Under-immunisation in migrant communities: the measles outbreak in southwestern

Transcription

1 Under-immunisation in migrant communities: the measles outbreak in southwestern Sydney in 2012 Prepared by Stephen Conaty Health Protection NSW 2 Formerly South Western Sydney and Sydney LHD Public Health Unit August 2013

2 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.

3 Apr May Jun Jul Aug Sep Oct Nov April 2012

4 Apr May Jun Jul Aug Sep Oct Nov May 2012

5 Apr May Jun Jul Aug Sep Oct Nov June 2012

6 Apr May Jun Jul Aug Sep Oct Nov July 2012

7 Apr May Jun Jul Aug Sep Oct Nov August 2012

8 Apr May Jun Jul Aug Sep Oct Nov September 2012

9 Apr May Jun Jul Aug Sep Oct Nov October 2012

10 Apr May Jun Jul Aug Sep Oct Nov November 2012

11 Apr May Jun Jul Aug Sep Oct Nov Apr-Nov 2012

12 Age distribution of measles cases. New South Wales, April to November Frequency <1 1-4 years 5-9 years years years years years years years years years 50+ years Age Group

13 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

14 Cultural background of measles cases. New South Wales, April to November 2012 Slide source: Zeina Najjar, Public Health Registrar, SWS&SLHD PHU

15 Reported symptoms and signs and morbidity Symptoms Frequency Percentage Rash % Fever (any time) % Fever at rash onset % Cough % Coryza % Conjunctivitis % Koplik s spots % Morbidity Indicator Hospital admission % Complications 6 3.8%

16 Reported vaccination status Vaccination Status Frequency (n=168) Percentage 1 dose MMR % 2 doses MMR 3 1.7% < 1 year of age and unvaccinated % 1 year not vaccinated or unsure % Reasons for non-vaccination (N=95) Conscientious objection % Forgetting to get vaccinated 5 5.3% Being born overseas 3 3.2%

17 Delay in Diagnosis Median (Days) Min (Days) Max (Days) Symptom onset to notification date Rash onset to notification date

18 Measles cases by place of transmission. New South Wales, April to November School Church GP Hospital Family Unknown % cases healthcare acquired Frequency Onset week 21.1% of cases health-care acquired

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20 Example of a typical alert to GPs

21 Sign distributed to GP surgeries

22 Poster resources

23 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

24 So why did this happen? Measles transmission Susceptibility Opportunity / contact rate Three important features Age: 29 cases were year-olds Geographical clustering around Campbelltown (note rate in Campbelltown LGA 47.2 per 100,000) Ethnicity: 36 cases of Pacific Islander descent

25 Measles IgG positive by birth cohort from 2002 serosurvey years in 2012 Heywood, Gidding, Riddell, et al. Bull World Health Organ January; 87(1): 64 71

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28 Campbelltown

29 Index of relative socio-economic disadvantage postcodes with > 10 cases Postcode Locality Usual resident population NSW Index rank 2168 West Liverpool 41, Liverpool 95, Claymore 3, Campbelltown 72, Minto 24, Narellan 33, NSW index decile

30 Claymore images

31 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

32 Simple map of the Pacific Island peoples

33 Source: Population Movement in the Pacific: Labour and Immigration Research Centre. Available from: dia/publications/research/_p df/pacific-populationreport.pdf

34 Source: Population Movement in the Pacific: Labour and Immigration Research Centre. Available from: media/publications/resear ch/_pdf/pacificpopulation-report.pdf

35 Note substantial numbers of New Zealand settlers who enter under the Trans-Tasman agreement Source: Australia s migration trends

36 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 [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.

37 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

38 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

39 Samoa WHO-UNICEF immunisation coverage estimates

40 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.

41 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