Southern District Health Board (SDHB) medical officer of health, Dr Derek Bell, said, as of Tuesday, there were 37 confirmed cases - 31 were in the Wanaka and Hawea area, where the outbreak started, there were two each in Cromwell and Dunedin, and another two in other parts of the district.
There were also 40 ''probable'' cases, Dr Bell said. Twenty-six were in the Wanaka and Hawea area, one was in Queenstown, three were in Dunedin and 10 were in the Cromwell and Alexandra area.
At this stage, Public Health South (PHS) had been notified of at least another 200 possible cases, 170 of which were in the Wanaka and Hawea area, 56 in Central Otago or Dunedin, and 10 in Queenstown.
Alexandra's largest primary school, The Terrace School, advised yesterday there were cases of the illness among its 390 pupils and asked parents to take action to reduce spread of the disease.
Dr Bell said, among the confirmed cases in Otago, 70% were children and the remainder were adults.
Of the affected children, 40% had not been vaccinated.
The immunisation data did not include adults, he said, as most were not up-to-date with their whooping cough vaccinations.
The number of confirmed cases of the disease, which was also called pertussis, had risen slightly since August 14, when 29 people had been diagnosed, there were 25 probable cases and 188 suspected cases. Most were in the Wanaka and Hawea area, plus some in Cromwell, Dunedin and Oamaru.
SDHB public health physician, Naomi Gough, said on Friday the number of suspected cases of whooping cough being notified to PHS daily was ''starting to drop.
''Over the last week [there] has been less than five, whereas it was approximately 15 per day during the peak,'' she said.
''It is expected that the notifications will continue to rise for more weeks to come, reflecting the fact that this is an outbreak.
''Not all notifications of suspected pertussis are found to have pertussis. So far, around a third of the notifications have been pertussis,'' Dr Gough said.
However, there were likely to be whooping cough cases which PHS was not aware of, as the symptoms could be mild in adults, who did not feel unwell enough to visit a doctor.
Dr Gough said PHS was continuing to urge people to get vaccinated against whooping cough, to increase both their own protection and that of people who could not be immunised, including babies and unwell people.
One of the difficulties with whooping cough, doctors say, was that the symptoms resembled a common cold or flu for the first two or three weeks, when patients were most contagious.
They advised people who were unwell to stay away from others.
by Jessica Maddock
