Meningococcal disease and available vaccines: a quick update

A national circulation to GPs on Tuesday noted there has been an increase in meningococcal W disease, asking us to be aware of this and noting it can present in a more atypical way.

This does not change our standard approach to the assessment, diagnosis and management of meningococcal disease, although we need to be aware of slightly more atypical presentations and a broader age group affected with the W strain.

So, what are the key points for us as GPs.

Since 2017, there has been steady rise is case numbers, although this continues to be a rare disease. To date this year we have just under 100 cases nationwide and there are higher rates in some regions, particularly in Northland

We have five main serotypes groups circulating in New Zealand. Serotype B is normally about two thirds of the cases, but in the last two years, we have seen an increase in type W. To date this year W is now around 25 per cent of all cases.

This particular W strain has been seen increasing in many parts of the world, including Africa, parts of Europe and Australia.

This strain appears to be more virulent (sometimes called “hypervirulent”), and has a higher mortality rate.

While the major age groups affected continue to be infants, young children and adolescent/young adults, W is more often seen across all age groups. (NB: Over 40 per cent of cases this year were in people over 40 years.) 

The other difference for this strain is it more commonly appears in more atypical fashion – of particular note is that gastrointestinal symptoms can be prominent.

Other atypical presentations include pneumonia, septic arthritis, endocarditis or epiglottitis.

Continue to be aware of meningococcal disease as a differential diagnosis in all influenza-like illnesses, unexplained fever and other presentations particularly in at risk age groups, and add in awareness of other symptomatology, particularly gastrointestinal. Administer antibiotics stat if concerned.

[Refer to IMAC data sheet for more details – see Sidenote or Related Link below]

There are two major groups of vaccines available on the private market and some are publically funded for a narrow group of high-risk people

Conjugate vaccines for A, C, Y and W

• Monovalent for serogroup C (NeisVac-C®)
• Quadravalent for serogroup A,C,Y and W (Menactra® and Nimenrix®)

Recombinant Meningococcal B vaccine

• Bexsero® (very recently available in New Zealand: since October 2018)

Which vaccine/s to use?

Fully funded vaccines are only available for a small group of very high-risk individuals, as listed below. All others require purchase on the private market.

• There is no one simple answer to this, both B vaccines and quadravalent vaccines are useful to offer best protection for most strains. To date this year B strains are around 50% of cases with the majority of the other cases covered by the quadravalent vaccines
• Vaccine immunity with any of these vaccines tends to last 3- 5 years, so boosters are needed if ongoing protection is required.

Funded

Menactra® for children from 2 years of age and adults with any of the following conditions:

• Pre/post splenectomy or with functional asplenia
• HIV positive HIV positive
• Inherited or acquired complement deficiency
• Pre/post solid organ transplantation or haematopoietic stem cell transplantation
• Following immunosuppression due to steroid or other immunosuppressive therapy longer than 28 days
• Close contacts of a meningococcal case

Recommended but not funded:

Menactra or Nimenrix (groups A, C, Y, W) and/or Bexsero (group B) are recommended but not funded for:

• Other infants and young children aged under 5 years, adolescents and young adults.
  • Particularly adolescents and young adults living in close proximity to each other, e.g. boarding school, university halls of residence or in long-term institutional care.
• Travellers to high-risk countries and Hajj pilgrims.
• Laboratory workers regularly exposed to meningococcal cultures.
• workers regularly handling meningococcal cultures