Invasive meningococcal disease, serogroup W: Information for health professionals

This page contains information regarding invasive meningococcal disease (IMD) caused by serogroup W (MenW) for health professionals.

Page last updated: 25 March 2020

National rise in MenW

IMD is caused by the bacterium Neisseria meningitidis. Approximately 10 per cent of the population are asymptomatic carriers of meningococcal bacteria in the upper respiratory tract, however, IMD only occurs in a small number of people.

Six serogroups of meningococcal bacteria (A, B, C, W, X and Y) account for most cases of IMD globally, with serogroup B, C, W and Y the predominant cause in Australia. Serogroup C cases have declined significantly since 2003 when the meningococcal C vaccine was added to the National Immunisation Program. Serogroup B is the most common cause of IMD in Australia, followed by meningococcal serogroups W, and Y. Serogroups A and X are rare in Australia despite being more common overseas.

The proportion of IMD notifications due to Neisseria meningitidis serogroup W has increased across Australia since 2013. Rates of serogroup W have also increased in all age groups.


Septicaemia (sepsis) and meningitis are common presentations in all age groups for MenW. However, there have also been a number of cases with atypical presentations for example pneumonia, septic arthritis or epiglottitis.

Be alert for presentations that could be due to IMD, including typical and atypical presentations.

Who is at risk?

Anyone is potentially susceptible to serogroups of meningococcus that they have not been vaccinated against.

People with certain pre-existing medical conditions, occupational exposures (some laboratory personnel) or overseas travel to endemic or high-risk areas (Hajj and African meningitis belt) are at higher risk of IMD.

Medical conditions associated with an increased risk of IMD in children and adults1 include:

  • functional or anatomical asplenia
  • HIV infection, regardless of stage of disease or CD4+ count
  • haematopoietic stem cell transplant
  • defects in or deficiency of complement components, including factor H, factor D or properdin deficiency
  • current or future treatment with eculizumab (a monoclonal antibody directed against complement component C5).

Diagnosis and treatment

Early diagnosis and treatment is essential. Although meningococcal disease is uncommon, it is a very serious disease. The infection can develop very quickly and can be fatal in 5-10 per cent of cases. Most people make a complete recovery if the infection is diagnosed early and antibiotic treatment commenced promptly.

Diagnostic testing should ideally occur prior to administration of antibiotics where possible, but should not delay administration of antibiotics. Empirical antibiotic options for different clinical presentations are described in the Therapeutic Guidelines.

When considering testing options, discussion with local infectious diseases or microbiology experts may be helpful. A blood (for serum) or CSF sample for nucleic acid testing or culture is usually sufficient.


Notify all suspected and confirmed cases of IMD to the state or territory health authority in your jurisdiction; do not wait for laboratory confirmation before notifying. (Refer to the contact details at the end of this document).

Following notification of suspected cases, the state or territory health department will identify who should receive vaccines as part of contact management. Contact details for each jurisdiction to report suspected information, or learn more about this requirement, are provided below.

Clearance antibiotics

Following notification of suspected cases, the state or territory health department will identify who should receive clearance antibiotics (generally close household and/or intimate contacts). Staff providing care do not require clearance antibiotics unless exposed to the case’s nasopharyngeal secretions without personal protective equipment (e.g. involved in intubation without wearing masks).

Clearance antibiotics for the general population are not necessary. Testing for meningococcal carriage in asymptomatic individuals and treatment with clearance antibiotics is not required for the general population, and can be harmful by removing protective strains of bacteria and leading to antibiotic resistance.

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The Australian Immunisation Handbook 10th Edition, online version provides current guidance on meningococcal immunisation.

The four most common meningococcal types in Australia are B, C, W and Y. There are vaccines available to protect against these types in Australia, which also cover meningococcal A.

Meningococcal ACWY vaccine is provided free through the National Immunisation Program (NIP) for eligible persons.

Information on meningococcal vaccination and on who is eligible for free vaccine through the NIP can be found meningococcal immunisation service webpage.

Children and adolescents not eligible for meningococcal vaccines through the NIP may be able to receive free vaccines through state-funded programs. Contact your state or territory health department for details.

Contact details to notify suspected and confirmed IMD in Australia

State/territory Public health unit contact details
ACT 02 6205 2155
NSW 1300 066 055
Contact details for the public health offices in NSW Local Health Districts (
NT 08 8922 8044 Monday-to Friday daytime and 08 8922 8888 ask for CDC doctor on call – for after hours
QLD 13 432 584
Contact details for the public health offices in QLD Area 
SA 1300 232 272
TAS 1800 671 738 (from within Tasmania), 03 6166 0712 (from mainland states)
After hours, follow the prompt “to report an infectious disease”
VIC 1300 651 160
WA 08 9388 4801 After hours 08 9328 0553
Contact details for the public health offices in WA 
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More information

  1. Australian Immunisation Handbook