Legionella and Summer, an Indivisible Pack

Legionella likes summer temperatures. Summer and heat are close to forced marches and with it, the need to be fresh and hydrated leads to the more widespread use of water and air conditioners.

But these two sources of summer well-being can also be the origin of one of the infectious diseases that periodically have public health in check: legionella.

The legionella, like other bacteria, is as natural habitat and water may be present in rivers or lakes

What is legionella?

As Sara Rodríguez, Doctor in Environmental Microbiology and Biotechnology from the University of Barcelona, in Ecosocial Water, affirms, this bacterium can be part of biofilms or get into single-celled organisms to multiply taking advantage of its resources. “Legionella can move from its natural habitats to our water systems, where it can multiply if they do not receive the appropriate treatments,” explains the microbiologist.

That is when the bacteria come into contact with our body, which, if it reaches our lungs, is “ingested” by our immune cells to try to fight them. Precisely here lies its danger, since this bacterium, as we have explained, multiplies within unicellular organisms, in this case, macrophages, until it breaks them. “This process is what produces the lung disease known as legionellosis ”.

Contrary to what is believed, it is not transmitted orally, but by inhaling microdroplets (aerosols) of water that the bacteria contains. It reproduces easily in a series of environmental conditions:

  • High temperatures, between 20ºC and 50ºC especially.
  • Absence of disinfectant.
  • Existence of amoebas or biofilms in which it can be introduced.

If the water is treated correctly in compliance with the quality regulations, the aerosols will not be contaminated by legionella. Even so, areas, where it can be generated (as long as it is not well treated), are cooling towers, sprinkler irrigation systems, decorative fountains, air humidifiers, hot tubs, city cleaning vehicles, car wash tunnels, etc.

Legionellosis is a periodically leading disease of the media. On several occasions, we have discussed this in this blog, as in 2012 when we inform you of the legionella outbreak that was detected in Osuna, in Seville. Also last February, 9 cases of legionella were detected in Vitoria-Gasteiz. The Ministry of Health of Cantabria closed in March 6 rooms of the Hospital Sierrallana de Torrelavega to prevent infections by the bacteria. The municipality of Murcia is cleaning in its main lakes. The authorities constantly take the necessary measures for the detection and elimination of the bacteria, so you don’t have to worry.

In addition to this type of initiatives by the administration, it is important that those in charge of facilities capable of being a legionella focus be aware of the protocols that must be followed and that are even stipulated by law: Royal Decree 865/2003 establishes Hygienic-sanitary measures necessary for the prevention and control of legionella.