Monday, 5 March 2012

News Update: Infection Control: Legionnaires' disease and dental unit water

We came across this brilliant article on : Infection Control: Legionnaires' disease and dental unit water - If you're a dentist, and worried about legionella, we don't blame you...

"On a certain Monday morning in February, some of us were getting the same question from our patients. The question was similar to the questions that dental offices received in 1987 regarding transmission of HIV in the dental setting, as well as questions in 2001 regarding the transmission of HBV in the dental setting. My hope was that you answered these questions without hesitation.
Your current answers should be that your office is doing everything they can to comply with the guidelines, regulations, and laws governing infection control in the dental setting, including infection control procedures that treat the water lines.
In Rome, Italy, it was confirmed that an 83-year-old Italian woman who died from Legionnaire’s disease contracted the infection from the water lines in a dental practice.
The case was quickly diagnosed, and the source of the disease is unquestioned. The woman was admitted into the hospital with breathing problems and a very high temperature. She was admitted to the intensive care unit with continued fever and respiratory distress.
Chest radiography showed several areas of lung consolidation. She had no underlying diseases or conditions. Legionnaires’ disease was promptly diagnosed by a Legionella pneumophila urinary antigen test; a bronchial aspirate was taken for microbiological examination. Oral ciprofloxacin (750 mg every 12 hours) was started immediately. Nevertheless, the patient developed fulminant and irreversible septic shock and died two days later. An investigation to find the source of L pneumophila infection was initiated. After testing, she was diagnosed with legionnare’s disease.(1,2)
The part of this story that makes it clear that the disease was a direct result of dental treatment is what led up to this. The patient left her house only two times within the incubation period of two to 12 days. Both of those trips were direct trips to the dentist and back.
The evaluation of the dental setting included an evaluation of the water in the dental lines. Samples of water were taken from the dentist’s tap, from the dental unit water line, and from the high-pressure pump supplying the waterline. The testing that was done revealed that all three samples of water tested positive for Legionella pneumophila bacteria and the sample from the water pump was particularly convincing. Aerosolised water from high-speed turbine instruments was most likely the source of the infection. Warm temperatures and periods of water immobility provide a breeding ground for the bacteria. Distributed in fine droplets by a spray, the bacteria are then breathed in. Elderly people or individuals with poor immune systems are most at risk.
Genetic sequencing confirmed that the bacteria found in the dental water line directly matched the bacteria that killed the patient. The bacteria is a particularly virulent substrain called Benidorm.
Legionnaire’s disease, as we all know, is unusual. Most cases have involved air conditioning units, spas, and water fountains that are not properly cleaned or looked after. No one previously has identified the dental setting as a possible source of this disease, but we all know it could happen. That is why we are all so diligent in applying infection control guidelines, regulations, and laws into our daily practice of dentistry.
The case report has suggested a number of recommendations, including the use of filters and sterile water and adding a continuous loop of disinfected water. 
What is Legionnaires’ disease? 
The Centers for Disease Control and Prevention (CDC) defines Legionnaires’ disease as a disease that is caused by a type of bacteria called Legionella. The bacteria got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of this disease, which is a type of pneumonia (lung infection). Although this type of bacteria was around before 1976, more illnesses from Legionnaires’ disease are being detected now. This is because we are now looking for this disease whenever a patient has pneumonia.
Legionella bacteria are found naturally in the environment, usually in water. The bacteria grow best in warm water. This is why you will find it in places such as hot tubs, air conditioning units, and water tanks. People acquire Legionnaires’ disease when they breathe in a mist or vapour (small droplets of water in the air) that has been contaminated with the bacteria. One example might be from breathing in the steam from a whirlpool spa that has not been properly cleaned and disinfected, or a dental hand-piece that has water flowing through to cool it down that is aerosolized. This disease is not spread from one person to another, but rather from the environment to the person.
The populations at the greatest risk for developing this disease are older people (usually 50 years of age or older), people who are current, former smokers, those who have a chronic lung disease (such emphysema), people who have weak immune systems from diseases, or those who take drugs to suppress (weaken) the immune system.
The problem with diagnosis of this disease is that symptoms are similar to other forms of pneumonia. It may be hard to diagnose at first. Symptoms of the disease can include a high fever, chills, and a cough. Some people may also suffer from muscle aches and headaches. Chest X-rays are needed to find the pneumonia caused by the bacteria, and other tests can be done on sputum (phlegm), as well as blood or urine to find evidence of the bacteria in the body. Symptoms usually begin two to 14 days after being exposed to the bacteria.
Legionnaires’ disease can be very serious and can cause death in 5% to 30% of cases. Most cases can be treated successfully with antibiotics, and healthy people usually recover from infection. "
Read more at DentistryIQ...
For more information on Legionella Bacteria and control measures call Spectrum Environmental Solutions on 0870 729 0199

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