Who should test and why

​Simply put everyone should test their water systems for potential Legionella. Legionella is found in all fresh water sources and can therefore occur in all human made water systems.

  • ​AT HOME legionella could be in a biofilm build up in the shower head, of in the water heater that had some trouble a couple of years ago, or in the Jacuzzi that is only properly used a few times a year.
  • AT THE GYM where taking a shower after a workout could end up in a couple of days of illness.
  • AT THE DENTIST who in good faith might not have done a thorough enough job of disinfection and is spraying out legionella while the teeth are being cleaned.
  • AT THE HAIRDRESSER where the hair wash could lead to Legionnaire’s Disease since the hairdresser has never checked or correctly disinfected any of the sinks.
  • AT THE CABIN or similar leisure homes that are empty for large parts of the year legionella can grow freely in water holding a perfect temperature.

These are just some examples on where legionella contamination can occur on any given day. Within industry and workplaces there are several more possibilities that all come in under Health and Safety laws. Most instructions on legionella will recommend flushing the system with water holding a temperature of 70°C or higher to remove legionella. This is not entirely correct since this method will only be able to kill bacteria already in the water, and not the bacteria hiding in biofilm. On average all water systems should be viewed as possible contaminants until the opposite is proven through monitoring of bacteria in the system.

This warning counts especially for places where people who are immunosuppressed, have a lowered immune system, are present. Hospitals and care homes for the elderly of course, but also at the dentist or hairdresser where older persons could have a somewhat lowered immune system without this necessarily needing hospitalization, or even in their own homes. Routine monitoring for potentially pathogenic bacteria is not only important for industries and workplaces with requirements for Health and Safety and maintenance it can be just as important at home.