The Health Protection Agency said the latest case brings the
total to 21.
The patient, who is being treated at the University Hospital
of North Staffordshire, is a man in his 70s.
Two patients being treated for the disease since the spate
of illnesses began in the middle of July have died.
An HPA spokeswoman said: "This new case is not
unexpected.
"It can take up to two weeks following exposure for
people to develop symptoms of Legionnaires' disease and a further few days
before they might see their GP."
A spokesman for University Hospital of North Staffordshire
said: "Three patients remain in hospital and all are in a stable or
improving condition."
It was revealed earlier this month that the probable cause
of the outbreak was a hot tub at JTF Warehouse in the city after samples were
found to have an unusual strain of legionella bacteria, which matched that of
the strain taken from patients with the illness.
Dr Sue Ibbotson, regional director of HPA West Midlands,
said the organisation has taken detailed histories from those with
Legionnaires' and the majority of confirmed cases visited the warehouse in the
two weeks before they fell ill.
The samples from the hot tub at JTF Warehouse in City Road,
Fenton, were confirmed by the Health Protection Agency's specialist laboratory
in Colindale as being the unusual strain legionella bacteria.
