legionella Risk in Display Hot Tubs section for recommendations to control Legionella in display-only to-use resources, CDC hopes to empower local
hot tubs at www.cdc.gov/legionella/wmp/control-toolkit/hot-tubs.html. communities to prevent outbreaks of Legion-
**Recommendation based on guidance from the Centers for Disease Control and Prevention’s Model Aquatic Health naires’ disease. Explore CDC’s free Legionella
Code (www.cdc.gov/mahc/editions/current.html).
resources at www.cdc.gov/legionella/health-
depts/environmental-inv-resources.html.
(Table 1). One additional module describes Updated Legionella Environmental Corresponding Author: Benjamin Clopper,
considerations if Legionella testing is conducted Assessment Form for Building Oak Ridge Institute for Science and Education,
for routine purposes, such as water manage- Water Systems From the Centers Division of Environmental Health Science and
ment program validation. The testing module for Disease Control and Practice, National Center for Environmental
contains practical information such as values Prevention Health, Centers for Disease Control and Pre-
for performance indicators and a multifactorial CDC has also updated the Legionella Environ- vention, 4770 Buford Highway, Mailstop S106-
approach to understanding test results. mental Assessment Form (LEAF) based on 5, Atlanta, GA, 30341. Email: oyx5@cdc.gov.
April 2021 • Journal of Environmental Health 33
A D V A N C E M E N T O F T H E PRACTICE
References
ASHRAE. (2020). Guideline 12-2020—Mini-
mizing the risk of legionellosis associated FIGURE 2
with building water systems. Identifying Cooling Towers Using Aerial and Satellite Imagery
Association of State and Territorial Health
Officials. (2019). Understanding Legion-
naires’ disease outbreak response gaps and
resource needs: Results from a survey of state
and territorial health agencies. https://www.
astho.org/Programs/Environmental-Health/
Documents/Legionnaires-Disease-Out
break-Response-Gap-and-Resource-Needs/
Centers for Disease Control and Preven-
tion. (2018). National Outbreak Reporting
System (NORS): NORS dashboard. https://
wwwn.cdc.gov/norsdashboard/
Centers for Disease Control and Prevention.
(2019). National Notifiable Diseases Sur-
veillance System (NNDSS): Notifiable infec-
tious diseases and conditions data tables. Cooling towers can cause outbreaks of Legionnaires’ disease when they are not adequately maintained. The Centers for
https://wwwn.cdc.gov/nndss/infectious- Disease Control and Prevention has tools for scanning aerial or satellite images to rapidly identify cooling towers.
tables.html Source: www.cdc.gov/legionella/health-depts/environmental-inv-resources/id-cooling-towers.html.
Centers for Medicare & Medicaid Services.
(2018). Requirement to reduce Legionella
risk in healthcare facility water systems to mental Health, 79(1), 24-26. https://www. Disease Control and Prevention. https://
prevent cases and outbreaks of Legionnaires’ cdc.gov/nceh/ehs/docs/jeh/2016/july-aug- www.cdc.gov/legionella/health-depts/surv-
disease (LD). https://www.cms.gov/Med legion.pdf reporting/2014-15-surv-report-508.pdf
icare/Provider-Enrollment-and-Certifica Shah, P., Barskey, A., Binder, A., Edens, C., Veterans Health Administration. (2014,
tion/SurveyCertificationGenInfo/Policy- Lee, S., Smith, J., Schrag, S., Whitney, C., August 13). Prevention of healthcare-
and-Memos-to-States-and-Regions-Items/ Cooley, L., & Division of Bacterial Dis- associated Legionella disease and scald
Survey-And-Cert-Letter-17-30- eases, National Center for Immunization injury from potable water distribution sys-
Kunz, J.M. & Cooley, L.A. (2016). Prevent- and Respiratory Diseases. (2019). Legion- tems (VHA Directive 1061). https://www.
ing Legionnaires’ disease: Environmental naires’ disease surveillance summary report, va.gov/vhapublications/ViewPublication.
health expertise is key. Journal of Environ- United States, 2014–2015. Centers for asp?pub_ID=9181
Choosing a career that protects the basic
necessities like food, water, and air
for people in your communities already
proves that you have dedication. Now,
REHS/RS take the next step and open new doors
with the Registered Environmental Health Specialist/
Registered Sanitarian (REHS/RS) credential from NEHA. It is
the gold standard in environmental health and shows your
commitment to excellence—to yourself and the communities
you serve.
Find out if you are eligible to apply at neha.org/rehs.
A credential today can improve all your tomorrows.
34 Volume 83 • Number 8You can also read
