Seven new cases of legionella bring to forty the number of people infected by the wave of legionella that has hit Bresso, a town on the outskirts of Milan in recent weeks.
The news was provided with a note from the Ats Metropolitan City of the Lombard capital. Three people died as a result of the infection. The Ats stated that "Although the alert remains high, the clinical situation of the citizens of Bresso who have contracted the bacterium is not worrying".
Deepening
Legionnaires 'disease or Legionnaires' disease is an infectious disease that affects the respiratory system, mainly caused by the bacterium Legionella pneumophila. Legionnaires, which still exist in about fifty different bacterial species, nest in the water and are transmitted through the nebulized water, by inhalation.
Legionellae prefer natural and artificial reservoirs, and temperatures between 25 and 55 ° C. Above or below this threshold, they do not survive. They can nest in spring waters, including thermal waters, in rivers, lakes, muds. From here they can reach city water pipelines and systems, such as fountains, swimming pools, plumbing, or sanitary facilities in homes.
Legionella are transmitted by inhalation, i.e. by breathing in aerosol droplets containing infected vapor. If these droplets are small enough, less than 5 micrometers (thousandths of a millimeter) in diameter, they more easily penetrate the airways, where they can spread the infection.
The Istituto Superiore di Sanità informs that "droplets can form either by spraying the water or by bubbling air into it, or by impact on solid surfaces".
The disease is therefore not transmitted from human to human, nor by drinking or using water for cooking. Instead, it can spread by air, through old and unclean air conditioning filters: the bacterium was isolated for the first time in 1976 following an epidemic that broke out among veterans of the American Legion at the Bellevue Stratford Hotel in Philadelphia. On that occasion, 221 people became infected with the hotel's air conditioning systems, and 34 died.