Keep your hot water cylinder thermostat set at 60ºC as water at this temperature will kill any legionella bacteria. Warning: Be aware that water at this temperature may cause scalding. After de- scaling, flush the shower thoroughly and soak in bleach, which helps sterilise and kill any bacteria.
A water temperature of 120°F does not kill the Legionella bacteria; a hot water temperature of 140°F is required at which Legionellae dies in 32 minutes. Hence it is recommended that the water heater be set at a safe hot water temperature of 140°F. The Legionella disinfection range is 158 – 176 °F.
Chlorine and hot water kill legionella, but not amoebae, so Ahlén now strongly recommends that our contingency planning for legionella outbreaks should be extended to include the demonstration and elimination of amoebae, both at sea and ashore.
Why are showers high risk? Legionella bacteria is dispersed in airborne water droplets, so the spray created by a shower is the perfect delivery mechanism. Anyone using a contaminated shower risks breathing in the bacteria and developing Legionnaires' disease as the bug takes hold in the lungs.
Above 70 °C (158 °F) – Legionella dies almost instantly. At 60 °C (140 °F) – 90% die in 2 minutes (Decimal reduction time (D) = 2 minutes) At 50 °C (122 °F) – 90% die in 80–124 minutes, depending on strain (D = 80–124 minutes) 48 to 50 °C (118 to 122 °F) – can survive but do not multiply.
People can get Legionnaires' disease or Pontiac fever when they breathe in small droplets of water in the air that contain the bacteria. Less commonly, people can get sick by aspiration of drinking water containing Legionella. This happens when water accidently goes into the lungs while drinking.
Depending on your facility's specific situation and where in the water system the Legionella was found, remediation could include:
- Super heating and/or chlorination of the water.
- Flushing and cleaning of hot water holding tanks and associated equipment.
- The addition of point-of-use filtration in high-risk areas.
Legionella are relatively resistant to standard water disinfection procedures and, can occur in potable water. These bacteria have been found in water distribution systems of hospitals, hotels, clubs, public buildings, homes, and factories.
So that's 212 degrees F (at sea level) to reliably kill bacteria and pathogens to make water potable. By contrast, most dish and clothes washing are done at temperatures lower than 120 degrees (the standard-setting on home hot water heaters), so it's not safe to assume you're killing a lot of germs with the hot water.
Chlorine and hot water kill legionella, but not amoebae, so Ahlén now strongly recommends that our contingency planning for legionella outbreaks should be extended to include the demonstration and elimination of amoebae, both at sea and ashore.
Somewhat to our surprise, virtually none of them have become reinfected. Apparently, they developed immunity with their first infection. It appears that you have some residual protection if you contract Legionnaire's disease; however, the most effective method of prevention is stopping cigarette smoking.
Molds in homes do no cause Legionnaires' disease. You should see a doctor about your symptoms.
Most people become infected when they inhale microscopic water droplets containing legionella bacteria. This might be from the spray from a shower, faucet or whirlpool, or water from the ventilation system in a large building. Outbreaks have been linked to: Hot tubs and whirlpools.
The condition may cause fever, headaches, and muscle aches, but the symptoms usually go away on their own. Typically, less than 5 percent of people exposed to the bacteria develop Legionnaires' disease. Of every 20 people who become ill from the condition, one to six will die of it, based on CDC statistics.
The most commonly used laboratory test for diagnosis of Legionnaires' disease is the urinary antigen test, which detects a molecule of the Legionella bacterium in urine. If the patient has pneumonia and the test is positive, then you should consider the patient to have Legionnaires' disease.
What are the long-term side effects of Legionnaires' disease?
- Fatigue in 75% of patients.
- Neurologic symptoms in 66%
- Neuromuscular symptoms in 63%
- Posttraumatic stress disorder in 15%
- Health-related quality of life > 1.5 years.
Water mist from cooling towers or evaporative condensers, evaporative coolers (swamp coolers), humidifiers, misters, showers, faucets, whirlpool baths and hot tubs can become contaminated with Legionella bacteria. If the contaminated water mist is inhaled or swallowed, it can cause the disease.
Swimmers are at risk for respiratory infections if they breathe in small droplets of water (mist) from a pool or hot tub that contains harmful germs. A respiratory disease caused by the germ Legionella is one of the most common waterborne diseases in the United States.
The filters achieved a greater than 99% reduction in HPC bacteria in the immediate and postflush samples. Point-of-use water filters could be used to eliminate Legionella and other pathogenic bacteria found in water. The filters can be attached to individual faucets and showers used by high-risk patients.
Slow moving or stagnant water allows Legionella bacteria the time to grow and multiply, if the water is constantly on the move it will just get flushed through the system. At this point, the bacteria identified were called Legionella.
Take the following precautions to help limit the risk of Legionella exposure in the home:
- Set your water heater temperature to 140 degrees Fahrenheit.
- Maintain your water heater properly.
- Perform hot-water flushes.
- Maintain hot tubs carefully.
- Use humidifiers with caution.
Experts advise that you should give your shower head a thorough cleaning at least once a month, but regular weekly cleanings are the key in preventing the serious buildup. For hassle-free cleaning, simply spray your shower head with a vinegar-based cleaning solution every week as you are getting out of the shower.
About 1 out of every 10 people who gets sick with Legionnaires' disease will die due to complications from their illness. For those who get Legionnaires' disease during a stay in a healthcare facility, about 1 out of every 4 will die.
Legionella bacteria are commonly spread through airborne water droplets. Mist or vapor contaminated with the bacteria can come from whirlpool spas, cooling towers (used as air-conditioning units in large buildings), and water used for drinking and bathing, according to the CDC.
In what conditions do Legionella grow? The bacteria have been found in water systems ranging in temperature from 6°C to 60°C, although they will grow best between 20°C and 45°C. Legionella bacteria will rapidly be killed at temperatures above 60°C, and do not multiply at temperatures above 50°C.
