Contact management: Recommend immunisation or NHIG to defined contacts. Exclude unimmunised contacts from school/ preschool/ childcare. Ask contacts to be alert for signs and symptoms of measles in their contacts and advise those who develop symptoms to avoid doctors' waiting rooms and to telephone the public health unit before presenting for health care. Ask school principals and childcare directors to notify any new cases promptly.
Updated SoNG to align with Immunisation handbook
The measles virus, a member of the genus Morbillivirus (a paramyxovirus).
Measles is transmitted by airborne droplets and direct contact with discharges from respiratory mucous membranes of infected persons and less commonly by articles freshly soiled with nose and throat secretions . It is one of the most highly communicable infectious diseases. Measles virus has a short survival time (less than 2 hours) in the air or on objects and surfaces and is inactivated rapidly in the presence of sunlight, heat and extremes of pH.
The incubation period is variable, about 10 days (varying from 7 to 18, occasionally longer) to the onset of fever and about 14 days to the onset of the rash. This period can be longer if immunoglobulin is given early in the incubation period .
Cases are considered to be infectious from 24 hours prior to onset of prodromal symptoms until 4 days after the onset of rash. Where the prodrome is undefined, the onset of the infectious period should be considered to be 4 days before the onset of the rash.
The disease is characterised by a prodrome that usually lasts 2 to 4 days and includes fever followed by conjunctivitis, coryza and cough. Koplik spots may be present briefly on the buccal mucosa. A characteristic maculopapular (non-itchy) rash appears about 2 to 7 days after the onset of the prodrome, and begins on the face or upper neck, spreads to become generalised and typically lasts 4 to 7 days. The rash is not itchy. Cases are usually very unwell and miserable; other symptoms can include anorexia, diarrhoea (especially in infants) and generalised lymphadenopathy3. People who have received one or two doses of measles vaccine may develop attenuated infection with mild symptoms.
Common complications of measles include middle ear infection and viral or bacterial bronchopneumonia. Acute encephalitis occurs rarely and subacute sclerosing panencephalitis is a very rare delayed complication, occurring in about 1 per 100,000 cases .
Unvaccinated or under-vaccinated people (i.e. those who have not had two doses of measles containing vaccine) are at increased risk of measles.
Those at risk of more severe disease include :
Endemic transmission of measles ceased in Australia by the late 1990s as a result of the introduction of a two-dose vaccination schedule and by improved vaccination coverage. In 2014 the WHO verified that Australia had achieved ‘measles elimination’ status, defined as the absence of endemic transmission in a defined geographical area for ≥ 12months1. Although measles is no longer endemic here, Australia continues to have imported cases in overseas visitors and returning residents, with the potential for limited transmission and small to moderate-sized outbreaks. Geographic areas and population sub-groups with low vaccination coverage are more susceptible to prolonged outbreaks and every attempt should be made to provide all children with two doses of measles-containing vaccine. Other than unvaccinated children, adults born during or after 1966 are at most risk due to less frequent exposure to wild-type virus and lower vaccination coverage 
Maintaining high rates of immunity to measles throughout the population is the mainstay of measles elimination in Australia. Measles vaccine, as MMR and MMRV, is currently recommended for all children at ages 12 and 18 months of age, respectively, as part of the National Immunisation Program schedule.
For persons born during or after 1966 who do not have documented immunity, two doses of measles-containing vaccine, given at least 4 weeks apart, are recommended. For those known to have received only one dose previously, a second dose is recommended.
Health facilities should ensure that healthcare workers and administrative staff are fully vaccinated or immune to measles, particularly those working with high risk persons such as children <1 year; pregnant and immunocompromised persons; and in high exposure risk areas such as emergency departments.
Immunisation recommendations for early childhood education and care service workers and overseas travellers should be promoted.
Control of measles relies on early diagnosis and notification of cases, prompt isolation of infectious cases, and timely and effective identification of contacts, with provision of advice and post-exposure prophylaxis and/or quarantine, as appropriate. In defined groups of susceptible people, where exposure has occurred but it is too late or not feasible to identify individuals for whom post-exposure prophylaxis may prevent infection, widespread vaccination is sometimes indicated to minimise ongoing transmission within the group.
As soon as is practicable and ideally within 1 working day following notification:
Case definitions can be found on the Department of Health's website.
The current measles case definition is:
Both confirmed cases and probable cases should be notified.
A confirmed case requires either:
At least one of the following:
An illness characterised by all of the following:
An epidemiological link is established when there is:
A probable case requires laboratory suggestive evidence and clinical evidence.
Detection of measles specific IgM antibody; except
As with confirmed case.
A suspected case requires clinical evidence only.
Same as for confirmed case.
Definitive laboratory evidence should be sought for all suspected measles cases. The results should be interpreted in the context of the clinical and epidemiological findings, and vaccination history. Depending on the context, tests for other clinically plausible infectious causes of fever/rash illnesses (such as rubella, roseola, dengue fever and other arboviral infections, scarlet fever, human parvovirus (B19) infection, enterovirus, adenovirus, HIV, Kawasaki disease) should usually be undertaken at the same time as measles tests when investigating suspected cases. If measles is the working diagnosis, make arrangements wherever possible for diagnostic specimens to be collected from suspected cases isolated at home, rather than having them visit a clinic or specimen collection centre where there is a risk of transmission to others.
Public Health Laboratory Network (PHLN) provides information on the laboratory diagnoses of measles.
The recommended laboratory tests for measles diagnosis and their timelines are outlined in Table 1
Table 1: Recommended laboratory tests for measles diagnosis based on symptom onset
In an established outbreak, laboratory confirmation by isolation or measles antigen/genome detection should be obtained on at least two cases, but may not be necessary for cases who meet the clinical case definition and have a clear epidemiological link to a confirmed case. Serological confirmation is encouraged for these cases.
The reliability of serological and direct detection tests for asymptomatic contacts is unknown. Testing of asymptomatic contacts is not recommended. However there are limited circumstances where it may be appropriate to test exposed contacts to determine if they are immune, such as healthcare workers for whom it is too late for post-exposure prophylaxis to be effective, and who need to be excluded from patient-care duties unless they have demonstrable immunity to measles, and pregnant women for whom normal human immunoglobulin (NHIg) may be recommended if susceptible.
On same day of notification of a suspected, probable or confirmed case, begin follow-up investigation using the Measles Investigation Form.
The response to a notification will normally be carried out in collaboration with the treating doctor. If possible, inform the treating doctor that you will be contacting the patient or their carer(s). However, where this cannot happen in a timely fashion, follow-up should proceed.
Regardless of who does the follow-up, PHU staff should ensure that action has been taken to:
PHUs should thoroughly investigate possible exposures while interviewing the case to determine whether infection was acquired overseas, or linked in some way to a known imported or locally acquired case.
The case or relevant caregiver should be informed and given written advice about the nature of the infection including the mode of transmission and the infectious period, with dates specific to the patient. A fact sheet is useful for this purpose (see Appendix 3).
The occurrence of a measles case may require the following response:
None routinely required.
The objective of contact tracing is to identify all potential contacts and then to target those at particular risk of disease for intervention. Identifying contacts of measles cases is required to determine who has been potentially exposed to an infectious case, to assess their susceptibility to infection and to provide advice and implement post-exposure prophylaxis, where appropriate.
Since measles is primarily transmitted by air-borne means, a contact is defined as anyone who has or may have shared the same air-space (enclosed area) for any length of time with an infectious case. Contact tracing should aim to identify those most susceptible to measles or at greater risk from infection, including infants, immunocompromised people and pregnant women.
In general, contacts may be prioritised in the following order, recognising that it may not be feasible for the PHU to identify and arrange post-exposure prophylaxis for all susceptible contacts, given the constraints of time, resources and logistics:
The following settings will generally not require individual contact tracing, and group level communication or a media release may be sufficient:
Contacts are considered susceptible to measles if they cannot provide evidence of immunity to measles. A person can be considered to have acceptable evidence of immunity to measles if they meet one of the following criteria, noting that more stringent levels of evidence should be obtained for contacts at higher risk of disease or severity:
Refer to Table 2 and Table 3 for detailed guidelines for measles post-exposure prophylaxis.
Consideration should be given to providing susceptible contacts with either MMR vaccine or in some circumstances normal human globulin (NHIG), according to the following criteria and using Table 2 and Table 3:
In general it is not feasible to perform timely serology in contacts to determine immunity, as resulting delays in providing post-exposure prophylaxis increase the likelihood of treatment failure. It is safe to give MMR (or NHIG, as indicated) to individuals who are already immune. For infants <6 months of age (and exposed pregnant women) it may be possible to check maternal IgG levels in stored serum from recent antenatal testing, or collect a further specimen if time allows.
In settings with large numbers of individuals with uncertain vaccination histories and immunity
(e.g. in high schools, adult workplaces) it is reasonable to recommend prompt MMR vaccination, even if it is >72 hours after the exposure. In these circumstances, further cases of measles may occur (as someone may already be incubating the disease), but the liberal use of MMR should reduce the likelihood of ongoing transmission of the measles virus within these groups.
MMR is recommended as the first dose of measles-containing vaccine in children under 4 years of age, due to an increased risk of fever and related adverse events when MMRV is given as the first dose.
MMRV can be used for the second dose of measles-containing vaccine in children aged between 12 months and under 4 years of age, and as the first or second dose in children aged between 4 years and under 14 years of age. MMR—and not MMRV—should be used in persons aged 14 years or above.
Broad use of NHIG, such as in large numbers of healthy adults who have had casual contact (e.g. in a medical waiting room or normal workplace) between 72 hours and 6 days previously, and who are not able to provide evidence of documented past vaccination or immunity, is likely to be impractical and unnecessarily wasteful of NHIG and of staff resources.
NHIG should usually be reserved for contacts at higher risk of disease or severity of disease such as:
NHIG may also be considered for use in school children exposed to a confirmed case, and may be used sparingly in exposed susceptible healthcare workers in situations where their exclusion from the workplace would affect service delivery significantly.
Note: People who receive NHIG for measles post-exposure prophylaxis will not be able to receive an MMR (or varicella-containing vaccine for at least 5 months (dependent on dose)). This may affect immunisation scheduling of children participating in the National Immunisation Program.
People who receive NHIG should be advised that they may still develop measles infection, however, signs, symptoms and time course of illness may be atypical.
The assessment of the severity of immunocompromise is often best determined by consulting with the treating clinician, with guidance from an appropriate senior PHU staff member or director.
MMR is a live vaccine and is contraindicated in ‘severely immunocompromised’ people as defined in the 10th edition of the Australian Immunisation Handbook. See ‘Vaccination for Special Risk Groups’ section 3.3.3 ‘Use of live viral or live bacterial vaccines in immunocompromised persons’. Section 3.3.3 also includes advice on immunocompromised contacts who are unable to maintain previously acquired antibody levels.
Most contacts who are immunocompromised should be able to maintain adequate antibody from prior measles vaccination or infection. However, because immunocompromised people may have severe disease if they are infected with measles virus, urgent IgG antibody testing should be performed where possible to correctly determine the person’s immune status, especially if there is an uncertain history of past immunisation or measles infection. If IgG is detected, they should be regarded as immune. If IgG serology is negative, they should be offered NHIG if they are within 6 days (144 hours) of exposure to the case.
Table 2: Post-exposure guidelines – within 3 days (72 hours) of first exposure to infectious case
*See discussion about immunocompromised contacts in section 11. Consult with treating clinician about interpretation of IgG results and use of NHIG.
Table 3: Post-exposure guidelines – from 3 days (72 hours) to within 6 days (144 hours) of first exposure to infectious case
For suspected, probable or confirmed cases among staff or patients in a healthcare facility, practice management, infection control and/or occupational health staff from the facility should consult immediately with the local PHU to institute a management plan appropriate to that facility. PHUs should liaise with and assist general practices and similar facilities (e.g. private allied health clinics) in follow-up of patients exposed in waiting areas and consultation rooms in these settings.
Whilst the PHUs coordinate the overall contact management strategy, PHUs should liaise with staff health or infection control teams (where they exist). Hospitals should take primary responsibility for implementing prevention and control measures for their facility, including identification and follow-up of potentially exposed inpatients, staff and discharged patients. The latter includes inpatients, outpatients and those who attended the emergency department, and those who accompanied them, as appropriate. Depending on respective work-loads and resources, PHUs may be able to assist hospitals with follow-up of patients discharged to the community.
See Appendix 4 for procedures and principles to include in management plans for healthcare facilities
Previous guidelines on the follow-up of measles cases on aeroplanes recommended contact tracing of passengers seated within 2 rows of the case. However, experience shows that most secondary cases resulting from transmission during aeroplane travel are seated outside this range of seats.[7-10] A recent review found that secondary infections occurred in 14% of flights that carried infectious measles cases notified in Australia over a 4.5 year period. Given delays in diagnosis and notification of the index case and the further time it can take to obtain passenger manifests and determine telephone/email contact information for people seated within a range of adjacent seating rows, it may not be feasible to locate potentially susceptible exposed passengers in sufficient time for post-exposure prophylaxis to be protective. Such individual level contact tracing of airline passenger contacts is also resource intensive.
Based on current evidence, direct contact tracing of passengers based on seating proximity should not be undertaken routinely. Rather, PHUs should consider less resource-intensive and possibly more timely strategies that reach more passengers, including, in collaboration with the airline:
Circumstances in which individual contact tracing for aeroplane flights might be justified include those where:
PHUs/CDBs should continue to promote and encourage pre-departure measles vaccination to travellers who do not have a documented history of measles vaccination and raise awareness among medical practitioners of the need to consider the diagnosis of measles in overseas visitors and returning travellers who have clinically compatible illnesses with fever and rash.
Where transmission of measles is identified within Australia, use of epidemiological data will be important to inform awareness raising in the relevant area to alert local doctors, hospitals, laboratories and the general public. This may encompass use of local print and electronic media, and fax or email distribution lists for medical practitioners, hospitals and pathology laboratories. In addition, identification of population groups at greater risk will be important for targeting prevention and control strategies.
PHUs should liaise with GPs and hospital EDs to promote early identification, isolation and appropriate testing of suspected cases, and their notification to PHUs.
Appendix 1 - PHU Checklist [PDF]Appendix 2 - Sample Letters for Child Care, Primary and High Schools [DOC]Appendix 3 - Sample Script: Waiting Room Contacts [DOC]Appendix 4 - Measles Investigation Form [PDF]Appendix 5 - Measles Fact sheetAppendix 6 - Measles Information for Contacts Fact sheet [PDF]Appendix 7 - Management Plan for Healthcare Facilities [PDF]Appendix 8 - Enhanced Measles Triage for Emergency Departments