More focus on Legionella in Denmark

After a record breaking number of #Legionella cases in Denmark in 2020, the Danish authorities has decided to intensify information to the public about how to handle Legionella. At the same time it is examined how ”risk assessment and control must be carried out and which authorities must carry out this risk assessment and control.” so Denmark can full fill the demands in the new ” EU Drinking Water Directive” regarding Legionella risk assessment.

Read more:

Government answers:

Article regarding the subject in the magazine Ingeniøren:

Legionella-rapporter samlede støv i et år før offentliggørelse

Fagtidsskriftet Ingeniøren har i dag sat fokus på at Trafik, Bygge- og Boligstyrelsen lod to vigtige rapporter om Legionella ligge i knapt et år, inden de kom ud offentligheden. Det afslører dokumenter fra Folketinget.

Rapporterne som kan hentes på Folketingets hjemmeside, bekræfter flere artikler publiceret i Ingeniøren gennem den seneste tid. Disse sætter bl.a. fokus på håndteringen af Legionella i kommuner samt udfordringen omkring Legionella på plejehjem.

Her kan også læses at 83% af de testede installationer i de 4 store byer havde forekomst af Legionella, og af dem lå ca. 50% over de reaktionsgrænser der normalt anvises.

Men mest skræmmende er det måske at læse, at man ikke kan identificere hvorfor man har høje og stigende Legionella forekomster i Danmark. Men samtidig konkluderes at ”Undersøgelsen viser, at ca. halvdelen af de adspurgte kommuner ikke havde formaliserede og entydige procedurer for håndtering af mistanke om eller konstatering af et højt niveau af Legionella.” – og samtidig skriver at ” Danmark har på nuværende tidspunkt ikke en nationalt fastsat grænseværdi for reaktionsniveauet for test af Legionella i vandinstallationer.” – måske der er en sammenhæng?

At man derudover helt undlader at nævne at det nye drikkevandsdirektiv som trådte i kraft 12/1-2021 og skal være implementeret inden for 2 år, rent faktisk har grænseværdier for Legionella og krav om risikovurdering virker også lidt mærkeligt.

Links til rapporterne, Ingeniørens artikel og det nye drikkevandsregulativ.

Who would have thought….

That a few spoons of salt can keep an elderly home or school free of water borne bacteria…


Pure and simple, by using a highly sophisticated process called “Electrolyzes”.

Opportunistic bacteria are hard to fight and to keep under control and need constant and continuous disinfection. The BacTerminator product range uses salt as a precursor and electrical power to convert chlorides in the water into active free chlorine.

The continuous consumption of water containing a low level of free chlorine, keeps bacteria in harm’s way of you and your loved once, in schools and elderly homes.

Read more on “Our Green Technology” page

What is the status of Legionella in Denmark?

In Denmark, the last update is from 2020. It is not immediately good reading. In Denmark, a total of 278 cases were found where 94.6% originated from infection in Denmark. The highest number ever – the mortality rate was 14%. One explanation for the high number may be that in some cases where testing for Covid-19 is also testing for Legionella – more people have simply been tested. But it is also a fact that Denmark has always been at the top when it comes to Legionella cases in Europe, for the last 5 years. Maybe it’s because Denmark is still lagging behind regarding legislation and risk management, when it comes to measures that prevent Legionella infection.

SSI – Legionnaires’ disease in Denmark in 2020
ECDC – Legionnaires’ disease. Annual Epidemiological Report for 2019

Legionellosis – you know the name, but do you know what it means?

At Adept Water technologies we are often asked about Legionella, the severity of Legionellosis and water treatment. This one-page overview gives you a brief introduction to the bacteria, the disease, transmission, and water treatment and can be downloaded below.

General Information

A severe outbreak of L. pneumophila among people attending a convention in the USA resulted in the identification of the bacterium in 1977. Legionella is a small gram-negative rod-shaped bacterium and over 40 individual species of legionella are known including L. pneumophila which causes most of the human infections.


Legionella are most commonly found in water – including groundwater, fresh water and potable (treated) water. The optimal environment for the bacteria is a warm, humid area with low water flow. The ideal growth temperature for legionella is between 20 – 45°C. This type of environment can e.g be found in dental chairs where the temperature often is above room temperature and the waterflow in the tubes are so low it creates the perfect environment for biofilm formation.


Drinking water supplies are the primary source of legionella. Once the bacteria have entered the water supply, amplification occurs and bacteria are distributed through waterpipes in e.g., hospitals, hotels, and large apartment complexes to patients or residents. The bacteria are transmitted from the environment to humans via aerosols or small water droplets containing legionella.


There are two forms of legionellosis (a illnesses caused by Legionella): one of them being more severe that the other.  The first one, Pontiac fever (less severe), is characterized by flu-like symptoms such as fever, chills, headache, and muscle plain. For the average patient it will last around 2-5 days.  The other one is legionnaires’ disease, which is more severe and can have a fatal outcome. The symptoms are similar, but Legionnaires’ disease is a pneumonia meaning the infection will inflame the air sacs in one or both lungs.

Healthy individuals (grey), like the general population, is fairly resistance to these kinds of infections. However, immunocompromised patients (blue) in e.g. hospitals are at increased risk at getting Legionellosis. It is therefore extremely important to be able to control and disinfect portable water in these settings.

According to WHO 75-80% of the reported cases of Legionellosis are over 50 years old and 60-70% are male.

Water Treatment

Legionellosis is a worldwide problem and cases have been reported in North and South America, Asia, Australia, New Zealand, Europe, and Africa. Therefore, national surveillance programs and study groups have been conducted such as ESGLI (ESCMID (European Society of Clinical Microbial and Infectious Diseases) Study Group for Legionella Infections).

There is no vaccine available for Legionnaires’ disease meaning that the only way to control this disease it through water monitoring and water treatment. There are different ways to disinfect water, however, using electrolysis to generated active chlorine is the designation used by EU in regard to the Biocidal Products Regulation.

Download one-page here

Add drinking-water and out comes softened and disinfected water of drinking water quality– how?

Most people do not think about that drinking water contain minerals as NaCl (salt), but it does – and this is the secret to inline electrolysis and disinfection. When the water enters our system, it first undergoes a filtration process to remove calcium carbonate and other impurities. A flowmeter measures the water volume, and an adequate number of electrons is led through the water using a set of special designed electrodes adjusted according to flow and salts in the water. This process generates active chlorine in form of hypochlorous acid and hypochlorite – a very powerful oxidant that kills bacteria and other potentially harmful microorganisms similar to the hypochlorous acid production in our body’s immune system. To receive extreme high degree of disinfection bacteria is caught in our biozone reaction filter that secures full effect of the active chlorine. Thus, the water comes out softened, disinfected and of drinking water quality – but still containing a residual of active chlorine ensuring biofilm control in the water system.

Adept Water Technologies is the manufacturer of medical equipment class-I drinking-water disinfection systems, for both stand-alone and build-in applications.

The Ugly Duckling – The perfect environment for biofilm formation

How many times a day do you encounter biofilm without knowing? Probably many! Biofilm surrounds us in our daily life. If we leave out the fact that biofilm formations can occur inside the human body, we are still in contact with biofilm regularly. Where? – you may ask. You can find biofilm on your toothbrush or inside your yellow rubber duck in your bathroom. You might also find biofilm on your teeth or in water pipes. The list is endless. 

The conditions found in a bathroom causes the perfect environment for many microorganisms with higher temperature and increased humidity.  Tap water can comprise microbial communities and in some cases also opportunistic pathogens, such as Pseudomonas aeruginosa, Legionella pneumophila, and Mycobacterium avium. However, the nutrients in tap water will normally not contribute to excessive microbial growth.

Source: Eawag (

On the picture a rubber duck has been split in half and the biofilm formation is visible for the naked eye. The polymeric material in contact with drinking water releases substantial amounts of organic material that microorganisms can use as a source of nutrition. The picture emphasizes the need to be able to control and limit the microbial communities in potable water. At Adept Water Technologies we specialize in systems disinfecting potable water. For more information regarding the study on microbial communities in bath toys:

The 3 kill-zones in a dental treatment center

For decades dentist and dental manufacturers has struggled to keep bacteria out of their units. It has been a losing battle, using various filters, or dosing of various chemicals. The picture below shows the inside of a water container that is part of a dental unit water line with bacterial growth.

None of it has proven a steady functional effectiveness, nor any sign of hygiene management that works on an everyday basis. Dentist are obliged to test for bacteria counts and to provide clean water with low counts of colonizing forming units (CFU) to the patient, having oral procedure.

The Hygowater© devices from Dürr Dental and the ActiveAqua© from Planmeca has changed all that.

Both systems provide a triple kill-zone for incoming bacteria and virus.

  • The integrated electrolysis chamber kills instantly most of all incoming bacteria and virus by producing a controlled amount of free chlorine in the water.
  • Ultrafiltration holds back bacteria and virus such as legionella and E-Coli and kills them. At the same time the free chlorine, produced by the electrolysis is keeping the ultrafilter clean.
  • The surplus of free chlorine produced, kills and eliminates the pre-existing bacteria and virus in the dental unit. Keeping the water clean from microorganisms such as Legionella, all the way to the patient.

The entire system provides “Peace-of-mind” to the dentist, the assistance and the patients.

For further information, please see:


Dürr Dental

Is pathogenic waterborne microorganisms a threat in the western world?

A question we often get at Adept Water Technologies is – why are you doing water disinfection, is it at all a problem in our part of the world?

In 2016 WHO published a report “The situation of water related infectious diseases in the pan-european region” with the definition of a water-related disease as, “any significant adverse effects on human health, such as death, disability, illness or disorders, caused directly or indirectly by the condition, or changes in the quantity or quality, of any waters”.

The report identified 36 microorganisms potential related to water-related infectious diseases. It also identified hundred thousand of cases over a 10-year period from all areas of Europe. In general this report only focuses on larger outbreaks, meaning case stories only involving a small number of individuals is not registered (legionella cases in EU is more than 10.000 / year).

In the end the report concludes:

“Available Water Related Disease data likely represent only a small fraction of the total number of disease cases occurring in the population.”

Even then the majority of countries has a surveillance system the conclusion is – “This indicates a need to prioritize and undertake systematic actions to strengthen and maintain the national surveillance capacities necessary to meet the requirements of the IHR, and to ensure effective WRD surveillance and outbreak response systems as required in article 8 of the Protocol on Water and Health.”

So, the answer to the question is – Yes – Water Related diseases is also a problem in our part of the world. Adept Water Technologies will therefore continue to develop and manufacture water disinfection systems – that is easy and safe to use – and in the end can guarantee us safe water at the dentist, in the shower, drinking water or other water sources where disinfection is necessary.

Report in full length can be found here: