- Legionnaires' disease increased
The number of people falling ill due to Legionella in Baden-Württemberg has increased. By the end of July, 222 cases had been reported, according to the Ministry of Social Affairs. In the whole of 2023, there were 350 cases, and in 2022, there were a total of 248. Legionella can cause flu-like symptoms in humans, up to severe lung infections. The bacteria are often transmitted through aerosolized water, such as in showers, hot tubs, humidifiers, or through water taps.
According to the Robert Koch Institute (RKI), possible reasons for the generally increasing numbers could be better case detection, an aging population, and changes in climate. The combination of high temperatures and more rain seems to lead to more Legionella cases, the RKI writes.
Swimming in hot tubs can pose an infection risk
In general, more Legionella cases are reported in the summer and autumn. Reasons for this could be travel during the holiday season and the associated infection risks, such as swimming in hot tubs, as the RKI writes. It could also be due to stagnant water in the pipelines of one's own apartment while the residents are on vacation. Additionally, higher temperatures can promote the growth of Legionella in cold water.
To protect against Legionella, the Ministry of Social Affairs therefore recommends occasionally running the water in empty apartments and houses, as well as in little-used showers and sinks.
Ideal growth conditions between 25 and 45 degrees
The bacteria are present in low concentrations almost everywhere in water. Ideal growth conditions are found at temperatures between 25 and 45 degrees. According to the RKI, the growth of bacteria is inhibited at water temperatures over 55 degrees. Above 60 degrees, the germs die.
In principle, the responsibility for the quality of drinking water lies with the waterworks, which must ensure that the water is supplied accordingly up to the building's pipelines. Owners of larger residential buildings are obliged under certain conditions to have the drinking water checked at least every three years. If a certain limit value for Legionella is exceeded, the local health authority must be informed. This in turn supports the elimination of the problem. The State Health Office has no figures on problematic Legionella occurrences in the past, according to the Ministry of Social Affairs.
The number of deaths from Legionnaires' disease has also increased compared to the previous year: by the end of July, 10 people had died - in the previous year, there were a total of 13. However, the number in 2022 was 26.
Particularly at risk from Legionella are people with a weakened immune system or certain underlying conditions such as diabetes, heart, and lung diseases. Smokers and older people are also considered at risk. According to RKI figures, the disease is fatal in about five to ten percent of patients.
There are regular reports worldwide of larger Legionella outbreaks, also with fatal outcomes. For example, in late summer 2023, at least 19 people died in the Polish city of Rzeszów and the surrounding region in a large Legionella outbreak.
First reported in 1976, Legionnaires' disease emerged during a convention of American war veterans: Several attendees fell ill with an atypical form of pneumonia.
The heavy rainfalls this summer might be contributing to the increased Legionella cases, as stated by the Robert Koch Institute. When using a shower or hot tub, ensure the water is heated above 55 degrees to prevent the growth of Legionella bacteria.
