Legionella

Legge-Perthe s disease Leghemoglobin Legionella pneumophila Legionnaires disease... 

Controlling legionella m nursing and residential care homes Chemical reaction hazards and the risk of thermal runaway... 

Withdrawn) 1992 Method for detection and enumeration of Legionella organisms m water and related materials. Withdrawn, superseded by BS 6068-4.12 1998... 

Legionella 0 Tt3 Legionnaire s Disease, commonly known as pneumonia Found naturally in water multiplies in heating systems... 

Legionella No limit, but EPA believes that if Giardia and viruses are removed/inactivated, Legionella will also be controlled. 

The aerosols formed in an open system, if inhaled, can cause various forms of Legionella. No one biocide is adequate to control these, as there are some 30 known groups, the most virulent being Legionella pneumophila. 

For all humidifiers, full consideration should be given to the possibility of the growth of fungi, algae, bacteria, and in particular Legionella pneumophila, the microbiological contamination that causes humidifier fever, etc. 

Legionella pneumophila (LD) Infections, particularly pneumonia, caused by inhaling Legionella pneumophila and other bacteria from the family Legionel-laceas in water droplets drifting from cooling towers, showers, etc. 

Cooling towers and other sources of standing water (e.g., humidifiers) are thought to be typical sources of Legionella in buildings. 

The best known example is Legionella, a bacterium that causes Legionnaires Disease and Pontiac Fever. 

For food and drink, medical, pharmaceuticals and cosmetics production the microbiological quality of the water becomes paramount. Even in applications where biological quality is not directly important, uncontrolled growth can be a damaging nuisance. Warm-water systems and cooling circuits in particular are a potential hazard (e.g. from Legionella). Some water treatment or conditioning is commonly required. 

Respirators should comply with BS 2091, BS 4555, BS 4558, BS 4771 and BS 4275. (Refer to Form F2486, published by HSE for suppliers of respirators suitable for use against aerosols containing Legionella.)... 

Cooling towers and evaporative condensers release into the atmosphere fine droplets of water, which may carry sources of contamination such as algae and bacteria. Many of these thrive at the temperatures to be expected in water cooling systems and one of them, Legionella pneumophila, has been identified as a particular hazard to health. Cooling apparatus should be cleaned and disinfected frequently to reduce these risks of contamination and should not be located where water droplets can be drawn into ventilation air intakes. 

It is now some 20 years since the recognition of Legionella pneumophila in condenser water, and the measures taken by industry to combat the hazards to human health. Worldwide indications are that the initial vigilance and care have lessened in recent years and attention is now drawn again to such precautions [2 7, 28, 28a, 28b]. 

Delaedt Y, Daneels A, Declerck P et al (2008) The impact of electrochemical disinfection on Escherichia coli and Legionella pneumophila in tap water. Microbiol Res 163(2) 192-199... 

Selective media for legionellas and listerias. Such have been devised. 

In addition to L pneumophila, 16 other species of Legionella of proven pathogenicity have been described. 

Roxithromycin has similar in vitro activity to erythromycin but enters leucocytes and macrophages more rapidly with higher concentrations in the lysosomal component of the phagocytic cells. It is likely to become an important drug against Legionella pneumophila. Clarithromycin is also of potential value. 

Streptococcus pneumoniae remains the commonest cause of pneumonia and responds well to penicillin. In addition, a number of atypical infections may cause pneumonia and include Mycoplasma pneumoniae, Legionella pneumophila, psittacosis and occasionally Q fever. With psittacosis there may be a history of contact with parrots or budgerigars while Legionnaires disease has often been acquired during hotel holidays... 

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