Why It Can Be Difficult to Kill Legionella

If you have read our Legionella news for U.S. states, you will notice that many facilities struggle to kill Legionella.

A classic example of this was the military barracks in Texas. Legionella was still being detected despite weeks of efforts to sanitize the area. The building was treated with a super-chlorination process. When that didn’t work, the base considered removing certain pipes or going through another round of super-chlorination in hopes of eliminating the bacteria.

We have discussed previously why super-chlorination and hyperchlorination can be poor choices for Legionella remediation. As noted, Legionella that is present in biofilm may not be fully eradicated during super-chlorination. As a truly independent Legionella consultant that is not tied to one particular chemical or Legionella remediation process, Legionella Control Systems often recommends other Legionella control methods because super-chlorination / hyperchlorination often are not effective.

A new study sheds light on one reason it can be so difficult to kill Legionella. It discovered that Legionella bacteria can infect an amoeba host. Once inside this host, it is more protected from disinfection strategies.

In the study, up to 75% of the drinking water and biofilm samples tested positive for free-living amoebae. Like Legionella bacteria, free-living amoebae are common in the environment and can cause opportunistic infections in humans. However, this may be the first time the amoebae have been discovered to be hosts of Legionella.

Given that amoebae are pathogens that can cause issues such as severe eye infections in contact lens users and immunocompromised people, it is important that water management programs consider treatment strategies to control amoebae as well as Legionella. Fortunately, robust treatment methods are likely to remediate both organisms, but it is imperative that consultants consider the protective effect of amoebae for Legionella.

If your Legionella consultant suggests super-chlorination as a treatment method for Legionella in your facility, contact Legionella Control Systems; right away. We can help you design a Legionella remediation strategy that works for your budget but is more likely to provide effective short-term and long-term Legionella control.