The Chesterfield Health District is investigating an increase in the number of cases of Legionnaires’ disease.
Since May 1, there have been 11 confirmed cases among older adults and persons with medical conditions.
Legionella bacteria has been found at the U.S. Defense Supply Center, Falling Creek Middle School, Reynolds Metal Co., Johnston-Willis Hospital, Ice Zone and two schools in the Midlothian area, Midlothian Middle and Greenfield Elementary, according to the Chesterfield County Department of Health.
Legionnaires’ disease is a type of pneumonia (lung infection) caused by Legionella bacteria, which naturally occurs in lakes and streams. Legionella can become a health concern if it is aerosolized into small droplets in private water systems like cooling towers that are part of the air-conditioning systems for large buildings, hot tubs and decorative fountains and then if people breathe in the bacteria. People do not get ill from Legionella by drinking water. Home and car air conditioning units do not use water to cool, so they are not a risk for Legionella.
“The risk to residents or visitors to Chesterfield County is very small,” said Chesterfield Health District director Dr. Alexander Samuel. “Out of an abundance of caution, the health district recommends that individuals who become ill with pneumonia-like or respiratory symptoms, such as fever, chills, cough, shortness of breath, muscle aches and headache, promptly seek medical care.”
The CHD is working with the federal Centers for Disease Control and Prevention to identify possible sources of exposure to Legionella. If any sources are identified, the CHD will recommend strategies to stop it from spreading.
Investigations into increased cases of Legionnaires’ disease are complex. It is often not possible to determine the origin of the bacteria that infected people. The investigation is currently aimed at ruling out possible sources.
A press release from Defense Logistics Agency states: “On July 30, 2019, we were alerted that preliminary testing of the non-potable water in Defense Supply Center Richmond’s HVAC water cooler towers, conducted by the Chesterfield County Health District, indicated the possible presence of bacteria in the HVAC system cooling tower in Buildings 34 and 430, which houses the Virginia National Guard Headquarters. We are currently awaiting final laboratory test results. Other facilities on DSCR were tested and those test results came back negative for bacteria. The drinking water in both buildings was not impacted, nor does the water circulate through the building’s ventilation system. As a precaution, the HVAC water cooler towers for both buildings are being disinfected and completely flushed. We are also planning to conduct additional testing and also shock the system three times weekly to prevent any bacterial build-up in the future.”
According to the Virginia Department of Health, “Legionella bacteria are found naturally in the environment and are commonly identified in building water systems and devices that are not adequately maintained.”
The VDH says it expects to find Legionella bacteria when they test for it. According to VDH, there are several types of Legionella bacteria and Legionella pneumophila serogroup 1 is the type most commonly associated with developing the disease.
Public health investigations into Legionnaires’ disease are complex and involve identifying cases of disease and assessing the environment for potential sources of exposure, the VDH reports. 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 Aug. 6, seven have tested positive for Legionella pneumophila serogroup 1 by either molecular methods and/or by culture. Testing has not been completed on all sites, and additional testing is pending.
While cases in the area have increased, it is important to remember that most people exposed to Legionella do not develop Legionnaires’ disease, VDH explained. 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.
“Legionnaires’ disease is not generally spread person to person or by drinking water,” Samuel said. “Chesterfield County drinking water supplies are treated to kill Legionella bacteria.”
On Friday, Aug. 9, Chesterfield County Public Schools said they are working with three independent contractors to accelerate a schedule to clean and provide preventative maintenance to water cooling towers found outside on school grounds, in light of Legionella bacteria recently found in cooling towers at Falling Creek Middle, Midlothian Middle and Greenfield Elementary schools.
The accelerated plan is being implemented out of an abundance of caution, the district said in a press release.