Meningococcal disease can cause death or permanent disabilities.
Canterbury Medical Officer of Health Dr Cheryl Brunton said all close contacts had been identified and treated with antibiotics.
To protect the person's privacy she could not provide comment on the location or clinical details unless there was a public health reason to do so.
In March, two 18-year-old students were admitted to Christchurch Hospital with meningococcal disease.
Dr Brunton strongly encouraged people who were eligible to get vaccinated for extra protection.
The meningococcal B vaccine is free for children under five, and people aged between 13 and 25 living in certain close living situations.
Meningococcal disease is a bacterial infection that causes two very serious illnesses: meningitis and septicaemia.
Te Whatu Ora said meningococcal disease symptoms typically develop very quickly over a few hours, but in some cases may develop more slowly over several days.
A person with meningococcal disease may only have some of the symptoms, and the symptoms do not develop in any particular order. Common symptoms of meningococcal disease include a fever although their hands and feet may feel cold, vomiting, muscle and joint aches and pains.
Common symptoms of meningitis include a headache which may be severe, a stiff neck, sensitivity to bright light and drowsiness and confusion, such as being hard to wake.
A red or purple rash is common, but it does not always happen. One or two spots can appear anywhere on the body then many more appear looking like rash or bruises.
The public is asked to call a doctor or 111 if there is concern that someone might have meningococcal disease.
