Public health officials in Romania are investigating a confirmed case of legionellosis involving a Metrorex employee. Epidemiological investigations remain ongoing to identify the source of the bacteria.
Epidemiological Investigation Status
According to the INSP, the infected employee was not exposed to the water that flooded the Piața Victoriei 2 station in early July. Authorities confirmed that the evacuation of the floodwater was conducted by firefighters and gendarmes, not by the affected individual. The INSP, in coordination with the Ilfov Public Health Directorate (DSP), the Bucharest DSP, and the Ministry of Transport’s medical department, is currently working to trace the origin of the exposure.
Legionellosis is a reportable condition under Romanian law, specifically HG 657/2022. Health providers are mandated to report all cases to public health directorates, which then update the National Registry for Communicable Diseases. Official data shows 82 reported cases of legionellosis in 2025, comprising 70 confirmed cases and 12 probable ones.
Legionella bacteria do not spread from person to person.
Understanding Legionella Transmission Risks
The INSP describes Legionella as a naturally occurring bacterium often found in low concentrations in lakes, rivers, and water reservoirs. The risk to human health increases when the bacteria migrate into man-made systems, such as building water networks, cooling towers, or humidifiers. The bacteria thrive in water temperatures between 20°C and 45°C, while temperatures exceeding 60°C typically limit their survival.
Factors that facilitate the growth of the bacteria include:
- The presence of biofilms, sludge, rust, or sediment in water systems.
- Nutrient availability from microorganisms like amoebae, algae, and other bacteria.
Common Environmental Exposure Sources
Experts emphasize that because there is no vaccine for Legionella pneumonia, prevention relies entirely on environmental management. According to the INSP, potential transmission sites include:
- Hot and cold water plumbing systems.
- Cooling towers and evaporative condensers.
- Industrial aeration tanks and cooling machine tools.
- Decorative fountains, sprinklers, and respiratory therapy equipment.
- Dental water lines and vehicle windshield washer reservoirs.
Pro Tip: Maintaining high hygiene standards in water systems and ensuring water temperatures remain outside the 20°C–45°C growth range are the most effective ways to mitigate the risk of bacterial colonization.
Frequently Asked Questions
Can I catch Legionella from a subway station flood?
The INSP clarified that the Metrorex employee confirmed with the infection was not exposed to the floodwaters at the Piața Victoriei 2 station.
Is there a vaccine for Legionella?
No. Currently, there is no specific vaccine to prevent pneumonia caused by Legionella. Prevention focuses on maintaining clean water systems and proper temperature control.
How does the bacteria enter a building’s water system?
Legionella typically enters through water supply networks and thrives in systems with poor maintenance, such as those with rust, sediment, or biofilms that provide nutrients for bacterial growth.
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