Notification requirements for meningococcal disease
Suspected or confirmed invasive meningococcal infection (Group A disease) must be notified immediately by telephone or fax, followed by a written notification within 5 days.
This is a Victorian statutory requirement.
School and children’s service centres exclusion for meningococcal disease
Contacts do not need to be excluded if they are receiving carrier eradication therapy. Contacts who have not received carrier eradication therapy should be excluded for 7 days from the onset date of the case.
Infectious agent of meningococcal disease
Neisseria meningitidis (or meningococcus) is a gram-negative diplococcus. There are 13 serogroups of N. meningitidis, with 6 serogroups (A, B, C, W135, X and Y) accounting for the majority of cases of invasive meningococcal disease (IMD) worldwide. Serogroup B is currently responsible for most IMD cases in Australia, with small numbers of cases due to serogroups C, Y and W135.
Identification of meningococcal disease
Clinical features of invasive meningococcal infection include an acute onset of meningitis or septicaemia. Typical symptoms include:
- intense headache
- neck stiffness.
A petechial or purpuric rash may occur on the trunk and limbs and may sometimes cover large areas of the body. The septicaemic form can be difficult to diagnose before the onset of the characteristic haemorrhagic rash that does not blanch under pressure.
Appearance of a rash can be relatively late (median onset 13–22 hours) or there may be no rash at all. In fulminating cases, there is sudden prostration and shock associated with the characteristic rash – this condition has a high fatality rate.
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. Rarely, chronic meningococcal septicaemia can also occur, with febrile episodes, skin rashes and fleeting joint pains.
Method of diagnosis
Diagnosis is usually made on clinical grounds confirmed by laboratory tests. Treatment, including antibiotics, should never be delayed by the need to get laboratory specimens. Laboratory tests include:
- Gram stain of cerebrospinal fluid (CSF), skin lesion smear or joint fluid
- culture of blood, CSF or other sterile site
- polymerase chain reaction (PCR), which is now the commonest means of diagnosis.
Meningococcal isolates from all cases of invasive disease should be sent to the Microbiological Diagnostic Unit at the Doherty Institute to ensure appropriate monitoring of serogroups and for susceptibility testing. This needs to be authorised by the department’s Communicable Diseases Section.
Incubation period of meningococcus
The incubation period is commonly 3–4 days, but can vary from 1 to 7 days (rarely, up to 10 days). People who do not develop the disease in the 7 days after colonisation may become asymptomatic carriers.
Public health significance and occurrence for meningococcal disease
Invasive meningococcal infections occur in endemic and epidemic forms. In Australia, epidemic disease has not occurred for many years. Endemic disease is at low levels of incidence, and cases are generally unrelated to each other. Despite this, IMD is of public health importance. It is frequently a cause of public alarm and receives a high level of media attention.
Meningococcal disease characteristically has a seasonal pattern, with incidence peaking in the winter and spring months. Although the reasons for this seasonality are not clear, there is evidence that influenza virus or Mycoplasma pneumoniae infections may predispose to invasive disease, and that closer personal contact or lack of ventilation may facilitate transmission of meningococci.
The three major serogroups of meningococci cause different patterns of disease. Serogroup A meningococci cause outbreaks of infection in areas such as the meningitis belt of Africa, where the incidence of meningococcal infection rises sharply towards the end of the dry season and declines rapidly with the onset of rains. The epidemics occur in 8–14-year cycles.
From 1990, New Zealand experienced an epidemic of serogroup B meningococcal disease, but has had a significant reduction in cases since a vaccination program in 2004–05. Age-standardised rates for Maori and Pacific islander people were three and six times higher, respectively, than for the European population.
Serogroup C meningococci are usually associated with sporadic disease, but can cause small or large outbreaks. Attack rates for serogroup C are between those seen with serogroups A and B.
Meningococcal disease has had cyclical peaks of incidence. Notification of ‘meningitis’ reached a peak of 33.1 cases per 100 000 in 1942 (2371 cases) as part of a pandemic of serogroup A disease during World War II. Apart from another peak of activity in the early 1950s, notifications steadily declined to less than 0.5 cases per 100 000 in 1987. The notification rate for meningococcal disease to the National Notifiable Diseases Surveillance System peaked at 4.3 per 100 000 in 2002 and declined to 0.4 per 100 000 in 2013. In 2013, 26 notifications were made in Victoria (one-sixth of the national total), of which 20 were serogroup B.
Reservoir for meningococcus
Humans are the natural host.
Mode of transmission of meningococcus
Respiratory droplets shed from the upper respiratory tract are primarily responsible for transmitting meningococci from one person to another. Humans are the only natural hosts for meningococci; the organism dies quickly outside the human host and cannot be isolated from environmental surfaces or samples.
Saliva has been shown to inhibit the growth of meningococci, and salivary contact (for example, by sharing drink bottles) is not considered to be a significant means of transmission.
Period of communicability for meningococcal disease
Meningococcal disease is communicable until the organisms are no longer present in discharges from the nose and mouth. With effective antibiotic therapy, meningococci usually disappear from the nasopharynx within 24 hours.
Susceptibility and resistance of meningococcal disease
Susceptibility to clinical disease is low, as evidenced by the typical high ratio of carriers to cases. The highest rates of disease are in children under 5 years, with a secondary peak of meningococcal meningitis in adolescents and young adults aged 15–19 years.
Laboratory personnel who work with N. meningitidis are at increased risk of IMD. 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
- exposure to cigarette smoke
- concurrent respiratory tract infections
- crowded living conditions or recreation spaces.
Aboriginal and Torres Strait Islander people are at significantly increased risk compared with the non-Indigenous population.
Close contacts are at an increased and prolonged risk of secondary infections, including household and intimate contacts. Contacts in childcare, school and university have a modest increased risk.
Healthcare workers who have unprotected close airway exposure to large particle respiratory droplets (for example, during airway management) from a case of IMD around the time of admission are at increased risk of disease in the 10 days after exposure. However, the absolute risk is very low – estimated at 0.8/100 000.
The risk in household contacts is 500–800 times higher than in the general population, with risk highest in the first week after onset and falling rapidly thereafter.
There is no maternal immunity.
Control measures for meningococcal disease
Most strains of meningococci do not cause disease, but instead provide protection. Other protective bacteria such as Neisseria lactamica also colonise the nasopharynx.
By giving chemoprophylaxis when it is not needed, these bacteria, which are protective, are also eradicated. People can carry meningococci with no ill effects for many months. Carriage produces protection. There is no evidence to suggest carriers will suddenly become cases after weeks or months of carriage. See ‘Control of contacts’ for recommendations on chemoprophylaxis.
There are two different types of meningococcal vaccine: the meningococcal C conjugate vaccines (MenCCV) and the tetravalent meningococcal polysaccharide vaccines (4vMenPV). Conjugate vaccines give long-lasting protection against meningococcal serogroup C disease. Under the National Immunisation Program (NIP), a single dose of meningococcal serogroup C vaccine is given at 12 months of age.
A single dose of a MenCCV is recommended as part of the NIP for all children at 12 months of age. MenCCV is also recommended for people at high risk of meningococcal disease (see the current edition of the Australian immunisation handbook).
Quadrivalent meningococcal conjugate (4vMenCV) and polysaccharide vaccines cover several serogroups not often seen in Australia. 4vMenCV is recommended and may be required for people travelling to places such as Africa and Asia, and pilgrims to the Haj. 4vMenCV is available for use in children 9 months or older. Polysaccharide vaccines are not recommended for children under 2 years of age, and they only provide protection for about 3 years.
In Australia, the Therapeutic Goods Administration included the 4CMenB on the Australian Register of Therapeutic Goods on 14 August 2013. The vaccine is registered for use in people 2 months old and older, for the prevention of invasive disease caused by serogroup B meningococci. It is available through purchase on the private market. This vaccine is not funded under NIP.
4CMenB is a recombinant multicomponent meningococcal B (MenB) vaccine that induces specific bactericidal antibodies against a range of MenB strains. In Australia, based on laboratory tests, about 76 per cent of MenB strains are predicted to be covered by this vaccine, but clinical effectiveness has not yet been shown. The vaccine is recommended for certain groups considered at higher risk (see the current edition of the Australian immunisation handbook).
The National Meningococcal C Vaccination Program was a 4-year program in 2003–06 in which all persons aged 1–19 years in 2003 were targeted for a dose of meningococcal C vaccine. MenCCV was also added to the NIP schedule at 12 months of age at that time.
Control of case
Treatment is the responsibility of the treating doctor. For antibiotic treatment recommendations refer to the current edition of Therapeutic guidelines: antibiotic.
Antibiotics in adequate doses should begin when a presumptive clinical diagnosis is made before laboratory confirmation. In cases with a very acute onset, such treatment should start before transferring the patient to hospital even though there may be some interference with laboratory confirmation by culture (but not PCR).
Some antibiotics, including penicillin, do not eradicate the organisms in the nasopharynx, so all patients should be additionally treated with a drug such as rifampicin before being discharged from hospital. If ceftriaxone is used in treatment, rifampicin need not be given. Consult the current version of Therapeutic guidelines: antibiotic.
Control of contacts
Meningococci are likely to have been acquired from an asymptomatic person (carrier) who either lives in the same household (or similar setting) or is an intimate partner of the case. Children tend to acquire their disease from adults (in their household), whereas teenagers and adults are more likely to acquire their disease from close friends.
Clearance antibiotics should only be given to the following people who have had contact with the case 7 days before the onset of the case's illness. They should be commenced as soon as possible after diagnosis:
Household contacts of a case are those who lived in the same house (or dormitory-type room) or were having an equivalent degree of contact with the case in the 7 days before the onset of the case’s symptoms.
Intimate kissing contacts in the 7 days before the onset of the case’s symptoms.
Childcare: Children and staff in childcare should have an equivalent degree of contact with the case as a household contact. As a guide, this should mean at least 4 hours/day on average, or 20 hours in total, in the 7 days before the onset of the case’s illness. Childcare includes any situation where children under 5 years of age are cared for with other children away from home. This setting includes kindergartens, preschools (preprimary) and primary schools.
Passengers seated immediately next to the case during long-distance travel (>8 hours duration) by aeroplane, train, bus or other vehicle.
Healthcare workers are rarely at risk. Only those who have come into direct contact with the nasopharyngeal secretions of a case (before the case receiving 24 hours of therapeutic antibiotics) during a procedure, such as intubation without wearing a surgical mask or mouth-to-mouth resuscitation, should be regarded as higher-risk contacts.
The risk of meningococcal disease in close contacts, although higher than the general population, is still very low. The risk is highest in the first 7 days after a case and falls rapidly during the following weeks. If antibiotic prophylaxis is not given, the absolute risk to an individual in the same household of developing disease 1–30 days after an index case is about 1 in 300. The increased risk in household members may be due to a combination of genetic susceptibility in the family, increased exposure to virulent meningococci and environmental factors.
Clearance antibiotics should only be given to those people who are at risk of either being the source of disease in the case or of having acquired the invading organism from the case. The aim of clearance antibiotics is to prevent further transmission.
Three antibiotics are used for clearance of meningococcal disease. Each agent has its advantages and disadvantages, and each is the preferred agent in specific circumstances. A recent review by the Cochrane group found that ciprofloxacin, rifampicin and ceftriaxone were effective in eliminating N. meningitidis after treatment. Also refer to the current version of Therapeutic guidelines: antibiotic.
Ciprofloxacin is the preferred clearance antibiotic for adult men, nonpregnant women and children. It is the medication of choice for women on the contraceptive pill. The recommended dosage for an adult or child at least 12 years old is a single oral dose of 500 mg.
Rifampicin is considered the clearance antibiotic of choice for young children. The recommended schedule for rifampicin is 600 mg every 12 hours for 2 days for adults; 10 mg/kg/dose (up to 600 mg) for children over 1 month of age every 12 hours for 2 days; and 5 mg/kg/dose for children aged less than 1 month every 12 hours for 2 days.
Note: The product information recommends a once-daily 4-day regimen of rifampicin for clearance antibiotics of meningococcal disease. The 2-day regimen above is recommended by the Communicable Diseases Network Australia, in accordance with the Cochrane review.
Ceftriaxone is the preferred antibiotic for pregnant women and in situations where access or compliance may be poor. The recommended dosage is a single dose 250 mg intramuscular injection (reconstituted with 1 per cent lignocaine).
Control of environment
Respiratory isolation is recommended for 24 hours after commencing treatment. There should be concurrent disinfection of articles soiled with discharges from the nose or throat. Articles used by the patient should be terminally cleaned.
Outbreak measures for meningococcal disease
The Communicable Diseases Network Australia has determined the following outbreak definitions and considerations for IMD.
Two or more probable or confirmed (where the available microbiological characterisation of the organisms is the same) cases with onset in a 4-week interval, among people who have a common organisation-based affiliation (such as attending the same high school) but no close contact with each other, in a grouping that makes epidemiological sense.
Clearance antibiotics should be considered for a wider group than household-like contacts, even though the evidence for preventing further cases is not strong. Co-primary or secondary cases should not be counted when determining whether criteria for provision of organisation-based clearance antibiotics have been met.
If cases have occurred in a household-like setting, then this may not meet criteria for an organisational 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 who are not close contacts of each other, and the primary attack rate is at least 10 per 100 000. Rate calculations should not be annualised. This is not an absolute threshold and should be considered in the context of other factors – for example, completeness of case reporting, whether there is continuing occurrence of cases after recognition of a suspected outbreak and population vaccination coverage, where relevant.
These outbreaks are difficult to define and manage. 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 subpopulation containing the cases
- MenCCV uptake rates (where relevant).
Vaccination of the population at risk should be considered if an outbreak of a vaccine preventable serogroup is identified. Community-wide clearance antibiotics should not be used.
Aboriginal and Torres Strait Islander communities
Based on outbreaks reported in the 1980s and early 1990s, the risk of sustained transmission of IMD in Aboriginal and Torres Strait Islander communities, especially remote communities, is probably higher than in the general community. For this reason, a low threshold should be used to determine the necessity for disease control measures. Action targeted to all community members should be considered (depending on community size and serogroup) if there are two 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.
Primary meningococcal conjunctivitis may also precede invasive disease in a case or in a close contact. Hence, it is recommended that contacts of individuals with meningococcal conjunctivitis receive information and antibiotic prophylaxis, as for contacts of IMD cases.
Advice for medical practitioners about meningococcal disease
Prompt diagnosis of meningococcal septicaemia and meningitis, and preadmission treatment of presumptive cases can be life-saving.
In children and adults, consider a diagnosis of meningococcal disease if signs and symptoms include:
- fever, pallor, rigors, sweats
- headache, neck stiffness, photophobia, backache, cranial nerve palsy
- vomiting and/or nausea, and diarrhoea
- lethargy, drowsiness, irritability, confusion, agitation, seizures or altered conscious state
- moaning, unintelligible speech
- painful or swollen joints, myalgia or difficulty walking.
Although the absence of a rash does not exclude meningococcal disease, note in particular any haemorrhagic rash, particularly of a pinprick, petechial or purpuric appearance.
In infants and young children, the following may also occur:
- irritability, dislike of being handled
- tiredness, floppiness, drowsiness
- twitching or convulsions
- grunting or moaning
- turning from light.
For people of all ages, note in particular:
- rapid deterioration in clinical condition
- repeat presentations to surgery or hospital
- normally calm friends or relatives who are more worried than symptoms apparently justify.
Immediate actions for treatment
Carry benzylpenicillin in the doctor's bag. If meningococcal disease is suspected, immediately call an ambulance and:
- administer antibiotics intravenously (IV) (intramuscularly [IM] if IV is impossible)
- collect blood for culture, but only if possible
- start immediate antibiotic therapy (all ages).
Empirical therapy before hospitalisation should be benzylpenicillin at 60 mg/kg up to 3 g IV/IM, or ceftriaxone at 50 mg/kg up to 2 g IV/IM.
Penicillin should only be withheld in people who have a definite history of penicillin-associated anaphylaxis. If in doubt, check with an infectious diseases physician at your nearest hospital.