Can I Get Legionnaires’ From My Shower?

A connection between your shower and a weird-sounding disease you’ve probably never heard of might seem a little odd. Don’t worry; all will be explained below.

Legionnaires’ (lee.juh.ney.uhz) disease is a relatively uncommon, often severe form of pneumonia. And yes, it is possible - but improbable - to get it from your shower. The organism that causes the disease has an affinity for water and has been found in private and public showers. 

Here, we will take a look at the disease and how your shower can act as a conduit for it.

About legionnaires’ disease

In the summer of 1976, over 4,000 members of the American Legion gathered at a hotel in Pennsylvania for a convention. Attendees returned home after a triumphant congress, only to be gripped by sickness. 221 of them fell ill and 34 died from a then-unknown infection, which was later dubbed legionnaires’ disease. The outbreak was subsequently traced to the hotel’s cooling system.^1,2

Since the discovery of the disease in 1976, several other outbreaks have occurred in different parts of the world. Numerous isolated cases have also been reported. 

Legionnaires disease is a potentially fatal form of pneumonia (lung infection) caused by a type or group of bacteria called Legionella. Several species of the bacteria are known but most cases are caused by Legionella pneumophila. 

The disease occurs worldwide and water is the most common source of infection. Legionella species can also cause another, much milder, disease called Pontiac fever.¹

The bacteria live in bodies of water - lakes, streams, artificial reservoirs - and in soil. Transmission happens when contaminated water in the form of fine mist (aerosol) is inhaled into the lungs. It can also happen when contaminated drinking water goes down the wrong pipe - the windpipe instead of the food pipe - and gets into the lungs instead of the stomach (aspiration).

Less commonly, the bacteria can be inhaled from contaminated soil; babies can also contract the disease from the birthing tub during water births.

Commonly implicated sources of infection include domestic and industrial water systems, air conditioning cooling towers, water fountains, hot tubs, and humidifiers. Although it is an infectious disease, human-to-human transmission is rare.²

How do I get legionnaires' disease from a shower? 

Legionella species have been found in showerheads and domestic water distribution systems in the course of several investigations. It is in fact, possible to get legionnaires disease from a shower because of the fine mist created from the shower spray. This allows the bacteria to be inhaled, potentially leading to infection.^2,3,4,5,6

The risk of shower contamination – and consequently human infection – depends on the maximum hot water temperature, the age of the building, and how frequently you use your shower. ^2,3

Legionella bacteria thrive in warm (below 50℃), but not in hot water. An older house with an older plumbing system is more likely to harbour the bacteria, and the more often you use your shower, the less time the bacteria have to multiply in stagnant water.^2,3 

Showers that are used at least once a day have been shown to harbour lower concentrations of the bacteria than those used once a month or less. So while it is possible to get legionnaires from your own shower, you are more likely to get it from a shower that is not used frequently - like in a holiday home or at a hotel.^2,3

Risk factors for legionnaires’ disease

Not everyone who is exposed to the bacteria develops the disease. Certain conditions can increase the risk of developing legionnaires’ disease after exposure.^7,8

These include: 

• Current or previous cigarette smoking
• Alcohol abuse
• Age above 50 years
• Cancer - especially blood cancers
• Diseases of the lungs like COPD
• Other conditions like diabetes and HIV/AIDS

Legionnaires’ disease symptoms 

These range from mild to severe (requiring hospital admission). Common symptoms include:

• Cough - this is usually dry but could bring up blood
• Fever 
• Fatigue and muscle aches
• Difficulty breathing
• Headache
• Confusion
• Stomach (abdominal) pain
• Nausea and vomiting
• Diarrhoea

Treatment of legionnaires’ disease

Legionnaires disease is curable with timely use of appropriate antibiotics. In severe cases, patients may be given oxygen in the hospital and/or connected to a machine to help them breathe.

Ways and tips to lower the risk of getting legionnaires’ disease

• Run showers more often or flush all your infrequently used taps and showers with hot water at least once a week
• Run hotter showers (not hot enough to burn!)
• Clean shower heads and water fountains frequently
• Ensure water systems are properly installed and maintained with regular inspection and cleaning
• Open bags of soil or compost away from your face, and always wash hands thoroughly after gardening

When do I need to consult a doctor?

You should contact your healthcare provider as soon as you begin to experience symptoms of legionnaires’ disease. They will let you know if you need to go to a hospital. You should also contact your healthcare provider if there is an outbreak of the disease in a building you have recently been in. 

Summary

Legionnaires disease is an infectious, often life-threatening form of pneumonia. Transmission occurs when Legionella species are inhaled or aspirated into the lungs from contaminated water or soil. Common sources of the bacteria include water systems, air conditioning cooling towers, and decorative water fountains. The disease is potentially curable with the use of antibiotics and other supportive measures. Speak to your doctor as soon as you believe you have the disease to ensure timely treatment!