THE control of the epidemic of Legionnaires' disease in Hereford has been supervised by Herefordshire Primary Care Trust, Herefordshire Council and the Health Protection Agency under Dr David Kirrage.

The three authorities have defended their action in not making public the fact that Legionnaires' disease had been found until two weeks after the first two cases were diagnosed.

They say those cases were thoroughly investigated, had no common denominator and were regarded as isolated cases.

Dr David Kirrage said there were no obvious links but they had continued with an investigation, gleaning information and being extra vigorous. He described subsequent action as 'prompt'.

But Hereford MP Paul Keetch says he cannot understand why information known on October 24 was not passed to relevant authorities.

He said GPs were not told until November 6.

Your questions about Legionnaires' Disease

What is it?

LEGIONNAIRES' disease, also known as Legionellosis, is a rare form of pneumonia. It takes its name from an outbreak which occurred in a hotel hosting a convention of the Pennsylvania Department of the American Legion in 1976 although the disease was confirmed as far back as 1947. It cannot be passed from one person to another and is fatal in around five to 15% of cases.

How do you catch it?

IT is mostly contracted by inhaling mist from water sources, such as whirlpool baths, showers and cooling towers which are contaminated with Legionella pnuemophila bacteria, or other bacteria in the family Legionellaceae.

If the bacteria reaches the lungs it can cause the disease. It can only be contracted from a contaminated water source. The most common cause is contaminated air conditioning systems and mass outbreaks of the disease are rare.

What are the symptoms?

THE incubation period ranges from two to 10 days but is usually three to six days although in rare cases some develop symptoms as late as three weeks after exposure. Initially it's like flu - headache, muscle pain and a general feeling of being unwell. These can be followed by high fever and shaking chills. Nausea, vomiting and diarrhoea may occur. On the second or third day dry coughing begins and chest pains might occur and there could be some difficulty in breathing. Mental changes can start, such as confusion, disorientation, hallucination and loss of memory out of proportion to the seriousness of fever.

Who is most at risk?

IT usually strikes the middle-aged and those more at risk are smokers and those with existing health problems. Many others may contract the bug and show no signs of infection and it is like many cases go undiagnosed.

How is it treated?

THE disease is most often treated with the antibiotic drugs erthryomycin and rifampin. Recovery often takes several weeks.

How common a disease is it?

Cases have been reported from industrial countries round the world, with an average of 200 a year in England and Wales and one case every two years expected in Herefordshire.

Can it be prevented?

The likelihood of infection can be best reduced by good engineering practices in the use and maintenance of air and water handling systems. Poorly maintained or faulty equipment can be responsible for triggering the disease.

Past cases to be checked

THE cases of all patients admitted to hospital in Hereford suffering with pneumonia are to be reviewed.

Samples taken during their stay in hospital will be tested to see if they show signs of Legionnaires' disease said Dr Mike Deakin.

Even if the patients have recovered and returned home the tests will still take place.

"In this way we will know if we have missed a case," he said.

If a test proved positive the patient would be asked to help the authorities in mapping out their previous movements in Hereford to help trace a possible source of the disease.

It is possible that some of those diagnosed with Legionnaires' disease may not have the illness after all.

While preliminary tests indicate the disease, further investigation could prove negative.

The initial tests are usually very accurate but further work on the samples could rule out Legionnaires.

Dr Mike Deakin told the Hereford Times that after the epidemic was cleared up 'a full and thorough' investigation would take place in to how it had been handled and this would be made public.