Meningococcal DISEASE

The meningococcal bacteria can cause meningococcal meningitis (inflammation of the meninges, the membrane lining of the brain and spinal cord) and/or septicaemia (blood poisoning).

There are thirteen different types of meningococcal bacteria including meningococcal groups A, B, C, W, Y and others. The most common in New Zealand are meningococcal group B and W, followed by group Y.

During 1991-2007, a New Zealand-only strain of group B caused an epidemic. The epidemic mainly affected under-one year old Māori and Pacific infants and children aged 1–4 years of other ethnicities.

Northland experienced an outbreak of meningococcal group C disease during 2012. Then in 2018, Northland experienced a disproportionately high number of meningococcal group W diseases cases (7.4 cases per 100,000 people) compared with New Zealand overall (2.5 cases per 100,000).

Meningococcal bacteria are commonly carried in the nose and throat, and do not usually cause disease. Carriage rates are highest in older teenagers and young adults. The bacteria can be transferred from person to person through contact with saliva, e.g. intimate kissing. In rare cases, the bacteria can invade and rapidly lead to severe disease. The underlying reasons for why invasion occurs in some individuals are not well understood.

Although the risk is low, meningococcal disease can affect anyone, anywhere, at any age, and may be devastating for patients and their families.

Meningococcal meningitis and septicaemia tends to be more common during winter and early spring.

Even when the disease is identified and treated early 1 to 2 people in 10 will die.

When someone is diagnosed with meningococcal infection, very close family contacts and other intimate contacts of the patient are at an increased risk of contracting the disease. A 'contact trace' is conducted by public health doctors to identify people who have been in 'high risk contact' with a person who has meningococcal disease, within the seven days prior to onset of the disease. 'High risk contacts' are usually people who have been living in the same household as the person who developed the disease or who had close contact with the patient. 'High risk contacts' are usually offered preventative antibiotics. They reduce, but cannot eliminate, the risk of family members or other high risk contacts also becoming ill. Because of this, if contacts who have received antibiotics become unwell or exhibit some of the symptoms of meningitis or septicaemia, it is vital they also seek urgent medical attention.

Where a case of meningococcal disease involves a patient who attends a childcare group, or school class, individual in-depth assessments of particular circumstances are made. Usually, other contacts such as school friends and workmates are normally not at any significant risk and generally do not need special treatment with antibiotics or investigation.