Under-immunisation in migrant communities: the measles outbreak in southwestern Sydney in 2012 Prepared by Stephen Conaty 1 2 1 Health Protection NSW 2 Formerly South Western Sydney and Sydney LHD Public Health Unit August 2013
Source case 25 year old male Returned from travelling in Thailand Presented twice to GP with fever sore throat cough and coryza Present to ED with fever rash and conjunctivitis Infected one individual at ED and two others elsewhere.
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov April 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov May 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov June 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov July 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov August 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov September 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov October 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov November 2012
80 60 40 20 0 Apr May Jun Jul Aug Sep Oct Nov Apr-Nov 2012
Age distribution of measles cases. New South Wales, April to November 2012 40 35 30 Frequency 25 20 15 10 5 0 <1 1-4 years 5-9 years 10-14 years 15-19 years 20-24 years 25-29 years 30-34 years 35-39 years 40-44 years 45-49 years 50+ years Age Group
Measles cases under 1, by month of age. New South Wales, April to November 2012 Slide source: Zeina Najjar, Public Health Registrar, SWS&SLHD PHU
Cultural background of measles cases. New South Wales, April to November 2012 Slide source: Zeina Najjar, Public Health Registrar, SWS&SLHD PHU
Reported symptoms and signs and morbidity Symptoms Frequency Percentage Rash 168 100% Fever (any time) 165 98.2% Fever at rash onset 130 77.4% Cough 158 94% Coryza 143 85.1% Conjunctivitis 101 60.1% Koplik s spots 43 25.6% Morbidity Indicator Hospital admission 49 29.2% Complications 6 3.8%
Reported vaccination status Vaccination Status Frequency (n=168) Percentage 1 dose MMR 37 23.8% 2 doses MMR 3 1.7% < 1 year of age and unvaccinated 33 19.6% 1 year not vaccinated or unsure 95 56.5% Reasons for non-vaccination (N=95) Conscientious objection 32 33.7% Forgetting to get vaccinated 5 5.3% Being born overseas 3 3.2%
Delay in Diagnosis Median (Days) Min (Days) Max (Days) Symptom onset to notification date 6 1 31 Rash onset to notification date 2-1 26
Measles cases by place of transmission. New South Wales, April to November 2012 35 School Church GP Hospital Family Unknown 30 25 21.1% cases healthcare acquired Frequency 20 15 10 5 0 1 2 3 4 8 10 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 31 33 35 Onset week 21.1% of cases health-care acquired
Example of a typical alert to GPs
Sign distributed to GP surgeries
Poster resources
Some specific actions relevant to the Samoan / Pacific Islander community MMR clinics at high schools in last week of July Sarah Redfern High School (242, 52% of roll vaccinated) James Meehan High School (188, 48% roll vaccinated) Eagle Vale High School (330, 53% roll vaccinated) Visit to church groups 5 August with Samoan doctor (Dr Patu) Distribution of material in Samoan to list of church groups
So why did this happen? Measles transmission Susceptibility Opportunity / contact rate Three important features Age: 29 cases were 15-19 year-olds Geographical clustering around Campbelltown (note rate in Campbelltown LGA 47.2 per 100,000) Ethnicity: 36 cases of Pacific Islander descent
Measles IgG positive by birth cohort from 2002 serosurvey 15-19 years in 2012 Heywood, Gidding, Riddell, et al. Bull World Health Organ. 2009 January; 87(1): 64 71
Campbelltown
Index of relative socio-economic disadvantage postcodes with > 10 cases Postcode Locality Usual resident population NSW Index rank 2168 West Liverpool 41,870 25 1 2170 Liverpool 95,108 131 3 2559 Claymore 3,801 1 1 2560 Campbelltown 72,211 179 3 2566 Minto 24,048 269 5 2567 Narellan 33,942 2017 9 NSW index decile
Claymore images
What I know about Samoan and Tongan and other pacific people living in Australia Where they come from How many live here and where they live - census and immigration data Presence in popular culture Immunisation status
Simple map of the Pacific Island peoples
Source: Population Movement in the Pacific: Labour and Immigration Research Centre. Available from: http://www.immi.gov.au/me dia/publications/research/_p df/pacific-populationreport.pdf
Source: Population Movement in the Pacific: Labour and Immigration Research Centre. Available from: http://www.immi.gov.au/ media/publications/resear ch/_pdf/pacificpopulation-report.pdf
Note substantial numbers of New Zealand settlers who enter under the Trans-Tasman agreement Source: Australia s migration trends 2011-12
Samoa and Tonga Samoa, Polynesian, became independent from NZ in 1962, admitted UN in 1976, population 194,320, GDP 630 million, GDP per capita $3,451 [source: Wikipedia] Tonga, Polynesian, 176 islands, population 103,036 (2011 census estimate), GDP 439 million, GDP per capita 4,220, ended NZ protection status 1970, joined Commonwealth 1970 and UN 1999. [source: Wikipedia] Samoans in NZ: 115,000 in 2001, 58% NZ born, 67% able to converse in Samoan [source: Statistics New Zealand Pacific profiles]. Note quota system for migration to NZ 1,100 per annum. Tongans in NZ 40,700 of total Pacific group population of 231,800.
Samoan / Pacific island peoples in western and south-western Sydney Communities of Pacific Islanders (PI) in Blacktown / Mt Druitt and Campbelltown Population in Campbelltown 2011 census 145,967: Born in NZ 3,779 (2.6%), born in Polynesia 4,406 (Samoa 1,516, Tonga 352, Fiji 2,297) Claim Maori ancestry 978, Samoan ancestry 2,723 Aboriginal or TSI 4,729 (3.2%) In NSW 7,877 report birth in Samoa
Samoan Australians in popular culture Samoans and many other Pacific people excel in sport and there are a number of well-known players Tim Cahill born Sydney Samoan mother and English father Digby Ioane born Wellington moved Melbourne aged 5 Karmichael Hunt born Auckland moved Brisbane aged 11
Samoa WHO-UNICEF immunisation coverage estimates
Conclusions Modestly sized outbreak of measles, largest in Australia since 1997, prolonged People of mainly Samoan descent were over-represented in the outbreak and probably contributed importantly to propagation We don t know the immunisation coverage of many people of Samoan or Tongan descent but we suspect that it is lower especially in older children and young adults born in Samoa or New Zealand Could it happen again? yes, but the size of the Pacific community in Australia is probably not sufficient to sustain a large outbreak.
Acknowledgements Staff from Sydney and South Western Sydney who did a great job with measles control All staff in public health network who contributed to measles control efforts Kirsty Hope and Zeina Najjar from Sydney and South Western Sydney LHD PHU who prepared much of the data in this presentation Dr Paniani Patu who generously gave his time to introduce me to some Samoan church communities