Public health priority: Urgent.
PHU response time: Respond to any report of meningococcal disease on day of notification. Enter probable and confirmed cases on NCIMS within 1 working day and enter serogrouping results within 1 working day.
This guideline is based on the Invasive Meningococcal Disease – Communicable Diseases Network Australia (CDNA) National Guidelines for Public Health Units (PHUs).
NSW guidance is included within these call-out boxes throughout the document, and guidance on urogenital and anorectal infections is within Section 12: Special situations. References included in NSW specific guidance can be found at Appendix 5.
The content of the CDNA National Guidelines has not been modified.
Developed by the IMD SoNG Working Group.
The Series of National Guidelines ('the Guidelines') have been developed by the Communicable Diseases Network Australia (CDNA) and noted by the Australian Health Protection Principal Committee (AHPPC). Their purpose is to provide nationally consistent guidance to public health units (PHUs) in responding to a notifiable disease event.
These guidelines capture the knowledge of experienced professionals and provide guidance on best practice based upon the best available evidence at the time of completion.
Readers should not rely solely on the information contained within these guidelines. Guideline information is not intended to be a substitute for advice from other relevant sources including, but not limited to, the advice from a health professional. Clinical judgement and discretion may be required in the interpretation and application of these guidelines.
The membership of CDNA and AHPPC, and the Commonwealth of Australia as represented by the Department of Health ('Health'), do not warrant or represent that the information contained in the Guidelines is accurate, current or complete. CDNA, AHPPC and Health do not accept any legal liability or responsibility for any loss, damages, costs or expenses incurred by the use of, or reliance on, or interpretation of, the information contained in the guidelines.
Endorsed by CDNA: 24 May 2017
Noted by AHPPC: 16 June 2017
Released by Health: 01 July 2024
Urgent
Isolate case and practise standard and droplet precautions for 24 hours after initiation of appropriate antibiotic treatment. Exclude from child-care, school, other educational institution or work until 24 hours of antibiotics completed.
Provide information to identified contacts and urgently arrange for clearance antibiotics to be given to eligible higher-risk contacts. Vaccination is advised for eligible higher-risk contacts if case confirmed to be caused by some vaccine preventable serogroups (A, C, W or Y).
Neisseria meningitidis is a Gram-negative diplococcus. There are 13 serogroups of N.meningitidis, with six serogroups (A, B, C, W, X and Y) accounting for the majority of cases of invasive meningococcal disease (IMD) worldwide.[1] From 2002 to 2015 the predominant meningococcal serogroup in Australia was serogroup B.[2] Notifications of serogroup W (MenW) increased nearly five-fold between 2014 and 2016, and in 2016, MenW was the predominant meningococcal serogroup notified in Australia.[3]
N. meningitidis is a commensal of humans, the only natural host. The bacteria normally colonise the mucosa of the upper respiratory tract without causing disease. The mean duration of carriage, in settings where prevalence is stable, has been estimated as about 21 months.[4] The carriage rate varies from around 3–25 percent of the population, depending primarily on age.[5] In European and North American studies carriage rates have been shown to be very low in the first years of life and then to sharply increase in teenagers, reaching a maximum in those aged between 20 and 24 years.[6] Meningococcal carriage is also associated with male gender, coincident viral or bacterial respiratory tract infections, low socio-economic status, smoking, frequency of intimate kissing and the number and closeness of social contacts.[6,7]
Transmission is primarily by respiratory droplets from the upper respiratory tract. Saliva has been shown to inhibit the growth of meningococci and salivary contact (e.g. by sharing drink bottles) is not considered to be a significant means of transmission.[8]
Usually from 1 to 7 days (rarely up to 10 days). Individuals who become asymptomatic carriers of meningococci are very unlikely to develop IMD.[1]
Until the organisms are no longer present in discharges from the nose and throat. With effective antibiotic therapy meningococci usually disappear from the nasopharynx within 24 hours.[9]
Invasive infections due to N. meningitidis can present as a spectrum of clinical illness, with meningitis and septicaemia, or a combination of the two, being the most common. Disease expression can also include pneumonia, septic arthritis, epiglottitis, pericarditis, gastrointestinal symptoms, conjunctivitis and urethritis.[10] Meningococcal meningitis typically presents with fever, meningeal signs (e.g. headache, neck stiffness, photophobia) and altered mental status.[10]
Septicaemia, with or without meningitis, can have a fulminant and rapidly fatal course (sometimes less than 24 hours) with initial symptoms that are nonspecific (e.g. fever, muscle aches, vomiting), especially in children.[11] The septicaemic form can be difficult to diagnose before the onset of the characteristic haemorrhagic (i.e. petechial or purpuric) rash that does not blanch under pressure. Appearance of a rash can be relatively late (median onset 13-22 hours) [12] or there may be no rash at all. Additionally, in the early stages of illness there is sometimes a maculopapular rash that blanches under pressure. This rash may progress to become haemorrhagic and non-blanching or may fade away.[13]
Leg pain, cold extremities, and abnormal skin colour – described as pallor or mottling – are frequently reported in the first 12 hours of meningococcal disease (median onset 7-12 hours), particularly in children and adolescents.[12]
Infrequently, chronic meningococcal septicaemia can also occur.
Overall mortality for IMD is approximately 5-10 percent of infected individuals.[14] An increase in case fatality rate (CFR) has been associated with a range of factors, including age,[15,16] the N. meningitidis serogroup,[17,18] concurrent HIV infection[19] and whether cases are associated with an outbreak.[20] Most deaths occur in the first 24 hours[21] and early diagnosis and treatment is associated with reduced CFR.[22,23]
Long term sequelae affect 10-20 percent of recovered IMD cases, including deafness, other neurological deficits, skin loss requiring grafts and partial or full amputation of limbs.[1]
See Section 12: Special situations for guidance on infections at urogenital and anorectal sites, including transmission and presentation.
Transmission from a symptomatic case is uncommon – the vast majority of cases are sporadic with transmission assumed to have occurred from prolonged close contact with an asymptomatic carrier in the network of close contacts.
The contacts most at risk of meningococcal disease are other members of the household of a case of IMD, during the first week after the case is detected.[24] Studies carried out in Europe and America before the routine use of clearance antibiotics showed that household contacts of a case of IMD had a 500 to 800-fold greater risk of meningococcal disease than the general population.[24,25] The risk was highest in the first week after onset of illness in the case and fell rapidly thereafter.[24]
The frequency of intimate kissing, involving close contact with respiratory droplets from the nasopharynx, increases the risk of both carriage [7,26] and disease.[27,28] However, contact with saliva per se, such as through sharing drinks or superficial mouth kissing, is not thought to significantly increase risk of carriage or disease. [8]
There is limited evidence in favour of providing clearance antibiotics to child-care contacts of sporadic cases of IMD. A Belgian study found that the relative risk of secondary IMD among day-care (aged under three years) and pre-school contacts (aged two to five years) was much less than that for similarly aged household contacts of an index case.[24] A British study of pre-school settings (including day care, play-groups and other pre-school groups) (most were aged less than four years) found that the relative risk of a cluster of cases in pre-school in the four weeks after an index case was 27.6 and the absolute risk was 49/100,000 contact children.[29]
United States (US) and United Kingdom (UK) studies have demonstrated a modestly increased risk of further cases in schools attended by index cases.[30,31] However, subsequent cases do not necessarily occur in the same classroom as the index case, with others occurring, for example, in contacts who share extracurricular activities with index cases.[30] In the US the relative risk of further cases among school students (5-18 years of age) was 2.3.[30]
Even though transmission from a symptomatic case is uncommon there is, however, a small increased risk of disease in people who have very close contact with a symptomatic case prior to completion of 24 hours of antibiotic therapy. Those healthcare workers who have unprotected close airway exposure to large particle respiratory droplets (e.g. during airway management) from a case of IMD around the time of admission, are at increased risk of disease in the 10–day period after exposure.[32] However, the risk is very low; in one study absolute risk was estimated to be 0.8/100,000,[33] far below the risk in household contacts.
Laboratory personnel who work with N. meningitidis are at increased risk of IMD.[34,35] Other risk factors for IMD include congenital or acquired immunoglobulin deficiencies and complement deficiencies, anatomic or functional asplenia, travel to or residence in countries where meningococcal disease is hyperendemic or epidemic,[36] exposure to cigarette smoke,[37,38] concurrent respiratory tract infections[39,40] and crowded living conditions or recreation spaces.[41,42,43] Indigenous Australians are at significantly increased risk compared to the non-indigenous population.[23,44]
IMD is endemic in Australia but the incidence has varied dramatically over time, with major epidemics following both world wars. More recently, incidence increased through the 1990s, but declined to historically low levels following a peak around the early 2000s.[45,46] Cases occur throughout the year, but there is a marked seasonality, with the highest number of notifications and hospitalisations occurring between June and September each year.[47] All age groups can be affected, but there is a bimodal age distribution, with the highest rates of disease in children aged under 5 years and a second peak in adolescents and young adults aged 15-19 years.[2]
While the overall incidence and mortality associated with IMD is low, the clinical and public health management of the disease can be demanding. This is related to the often dramatic course of the disease, the potential for deaths and serious complications, the fact that incidence is highest in young children, teenagers and young adults, and that clusters of cases may occur, albeit infrequently. Hence, it is essential that the public health follow-up of IMD is undertaken as a priority, that guidelines are followed closely, and that information provided to families of those affected, contacts and the media is consistent and evidence-based.
Universal childhood vaccination using the conjugate serogroup C vaccine, introduced in 2003, along with catch-up vaccination of children and adolescents through school based programs, has been associated with a marked reduction in serogroup C IMD cases in Australia.[2,16]
Vaccines are available in Australia for serogroups A, B, C, W and Y meningococcal disease.
The Australian Immunisation Handbook 10th Edition, updated online version provides current guidance on meningococcal immunisation.
Meningococcal C conjugate vaccine (MenCCV) - Available through the National Immunisation Program. Recommended for all children at 12 months of age.
Meningococcal B vaccine (MenBV) – Available on private script. Recommended for infants and young children, adolescents, young adults living in close quarters, some laboratory personnel and individuals with certain medical conditions.
Quadrivalent meningococcal vaccines (4vMenCV and 4vMenPV) which protect against serogroups A, C, W and Y. Available on private script. Recommended for occupational exposures, some travel and certain medical conditions. This can be also offered to those who wish to protect themselves or their family from these serogroups of meningococcal disease.
Check the National Immunisation Schedule and the relevant jurisdictional schedule for up-to-date information on currently funded vaccines, as schedules change from time to time. For example, in early 2017, some states implemented a time-limited adolescent ACWY vaccination program to address the changing epidemiology of serogroup W disease.
Meningococcal C conjugate vaccine (MenCCV) was replaced as the funded vaccine for infants and adolescents with 4vMenCV in July 2018. Quadrivalent polysaccharide vaccine 4vMenPV has been discontinued in Australia.
Meningococcal B vaccine (MenBV) was made available under the National Immunisation Program in July 2020 for people with certain medical conditions and Aboriginal and Torres Strait Islander infants. An ongoing catch-up program for Aboriginal and Torres Strait Islander children less than 2 years of age was funded in July 2023.
Quadrivalent meningococcal vaccines (4vMenCV) are available under the National Immunisation Program for certain groups including infants at 12 months of age, adolescents 14 -16 years old and people with certain medical conditions. Catch-up vaccination is also available for people under the age of 20 years, and for refugee and humanitarian entrants of any age.
Meningococcal ACWY (4vMenCV) and B (MenBV) vaccines are also available on private script for other groups that are strongly recommended to receive the vaccines but are not funded under the National Immunisation Program.
The main aims of public health measures for meningococcal disease are:
Probable and confirmed cases of meningococcal disease should be entered onto the notifiable diseases database within one working day of notification. Ensure that data on Aboriginal or Torres Strait Islander status and vaccination history are collected and entered into the jurisdictional database.
Serogroup, sub-serogroup and case outcome should be added to the database when available.
See Section 12: Special situations for guidance on infections at urogenital and anorectal sites, including data management.
Where applicable in a jurisdiction the laboratory or clinician notifies the state/territory communicable diseases branch or public health unit (PHU) of the case’s age, sex, date of onset, clinical status, laboratory findings and vaccination history (if relevant).
Probable and confirmed cases of invasive meningococcal disease are notifiable.
A confirmed case requires either:
Detection of Gram-negative diplococci in Gram stain of specimen from a normally sterile site or from a suspicious skin lesion.
Disease which in the opinion of the treating clinician is compatible with invasive meningococcal disease.
A probable case requires clinical evidence only.
A probable case requires:
The current surveillance case definition can be located at the Australian national notifiable diseases and case definitions.
Although meningococcal conjunctivitis is not included in the IMD surveillance case definition, cases should still be notified in order to enable a public health response as, on occasion, it may precede invasive disease[48] or IMD in a contact[49] (refer to Section 12).
See Section 12: Special situations for guidance on infections at urogenital and anorectal sites, including case definition.
All patients with suspected meningococcal infection should have blood collected as soon as possible for culture, polymerase chain reaction (PCR) testing, c-reactive protein and full blood count. Where appropriate, a sample of cerebrospinal fluid (CSF) should be collected for PCR, microscopy and culture. For meningococcal conjunctivitis (refer to Section 12: Special Situations).
For further details of specimen collection, handling requirements and availability of testing, which may vary between locations, contact the relevant laboratory (refer to Appendix 4: National Neisseria Network (NNN) Laboratories).
PCR-based diagnosis provides confirmation of IMD from blood, CSF or other normally sterile sites with validity comparable to that of culture-based diagnosis. Additionally, PCR methods can provide diagnostic information pertinent to patient care and public health management. For these reasons it is recommended that CSF and/or EDTA blood samples from which DNA was extracted for PCR-based diagnosis as well as the remaining DNA extract, both be sent to the appropriate NNN laboratory (refer to Appendix 4: National Neisseria Network (NNN) Laboratories).
Early antibiotic therapy has contributed to PCR, particularly in blood specimens, now being the most common means of laboratory diagnosis of IMD. PCR-based assays are generally directed at the ctrA gene. Test sensitivity is >95 percent for CSF using ctrA gene PCR [50] and approximately 87 percent when testing blood samples.[51] Data are not available for skin lesions.
PCR tests for serogroup determination should be performed both from a confirmatory and epidemiological point of view. Serogroup identification can guide the public health response, particularly vaccination recommendations. PCR-assays for detecting regions in the siaD gene specific for serogroups B, C, W and Y are widely performed in Australia.
Although meningococcal DNA can be detected up to 72 hours after initiation of systemic antibiotics, caution should still be taken when interpreting negative PCR results. In probable cases results should be assessed in conjunction with clinical presentation, duration and severity of disease and the timing of the initiation of systemic antibiotics in relation to collection of the specimen. [51]
Detection of Gram-negative diplococci by Gram stain of CSF or specimens from other normally sterile sites constitutes laboratory suggestive evidence in the CDNA case definition. In conjunction with a clinically compatible illness, this fulfils criteria for a confirmed case of IMD. The reported sensitivity of Gram stain on CSF is about 62 percent[52,53] and of skin lesion aspirates or biopsies about 50 percent.[53,54] Prior use of antibiotics reduces the likelihood of a positive Gram stain and culture.
Culture of N. meningitidis from blood, CSF or other normally sterile sites confirms a diagnosis of IMD. Additionally, cultures provide isolates for strain differentiation and antibiotic susceptibility testing. When meningitis is present CSF offers the best chance of yielding an organism for culture, but sensitivity is reported to decline from 72 percent to 42 percent after antibiotic treatment.[52] The sensitivity of blood culture is reported to vary from 24-47 percent [52,55] but falls to 5 percent or less if antibiotics have been given before collection. [52]
The collection of throat swabs is not recommended for either cases of IMD or their contacts.
Strain differentiation or typing can assist in establishing linkages between cases or cases and carriers that are identified epidemiologically. Laboratory typing results can exclude true relatedness of apparently linked cases if they emerge as being distinct. Also, if the method used is highly discriminating and the prevalence of particular types is taken into account, detection of indistinguishable case isolates can provide quite strong evidence of relatedness.
Isolates and samples for typing are referred to NNN Laboratories (refer to Appendix 4). Historically, phenotyping (serotyping) has been used to separate isolates into serogroups (using capsular polysaccharides), serotypes and sub-serotypes (using OMP).
Genotyping (molecular) techniques are now used by most state laboratories to type strains in addition to serotyping. Techniques available include pulsed-field gel electrophoresis (PFGE), porA/ porB, or fetA sequencing and multi-locus sequence typing (MLST).[56] Whole genome sequencing, where available, can also be used to establish strain relatedness of cases and guide public health interventions.
Further information is available from the Public Health Laboratory Network (PHLN) case definition.
Public health action should commence immediately where the clinical picture is consistent with IMD – in the opinion of the treating clinician – or definitive or suggestive laboratory evidence is received. Begin investigation and response on the same day of notification of a probable or confirmed case of IMD or of confirmed meningococcal conjunctivitis.
Although meningococcal conjunctivitis is not included in the surveillance case definition for IMD, cases should still be notified in order to enable a public health response as, on occasion, it may precede invasive disease [48] or IMD in a contact [49] (refer to section 12 special situations).
See Section 12: Special situations for guidance on infections at urogenital and anorectal sites.
The response to a notification will usually be carried out in collaboration with the case’s medical team.
Ensure that action has been taken to:
Treatment is the responsibility of the treating doctor. For antibiotic treatment recommendations refer to the current edition of Therapeutic Guidelines: Antibiotic. Some antibiotics, including penicillin, do not reliably clear nasopharyngeal carriage of meningococci, [1] so appropriate clearance antibiotics must also be used (refer to Table 2).
Vaccination of cases is not recommended unless the case has underlying risk factors as outlined in the Australian Immunisation Handbook.
Droplets and nasopharyngeal secretions are considered to be infectious from the onset of the acute illness until completion of 24 hours treatment with effective systemic antibiotics.[9] Hence, during this period both standard and droplet precautions should be practised for suspected, probable or confirmed cases, especially while undertaking airway management during resuscitation.
Contacts (refer to below) who develop symptoms consistent with IMD should be advised to seek medical advice urgently and to inform the PHU.
A single case of serogroup A meningococcal disease in an Aboriginal or Torres Strait Islander person may be the sentinel event of a community outbreak and requires appropriate action.
None routinely required (refer to Section 12. Special situations).
See Section 12: Special situations for guidance on infections at urogenital and anorectal sites, including case treatment and vaccination.
The aim of identifying contacts is to:
Public health follow-up focuses on identifying the subset of ‘higher-risk’ contacts who require information and clearance antibiotics and vaccination in some instances. Other lower-risk contacts groups may be given information only.
In establishing the timing and degree of contact with a case, the time period of interest is from 7 days prior to the onset of symptoms in the case to the time the case has completed 24 hours of appropriate antibiotic treatment.
Higher-risk contacts fall into the following groups:
Only students who are household-like contacts of a case - refer to Contact definition Section 11
See Section 12: Special situations for guidance on infections at urogenital and anorectal sites, including contact management.
The main rationale for provision of clearance antibiotics is to eliminate meningococci from any carrier within the network of contacts close to each case, thereby reducing the risk of further transmission of what may be a more virulent strain of the organism within the social network and preventing further cases of invasive disease. Clearance antibiotics given to household contacts was estimated to be 89 percent effective in preventing secondary cases.[58]
Clearance antibiotics should also be provided for contacts of meningococcal conjunctivitis because secondary cases of IMD have occurred.[49]
Wider provision of clearance antibiotics outside the recommended groups should be avoided due to the risk of doing more harm than good, including elimination of protective flora, risk of side effects and development of antibiotic resistance. Following even a single case of IMD there may be considerable demands and pressure from parents or others for clearance antibiotics to be administered more widely than is recommended. It is important that public health personnel do not acquiesce to these demands, but rather provide reassurance on the low risk of IMD in contacts and carefully explain the purpose for clearance antibiotics.
All identified contacts, regardless of whether or not they are eligible to receive clearance antibiotics, should be advised to remain alert for symptoms and to seek medical review if appropriate.
The current (April 2019) Therapeutic Guidelines: Antibiotic lists ciprofloxacin, ceftriaxone and rifampicin as suitable agents. Characteristics of these agents are shown below in Table 2. Clearance antibiotics should be given to contacts of confirmed cases of IMD as soon as possible after the contact is identified. However, there is no purpose in administering antibiotics if more than four weeks have elapsed since the most recent contact with the case.
Preferred
agent for
*Ciprofloxacin suspension contains 250mg/5ml
IM administration:
2-day course could reduce compliance:
Meningococcal vaccination may be offered to higher-risk contacts to further reduce the small risk of secondary cases. The rationale for vaccination in this context is to protect individuals from infection with an invasive strain of meningococcus that may still be circulating in their social network, including among persons who did not receive clearance antibiotics.
In addition to clearance antibiotics, vaccination with an appropriate vaccine is indicated for unimmunised household-like contacts of cases of IMD and meningococcal conjunctivitis confirmed to be caused by serogroup C, A, W or Y.
Public health units should facilitate access to appropriate vaccine either directly or through existing jurisdictional arrangements with primary care or immunisation providers.
Contacts should be informed that, depending on their age, further doses may be required if they wish to have long term protection against meningococcal A, C, W and Y disease [Australian Immunisation Handbook]. Completion of the vaccination course, if necessary, is at the discretion of the contact and can be arranged via their primary care provider.
Vaccination with 4CMenB vaccine, however, is not recommended after a single case of IMD caused by serogroup B, primarily because it is a multi-dose course, and a single (first) dose is unlikely to confer protection to the contact during the period of higher risk of disease.
Vaccination of household contacts with 4CMenB vaccine should, however, be considered if a second serogroup B case occurs in the same household (even if >30 days later), as this may indicate increased susceptibility of family members to IMD and/or ongoing transmission within the household.
Following confirmation of IMD, provide information to the network of contacts (or to the responsible guardians of children in the network) about the disease and how it is spread. For lower-risk contacts, information should be provided as soon as possible and by no later than the end of the next business day. A fact sheet, appropriate to the cultural and literacy needs of recipients, should be provided (refer to example at Appendix 2: Meningococcal disease: Information for the public). This information should include the message that contacts, or anyone close to them, who develop symptoms consistent with meningococcal disease, should seek urgent medical attention.
None required
Outbreaks of meningococcal disease can be particularly challenging for public health authorities due to the intense public concern and media interest they generate, [23] the potential for significant morbidity and mortality and the limited published evidence to guide best practice. [60]
The term ‘outbreak’ is taken to mean the occurrence of more cases than expected for the population or group under consideration. The objective of public health management of outbreaks of IMD is to interrupt transmission and prevent further cases. Once an outbreak is either suspected or recognised there is an immediate need to initiate a coordinated response. Elements of this response include:
Sporadic case - a single case in the absence of previous known close contact with another case (refer to Contact definition above).
Primary (index) case - a case that occurs in the absence of previous known close contact with another case and is subsequently associated with a co-primary or secondary case.
Co-primary case - a close contact who develops disease within 24 hours of onset of illness in a primary case.
Secondary case - a close contact who develops disease more than 24 hours after onset of illness in a primary case where the available microbiological characterisation of the organisms is the same.
Organisation-based outbreak - two or more probable or confirmed (where the available microbiological characterisation of the organisms is the same) cases with onset in a four week interval, among people who have a common organization-based affiliation (such as attending the same high school, extended families and/or social groups) but no close contact with each other, in a grouping which makes epidemiological sense.
Community outbreak - three or more confirmed or probable cases of IMD where there is no direct epidemiologic link between the cases, with onset in a 3 month interval among persons residing in the same area and the primary attack rate is at least 10 per 100,000.[57] Rate calculations should not be annualised. This is not an absolute threshold and should be considered in the context of other factors, e.g. completeness of case reporting, whether there is continuing occurrence of cases after recognition of a suspected outbreak and population vaccination coverage where relevant.
The following changes in epidemiology of meningococcal disease are suggestive of an outbreak [61]:
Suspected outbreaks should be reviewed in order to identify the microbiological features of the cases and any epidemiologic links between cases. Microbiological investigation should focus on confirmation of the diagnosis and rapid characterisation of organisms in as much detail as locally possible. Cases that occur closely in time and place, but are infected with different serogroups (or serotypes, sub-serotypes or genotypes if known), should be managed as sporadic cases.[62] The identification of possible epidemiological links should include a search for contacts in common, particularly in childcare, educational institutions or other groupings or organisations.[30,63,64,65,66] Examples include attendance at nightclubs or parties.[67]
In settings such as childcare centres and aged care facilities, the population at risk is a natural grouping that makes epidemiological sense. Identification of populations at risk may be more difficult in other organisational settings, such as schools, universities and workplaces; or in extended families or social groups.
Clearance antibiotics should be considered for a wider group than household-like contacts, even though the evidence for preventing further cases is not strong.[29,68] Co-primary or secondary cases should not be counted when determining whether criteria for provision of organisation-based clearance antibiotics have been met. This is because they are the household-like contacts.
If cases have occurred in a household-like setting, then this may not meet criteria for an organisational outbreak. For example, two cases in university students in the same class who share accommodation do not define a university-based outbreak, since the risk is assumed to arise from the household-like setting of the shared accommodation.
The use of meningococcal vaccine in addition to clearance antibiotics should be considered if the outbreak is due to a vaccine-preventable serogroup. [62,67,69,70,71]
These outbreaks are difficult to define and manage. At-risk populations are usually defined geographically by using natural or administrative boundaries that most closely fit the residence data for the majority of the outbreak cases. However, physical or administrative boundaries do not limit factors that contribute to the increasing risk of meningococcal disease and accurate identification of the at-risk population should not be inappropriately constrained by them.
Assess carefully all available epidemiological information, including both confirmed and probable cases, serotyping and/or genotyping data, dates of onset, direct and indirect links between cases, the size of the population or identifiable sub-population containing the cases and meningococcal vaccine uptake rates (where relevant).[54]
From an epidemiologic perspective, when determining if the criteria for an outbreak are met, secondary and co-primary cases should be counted as one case[57] for the purpose of calculating community attack rates.
Vaccination of the population at risk should be considered if an outbreak of a vaccine preventable serogroup is identified, as defined above. Other factors should be taken into account, including logistic and financial considerations. The decision to vaccinate a large population is a difficult one for several reasons:
Community-wide clearance antibiotics should not be used. The widespread use of clearance antibiotics in community outbreaks has not been shown to be of value. It may result in:
Based on outbreaks reported in the 1980s and early 1990s, the risk of sustained transmission of IMD in Aboriginal and Torres Strait Islander communities, is probably higher than in the general community.[72] For this reason a low threshold should be used to initiate disease control measures. Action targeted to all community members should be considered if there are 2 or more cases in a remote Aboriginal or Torres Strait Islander community within a 4 week period and where available characterisation indicates they are the same strain. The nature of any action will depend on factors including the size of the community and the serogroup of the organism.
Clusters of serogroup W disease occurred in Aboriginal communities in some states in 2016/17, and population-based vaccination interventions were undertaken in response.
Primary meningococcal conjunctivitis may also precede invasive disease in a case or in a close contact.[48,49] Hence, it is recommended that contacts of individuals with meningococcal conjunctivitis receive information and clearance antibiotics as for contacts of IMD cases.
Conjunctival swabs should be collected from suspect cases of meningococcal conjunctivitis as soon as possible for microscopy and culture. Gram staining of conjunctival exudate or scrapings from suspect cases of meningococcal conjunctivitis consistently reveals Gram-negative diplococci and abundant polymorphonuclear leukocytes. This provides a preliminary diagnosis of meningococcal conjunctivitis (with N. gonorrhoeae and M. catarrhalis considered in differential diagnosis), but culture is essential for diagnostic confirmation, strain characterization and antibiotic susceptibility testing.[49]
Prophylaxis is only advised for passengers seated immediately beside the index case (but not across the aisle) during long distance travel (>8 hours duration) by aeroplane or those who have had direct contact with respiratory secretions or vomitus (32, 33).
Other passengers and airline crew members do not require prophylaxis on a flight of any duration (34) unless there has been contact as defined under healthcare workers (see Section 11: Contact definition).
The ability of N. meningitidis to colonise and cause infection of urogenital and anorectal sites has long been established (1-8) and increasing identification of N. meningitidis as a cause of symptomatic urethritis has been noted in the USA, UK, and New Zealand in recent years (9-13). There is some evidence for potential progression to invasive disease from these sites, particularly among certain high-risk groups such as men who have sex with men (MSM) (14).
Transmission of N. meningitidis at urogenital and anorectal sites is primarily through sexual contact, particularly oro-genital and oro-anal (1, 2, 4-9, 11-13, 15-23). Transmission via ano-genital and genital-genital contact (1, 7, 24) as well as auto-genital (3, 15) contact has also been documented. Vertical transmission can also occur from mother to baby during transit of the birth canal (30).
Symptomatic infection with N. meningitidis at urogenital and anorectal sites generally presents similarly to N. gonorrhoea infection (5, 15). Like gonorrhoea, N. meningitidis infection can progress to cervicitis, vulvovaginitis, pelvic inflammatory disease, salpingitis, endometritis, epididymitis and proctitis. Neonatal conjunctivitis and pre-term birth have also been reported (1, 3, 15-20, 25). The Australian STI guidelines for gonorrhoea may aid in the understanding and identification of symptomatic infection.
Cases of IMD secondary to infection at urogenital or anorectal sites have also been reported, largely in females (3, 25, 27, 28), although recent increases in IMD among men who have sex with men have also been associated with N. meningitidis colonisation of the rectum and urethra (11). While rare, N. meningitidis genital colonisation has been considered the likely route (29), and confirmed route (26, 30) in cases of neonatal IMD immediately after birth.
Cases of infection with N. meningitidis at urogenital and anorectal sites should be entered into NCIMS within 3 working days of notification.
Events for non-sterile sites requiring public health follow up (conjunctivitis and urogenital/anorectal sites) should be classified as “Possible" cases while public health follow up is being conducted.
Once public health follow up is complete, these events should be re-classified as “Excluded".
For the purposes of public health follow up, a case of infection with N. meningitidis at urogenital and anorectal sites requires both:
Public health follow up is not indicated for events where the individual is asymptomatic and testing was done as part of routine sexually transmitted illness (STI) screening.
Initiate response within one working day to notifications of infection with N. meningitidis at urogenital and anorectal sites. Cases should be entered into NCIMS within 3 working days. Serogroup results and follow up outcome should be added when available.
Though public health action should not be delayed while awaiting serogroup results, follow-up of cases of infection at conjunctival, urogenital, or anorectal sites can be ceased or averted if the infection is found to be caused by an unencapsulated strain of N. meningitidis.
While no therapeutic guidelines for the treatment of N. meningitidis infection at urogenital or anorectal sites exists, there is evidence that presumptive treatment as gonococcal infection at the same site is effective (31). Where presumptive treatment for gonococcal infection has not occurred then ceftriaxone as a single IM dose is sufficient for urogenital or anorectal meningococcal infection.
Should the diagnosing medical practitioner require advice regarding treatment of the case and/or their contacts, consultation with a sexual health or infectious disease physician is recommended.
If invasive disease is clinically suspected in a person with N. meningitidis infection at a urogenital or anorectal site, standard IMD management guidelines should be applied.
Vaccination can be offered to cases of N. meningitidis infection at conjunctival, urogenital, and anorectal sites. Unlike IMD, these are considered “non-immunising events", as there is less evidence that these events provide future protection. As such, vaccination for these cases may be offered at the discretion of PHU staff and treating sexual health, infectious disease clinician or general practitioner.
As with IMD, vaccination recommendations only apply when the infection is caused by serogroups A, C, W and Y, but not B. Depending on the age of the case, ACWY vaccination may be covered by the National Immunisation Program.
Sexual contacts (oro-genital, genital-genital, oro-anal, ano-genital) in the 7 days preceding the onset of symptoms in cases with urogenital and anorectal meningococcal infection are considered higher-risk contacts (refer to Section 11: Contact definition on previous page) and should be managed as per Table 1.
As a potential STI, where a N. meningitidis infection at urogenital and anorectal sites is reported in a child <16 years old (outside of the neonatal period), the PHU must confirm that the treating doctor has undertaken an assessment of the risk of harm according to the mandatory reporting guidelines and obligations under the Children and Young Persons (Care and Protection) Act 1998.
If a case is reported in a child aged 12 or under, the PHU must also directly contact the doctor to ensure that mandatory reporting obligations have been addressed. If no contact can be made, the PHU should contact the NSW Health Child Wellbeing Unit (1300 480 420) or make a direct report to the Child Protection Helpline on 13 21 11.