Update – Chesterfield Health District Investigating Increase in Legionnaires’ Disease

August 8, 2019

Media Contact: Lorrie Andrew-Spear – Lorrie.Andrew-Spear@VDH.virginia.gov

The Chesterfield Health District (CHD) investigation of an increase in cases of Legionnaires’ disease associated with the northeast quadrant of Chesterfield County is ongoing. No additional cases have been identified as of Aug. 6, 2019. As previously reported, there have been 10 confirmed cases among older adults and people with certain medical conditions since May 1, 2019.

Legionella bacteria are found naturally in the environment and are commonly identified in building water systems and devices that are not adequately maintained.  We expect to find Legionella bacteria when we test for it.  However, there are several types of Legionella bacteria, and Legionella pneumophila serogroup 1 is the type most commonly associated with developing Legionnaires’ disease.

Public health investigations into Legionnaires’ disease are complex and involve identifying cases of disease and assessing the environment for potential sources of exposure.  Local health department staff identified an increase in cases that were clustered in the northeast quadrant of Chesterfield County. Because there were no common water or facility exposures identified among cases, cooling towers became a suspected mode of transmission. As part of the environmental investigation, cooling towers were identified within common geographical areas. Facilities cooperated and allowed health officials to collect samples for Legionella testing. Samples were collected from 12 sites. As of August 6, seven of twelve sites (58%) have tested positive for Legionella pneumophila serogroup 1 by either molecular methods and/or by culture. Testing has not been completed on all 12 sites, and additional testing of these samples is pending.

The goal of public health investigations such as this one is to reduce health risk to the public as well as to identify sources of exposure.  When Legionella is identified, it is essential to implement plans to remediate these sources and ensure proper maintenance moving forward. The Chesterfield Health District is providing recommendations to facilities on remediation and disinfection to eliminate the presence of Legionella bacteria. To date, facilities have remained cooperative in implementing all remediation recommendations.

While cases in the area have increased, it is important to remember that most people exposed to Legionella do not develop Legionnaires’ disease. Those over the age of 50, people who smoke, and people with weakened immune systems, chronic lung disease, or other chronic health conditions are at increased risk for developing disease. Legionnaires’ disease is treatable with antibiotics.

“The risk to residents or visitors to Chesterfield County remains small,” said Chesterfield Health District Director, Dr. Alexander Samuel. “The health department continues to make every effort to identify cases of Legionnaires’ disease and will continue to work with facilities to remediate any potential source of exposure.”

More information on Legionnaires’ disease can be found at https://www.vdh.virginia.gov/epidemiology/epidemiology-fact-sheets/legionellosis/.

For details on testing sites and updates on this investigation, visit www.vdh.virginia.gov/surveillance-and-investigation/legionellosis/. That site will be updated weekly on Thursdays with any new information.