Three people have died in an outbreak of legionnaires' disease in Christchurch, New Zealand.
It appears that in recent weeks, thirteen others in the same area have also contracted the disease.
According to Canterbury's Medical Officer of Health Dr Mel Brieseman, the latest to die was an elderly patient who was diagnosed with the disease in July.
Legionellosis is an infection caused by the bacterium Legionella pneumophila. The disease has two distinct forms:
Legionnaires' disease, the more severe form of infection which includes pneumonia, and
Pontiac fever, a milder illness.
Legionnaires' disease acquired its name in 1976 when an outbreak of pneumonia occurred among persons attending a convention of the American Legion in Philadelphia. Later, the bacterium causing the illness was named Legionella.
It is so-called after an outbreak of pneumonia occurred among people attending a convention of the American Legion in Philadelphia 1976.
Air conditioning cooling towers remain the chief suspect at present, says Brieseman.
Dr Brieseman says independent building inspectors have been contacting the owners of around 70 buildings they know to have cooling towers, and are working with the Christchurch City Council to produce a comprehensive list which should be completed in the next few days.
The building owners are responding positively to the calls to check the systems, but it seems testing cannot be enforced and there is no legal requirement for test results to be reported.
Fortunately Legionnaires disease is not spread between people and can be treated with antibiotics.