Two cases of whooping cough have been confirmed on the Taieri, in Mosgiel and Outram, Public Health South confirmed yesterday.
There were also ''at least five cases'' in Wanaka and Hawea.
''Public Health South is investigating to determine if there are more cases in the wider area.
''Public Health South is also following up with medical centres regionally to determine if there are more cases of pertussis not yet notified,'' the authority said in a statement.
Medical officer of health Dr Derek Bell said the Taieri cases were not related to each other, and did not constitute an outbreak.
''It's really important that those places don't get labelled in the same way as Hawea Flat, where we have got a proper outbreak going.''
Dr Bell said he would have a clearer picture of the extent of the problem in Wanaka and Hawea Flat next week.
''It's a confused picture [at the moment].''
''There are quite a lot of people with coughs who are getting tested by GPs in Wanaka.''
There have been significant outbreaks of whooping cough in New Zealand in recent years, in 2000, 2004, 2009 and 2012.
