Many different species of bacteria called Legionella are found in the environment. One such bacteria, called Legionella pneumophila, causes Legionnaires’ disease in humans. Legionnaires’ disease is a lung infection that needs antibiotics to treat and can necessitate a stay in the hospital. It can cause severe pneumonia and in some cases, it can be fatal. Here’s everything you need to know about the disease, including how to prevent it.

What Is Legionella Pneumohila?
Legionella Pneumophila is a bacteria from the genus Legionella. It thrives in droplets of water and moist conditions. The bacteria is found in both potable and non-potable water systems and can be detected in rivers, lakes, and streams. One type of Legionella species has even been found in potting soil. The bacteria reproduce in high numbers in water that is warm and stagnant.
Meticulous cleaning and disinfection of water systems, pools and spas is imperative to prevent Legionella bacteria from growing. If you need water and sewer pipe repair, call in the experts to ensure the job is done right the first time so you and your family can enjoy peace of mind when it comes to your water.
Air Conditioning Systems
The Legionella bacterium also thrive in the mist aerosolized from air conditioning ducts so it can infest an entire building or airplane. The first outbreak of Legionnaires’ disease was at a Philadelphia hotel during an American Legionnaires’ convention in 1976. Air conditioners were suspected to be the source of the infection, however, new data suggests that the water in the hotel was actually to blame.

Where Can You Become Exposed to Legionella Pneumophila?
Legionella organisms have been found in the following places:
- Plumbing and water systems
- Showers, taps and toilets
- Hot water tanks
- Cooling towers
- Evaporative condensers of large air-conditioning systems
- Hot tubs
- Mist machines, such as those in grocery stores
- Ice machines
- Humidifiers
- Whirlpool spas
- Hot springs
- Decorative Fountains
- Swimming pools
- Physical therapy equipment
- Nebulisers
- Home birthing pools
Can You Catch Legionnaire’s Disease?
Every year, around 10,000 to 18,000 people are infected with the Legionella bacteria in the United States.
You can develop Legionnaires’ Disease if you inhale the bacteria from a water source that is contaminated with Legionella bacteria. This could be if the bacteria is present in an air conditioning system where you work, live or visit, or you come into contact with contaminated water, as detailed in the section above. Not everyone who is exposed to Legionella bacteria becomes sick. You are more likely to develop Legionnaires’ disease if you are a high-risk person, for example, you are a smoker or you have a weekend immune system.
In the past, people have become infected after staying in the hospital, hotels, cruise ships, and nursing homes. There have been outbreaks in gyms and even in a police station in New York.
Another way of contracting Legionella is through aspiration, which means choking to a degree that secretions in the mouth get past the choking reflexes and enter the lung. This can sometimes happen if you cough or choke when you are drinking. Patients who smoke or who have lung disease do not have the protective mechanism to prevent this from happening.
The bacteria must be inhaled to cause the disease. You cannot catch Legionnaires’ disease off of somebody else because an infected person cannot infect another person. Even pregnant women do not need to worry if they come into contact with a person who is infected with Legionnaires’ disease.

Symptoms of Legionnaires’ Disease
The incubation period, or the time between becoming infected and developing symptoms, is around two to 10 days, but it could be longer.
Symptoms include:
- High fever (104 F or 40ºC or higher)
- Chills
- Coughing
- Chest pain
- Breathlessness
- Diarrhea
- Nausea and vomiting
- Stomach discomfort
- Headache
- Tiredness
- Loss of appetite
- Confusion
Legionnaires’ disease generally infects the lungs and can cause severe pneumonia. It can seriously affect a person’s breathing and lead to respiratory failure and adult respiratory distress syndrome.
If you think you have been exposed to Legionella bacteria or you notice any symptoms of pneumonia, you should see a doctor as soon as possible. If you have Legionnaires disease, the sooner it is diagnosed and treated, the better. Getting treatment quickly can result in a faster recovery time and prevent serious complications. If you are classed as high-risk, it is even more important that you seek medical advice fast.
Those at a Higher Risk of Developing Legionnaires’ Disease
People who smoke are more likely to develop a respiratory illness and they are particularly vulnerable to infection from Legionella. You are also more at risk if you have:
- Chronic heart or lung disease
- AIDS
- Diabetes
- Kidney failure
- Some forms of cancer place you at a higher risk
- Patients who take corticosteroid medicines
- People that take medications to suppress their immune system are also at risk
Anyone at any age can become infected with Legionella, but people with weak immune systems are more vulnerable. It is more common in middle-aged and older people, and more men are affected than women.
Pontiac Fever
Pontiac fever is a milder form of the illness. It can develop just hours after infection and resolves spontaneously. The symptoms of Pontiac fever are like the flu so you might notice a fever, chills, a headache and muscle aches. People with Pontiac fever usually recover in two to five days, without any treatment.
Tests for Legionnaires’ Disease
If your healthcare professional suspects that you might have Legionnaires’ disease, you will need specific tests. Symptoms and the chest x-ray of a person with Legionnaires’ disease may resemble those of other types of pneumonia, so additional tests are needed to pinpoint Legionnaires’ disease.
Tests might include:
- Chest x-ray to confirm the extent of infection in your lungs.
- You might also need a CT scan or lumbar puncture if you present with neurological symptoms such as confusion.
Tests specifically for Legionnaires’ disease:
- A urine test can detect identifiable proteins of the Legionnaires’ bacterium.
- A sample of sputum, phlegm or lung fluid can be tested for the bacteria.
- Blood tests can detect antibodies in the blood against the bacterium.
The most effective way to determine if a person has Legionnaires’ disease is to test secretions from the respiratory tract to isolate, or grow, the bacterium.
Treatment
Legionnaires’ disease is treated with antibiotics. It will depend on a person’s individual circumstances and how certain the healthcare professional is that they are treating Legionnaires’ disease as to what they are prescribed. The three major classes of antibiotics for Legionnaires’ disease are the fluroquinolones, the macrolides, and the tetracyclines. A second drug called rifampin may be used if the disease is proving to be resistant to a single antibiotic.
Some patients with Legionnaires disease will need to be admitted to the intensive care unit. They might need antibiotics into a vein, an oxygen face mask or tubes in their nose, or a machine to help them breathe.
After Treatment
Some patients will suffer from fatigue, neurologic symptoms, and neuromuscular symptoms for months after an outbreak, or will suffer long-term from an impaired quality of life. However, most patients will recover completely from Legionnaires’ disease within one year.
Prevention: What Can You Do?
The most important thing you can do to lower your risk of Legionnaires’ disease is to stop smoking. If you smoke and you are exposed to Legionella bacteria, you are more likely to develop the disease.
Guidelines are now in place to test for Legionnaires’ in several US states and by the Veterans Affairs health care system.
Now, improved designs of cooling towers and plumbing systems minimize the risk of Legionella bacterium. Copper-silver ionization, superheating and monochloramine disinfection are newer ways of controlling and eliminating the growth of Legionella bacteria.
Here are some tips for the prevention of Legionella bacteria at home:
- Set hot water tanks to 140ºF or greater. Use water temperature controlling devices to reduce the risk of scalding.
- Flush hot water taps for 15 seconds to eliminate stagnant water, particularly if they are not used on a daily basis.
- Follow maintenance advice for spa pools and conduct regular cleaning and disinfection.
- Empty therapeutic humidifiers after each use, clean components and allow them to air dry.
- Regularly drain, clean and disinfect water fountains.
- Follow the correct maintenance guideline for evaporative air conditioners. Drain, clean and dry the unit and internal components at the end of summer.
- Drain portable evaporative cooling units at least once a week during summer. Drain, clean and dry units when they are not being used for an extended period.
To prevent Legionella, water symptoms must be maintained regularly according to the manufacturer’s instructions and any relevant legislation. Meticulous cleaning and disinfection of water systems, pools and spas are imperative. Always seek advice from the experts when it comes to water and sewer pipes.
San Diego Pipelining is the County’s premier water and sewer pipe repair company. If you need sewer or drain pipe repairs from a cost-effective, reputable company, get in touch with us for a free quote.