The current coronavirus outbreaks have forced schools, gyms, nightclubs, offices and other buildings to close at a level never seen before. As countries begin to reopen after closure, previously closed buildings could become a breeding ground for another infection: legionellosis.
Legionellosis: why you should be concerned from October
Caused by inhaling small drops of water that contain, in most cases, the bacteria Legionella Pneumophilia, in Spain it has an incidence of about 1,000 cases per year. Long periods of inactivity in buildings increase the risk of this disease.
What is the risk?
One of the peculiarities of Legionella Pneumophilia is that it grows especially in the summer months (the optimum growth temperature is between 25ºC-45ºC). It is present in small amounts in water sources such as rivers, lakes or groundwater, but it also grows in built environments, especially in the nooks and crannies in pipes buildings and other complex water systems that are not properly maintained.
In these areas, bacteria thrive in warm water that is stagnant or has little flow. The risk appears in any place where water droplets can be createdsuch as hot and cold water systems, cooling towers and air conditioners, machine cooling systems, hot tubs, sprinkler irrigation systems or ornamental fountains.
As a result of the measures imposed by COVID-19, many of these facilities have had to temporarily close or their operation has been reduced during the last eight months. This irregularity in operation, if poorly controlled and managed, can carry risks.
An extended period can be weeks or months, recognize the Centers for Disease Control and Prevention of the United States (CDC). For example, in cold water facilities for human consumption, after a stoppage of more than one month, a shock cleaning and disinfection should be performed according to the Royal Decree 865/2003, which includes the hygienic-sanitary criteria for the control of legionellosis.
As the National Association of Environmental Health Companies advises (ANECPLA), The months of September and October They are also the ones with the highest risk of contracting legionellosis, since that is when temperatures tend to drop and, therefore, when the cooling towers are disconnected.
But autumn is changeable and the first drops in temperature tend to be followed by warmer days, which is when many of these towers start up again, especially in hotels and hospitals. Without a proper review, the risk of proliferation of the bacteria in these cases increases.
How to control and prevent Legionella
It is very important that, during this pandemic, all water systems are kept safe while closed or during partial closures. The key is, as ANECPLA recalls, in not letting the bacteria find the conditions it needs to live, such as accumulation of dirt, optimal temperature and time.
If all this is favorable, Legionella can multiply to dangerous levels for people. To avoid this, experts urge not to lower your guard and apply controls like:
- Prior and regular cleaning and disinfection of the cooling towers.
- Adequate checks to reduce water stagnation in taps where they are not used.
- Correct mechanical maintenance, especially of hot and cold water systems and keep the hot water above 50ºC and the cold one below 25-20ºC.
- Dosing of the corresponding biocide, such as chlorine, in areas such as a spa pool along with a complete drainage and cleaning of the entire system once a week.
This will prevent the bacteria from spreading easily because:
- The environmental conditions it needs are avoided: temperatures between 25-45ºC, stagnation of water and accumulation of substrates that serve as food.
- The risk of infection is reduced: regular cleaning checks by professionals Before starting the refrigeration systems, especially in medical centers, they are essential to prevent the spread of the bacteria.
The most important way to prevent legionellosis, therefore, is to maintain the water supply properly. In this way, the bacteria cannot grow or multiply. As the European Society for Microbiological Clinic and Infectious Diseases recalls (ESCMID), it is very important that even though many buildings and offices are closed during this COVID-19 outbreak, the water systems continue to be maintained to prevent future health problems.
Instead, according to the CDC, home and car air conditioning systems They don’t use water to cool the air, so they don’t pose a risk to Legionella growth.
COVID-19 or legionellosis?
Fever, cough, shortness of breath, headache and muscle pain. We now easily associate these symptoms with COVID-19. But also can define legionellosis very well, a respiratory disease that comes from bacteria present in small droplets of contaminated water in the air and from sources such as air conditioning systems, cooling towers, spa pools, hot tubs or water sources.
Like the SARS-CoV-2 virus, Legionella bacteria infects the lungs of a person and causes pneumonia. Therefore, there is the possibility that many of these pneumonias are misdiagnosed and attributed to COVID-19. In addition, both diseases tend to occur in places where many people are concentrated (COVID-19 seems to spread more easily when there are many people in the same place).
But, unlike the coronavirus, studies done so far do not show that lLegionellosis is spread from one person to another, as is the case with COVID-19. To distinguish legionellosis from pneumonia due to other causes, laboratory tests are performed to isolate the bacteria from respiratory secretions or by analyzing the patient’s blood or urine.
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