Source found Legionella outbreak in Basel: Canton gives warning

The canton of Basel has declared an end to the legionella outbreak that affected 29 individuals, including one fatality, after confirming the source of the infection. Health authorities announced on Thursday that no new cases have been recorded since early August, marking the conclusion of the outbreak. A single patient remains hospitalized with a stable condition, though intensive care is not required. The outbreak originated from a cooling unit located on the roof of the Manor headquarters in the Rebgasse. This was confirmed through laboratory analyses comparing bacterial samples collected from the cooling unit with those taken from infected patients. The findings showed a match in the bacterial strains, scientifically verifying the source of the outbreak. The company, Manor, had already shut down the unit following initial reports of the illness. Investigations into water samples from the residences of affected individuals have not uncovered evidence linking domestic shower water to the outbreak. Despite this, health officials emphasize that legionella bacteria remain a potential risk, particularly in environments where water temperature is high or where there is prolonged stagnation. These conditions allow the bacteria to multiply, increasing the likelihood of inhalation of contaminated aerosols. Health departments in Basel advise private households to maintain appropriate temperatures for both hot and cold water, avoid long periods of stagnant water, and thoroughly flush pipes after extended absences. These measures aim to reduce the risk of legionella proliferation within residential settings. Additionally, the canton plans to advocate for uniform national guidelines on managing legionella risks at the federal level. Legionella bacteria are commonly found in showerheads and other plumbing fixtures, especially when water sits undisturbed for extended periods. Infection occurs when microscopic droplets containing the bacteria are inhaled, typically during activities such as showering. It is important to note that the disease does not spread directly from person to person. The confirmation of the cooling unit as the source has allowed local authorities to issue an official statement of reassurance. While the immediate threat has been mitigated, ongoing vigilance is advised due to the persistent nature of legionella in certain water systems. Public health officials continue to monitor the situation closely, ensuring that all necessary precautions are in place to prevent future occurrences.