Manawatu health officials investigating a tuberculosis case are testing 90 people who attended a school chess tournament in Palmerston North in June.
More than 1800 Palmerston North Boys' High School students, staff and close contacts have been tested for the disease since the discovery last month of a Year 9
pupil with active tb.
Of those 1800-plus people, tests have shown 206 had been exposed to the disease. They have begun taking a four-month course of antibiotics, to be taken twice a week.
None of those cases has progressed to the point where the patient was infectious.
MidCentral Health communications manager Dennis Geddis said only people who had close contact with the infectious boy were in any danger of having been exposed to tb.
"These people actually had to be really up close for a long period to get anything," Mr Geddis said.
Schools from the Manawatu and Horowhenua area had taken part in the chess tournament. Participants were being tested as a precaution, he said.
"It's like a pond. We do the closest contacts first, that was the class and their families. Then we moved out into all the Year 9 ones, then the next circle is wider and even wider. This is a wider one still. It's fairly unlikely we will get many [positive tests]."
On average there are about 400 cases of tuberculosis diagnosed in New Zealand each year. Last year there were 348 cases. It is not a highly contagious disease, and is curable if treated early with specific antibiotics.
The student whose tb case sparked the wide-ranging series of tests is still undergoing treatment in isolation.
Medical Officer of Health Patrick O'Connor said there was no need for community panic.
"We have always said we have the situation under control and that has not changed. The social contact tracing now under way is part of the wider process we began last month. We have to wait for the results before determining if any further action is needed."
