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Legionella
is a bacterium, bacillus shaped, gram-negative, with
notorious biological risk that causes serious diseases, always associated to
droplets of water. There are more than 50 species and subspecies listed, with
approximately 71 serological types of
Legionella
(KONEMAN et al, 2008).
One of the noticeable characteristics of this microorganism is the ability
to survive in a wide range of physical-chemical conditions, as for example,
• Wide range of pH – between 5 and 8;
• Variable temperature range, between 5.7 °C and 63 °C, with preference
to warm waters.
Other factors that favor the proliferation of the bacteria is the contact
with biofilm and iron oxides, common in pipes with corrosion and
incrustations, and the presence of other microorganisms in the water, like
protozoa and algae.
The infection caused by this microorganism in humans affects
exclusively the respiratory tract, which can translate into two forms of
disease: the Legionnaire’s disease and the Pontiac Fever:
Legionnaire’s Disease:
Severe pneumonia, with incubation of 2 to 10
days and mortality rate of 15%. The most specific symptoms are dry cough,
high fever with chills, abdominal pains, vomits, diarrhea and delirium;
kidney failure and encephalopathy may also occur.
Pontiac Fever:
Minor form of the disease, caused by the same type of
bacteria. Symptoms in general last for 2 to 5 days and can also include fever,
headache, muscle aches.
