Legionella classification

Family: Legionellaceae 
Species: pneumophila

General information Legionella

Legionella mainly occurs in soil and freshwater. Usually these are small numbers. However, it appears that Legionella can multiply under certain favorable conditions. These favorable conditions are standing with a between 25°C and 60°C (optimal is 37°C) and the presence of material. 

The ideal growing conditions for Legionella are common in man-made hot water systems such as drinking water pipes, swimming pools, fountains and air coolers. When the water cannot storm through the entire water system, it is possible that the water remains stagnant for a long time in the ‘dead' corners. This gives the the opportunity to multiply in slime layers on the inside of the pipes or in the sediment at the bottom of pipes and reservoirs. Humans can inhale the through, for , a shower or sprinkler system.


Legionella is caused by inhaling the bacteria through, for example, a shower or sprinkler system. The is characterized by an acute severe pneumonia with high fever, which causes a lot of death without treatment. One to four days after the infection the are: malaise, no appetite, muscle pain, headache, sometimes diarrhoea. From the sixth day these are: chills, high fever (> 39°C), diarrhoea, abdominal pain and sometimes nausea, vomiting, dry cough, chest pain. Ten to fourteen days after the infection, symptoms such as confusion and chest pain also appear.

Incubation time

The incubation period, which is the period between infection and the first symptoms of the disease, for Legionella is two to ten days.

Risk groups

Legionella generally does not pose a great . However, there are professions where there is an increased risk because they work with water misting or water sprayers. These professions are, for example, in horticulture, dentists, cleaners, employees in swimming pools, saunas, campsites, etc. 

Furthermore, anyone can come into contact with Legionella. It is therefore important to allow pipes that have not been used for a long time to run cold water for some time before they are used again.


Heating of water > 65°C.

TwitterFacebookLinkedInPin It

Related articles to What is Legionella and what are the Legionella risks?

Many customers and visitors to this page 'What is Legionella and what are the Legionella risks?' also viewed the articles and manuals listed below:

We are a Food Tech firm in Food Safety Compliance. Experts in setting up and maintaining Food Safety Systems for companies in the Food Supply Chain. We are dedicated to breaking down the barriers for Transparency and Trust in the Global Food Supply Chain.
In our Partnership Program we would like to work together with (Non)Governmental Organizations, Universities, Multinationals and Food companies.

iMIS Food is a fully equipped Food Safety Compliance platform. Unique is the installation of an iMIS Food server at the Food company, for online and offline availability. The online (no travel costs) iMIS Food implementation process includes 6 to 10 days of support and has a lead time of 3 months.

Monthly iMIS Food Update

Would you also like to receive the monthly iMIS Food Update and be invited to our events? Then please fill in this form.

Food Safety news 7-2024

Salmonella in an egg, no surprise

QAssurance records as a reaction to the ECDC and EFSA Salmonella in a chocolate egg Investigation.
food systems

The Food Systems Countdown 2023

Read this summary article on the state of food systems worldwide in 2023, based on the report "The Food Systems Countdown”.
Food materials for EU market clearance

Food materials for European market clearance

European Food Law is a hard and wide-ranging subject to study. The General Food Law Regulation makes sure that people's lives are well protected.