A Mt Aspiring College pupil is being treated for meningococcal disease in Dunedin Hospital.
In a letter to parents and pupils, Southern District Health Board medical officer of health Dr Marion Poore said the health board did not believe there was a increased risk to staff and pupils, but people did need to be aware of the symptoms and signs of meningococcal disease.
Close contacts of the pupil had already been identified and been offered antibiotics to reduce the risk of contracting the disease.
Principal Wayne Bosley said the school had been advised to continue as usual and to reassure and support the pupils.
It was a difficult time for the school community and everyone's thoughts and wishes were with the pupils and her family, Mr Bosley said.
The latest case comes after the Otago Daily Times reported cases of the disease in 2016 had almost doubled on average from 2007 to 2015 in the SDHB area.
Last month University of Otago nursing student Brittany Arthur died after contracting meningococcal meningitis.
People who believe they have been in close contact with the pupil and have not talked to someone from Public Health South should contact health protection officer Sam Anderson-Mangai on 03 474 0999.