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 Image source: www.cdc.gov/legionella/resources/ • Cooling towers materials.html • Water used for showering 2
Evolving science of Legionellosis Legionnaires’ disease - 1976 2017 – 2019 studies: Legionella American Legion convention species and Lp1 detected through routine sampling Engineered water systems • 2017 CDC convenience study • Water management plans of U.S. cooling towers 2017 - 3 NYC outbreaks • 2017 U.K. study and 2019 • Cooling towers – linked Australia study samples from environmental and human household showers isolates Lack data to quantify relative Studies did not correlate risk in homes presence of bacteria with Distinct seasonal pattern illness 3
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 or complex water systems • Leading cause of death from U.S. waterborne outbreaks Image source: www.cdc.gov/legionella/resources/ materials.html 4
Surveillance and investigation of reportable conditions in Virginia Systematic, ongoing collection, analysis, interpretation and dissemination of health outcome data Link to public health action • Investigation • Control • Prevention 5
Investigating Legionellosis cases – Identify outbreaks to reduce ongoing risk Legionellosis Case Healthcare- Community- Travel-Associated Associated Associated Sporadic case(s) 1 case 1 possible case or below baseline 1 definite case or 2 cases ≥2 possible cases within 12 months within 12 months >2 cases More cases Cases above within 12 months within 12 months baseline 6
Legionellosis U.S., South Atlantic Region and Virginia, 2000-2018 7
Legionellosis Cases in Virginia January – September, 2019 Outbreak or Age Range Geographic Area # Cases Cluster-Related (Years) Cases, #(%) 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
Chesterfield County LEGIONNAIRES’ DISEASE INVESTIGATION 9
June activities and findings May 28 Public Health Actions Findings Identified a Completed detailed case Ruled out possible increase travel- investigations in cases associated or health care June facility outbreak Created line list to Additional cases summarize case information reported Initial mapping of cases to identify any geographic clustering
July activities and findings July 2 Public Health Actions Findings Notified local health No risk with water Contacted CDC Legionella experts for care partners about supply identified; testing and reporting of technical assistance Accuracy of lab cases results confirmed Used advanced techniques to map cases’ residences and travel July 19 Identified 3 geographic areas Requested CDC Epi Aid of risk (greatest Met with Office of Drinking Water to overlap of determine any risks with water supply residences, travel Alerted clinicians about and locations increase in respiratory Contacted clinical lab to ensure visited) illness accuracy of cases’ lab results CDC advised pattern most July 25 CDC led environmental sample consistent with Issued press release collection (12 sites) cooling tower about cluster and exposure Some field testing was performed • geography area at risk
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 August 8 Press release Communicated public health Could not about results identify recommendations (next slide) of testing source of the cluster based on molecular Launched webpage to provide testing of testing results samples from CDC completed whole genome the patient and cooling sequencing (WGS) of Legionella towers organisms isolated from patient and cooling towers
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 15
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 16
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 17
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) 18
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