Published Tuesday, 16 June 2009
The total number of confirmed cases in the province is now nine, and another six possible cases are under investigation.
The latest case relates to travel outside the UK and does not involve a school, workplace or other setting in Northern Ireland, the Public Health Agency said.
The sufferer has mild symptoms and is at home and taking antiviral treatment.
The patient has asked the authorities to ensure no identity details are revealed.
Anyone who has been in close contact is being followed up by the agency.
Director for Public Health Dr Carolyn Harper said: "People should not be alarmed by this further case and we should expect to see more over the next few days and weeks."
"That has been the pattern in other countries and we are planning for a similar picture here."
"We have good systems in place, though, to respond to any cases that appear."
The PHA said the other eight cases in Northern Ireland have either recovered or are doing well.