Legionnaires' spreading across UK

The HPA figures show there were 163 cases up to the end of June, a third higher than the same period of 2006 (120 cases) and 60 per cent up on 2005 (103 cases).

Legionnaires' disease rises in spring and summer with the advent of warmer weather and peaks in August and September. Last year, total recorded cases of 559 were the highest since records began in 1980 and experts said the increase could be the result of climate change.

The summer of 2006 saw the hottest July on record and a wetter than normal August which provided the ideal breeding conditions for legionella bacteria.

In Health Protection Report, published yesterday, the Agency said: "Over 200 cases occurred in August and September and are being investigated for links to the warm weather experienced in 2006 and possible climate change effects on the ecology of the disease."

The weather since June this year has been very different to the previous two summers so it is "not clear" whether high numbers will be repeated this month and next, the report says.

However, the theory that climate change is driving the disease is borne out by the rapid growth in community-acquired infections which for the first time in 2007 have accounted for more than half (57 per cent) of the total. The remainder were in travellers and in hospital patients.