Water is one of the most crucial components to living a healthy life. However, the water sources may expose it to harmful organisms such as Legionella, a type of bacteria that thrives in water sources, but it is not immediately visible to the human eye. Due to this, many homeowners and businesses are slow to realise they have a legionella infestation, particularly in areas where large amounts of water are cooled or kept.

Once the legionella bacteria begins to spread throughout the water pipes and reach evaporative coolers, it can lead to long-term health risks for those who are exposed to it. That being a serious case, this blog by an accredited legionella testing lab in UAE goes into detail about the different types of legionellosis and how we can eliminate them from our water sources.

Defining Legionella

Legionella is a genus of Gram-negative bacteria that causes Legionnaires’ disease, a form of pneumonia. Legionella bacteria are found naturally in the environment, but certain species can cause disease when inhaled. It only needs two things: warm temperatures and water with high levels of organic matter. They are also known to grow in areas where there are low levels of chlorine. The bacteria can live in standing water or small droplets of water that are suspended in the air.

Legionellosis is caused by infection with Legionella pneumophila serogroup 1 and other species of Legionella. The most common places where you will find Legionella include:-

  • Natural sources such as rivers, lakes, ponds and streams
  • Hot tubs, pools, spas and other recreational water facilities
  • Air conditioning systems
  • Cooling towers
  • Humidifiers and other devices that use potable water
  • Home plumbing systems

Understanding the Discovery of Legionella pneumophila

Legionella pneumophila, sometimes called Legionnaire’s disease, is a type of pneumonia caused by the bacterium Legionella pneumophila. The bacterium was first discovered in 1976 by Dr.Joseph McDade, a scientist at the Centers for Disease Control and Prevention (CDC),  when an outbreak of pneumonia occurred at a Philadelphia hotel and convention centre during an American Legion convention. The bacterium was named Legionella pneumophila (Greek: πνευματος nephos “lung” + φιλος philos “loving”).

McDade also discovered that L. pneumophila could survive for long periods in water supplies if kept at temperatures between 35°C and 45°C (95°F–113°F).[2] Today these high temperatures are used to disinfect municipal water supplies to prevent the spread of Legionnaire’s disease.

Legionella pneumophila is the most common, but not the only, species of Legionella that causes illness. Non-pneumophila Legionella (NPL) species include:-

  • Legionella bozemanii (formerly called L. gormanii)
  • Legionella dumoffii
  • Legionella sainthelensi
  • Legionella hoshinae

Another type of non-pneumophila Legionella species is Legionella longbeachae. This type of Legionella is less common than L. pneumophila and tends to occur in smaller buildings with a lower population density. It’s more likely to cause LGV than L. pneumophila, which can make it harder to diagnose if you’re at risk because it has no symptoms.

Where does Legionella come from?

  • Bacterial Legionella

Bacterial legionellosis is caused by the bacterium Legionella pneumophila. This bacterium is found in water and soil and can be spread through inhalation of contaminated aerosols. Water systems that use air-cooled heat exchangers, such as large cooling towers, are at risk for having high levels of contamination.

  • Free-living Legionella

Free-living Legionella is a type of organism that exists outside of cells and can cause infections in humans and animals. The most common free-living Legionella species, L. pneumophila serogroup 1 causes the disease Pontiac fever or Pontiac illness in humans. This illness is characterised by fever, cough, chills and muscle aches. It is more common among smokers who have been exposed to cigarette smoke.

  • Parasitic Legionella

This type of Legionella grows inside protozoa that live on plant roots in freshwater bodies like lakes, rivers and ponds. The protozoa provide protection for the bacteria while they grow and multiply inside them until they’re ready to infect humans through water vapour inhalation or consumption of contaminated food or beverages.

These types of legionella are more common in warmer climates and are found in water that has been stagnant for a long period of time. Parasitic legionella is not as deadly as the other forms, but it can still cause illness if you come into contact with it.

How does Legionella end up in building water systems?

Legionella is often introduced into buildings through the activities of people working within them. For example:-

As a result of human activity: People can accidentally introduce this bacteria into their building’s water system through activities like maintenance work and plumbing repairs. Maintenance or repair work on hot water systems can introduce Legionella into the pipes. This includes fixing leaks and replacing filters or heat exchangers (which are used to heat the water).

Incorrectly maintained/installed cooling towers may also cause problems if they draw in contaminated water from nearby sources such as lakes or rivers and then spray it back over large areas when they operate. This could lead to Legionnaires’ disease outbreaks if people inhale airborne droplets containing the bacteria that were created when the mist was sprayed from the cooling tower onto surfaces inside buildings (e.g., air conditioning units). The building manager needs to engage with a Laboratory expert in water testing in Dubai to ensure the safety of the inhabitants.

Spread by animals: Pets such as dogs and cats can carry the bacteria without having any signs or symptoms themselves. If they use the same water source as humans, they can pass along their infection through their urine or faeces — which is why pets should not be allowed access to building drinking water sources unless they are on medication that prevents them from carrying this type of illness.

Legionella Monitoring

Legionella assessment: The risk assessment identifies possible dangers and outlines steps that can be taken to reduce the spread of bacteria. Testing allows us to gauge whether risk management steps are working properly, which is a good indication of the effectiveness of our approach. If we find any problems with our water system, we can make adjustments until we get it right.

Legionella Testing and Water Analysis: Legionella bacteria can be found in many different environments. The water sources that need to be tested depend on the type of building and its use. For example, public buildings such as hospitals and nursing homes may have a greater risk of legionella contamination than private homes.

Legionella testing is usually carried out using one of the following methods:

  • CDC Culture Method uses enrichment broth to culture samples.
  • ISO Culture Method uses agar plates to culture samples.
  • Legiolert Method uses filter paper to detect gene sequences.
  • The qPCR Method uses real-time PCR technology to detect gene sequences.

The Legionella Culture Test is the gold standard for identifying the presence of Legionella bacteria in water sources. It takes 7-10 days for results from this method; however, other methods are available which can provide results within 24 hours.

Hygiene audits: These involve assessing how clean your workplace is and whether there are any risks associated with contamination by Legionella or other types of bacteria. This can be done through visual inspections or through using equipment such as thermometers or test strips which detect the presence of certain types of bacteria at specific temperatures.

The Best Legionella Testing, Water Quality Analysis and Water Microbiology Testing Services

URS Laboratory provides the best legionella microbiology testing in Dubai testing services for your business or home. We have experts in microbiology and water quality analysis who will help you understand the risks and how to prevent them. We follow strict quality control measures and ensure accuracy and reliability of test results.

Our cost effective, accurate and reliable testing services will help you meet all government regulations for Legionella control in water systems. Our team also helps you meet OSHA requirements for employee safety as well as reduce your insurance premiums by meeting EPA guidelines for Legionella control in water systems.

URS Laboratory meets ISO 17025 standards which ensures accuracy and reliability of test results at an affordable price. All our laboratory technicians are certified by leading organisations . We also follow standard operating procedures to maintain quality control measures throughout the entire process from sample collection to reporting of results back to clients.