Legionellosis, recognized as an acute bacterial disease, whose etiological agent is Legionella bacteria, has two very well defined and different epidemiological and clinical forms: legionnaires disease (legionnaires Pneumonia) and Pontiac Fever (Non-pneumonic Legionellosis).
Legionella species are ubiquitous bacteria in natural environments and in artificial water reservoirs. They proliferate in streams, rivers, lakes, ponds, mud, and soils. Until now, no less than 35 different species of Legionella have been identified. Legionella pneumophila is the species most commonly associated with the disease; of this, 14 different serogroups have been described. Among them, L. pneumophila serogroup 1 is the one that is usually associated with Legionellosis and other species different than Legionella, such as L. feelei and L. micdadei have been isolated in patients with immune deficiencies and pneumonia.
Can You Get Legionnaires Disease From Drinking Water?
The ecology of Legionella (which causes legionnaires disease) in water systems is not completely understood. However, studies indicate that water at temperatures between 20 ºC and 45 ºC promotes the growth of Legionella (which causes legionnaires disease). The bacterium does not multiply below 20 ºC and does not survive at temperatures above 50 ºC. These organisms can remain dormant and proliferate when temperatures are adequate. The presence of sediments and organic matter can serve as a source of nutrients for this bacterium.
In places such as showers, faucets, steam boilers, heat exchangers and other sources of water, Legionella bacteria can proliferate, due to the accumulation of sediments that usually occur as a result of the effect caused by high temperature water. In addition, pipes with little or no water, or those containing mud and dirt, constitute a favorable environment for the growth and development of L. pnemophila.
When the bacteria remain in stagnant water at a high temperature, such as in a boiler system, in a cooling tower, or in a condenser, it can easily reproduce and significantly increase the level of risk. If the contaminated water comes into contact with our respiratory system, through ingestion or via drops of water suspended in the air, a severe form of pneumonia can manifest itself; also known as Legionnaires’ Disease.
Individuals usually contract the legionnaires disease through the inhalation of contaminated water droplets. The symptoms will take between two and ten days to appear. Symptoms that manifest as headaches and muscle aches quickly turn into breathing difficulties and gastrointestinal discomfort. The disease is similar to pneumonia, but more severe, so public agencies in all categories must pay attention to the signs. Those organizations related to the tourist sector, such as large recreational complexes, tourism complexes, leisure centers and gyms where we can find saunas, jacuzzis or swimming pools should check and inspect the equipment frequently.
Residences and hospitals are high-risk environments since most individuals are prone to infection due to their weak immune system and suffer from underlying diseases. Therefore, ensuring bacteria-free water becomes the highest priority.
Airports, office buildings, and housing are other bacterial development foci since they use large boiler systems and cooling towers to eradicate legionnaires disease.
Prevention of Legionnaires Disease
Since the identification of the etiological agent, numerous nosocomial outbreaks of Legionnaires disease have been reported, which promotes the need to implement prevention measures.
It is worth mentioning that the appearance of contamination by legionnaires disease in water distribution systems is relatively frequent. The heating of the water and circulation through the network of the affected building at temperatures of 60 to 77 °C is the most effective disinfection system. The problem is to get all points of the distribution network to reach this temperature and the need to periodically repeat the process. The ventilation towers in which Legionella is detected should be disinfected according to existing protocols and then the effectiveness of disinfection is controlled, which should lead to the end of the epidemic in 10 to 15 days.
Given that governments work systematically to provide access to drinking water, it is easy to take it for granted. However, many people are not aware that even drinking water in appearance can entail dangers of legionnaires disease. The aforementioned preventive measure should be considered in order to avoid future outbreaks of the legionnaires disease.