INFECTION control experts have warned cases of Legionnaires' disease in the Glasgow area could rise further as investigations continue into the source of an outbreak.

NHS Greater Glasgow and Clyde (NHSGGC) has confirmed no new cases of the potentially fatal disease have been detected, but the true scale of the outbreak might not become clear for several days due to the incubation period of the disease, which can range from two to 14 days.

Bacteria samples have been taken from water cooling towers within a three-mile radius of Renfrew, where the five confirmed cases are known to have links.

Three patients are being treated in hospital and are continuing to respond well to treatment.

Dr Gillian Penrice, NHSGGC Consultant in Public Health, said: "I am pleased there have been no further reported cases however there is still the possibility some cases may be identified given the two week incubation period of the disease.

"We have notified all GPs and our frontline hospital teams to keep this outbreak uppermost in their minds when dealing with patients displaying symptoms of headache, fever, dry cough, breathing difficulties, stomach pains and diarrhoea."

The health board is working with the Health and Safety Executive, Health Protection Scotland, and Renfrewshire Council to investigate the outbreak of the disease.

Legionnaires' disease is an uncommon but serious form of pneumonia, caused by bacteria distributed widely in natural and artificial water supplies, such as water cooling towers, air conditioning systems and showers.

The disease is particularly associated with hotels, fountains, cruise ships and hospitals with complex drinking water systems and cooling systems.

Other potential sources include hot-tubs, humidifiers and ice-making machines

It cannot be spread person to person or through drinking contaminated water, and residents in Renfrew are advised to continue to drink tap water and prepare food as normal.

On Monday, all 14 active water cooling towers within a three-mile radius of the homes of two of the Legionnaire's patients from Renfrew were treated with chemicals to kill any Legionella bacteria which may have been present.

A number of the towers have also been sampled for the bacteria in line with national guidance. However, due to the complex laboratory processes used to confirm or identify Legionella the results of these samples will not been known for some time.

Three cases of Legionella were reported last week by the health board, with two of the patients having been released from hospital and the third described as in a stable condition and responding well to treatment.

Two of the five cases live in the Renfrew area and the other three cases have either visited or worked there during the two-week incubation period of the disease.

An outbreak of the disease in south west Edinburgh between May and June last summer led to the deaths of three men among 101 confirmed and suspected cases.

The outbreak was blamed on cooling towers in the area, although the exact source has never been identified.

Anyone currently displaying symptoms of Legionnaires' disease is advised to contact NHS 24 on 08454 24 24 24 or their own GP.