Overview
Meningococcal disease is caused by the bacterium Neisseria meningitidis. Humans are the only host for these bacteria.
It is a serious disease that can cause death or long-term complications, including extensive skin scarring, loss of limbs or extremities, hearing loss, seizures, or brain injury.
Vaccination is the most effective way to reduce the risk of disease.
Introduction
At least 12 groups have been identified. Groups that cause disease include A, B, C, X, Y and W (previously called W-135). The pattern of disease caused by each group varies by time and country or geographical areas.
In 2025, group B was the predominant cause of meningococcal disease in New Zealand, although groups Y, W and C also caused disease. Meningococcal group A rarely causes disease in New Zealand.
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. The rate of meningococcal disease in 2014 was the lowest since 1990. Isolated outbreaks of meningococcal groups A and C have occurred in New Zealand: the last group A outbreak was in 1985/86 in Auckland. Northland experienced an outbreak of meningococcal group C disease during 2012. Then in 2018, Northland experienced a disproportionately high number of meningococcal diseases cases (7.4 cases per 100,000 people) compared with New Zealand overall (2.5 cases per 100,000). Group W was the predominant cause of meningococcal disease in Northland in 2018.
In New Zealand, meningococcal disease follows a seasonal pattern, with cases typically peaking in winter and continuing into spring.
Transmission
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 respiratory droplets or direct contact with nose and throat secretions, usually during close or prolonged contact, 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.
Symptoms
The initial symptoms are difficult to distinguish from other infectious illnesses, particularly flu-like illnesses. Symptoms usually progress quickly to a severe illness, with some people becoming very unwell within a few hours. Seek medical advice immediately if meningococcal disease is suspected. Do not wait for all symptoms to appear. Call a healthcare provider or Healthline on 0800 611 116. Call 111 in an emergency.
- Infants may have: a more gradual onset than adults, fever, cry, appear unsettled, feed poorly, vomit, be sleepy or hard to wake, dislike bright light, or have a rash or spots. They may have a bulging fontanelle.
- Older children and adults may have: a fever, malaise, nausea, vomiting, muscle aches and pains, drowsiness, headache, dislike of bright light, neck stiffness, or have a rash or spots.
- Individuals may also present with atypical symptoms, including gastrointestinal symptoms, pneumonia, septic arthritis, endocarditis, epiglottitis or supraglottitis.
A non-blanching rash, which does not become pale or go white when pressed, may develop. This is often a late sign of infection and may not occur in every case. Do not wait for a rash before seeking medical advice.
Treatment
Meningococcal disease requires urgent hospital assessment and antibiotic treatment. Early diagnosis and treatment can save lives.
Risks
- In New Zealand, infants and children aged under 5 years and adolescents aged 15–19 years have an increased risk of meningococcal disease. Māori, particularly infants aged under 1 year, and Pacific peoples have a higher risk of meningococcal disease than other ethnic groups. Over 2018–2019, a high rate of group B and groups C, Y and W disease cases were also seen in young adults aged 20—29 years.
- Exposure to tobacco smoke, binge drinking, or having another respiratory infection, e.g. influenza.
- Living in close proximity to others, e.g. in a crowded household, at boarding school, in university halls of residence, group accommodation or long-term institutional care.
- In children, living in more socioeconomically deprived areas is also associate with higher rates of meningococcal disease.
- Being in a household or other close contact of someone carrying the bacteria or with the disease, e.g. those who have been intimate, or infants and children attending an early childhood education centre.
- Having a medical condition or receiving treatment that affects the immune system, e.g., having no spleen or reduced spleen function, complement deficiency, or receiving immunosuppressive treatment.
If meningococcal bacteria pass into the blood, the disease usually progresses very quickly. A person with meningococcal disease may develop:
- Meningitis (inflammation of the membranes around the brain)
- Septicaemia (blood infection)
- Pneumonia (lung infection)
One to two people out of every ten who survive meningococcal disease have long term complications, such as extensive skin scarring, amputation of limbs and extremities, hearing loss, seizures or brain injury
Even when the disease is identified and treated early 1–2 people in 10 will die.
Prevention
The risk of infection for household contacts of a person with the disease is highest during the first seven days and may persist for many weeks. Preventive antibiotics should be given to eligible close contacts as soon as possible following public health assessment. In some circumstances, close contacts may also be offered an appropriate meningococcal vaccine.
During an outbreak, a meningococcal immunisation programme may be commenced for those in the highest risk groups if a vaccine is available. Meningococcal conjugate vaccines reduce the number of people carrying N. meningitidis in the back of their throat thereby reducing the spread of the bacteria around the community. This contributes to ‘herd immunity’ while protecting the individual from invasive disease.
Meningococcal B vaccine is included in the National Immunisation Schedule for infants and is funded for all children under 5 years of age. MenB and MenACWY vaccines are also funded for certain people at increased risk of meningococcal disease and for eligible young people aged 13–25 years in specified close-living settings. No single meningococcal vaccine protects against all groups that can cause disease. Check the current New Zealand Immunisation Handbook for eligibility and schedules. A factsheet about meningococcal vaccines can be downloaded from the Resources section on this page.
