- Legionnaires increasingly found in water pipes
Legionella are often transmitted through aerosolized water, such as in showers, hot tubs, humidifiers, or through water faucets. They can cause flu-like symptoms to severe pneumonia. In Baden-Württemberg, the number of people affected by Legionella has increased. As of late July, 222 cases have been reported, compared to 350 in the entire year of 2023 and 248 in 2022.
According to the Robert Koch Institute (RKI), possible reasons for the overall increase in cases could be better case detection, an aging population, and changes in climate. The combination of high temperatures and increased rainfall seems to be leading to more Legionella cases, the RKI writes.
Hot tubs increase infection risk
In general, more Legionella cases are reported in the summer and fall. Reasons for this could be travel during vacation time and the associated infection risks, such as swimming in hot tubs, as the RKI writes. Additionally, bacteria can multiply more easily in the water in pipes in homes that are not regularly used during vacations. Higher temperatures also promote the growth of Legionella.
To protect against Legionella, the Ministry of Social Affairs recommends occasionally running water in empty apartments and houses, as well as in little-used showers and sinks.
The bacteria are present in low concentrations almost everywhere in water. Ideal growth conditions are at temperatures between 25 and 45 degrees Celsius. According to the RKI, the growth of bacteria is inhibited at water temperatures above 55 degrees Celsius, and they die at temperatures above 60 degrees Celsius.
More people dying from Legionella
In principle, the responsibility for the quality of drinking water lies with the waterworks, which must ensure that the water is supplied accordingly to the buildings' pipes. Owners of larger residential buildings are obliged, under certain conditions, to have the drinking water tested at least every three years.
If a certain limit value for Legionella is exceeded, the local health authority must be informed. This then 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 people who ultimately died from Legionella has also increased compared to the previous year: By the end of July, there were ten deaths, compared to 13 in the previous year and 26 in 2022.
Diabetics and immunocompromised people particularly at risk from Legionella
People with weakened immune systems or certain underlying conditions such as diabetes, heart, and lung diseases, as well as smokers and the elderly, are particularly susceptible to Legionella. In about five to ten percent of patients, the disease takes a fatal course, according to RKI figures.
The last major Legionella outbreak in Baden-Württemberg occurred in the fall of 2023, according to the Ministry of Health. Between August and November, a total of 39 women and men fell ill - 35 of them had to be hospitalized, but none died.
The health department and the environmental protection agency ultimately concluded that an evaporative cooling system in the city center was the source of the illnesses and shut it down. "Evaporative cooling systems are used in technical systems to transport the heat generated there," the Federal Environment Agency writes about these systems.
Major Legionella outbreak in Poland: at least 19 deaths
There are frequent reports worldwide of larger Legionella outbreaks with fatalities. For example, at least 19 people died in a major Legionella outbreak in the Polish city of Rzeszow and the surrounding region in late summer 2023.
The Legionnaires' disease was first identified in 1976 during a convention of a veterans' association in the USA: Several participants fell ill with the atypical pneumonia.
Germany experienced an increase in Legionella cases, with 222 cases reported in Baden-Württemberg as of late July 2023, surpassing the annual totals of 2022 and 2023. Travel and use of hot tubs during vacation periods are thought to contribute to the increase in cases, as the bacteria can multiply more easily in warm water.
The risk of Legionella infection from hot tubs is particularly high in Germany, as the bacteria can thrive in the water at higher temperatures, especially during vacations when water is not regularly used.
