The risk of Legionella at sea

The problems and symptoms of Legionella, where it’s found, and what you can do to protect your crew

Managing the water supply on ships can be troublesome. If you don’t monitor it correctly, it will have serious effects on both your crew and your operations.

Poorly maintained water can easily result in contamination from bacteria and pathogens leading to outbreaks of noroviruses, Salmonella, E-Coli and Legionnaire’s disease.

Here we look at some of the dangers of Legionella and how you can avoid them.

What is Legionella?

Legionella is a type of bacteria that can cause diseases such as Pontiac Fever, Lochgoilhead Fever and, the most serious, Legionnaire’s Disease.

The bacteria gets into your lungs when you breathe in aerosols – small droplets of water suspended in the air. If not treated with antibiotics, it begins to affect the heart, brain, and other organs. The drop in blood pressure can also lead to septic shock as well as lung and kidney failure.

Where is Legionella found?

The bacteria is common in natural water sources like rivers, lakes and reservoirs but usually in low quantities. It becomes a major problem in purpose-built water systems where conditions are right for it to thrive.

It’s pretty resilient to low temperatures but prefers a temperature between 20-50 °C. Showers, cleaning systems, hot and cold water systems, air conditioning systems and drinking water systems all provide the right environment for contamination.

If these systems are poorly maintained, the bacteria will grow and increase the risk of Legionnaires’ disease.

What is Legionnaire’s Disease?

This is a potentially fatal form of pneumonia. The symptoms are similar to the flu – you’ll have a high temperature with fever and chills, muscle pain and tiredness, a cough, and probably a headache. You might also feel confused and experience vomiting or diarrhea.

Everyone is open to infection. However, the risk increases even further if you are over 45 years old, smoke or drink heavily, have an impaired immune system or a pre-existing condition like diabetes, heart disease or respiratory issues.

Given that a 2018 study found that 46% of UK officers (holding Certificates of Competency) were over the age of 45, this suggests a large number of seafarers are at increased risk.

Because of its similarity to the flu, it’s not always easy to diagnose – especially at sea where they may not be easy access to a medical professional who can conduct urine or blood tests. Access to antibiotics to treat the disease will also be much harder to find.

In the past 30 years, there have been over 200 cases of Legionnaires disease on ships and it can have a devastating effect on your crew and operations. In one incident alone, 50 seafarers were infected and one crew member died.

Legionella at sea

All man-made water systems can be a breeding ground for Legionella and the conditions onboard ship provide the perfect environment for the bacteria to thrive. You should be paying particular attention to these areas:

– Any part of your water system that has a temperature between 20–50 °C.

– Any outlet that creates and disperses water droplets. This includes showers, sink taps, air conditioning units, fire hoses, and washing equipment.

– Anywhere that water is stored or re-circulated.

– Places where there are deposits containing nutrients that allow bacteria to grow such as rust, sludge, scale, organic matter, and biofilms.

What can I do to prevent it?

There are a few simple measures that you can perform to reduce the risks from Legionella at sea.

Boiler outlets
Make sure the water is more than 60 °C.

Taps, toilets and showers
If they’re not frequently used, they need to be flushed through at least once a week.

Hot and cold water supply
The hot water supply temperature should be greater than 60 °C and the cold below 25 °C. If they aren’t, then the water needs to be tested for legionella.

Showerheads and pipework
At least every three months, dismantle, clean and soak for a few hours in a disinfectant or chlorine solution. If a shower hasn’t been turned on for 2-4 weeks, you should do this before it’s used again. You also need to find and remove any plumbing that’s become isolated from the regular flow of water or is no longer used.

Freshwater tanks
To prevent the growth of bacteria, make sure the residual disinfectant level is maintained at more than 0.2ppm free chlorine. They also need to be super chlorinated twice a year with the water flushed through outlet points.

Testing

Ship operators have a responsibility to protect their employees from legionella, as outlined in the guidance from the Health and Safety Executive.

You should conduct regular tests to check for bacteria present in the water onboard ship – both your sewage effluence and your freshwater.

Drinksafe will allow you to maintain the safety of your water source as well its distribution system. It will test for bacteria and toxins in the water that you use every day for drinking, hygiene, and food preparation. For extra peace of mind, we can also provide a special add-on that’s specifically designed to protect against the dangers of legionella.

Know the risks and always ensure that your water supply is safe.

Contact us to learn more about our onboard legionella and potable water test kits.