Chesterfield Legionnaires' Investigation Overview and Update - - PowerPoint PPT Presentation

Chesterfield Legionnaires' Investigation

Overview and Update

Alexander Samuel, MD, MPH, District Health Director Chesterfield Health District Lilian Peake, MD, MPH, State Epidemiologist Virginia Department of Health October 7, 2019

Legionella bacteria

Common in soil and fresh water

• Approx. 60 species

Uncommon cause of disease in people

• Most cases caused by Legionella

pneumophila serogroup 1 (Lp1)

Most likely sources of exposure

• Hot tubs
• Decorative fountains
• Cooling towers
• Water used for showering

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Image source:

www.cdc.gov/legionella/resources/ materials.html

Evolving science of Legionellosis

Legionnaires’ disease - 1976 American Legion convention Engineered water systems

• Water management plans

2017 - 3 NYC outbreaks

• Cooling towers – linked

environmental and human isolates Lack data to quantify relative risk in homes Distinct seasonal pattern 2017–2019 studies: Legionella species and Lp1 detected through routine sampling

• 2017 CDC convenience study
• f U.S. cooling towers
• 2017 U.K. study and 2019

Australia study samples from household showers Studies did not correlate presence of bacteria with illness

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Legionnaires’ disease

Serious type of pneumonia

• Infection caused by breathing in

small droplets of water containing Legionella

• Most healthy people not affected
• Risk Factors: Age >50, smoking, lung

disease, weakened immune system

• Outbreaks associated with large
• r complex water systems
• Leading cause of death from U.S.

waterborne outbreaks

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Image source: www.cdc.gov/legionella/resources/ materials.html

Surveillance and investigation of reportable conditions in Virginia

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Systematic, ongoing collection, analysis, interpretation and dissemination of health

• utcome data

Link to public health action

• Investigation
• Control
• Prevention

Investigating Legionellosis cases –

Identify outbreaks to reduce ongoing risk

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Legionellosis Case Travel-Associated 1 case 2 cases within 12 months >2 cases within 12 months Healthcare- Associated 1 possible case 1 definite case or ≥2 possible cases within 12 months More cases within 12 months Community- Associated Sporadic case(s)

• r below baseline

Cases above baseline

Legionellosis

U.S., South Atlantic Region and Virginia, 2000-2018

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Legionellosis Cases in Virginia

January – September, 2019

Geographic Area # Cases Outbreak or Cluster-Related Cases, #(%) Age Range (Years)

Virginia 135 13 (9.6%) 24-97 Central 34 13 (38.2%) 35-87 Eastern 24 0 (0.0%) 34-87 Northern 24 0 (0.0%) 25-97 Northwest 32 0 (0.0%) 35-87 Southwest 21 0 (0.0%) 24-93 Chesterfield County 13 10 (76.9%) 52-81

LEGIONNAIRES’ DISEASE INVESTIGATION

Chesterfield County

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June activities and findings

May 28 Identified a possible increase in cases June Additional cases reported

Public Health Actions Findings Completed detailed case investigations

Ruled out travel- associated or health care facility outbreak

Created line list to summarize case information Initial mapping of cases to identify any geographic clustering

Public Health Actions Findings

Contacted CDC Legionella experts for technical assistance

No risk with water supply identified; Accuracy of lab results confirmed Identified 3 geographic areas

• f risk (greatest
• verlap of

residences, travel and locations visited) CDC advised pattern most consistent with cooling tower exposure

Used advanced techniques to map cases’ residences and travel Met with Office of Drinking Water to determine any risks with water supply Contacted clinical lab to ensure accuracy of cases’ lab results CDC led environmental sample collection (12 sites)

• Some field testing was performed

July 2

Notified local health care partners about testing and reporting of cases

July 19

Requested CDC Epi Aid Alerted clinicians about increase in respiratory illness

July 25

Issued press release about cluster and geography area at risk

July activities and findings

Test results

CDC tested all environmental samples for Legionella

Facility Type Facility Result LP1 Public Greenfield Elementary Legionella + Yes Midlothian Middle Legionella + Yes Falling Creek Middle Legionella + Yes Meadowbrook High Legionella - Hopkins Road Elementary Legionella + Private Johnston-Willis Hospital Legionella + Yes Aleris Legionella - Kaiser Aluminum Legionella + Yes Reynolds Legionella + Yes Marine Corps Services Center Legionella + Richmond Ice Zone Legionella + Yes US Defense Supply Legionella + Yes

Results posted on VDH Website

August activities and findings

Public Health Actions Findings Communicated public health recommendations (next slide)

Could not identify source of the cluster based

• n molecular

testing of samples from the patient and cooling towers

Launched webpage to provide testing results CDC completed whole genome sequencing (WGS) of Legionella

• rganisms isolated from patient

and cooling towers

August 8 Press release about results

• f testing

Public Health recommendations

Facilities with positive Legionella results were asked to:

• Remediate immediately
• Establish or review water management programs
• Sample the towers monthly for a period of 3 months
• Follow CTI and ASHRAE guidelines for cooling towers
• Proper operation of mechanical parts
• Regular cooling tower cleaning
• Ensuring water management programs in place with

Legionella testing

Actions taken by facilities

All sites with positive test results cooperated and responded to recommendations Chesterfield County Public Schools (CCPS)

• Immediately closed schools that had cooling towers

that tested positive

• Immediately inspected all CCPS cooling towers
• Included schools beyond the geographic areas at

risk

• Quickly cleaned all CCPS cooling towers

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Current status and next steps

Investigation of Legionaries' disease cluster has concluded

• Last case reported within geographic areas of risk

was on 7/19/19 Close surveillance will continue through rest of CY 2019

• Monitor for new clusters
• Expect increase in sporadic cases due to increased

testing by providers

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In conclusion - What we know

• Cases of Legionnaires’ disease are reported every year

in Virginia

• Chesterfield County observed higher than expected

number of cases, clustered in geographic space and time

• Several cooling towers, but not all, within the

geographic boundaries of interest tested positive for Legionella

• Recommendations to mitigate environmental exposures

associated with cooling towers were implemented

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In conclusion - What we don’t know

• There may be unidentified cooling towers in the area

that were not tested

• It is not known whether the Legionnaires’ cases in

Chesterfield County were caused by the presence of Legionella in these cooling towers

• Some cases may not have been reported due to

misdiagnosis or under-reporting (Occurs in every investigation)

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QUESTIONS