Date updated: 30 November 2018
There has been a significant increase in Neisseria meningitidis serogroup W (MenW) in New Zealand since mid-2017. Between 1 January 2017 and 31 December 2017, there were 12 cases of MenW reported, including three deaths. This number has more than doubled to date for 2018, with 27 cases reported so far (as of 23 November), including six deaths. Prior to 2017, zero to six MenW cases were reported each year. The Northland region has been the most affected in 2018, with seven of the 27 cases reported in this region, including four cases in September and October.
This particular strain of MenW (sequence type ST11) affects all age groups and is associated with a high case-fatality rate. MenW can present with the classical signs of meningococcal disease but also atypically with gastro-intestinal symptoms, as well as pneumonia, septic arthritis, endocarditis or epi/supraglottitis. MenW was previously referred to as W135. Similar increases in MenW have been seen in other countries, including the UK and Australia.
Overall the annual number of meningococcal disease cases due to all serogroups has been increasing steadily since 2014, when there were 45 cases, to 112 cases in 2017. There have been 102 cases to date this year (as of 23 November). Group B remains the most prevalent serogroup, though this year the number of group B infections is lower (44 cases) than in 2017 (60 cases) at the same time of the year.
- GPs and EDs should be aware of that there has been an increase in meningococcal disease, caused by serogroup W in New Zealand over the past two years. They should be aware that this strain presents atypically and keep a high level of suspicion for the disease.
- Because of the fulminant nature of meningococcal sepsis, antibiotics should be administered on suspicion of diagnosis before transferring the patient to hospital.
- GPs do not need to be concerned that administering antibiotics will obscure the diagnosis for hospital clinicians. Over-treatment is acceptable in this case, as failure to treat may be fatal.
Update on antibiotic treatment of suspected meningococcal infections presenting in primary care
The recommended treatment options are now as follows.
|First choice||Ceftriaxone||100mg/kg IV (or IM) up to 2g||2g IV (or IM)|
|Second choice||Benzyl-penicillin||50mg/kg IV (or IM) up to 2g||2.4g IV (or IM)|
- Early treatment of meningococcal infection is recommended, especially when there will be a delay for the patient to reach the Emergency Department.
- Ceftriaxone is the preferred first-line treatment for all individuals.
- If ceftriaxone is not available, benzyl-penicillin can be used. If benzyl-penicillin is used, it is important to note that the treatment dose is higher than previously recommended.
- Patients allergic to penicillin who do not have a documented history of anaphylaxis to penicillin can be given ceftriaxone.
- There is no routine community treatment recommendation for patients with a documented history of anaphylaxis to penicillin. These patients must be transferred immediately by ambulance to the closest hospital. This hospital should be made aware of the patient transfer. If you are in a remote location or at a significant distance from secondary care, or if there is any delay, you should seek urgent advice from an Infectious Disease Physician regarding treatment options prior to transfer to hospital.
- IV administration is preferred to IM (where available and not leading to delays).
This advice has been provided following new information on lower susceptibility of Neisseria meningitidis to penicillin in New Zealand, and in consultation with the Australasian Society for Infectious Diseases (NZ ASID).
- Antibiotics given prior to transfer should be clearly noted on the clinical information that accompanies the patient to hospital.
- A blood sample should be taken as soon as possible for laboratory testing, but should not delay patient treatment or transfer.
- If you are not sure if it is meningococcal disease:
- advise parents/caregivers to check the sick person frequently (eg, every hour). The sick person should not remain on their own
- make sure the case seeks immediate medical attention if they deteriorate
- reassess the case within 6 hours.
- The quadrivalent MCV4-D vaccine (Menactra) protects against MenW (as well as MenA, MenC and MenY) and is available in NZ. It is recommended for high risk groups and funded for some of them – please refer to the meningococcal disease chapter in the Immunisation Handbook. Please make sure that high risk patients for whom the vaccine is funded are protected.
- Please note that the Meningococcal B strain is still the most prevalent strain. Men B vaccine (BEXSERO) is available for prophylaxis of close contacts, but is not currently funded. Further details are available in the Communicable Disease Control Manual, at the subheading ‘If case is group B.’
Information on public health management of Neisseria meningitidis invasive disease can be found in the Communicable Diseases Control Manual.
Updated information on group W meningococcal disease surveillance is available on the ESR webpage.