Pertussis – the continuing epidemic

Dr Rosemary Lester Acting Director and Acting Chief Health Officer Health Protection Branch 14 February 2012

Outline

Rosemary Lester Overview of pertussis The epidemiology of pertussis in Victoria The Government’s response – parental vaccination program Initial uptake – 2010 survey Stacey Rowe Parental Whooping Cough Vaccination Survey • Methodology • How to administer the survey • Questions

Overview of pertussis

Respiratory illness caused by bacterium

Bordetella pertussis

Highly infectious – spread by respiratory droplets Incubation period – 6 to 20 days, usually <14 days Infectious period – just prior to onset and, if untreated, for up to 21 days after cough onset Infants <12 months are most at risk of complications and death • Most hospitalised, many ICU admissions • Morbidity – hypoxia and resultant brain damage, seizures lung scarring, broken ribs etc.

• Mortality – approx 1 in every 200 cases <6mo will die

The continuing epidemic

Epidemics observed every 3-5 years Remains endemic in developed countries: • Australia, Canada, Japan, Italy, The Netherlands, Sweden, USA All report recent increases Victoria’s current epidemic • Notifications increased markedly since 2008 • 8,489 cases notified in 2011 alone; nearly 8-times greater than the 2007 annual total

Notified cases 2007 to 2011

Notified cases of pertussis by month and year of notification, 2007-2011, Victoria

1200 1000 800 600 400 200 0 ay Ju 2007 ay Ju 2008 ay Ju 2009

Year and month of notification

ay Ju 2010 ay Ju 2011

The continuing epidemic: infants aged < 12 months

Whilst the vast majority of cases are among adults, infants aged less than12 months are most vulnerable In five years (2007 – 2011), 634 cases of pertussis were notified in children <12 months of age Of these, 477 (75%) were aged <6 months • no immunity until received 3 doses of pertussis – containing vaccine at 2, 4, and 6 months of age

Notified cases 2007 to 2011 (<12 and <6 months)

40 25 20 35 30 15 10 5 0

Notified cases of pertussis in children aged less than 12 months, by month and year of notification, 2007 to 2011, Victoria

< 6 months 6-11 months ay Ju 2007 ay Ju 2008 ay Ju 2009

Month and year of notification

ay Ju 2010 ay Ju 2011

100 95 80 75 90 85

Pertussis-containing vaccination coverage

DTPa coverage by quarter and childhood age cohort, Victoria, March 2007 to December 2011

12-15 months 24-27 months 60-63 months 95.22

93.53

92.05

Date of calculation

The Government’s response

15 June 2009 - Parental whooping cough vaccination program • Free pertussis-containing vaccine (Boostrix ® ) • Parents of new babies eligible (incl. adoptive/foster) • Time-limited program Program rationale – to protect unimmunised babies from infection with pertussis by vaccinating parents – referred to as “cocooning strategy” Delivery of vaccine is being encouraged through: • Maternity hospitals • General practice • MCH nurses • Local Government immunisation

2010 survey

Attitudes, awareness, uptake survey • Smaller sample of parents whose babies were born in Q1 2010 • 10 LGAs – 5 rural, 5 metro • Mail-out survey direct to parents Results • 166 families participated from 9 LGAs • 69% mothers and 53% fathers had had the vaccine • Reasons for not being vaccinated: • Not being aware of the availability of the free vaccine • Time and effort involved to be vaccinated Limitations • Poor response rate – 41% • Logistical challenges – Sampling and distribution

Next steps

Nationally • Vaccine effectiveness studies • Various laboratory research going on – to examine molecular characteristics of

Bordetella Pertussis

• ? Additional booster in second year of life • Repeat survey to measure uptake of vaccine (Vic) – Stacey…

Parental whooping cough vaccination survey

Stacey Rowe Senior Epidemiologist Communicable Diseases Prevention and Control Unit 14 February 2012

Survey Aim and Methodology

Aim To obtain a coverage estimate on the parental whooping cough vaccination Methodology State-wide distribution Four consecutive weeks – 15 February to 14 March, inclusive Parents attending 4 month Key Ages and Stages consultation MCH nurse administered The survey • Short: focuses on whether, where and when • No personal identifying information being collected • Not onerous for either MCH nurses/parents

Distribution of survey and related materials

Distribution Sent fro m our warehouse to all MCH coordinators on Friday 3 February Most of you will have received it already What will you receive?

1. The survey

(1 pager) – 1 for each child expected to attend 4 month KAS consultation

2. Plain Language Statement

(1 pager) – 1 for each parent(s)

3. Information sheet

(1 pager, double-sided) – 1 for each MCH Office

4. Reply-paid envelopes

– At least 1 per 20 surveys

The survey

How to administer survey

How to administer survey Who can participate?

• Birth, foster and adoptive parents • One parent can respond for both – complete two columns • Single parent – complete one column Informed consent Explain to parents: • What the survey is about • Why it’s being conducted • What their participation will involve Provide parents with Plain Language Statement Request their consent – tick box on front of survey

Consent + initial questions

Vaccinated: Whether, where, when, + why not

Frequently asked questions

Some explanation about the questions

Question 4 – Have you had the whooping cough vaccine in relation to the birth of your most recent child?

• Why “in relation to”?

It excludes those who may have already had the vaccine for other reasons (captured elsewhere): – Previous child, or newborn relative – Vaccinated in year 10 at school It helps narrow the subsequent question of “when”

Question 4b – What date did you have the vaccine?

• Ideally – obtain actual date (dd,mm,yyyy) • Otherwise, use approximations (check boxes)

Frequently asked questions (cont.)

Question 4c – If you did not have the vaccine, why not?

• Already had the vaccine since 2004 – Boostrix only became available in 2004 – People who have had vaccine since 2004 don’t need it again • Did not know the free vaccine was available • Other (use back of survey if need more room) – Not being aware of the risks of the disease – Don’t consider the disease serious enough to be vaccinated – Costs associated with going to the doctor – Time and effort involved with getting vaccinated – Potential side effects of the vaccine – Concerns regarding how well the vaccine works – Don’t like needles – My religious beliefs

Demographics

Other considerations

Parents need not feel that they are being criticised for not having received the whooping cough vaccination You may wish to use this conversation with parent(s) opportunistically, and link unvaccinated parents in to your immunisation providers to encourage vaccination

Survey returns

Return of surveys to Department of Health • End of survey period – 15 March 2012 • Intermittently throughout survey period (large caseloads) • Reply-paid envelopes (call 1300 651 160 if requiring more) Questions?

• Stacey Rowe – 1300 651 160 • [email protected]

Distribution of results

Survey results reported to: • MCH workforce • LGA immunisation committees • Chief Health Officer • DEECD • National communicable disease networks