Borussia Dortmund’s players left Baku’s Olympic Stadium without showering after their Champions League win on 20 October 2026. German newspaper Bild reported the club feared Legionella bacteria in the stadium’s water system. The story shines a light on the risk of Legionella in showers that sit unused for days. That risk exists in sports clubs, leisure centres and hotels across Ireland.
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What Happened in Baku?
Dortmund beat Azerbaijani champions FK Sabah 2-1 on matchday three of the Champions League. Instead of using the dressing room showers, the squad boarded the team bus in their training gear and returned to the hotel.
Head coach Niko Kovač said the players had skipped the showers after training the day before as well. “We were told not to shower here,” he told reporters after the match.
Sporting director Ole Book was less direct. He said the showers at the team hotel were “a bit more inviting” and declined to explain further.
Why Dortmund Feared Legionella
According to Bild, cited by Der Spiegel, Dortmund did not want to risk the health of its players. The concern was possible Legionella contamination in the stadium’s water system. Reports noted the stadium hosts few matches.
This matters because Legionella thrives in stagnant water. When pipes and outlets sit unused, water cools or warms into the range where bacteria multiply. Showers then release a fine mist that people breathe in.
No contamination has been confirmed. Neither club has published test results. Sabah player Joy-Lance Mickels said his team used the same showers a week earlier, before their game against Slavia Prague, without any problem. Dortmund’s decision was a precaution based on suspicion, not a confirmed result.
How Legionella in Showers Causes Illness
Legionella bacteria live in rivers and lakes in low numbers. Problems start when they colonise man-made water systems. The Health Protection Surveillance Centre (HPSC) states the bacteria multiply in water between 20°C and 50°C. They do not appear to grow below 20°C and die within minutes above 60°C.
People become infected by breathing in contaminated aerosols, the tiny droplets produced by showers, spa pools and cooling towers. There is no evidence of person-to-person spread.
Legionella causes two illnesses:
- Legionnaires’ disease: a severe form of pneumonia. It begins with fever, tiredness, headache and muscle pain, followed by a dry cough and breathing difficulty.
- Pontiac fever: a milder, flu-like illness without pneumonia. Patients recover within two to five days without treatment.
The incubation period for Legionnaires’ disease is two to ten days. HPSC states the disease kills 10% to 15% of otherwise healthy people who contract it. Most cases occur in people over 40. Men, smokers, heavy drinkers and people with chronic illness or weakened immune systems face higher risk.
Young, fit athletes sit outside most of these risk groups. Dortmund still chose not to take the chance.
Legionnaires’ Disease in Ireland
Legionnaires’ disease is a notifiable disease in Ireland. Doctors and laboratories must report every diagnosed case. The HPSC’s most recent annual report, published in November 2025, shows:
- 28 cases notified in 2024, a rate of 5.4 per million people
- 32 cases in 2023, a rate of 6.2 per million
- 17 of the 2024 cases (61%) were linked to travel abroad
- One death in 2024, a case fatality rate of 3.6%
- A median patient age of 59
- Higher case numbers in August, September and November
- A rising trend in notifications over the past ten years
HPSC also warns that many cases go undiagnosed. Legionnaires’ disease is hard to tell apart from other types of pneumonia without specific laboratory tests.
Why Underused Showers Carry the Highest Risk
The Baku case points to a common weak spot for Legionella in showers. Showers that sit idle allow water to stagnate in the showerhead, hose and pipework. Temperature control fails, disinfectant levels drop and biofilm builds up inside pipes. Biofilm feeds and shelters Legionella.
UK guidance HSG274, used as best practice in Ireland, classes any outlet unused for seven days or more as an infrequently used outlet. HPSC guidance advises running all taps and showers for several minutes at least once a week, whether rooms are occupied or not.
Many Irish facilities fit this pattern:
- GAA, rugby and soccer clubhouses where showers run on training nights and match days
- School and college sports halls closed over holidays
- Hotels and B&Bs with empty rooms in the off-season
- Gyms, spas and leisure centres with little-used changing areas
- Holiday homes and seasonal businesses reopening after months of closure
How to Control Legionella in Showers
Prevention depends on keeping water moving and at the right temperature. The UK Health and Safety Executive sets out these core controls:
- Store hot water at 60°C or above
- Distribute hot water at 50°C or above
- Store and distribute cold water below 20°C
- Flush little-used showers and taps at least once a week
- Dismantle, clean and descale showerheads and hoses at least every quarter
- Remove dead legs and redundant pipework
In Ireland, employers have a legal duty to manage this risk. The Health and Safety Authority (HSA) requires a written risk assessment for workplace water systems under the Safety, Health and Welfare at Work Act 2005.
Chlorinated mains water does not remove the risk. HPSC notes that chlorination does not guarantee the elimination of Legionella. Testing tells you what is in your system. HPSC advises that samples be taken by trained personnel and examined by accredited laboratories.
Test Your Water Before You Need To
Dortmund acted on suspicion because they had no data. Facility managers in Ireland do not need to guess. Regular Legionella testing confirms whether your controls are working and flags problems before anyone falls ill.
Southern Scientific provides INAB-accredited, ISO 17025 Legionella testing for sports and recreational clubs, gyms, hotels, care homes and other businesses. With testing facilities in Leinster, Munster and Connacht, we deliver a national service with clear reports and expert advice on corrective action.
Routine testing of Legionella in showers means moving from reactive crisis management to proactive protection. Book Legionella testing for your business with Southern Scientific and protect your staff, members and customers.
