A case of Legionella infection in a newborn, who remains hospitalised at Makarios Hospital, has brought renewed attention to a largely hidden public health risk.
The bacteria can develop in pipes, water tanks and showers, including in buildings housing people whose health is particularly vulnerable.
The case has raised questions over who is responsible for preventing such risks, how frequently hospitals, care homes, hotels and military camps are inspected, and what happens when Legionella is detected. It has also highlighted the potential risks in domestic water systems.
How Legionella spreads
Legionella bacteria can cause Legionnaires’ disease, a serious form of pneumonia that primarily threatens older people, those with weakened immune systems and people with underlying health conditions.
The bacteria multiply more readily when water is stagnant, installations are poorly maintained and temperatures are between approximately 20C and 45C.
Infection usually occurs through inhaling tiny droplets of contaminated water, such as those produced by showers or cooling towers. The disease is not generally transmitted from person to person, while drinking water is not the usual route of infection.
This means that the safety of a building’s water supply depends not only on the quality of the water entering the premises but also on the condition and maintenance of its internal plumbing system.
Hospital inspections and water testing
Cyprus’s Private Hospitals Law of 2001 provides for annual and ad hoc inspections. Oversight is exercised by the Registrar of Private Hospitals, while inspectors examine operating conditions and relevant records.
Operating licences are valid for two years, although this does not mean inspections take place only when licences are renewed.
General inspections are separate from water sampling specifically intended to detect Legionella.
The 2023 legislation on the quality of water intended for human consumption provides for particular attention to so-called priority premises, including healthcare facilities, residential care homes, prisons and large tourist establishments.
Herodotos Herodotou, head of the Health Services, told Politis that a preventive testing protocol is being implemented in cooperation with the State General Laboratory. It covers hospitals, care homes, hotels and military camps.
The Health Services collect samples, which are then analysed by the State General Laboratory.
Published guidance refers to monthly testing at hospitals and health centres, as well as testing at military camps before new recruits arrive. However, it remains unclear whether the monthly frequency applies to all private hospitals or how often the other types of premises are tested.
Source of contamination remains unclear
At the Nicosia maternity clinic where contamination was detected, a scheduled round of sampling took place on 7 October, before the infection became known.
Initial tests detected Legionella at two points in the water supply network. Further samples were subsequently collected at the clinic and at the family’s home.
However, according to an update issued on Friday, preliminary results did not provide a clear answer about the source of the infection.
More specialised analyses were deemed necessary, with final results expected next week.
The clinic remains closed, while the newborn’s condition has been described as critical but stable.
The detection of bacteria in a water system does not, by itself, establish that the system was the source of a patient’s infection. Determining the source requires further investigation and assessment of the available evidence.
Prevention and action when bacteria are detected
Responsibility for preventing Legionella is not limited to the state. Those managing buildings and facilities must maintain water systems, monitor temperatures and disinfectant levels, and keep appropriate records.
The Department of Labour Inspection highlights the need for a written risk assessment and a preventive maintenance programme. A negative laboratory result does not replace the need for continuous maintenance.
When Legionella is detected, the appropriate response depends on factors including the concentration of bacteria, the location where they were found and the people who may have been exposed.
Legislation sets a parametric value of fewer than 1,000 colony-forming units per litre. However, intervention may be necessary even at lower concentrations, particularly when a case of infection has been identified.
Measures may include disinfection, technical modifications, repeat sampling or restrictions on the use of affected facilities.
Where there is a serious risk to public health, the authorities can temporarily suspend the operating licence of a private hospital. This measure has been taken in the current case.
Disinfection and confirmation that a water system is safe again are two separate stages. Following remedial work, the system must be reassessed, with repeat sampling where appropriate.
In neonatal and intensive care units, where patients are particularly vulnerable, early identification of cases, monitoring of potentially exposed people and effective infection control committees are especially important.
What about Legionella in our homes?
Legionella can also develop in domestic water systems, particularly where water is left standing for prolonged periods.
In Cyprus, where storage tanks and solar water heaters are widely used, proper maintenance is especially important.
Potential sites for bacterial growth include pipes, showers, taps, storage tanks and certain humidifiers.
By contrast, conventional split-unit air conditioners are not a usual source of Legionella, Herodotou clarified.
The Health Services of the Ministry of Health stress the importance of maintaining water installations and avoiding stagnant water. Based on these principles and practical guidance from the US Centers for Disease Control and Prevention (CDC), householders can take several precautions:
- Clean showerheads and tap fittings to remove limescale and other deposits.
- Maintain tanks, filters and water heaters in accordance with manufacturers’ instructions.
- Flush little-used taps and showers. If they have not been used for at least a week, run the water while avoiding inhaling any resulting spray.
- Clean humidifiers regularly and ask a qualified technician to check hot water temperature settings, while taking precautions to prevent scalding.
These measures can help reduce risks, although they do not replace appropriate professional assessment where contamination is suspected.
Other bacteria can pose risks in water systems
Legionella is not the only bacterium that can grow in water installations and cause health problems.
Some microorganisms pose a direct threat to vulnerable patients, while others are used primarily as indicators of contamination. Different bacteria behave differently and require different testing methods.
One example is Pseudomonas aeruginosa, which thrives in damp environments such as sinks and drains. It can also contaminate equipment if appropriate hygiene and maintenance procedures are not followed.
The bacterium is of particular concern in healthcare facilities because it can cause pneumonia, wound infections, urinary tract infections and bloodstream infections. Some strains are resistant to antibiotics.
Non-tuberculous mycobacteria can also survive in water systems and the biofilms that form inside pipes. They may cause infections, particularly in people with weakened immune systems or chronic lung conditions.
E. coli and enterococci present a different concern. Their presence in drinking water indicates possible faecal contamination rather than the same mechanism of risk associated with Legionella.
Legislation requires both to be absent from a 100ml water sample.
The distinction underlines why monitoring programmes must use different criteria, tests and corrective measures depending on the microorganism involved.
The Legionella case has therefore highlighted a broader challenge for public health authorities and building managers: ensuring that water systems remain safe through consistent maintenance, appropriate testing and timely action when risks are identified.
