Measles is a highly infectious viral

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1 YOUTH Challenges in managing a school-based measles outbreak in Melbourne, Australia, 2014 Katherine B. Gibney, 1,2 Aicha Brahmi, 1 Miriam O Hara, 1 Rosemary Morey, 1 Lucinda Franklin 1 Measles is a highly infectious viral disease for which a safe and effective vaccine is available. After a prodromal illness which can include fever, cough, coryza, conjunctivitis and Koplik spots, cases develop a characteristic maculopapular rash. Potential complications include otitis media and pneumonia, and less frequently encephalitis and subacute sclerosing panencephalitits. Measles vaccine has been available in Australia since 1968, with funded vaccination for children aged months from 1972 for all states and territories. A second dose of measles-mumps-rubella vaccine (MMR) was funded nationally from In 1997 the Australian government developed the Immunise Australia: Seven Point Plan. It included a program to eradicate measles and, in 1998, provided funding for a primary school-based catch-up MMR vaccination for children aged 5 to 12 years. This Measles Control Campaign resulted in vaccination of 96% of primary school children and averted an estimated 17,500 cases of measles, with seroprotection demonstrated for 84% of 6 12 year old children before and 94% after the campaign. 2 Adults born before 1966 are considered immune due to high levels of exposure to locally circulating measles virus during their childhood. Persons born from the late 1960s to mid-1980s (especially ) are recognised to be at greater risk of measles infection as many missed being vaccinated as infants (when vaccine coverage was low); and, during their childhood years, a 2 nd dose of measles-containing vaccine was not yet recommended; and disease exposure was decreasing. 3 In 2014, the two-dose Abstract Objective: To identify barriers to control of a Victorian primary school-based measles outbreak. Methods: Confirmed measles cases notified in Victoria in 2014 were reviewed. Surveillance data, correspondence, and investigation notes for the school-based outbreak were assessed regarding timeliness of diagnosis and notification, and adequacy of school-based immunisation records. Results: Twenty-three (31%) of the 75 measles cases notified in 2014 were school-aged (5 18 years); three had documentation of measles vaccination, 17 were unvaccinated, and three had unknown vaccination history. Eight measles outbreaks were identified, including a primary school-based outbreak with ten cases. Of the six unvaccinated pupils in the affected school, five (83%) contracted measles. The proportion of the school s prep students with documented vaccination records, as required by law, ranged from 39% in 2013 to 97% in Conclusions: Inadequately vaccinated students constitute a vulnerable population and schools are a potential site for measles outbreaks. Inadequate enforcement of schoolbased immunisation records impact the management and control of school-based measles outbreaks. Implications for Public Health: There is a need to educate clinicians on measles diagnosis and notification, and schools on the requirement to maintain up-to-date vaccination records. School entry is an opportunity to review student vaccination history and offer immunisations. Key words: measles, measles vaccine, schools, students, disease outbreaks, Australia MMR immunisation coverage rate was 93% among Victorian children aged months [Australian Childhood Immunisation Register Coverage Report 30 th June 2014]. Under Victoria s Public Health and Wellbeing Act 2008, at the time of primary school enrolment, the parent of a child must give an immunisation status certificate in respect to each vaccine preventable disease to the person in charge of each primary school that the child is to attend. A person in charge of a primary school must take reasonable steps to obtain an immunisation status certificate and ensure that the student immunisation record is kept up to date. The Act describes the evidence required to complete the document, who can issue it, and the effect of the certificate. Furthermore, the Public Health and Wellbeing Regulations 2009 requires school exclusion for a confirmed measles case for at least four days after rash onset as well as school exclusion for susceptible contacts (including those with unknown measles vaccination status) for 14 days after rash onset of the last case. If unimmunised contacts are vaccinated within 72 hours of their first contact with the first case, or if this time has elapsed received normal human immunoglobulin (NHIG) within 144 hours of exposure, they may return to the school Health Protection Branch, Department of Health & Human Services Victoria 2. The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria Correspondence to: Dr Katherine Gibney, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, 792 Elizabeth Street, Melbourne, Victoria 3000; Katherine.Gibney@unimelb.edu.au Submitted: April 2016; Revision requested: July 2016; Accepted: August 2016 The authors have stated the following conflict of interest: K. Gibney received the NHMRC Gustav Nossal Postgraduate Scholarship sponsored by CSL in This award is peer reviewed through the standard NHMRC peer review process; CSL (now Seqirus) does not play any part in the selection of the awardee. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Aust NZ J Public Health. 2017; 41:80-4; doi: / Australian and New Zealand Journal of Public Health 2017 vol. 41 no. 1

2 Youth Primary school measles outbreak in Australia In Victoria, measles is classified as a Group A notifiable condition which, under the Public Health and Wellbeing Act 2008, requires doctors and laboratories to immediately notify the Department of Health & Human Services (DHHS) by telephone upon initial diagnosis (presumptive or confirmed), with written notification to follow within five days. This paper provides a brief review of recent measles cases in Victoria, focussing on the public health challenges associated with a primary school-based measles outbreak which occurred in Methods Confirmed and probable measles cases notified to the Victorian Government DHHS from 2005 to 2014 were reviewed to identify affected school-aged children. We report the proportion of notified cases that were school-aged and the number and proportion of outbreaks that involved school-aged children. Measles cases were classified according to the national case definition. 4 A school-aged child was defined as a child aged 5 18 years. A measles outbreak was defined as two or more confirmed cases which were epidemiologically linked. In accordance with the national case definition, an epidemiological link requires contact between two people involving a plausible mode of transmission at a time when one of them is likely to be infectious (approximately five days before to four days after rash onset) and the other has an illness with rash onset 7 18 days after this contact, and at least one case in the chain is laboratory confirmed. 4 A measles case was classified as imported if the infection was acquired overseas and import-related if the infection was acquired in Australia but epidemiologically linked to an imported case. Surveillance data entered into the Public Health Event Surveillance System (PHESS) Victoria s notifiable diseases surveillance Figure 1: Measles notifications among school-aged children and others, Victoria Measles cases notified School-aged March 2014 measles elimination achieved in Australia (WHO) Other age Figure 2: Flow chart of persons affected during the primary-school based measles outbreak, Melbourne Case 2: 11yF Rash 18 July Source: brother Case 5: 8yF Rash 19 August Case 8: 32yM Rash 31 August Source: football club Case 1: 7M Rash 9 July Source: Taiwan Case 3: 5yF Rash 26 July Source: shopping centre Case 4: 5yF Rash 5 August Source: sister Case 6: 11yM Rash 18 August Case 9: 35yM Rash 30 August Source: football club Genotype D8 Not genotyped Students at affected primary school All unvaccinated Case 7: 11yM Rash 17 August Case 10: 11mM Rash 2 August Source: local area system along with public health staff correspondence and investigation notes related to a primary school-based measles outbreak in July September 2014 were reviewed to describe the outbreak and identify barriers to timely public health action to manage the outbreak. Results From 2005 to 2014, 237 confirmed measles cases were notified in Victoria of whom 61 (26%) were school-aged children (aged 5 18 years)(figure 1). Of these 237 cases, 95 (40%) were imported, 81 (34%) import-related, and importation status was unknown for 61 (26%) cases. Also over this period, 28 outbreaks of measles were identified and 11 (39%) involved at least one school-aged child. Seventy-five measles cases were notified in 2014, more than any year from 2005 to 2013 (median 12 [range 2 40] cases/year) or 2015 (37 cases). Of the 23 school-aged measles cases notified in 2014, three (13%) had a documented history of at least one measles vaccination, 17 (74%) were unvaccinated, and three (13%) had unknown vaccination history. Eight measles outbreaks involving two or more epidemiologically linked cases were identified in Victoria in 2014, involving a total of 44 cases. We describe the equal largest of these outbreaks, with 10 laboratoryconfirmed measles cases. Outbreak Summary: The outbreak began with an importation of measles virus from Taiwan by a seven-year-old boy with rash onset while in Melbourne on July 9, 2014 (Figure 2). His 11-year-old sister (Case 2) was subsequently diagnosed with measles during public health follow-up in another Australian state. One month later, a five year-old girl (Case 4) was notified with measles; her twin sister (Case 3) had previously undiagnosed measles which was likely acquired from Case 1 during a trip to a local shopping centre. A further three children at the primary school attended by Cases 3 and 4 developed measles (Cases 5 7), two of whom were siblings. Three community cases were subsequently diagnosed: two adults (Cases 8 and 9) were infected at a local football club, while a nine month-old infant in the local area (Case 10) had unknown source of infection. Cases 2 10 were identified as genotype D8; no genotyping information was available for Case 1. All cases were unvaccinated. There were five generations of measles cases, with infectious periods extending over nine weeks from July 4 to September 6 (Figure 3) vol. 41 no. 1 Australian and New Zealand Journal of Public Health 81

3 Gibney et al. Article Diagnosis and notification timeliness: Measles was diagnosed at first medical presentation for five cases, including Case 2, an unwell sibling contact for whom a GP visit and testing was recommended by DHHS; another case, an unwell sibling contact, was tested at home without visiting a doctor (Case 4); with others requiring 2 5 doctor-visits before a diagnostic test for measles was performed (Figure 3). DHHS issued letters detailing measles exposure for contacts including 558 pupils and 47 staff at the affected school. Of these, three school children (cases 5 7) were diagnosed on first medical review. The two adults (cases 8 and 9) required two and three doctor visits respectively before a measles test was performed; despite providing their doctors with a DHHS letter detailing measles exposure the diagnosis was missed, albeit in the prodromal phase for the initial visits. Only one case was notified on suspicion of measles without waiting for laboratory confirmation (in accordance with regulatory requirements); testing was arranged on the recommendation of DHHS for one; three cases were notified the day after their first medical contact when laboratory results were available; and one case each at three, five, six and 20 days after first medical contact (Figure 3). Two cases were notified by fax or online over the weekend which delayed public health followup as fax and online notifications are not monitored over the weekend. Documentation of student vaccination status by the affected school: At the time of the outbreak, DHHS requested student vaccination records to identify susceptible students for provision of post exposure prophylaxis or quarantine. The school was unable to provide details of student vaccination histories; rather they could specify the number of students for whom a School Entry Immunisation Status Certificate (SEISC) was sighted at the time of Prep enrolment (when children were aged 4 6 years) from 2007 to 2014, which ranged from 39% to 97% of Prep students each year. There were no details about the children s vaccination histories (i.e. whether or when immunisation occurred); no records for children who entered the school at a higher year level; and no documentation of updated vaccination histories for immunisations received after Prep enrolment. Additional public health investigation and response: Public health follow-up resulted in identification of two cases (Cases 2 and 3) and 12 non-immune persons in the school community. Case follow-up identified 103 sites of potential exposure (places visited by measles cases during their infectious periods). DHHS requested staff at the affected school to check their immunisation records. Non-immune contacts were offered post-exposure prophylaxis (PEP) according to national and state protocols (generally MMR vaccination if within 72 hours of first contact with the infectious case or NHIG if hours from first contact with the infectious case). 4 All cases were diagnosed and notified too late in their illness to warrant provision of PEP to household contacts. PEP was offered to non-household contacts including people exposed in health services and workplaces, however cases 8 and 9 were not offered PEP as their exposure was considered low-risk. The exact number of contacts who received PEP was not recorded by DHHS. Twenty-eight teachers had measles serological tests arranged through DHHS because of unknown immunity; others may have attended their GP for serological testing. Six unvaccinated children were identified in the affected primary school, of whom five (83%) developed measles. The remaining unvaccinated child, one immunocompromised child, and six nonimmune adults from the school community (five staff and one parent-volunteer) were excluded from school in accordance with the Public Health and Wellbeing Regulations Media and Chief Health Officer alerts were issued on 20 August and 9 September to raise public and clinician awareness during this outbreak. Discussion Australia enjoys comparatively high childhood immunisation rates, with >92% Figure 3: Timeline of symptom and rash onset, medical visits, measles testing and notification. Chief Health Officer alerts issued 82 Australian and New Zealand Journal of Public Health 2017 vol. 41 no. 1

4 Youth Primary school measles outbreak in Australia of five year olds fully vaccinated [Australian Childhood Immunisation Register Coverage Report June 2014]. In 2014 Australia was recognised by the World Health Organization to have eliminated measles. 5 Despite this, measles importations continue to occur and pockets of the community with lower vaccination coverage remain at risk. The 2014 notification incidence rates of measles in Victoria and Australia were similar (1.3 and 1.4/100,000, respectively), with a jurisdictional range from /100, Of the 158 measles cases notified nationally in 2013, about one-third were imported, one-third import-related, and one-third of unknown source, 7 which is similar to the breakdown for Victorian cases notified in Our report confirms the findings of other recent reports of outbreaks in New South Wales that under-vaccinated persons in Australia are at ongoing risk for measles. 8,9 Several new government initiatives are aimed at improving immunisation coverage in order to protect children, including those for whom vaccination is contraindicated on medical grounds. In 2016, the Australian Immunisation Register (AIR) replaced the Australian Childhood Immunisation Register (ACIR); this national register will capture all vaccines administered through a person s life. This has the potential to assist the public health response to vaccine preventable disease outbreaks such as the one described. 10 The Australian Government is providing incentive payments to immunisation providers to encourage active follow up of children overdue for vaccinations as well as investing in a communication campaign to improve awareness regarding vaccination and address the concerns of vaccine-hesitant parents. 11 Victoria s No Jab, No Play legislation requires children to be fully immunised for their age or on a vaccination catch-up program before they can be enrolled in early childhood services. 12 The Australian Government s No Jab, No Pay policy restricts certain federal government family assistance payments and benefits to parents of un- or under-vaccinated children. 13 Financial incentives have been shown to improve vaccination rates in Australia, with only 31% of parents in 2001 reporting they could afford childcare without family assistance payments linked to childhood vaccination. 14 Both the No Jab, No Play and No Jab, No Pay policies accept exemptions on the grounds of medical conditions but not conscientious or religious objections. Such stringent criteria have not been applied at school entry, where non-medical grounds for exemption are accepted and compulsory vaccination would not be considered. It has been argued that allowing non-medical exemptions is inequitable because exempted children avoid the personal risks, however small, associated with vaccination while benefitting from herd immunity that results from high vaccination rates. 15 Conversely, there is a danger that compulsory vaccination of children whose parents strongly oppose vaccination could increase the profile of and support for anti-vaccination groups. 15 We have highlighted a number of barriers to controlling this measles outbreak, including delays in diagnosis, notification and identification of susceptible contacts, which limited the effectiveness of timesensitive interventions such as provision of immunoglobulin, vaccine, or school exclusion. Only four of eight measles cases were diagnosed at first medical contact in this outbreak, with one further case referred to a GP for measles testing by DHHS and another case tested at home without seeing a doctor. Of the four cases not diagnosed on first presentation, one was missed during the prodromal illness and three while a rash was present. This is similar to a report of 17 locally acquired measles cases in NSW in 2011, where only six were diagnosed on their first contact with a health service; one case was diagnosed on sixth visit to a health facility and two were diagnosed retrospectively on review of emergency department triage notes five months later. 8 There have been only 237 measles cases over the last decade; therefore many Victorian medical practitioners would never have had first-hand experience with measles. Medical practitioners might not recognise clinical measles, including the non-specific prodromal symptoms before rash onset, and might be unaware of the requirement for immediate notification by telephone on suspicion of measles. Strategies aimed to improve measles recognition identified in Australia s national public health guidelines include provision of written advice to measles contacts which they can share with their doctor if they become unwell, generation of Chief Health Officer alerts and press releases during an outbreak, and ongoing education of doctors regarding measles and other vaccine preventable diseases. 4,8 We were unable to assess the usefulness of these actions during this outbreak. The affected school cooperated fully with the public health response to this outbreak; however identification of susceptible students and staff was hampered by the lack of SEISC held by the school. The Public Health and Wellbeing Act 2008 specifies that parents need to provide a SEISC at school enrolment, and that schools should maintain up-to-date vaccination history records for the duration of a child s enrolment. This enables schools to promptly identify unimmunised children in the event of a vaccine preventable disease outbreak. The addition of a financial penalty for schools non-compliant with this requirement might be an effective way to improve the completeness and usefulness of school-held immunisation records. Review of the SEISC at school enrolment presents an opportunity to provide families of underor un-immunised children with health information about the benefits of vaccination and how to access overdue vaccines. The lack of immunisation records of adult contacts such as staff, contract staff, visitors and volunteers at the school and trainers at the football club further delayed public health interventions and might have contributed to ongoing transmissions. The Australian Immunisation Handbook identifies adults born in 1966 or later as being at greater risk of measles infection due to lower rates of naturally acquired immunity. 3 Although beyond the scope of government regulation, the public health response to vaccine preventable disease outbreaks in primary schools and other institutions (e.g., afterschool care centres and secondary schools) could be improved if they maintained up-todate and detailed vaccine histories for staff and volunteers with student contact, as well as students. This would be similar to existing recommendations that health services and early childhood education and care services maintain an up-to-date, secure and accessible register containing details of staff vaccination and vaccine preventable disease history. 16,17 Annual review of the immunisation records of students and staff who are not fully vaccinated (as recommended in centres caring for preschool-aged children) provides further opportunity to promote vaccination to appropriate families and staff and provide education about the need for school exclusion of susceptible persons in the setting of a vaccine-preventable disease outbreak. 16 A limitation of this study is that the conclusions and recommendations are based on a single outbreak comprising 2017 vol. 41 no. 1 Australian and New Zealand Journal of Public Health 83

5 Gibney et al. Article only a minority of all school-aged measles notifications from the 10-year period originally described. The findings from this one school-based outbreak are not necessarily generalisable to all Victorian schools and all school-aged notifications. In this outbreak we have again identified the need for ongoing clinician education about the clinical presentation of measles, appropriate tests, and notification requirements. The high attack rate among unimmunised students highlights the infectivity of measles and the need for strategies to improve measles vaccine coverage in families with unvaccinated children. Strategies required will vary according to whether the lack of vaccination was inadvertent or intentional, but the requirement to present a SEISC provides an opportunity to promote vaccination to students who are not fully immunised. Policies to promote vaccination among pre-school children have recently been introduced nationally and in Victoria including no longer accepting vaccine exemptions made on non-medical grounds. The impact of these policies on immunisation coverage rates, vaccine preventable disease notifications and public anti-vaccination sentiment will need to be monitored to inform future measures to improve vaccination rates and protect vulnerable Australians against vaccine preventable diseases. References 1. National Centre for Immunisation Research and Surveillance. Significant Events in Measles, Mumps and Rubella Vaccination Practice in Australia [Internet]. Westmead (AUST): NCIRS; [cited 2015 Sep]. Available from: provider_resources/history/measles-mumps-rubellahistory-december-2013.pdf 2. National Centre for Immunisation Research and Surveillance. Let s Work Together to Beat Measles: A Report on Australia s Measles Control Campaign. Canberra (AUST): Asutralian Department of Health and Aged Care; Department of Health and Ageing. The Australian Immunisation Handbook, 10th Edition 2013 Canberra (AUST): Government of Australia; Communicable Diseases Network Australia. Measles: National Guidelines for Public Health Units [Internet]. Version 2.0. Canberra (AUST): Government ofaustralia; [cited 2015 Dec]. Available at gov.au/internet/main/publishing.nsf/content/bd2a D79FD34BFD14CA257BF0001D3C59/$File/Measles- SoNG-final-April2015.pdf 5. World Health Organization. Four Western Pacific Countries and Areas are the First in their Region to be Measles-free [Internet]. Geneva (CHE): WHO; 2014 [cited 2015 Dec]. Available at int/mediacentre/releases/2014/ /en/ 6. Department of Health. National Notifiable Diseases Surveillance System [Internet]. Canberra (AUST): Government of Australia; 2015 [cited 2015 Dec]. Available at cda-index.cfm 7. NNDSS Annual Report Writing Group. Australia s Notifiable Disease Status, 2013: Annual Report of the National Notifiable Diseases Surveillance System. Commun Dis Intell. 2015;39:E387-E Hope K, Boyd R, Conaty S, Maywood P. Measles transmission in health care waiting rooms: Implications for public health response. Western Pac Surveill Response J. 2012;3: Najjar Z, Hope K, Clark P, Nguyen O, Rosewell A, Conaty S. Sustained outbreak of measles in New South Wales, 2012: Risks for measles elimination in Australia. Western Pac Surveill Response J. 2014;5: Australian Department of Human Services. Australian Immunisation Register Canberra (AUST): [cited 2016 Nov]. Available from: humanservices.gov.au/customer/services/medicare/ australian-immunisation-register. 11. Immunise Australia Program. Improving Immunisation Coverage Rates Fact Sheet. Canberra (AUST): Australia Department of Health; Parliament of Victoria. Public Health and Wellbeing Amendment (No Jab, No Play) Bill Department of Health. No Jab, No Pay New Immunisation Requirements for Family Assistance Payments. Canberra (AUST): Government of Australia; Lawrence G, MacIntyre C, Hull B, McIntyre P. Effectiveness of the linkage of child care and maternity payments to childhood immunisation. Vaccine. 2004;22: Salmon D, Teret S, MacIntyre C, Salisbury D, Burgess M, Halsey N. Compulsory vaccination and conscientious or philosophical exemptions: past, present, and future. Lancet. 2006;367: National Health and Medical Research Council. Staying Healthy: Preventing Infectious Diseases in Early Childhood Education and Care Services. Canberra (AUST): Government of Australia; Department of Health and Human Services. Immunisation for Health Care Workers. 7th ed [Internet]. Melbourne (AUST): State Government of Victoria; 2014 [cited 2016 Aug]. Available at: health.vic.gov.au/public-health/immunisation/adults/ vaccination-workplace/vaccination-healthcareworkers 84 Australian and New Zealand Journal of Public Health 2017 vol. 41 no. 1