From control to re-emergence - the story of pertussis

Dr Suzanne CotterDr Sarah Gee (PhD)

Dr Darina O’FlanaganHealth Protection Surveillance Centre

www.hpsc.ie

1

Winter Scientific MeetingWednesday, 5th December 2012

Background• Highly contagious respiratory disease• “100 day cough”• Morbidity and mortality highest among infants• Estimated worldwide deaths > 300,000/yr• Vaccine-preventable

2

Clinical Course (in weeks)

-3 0 2 128

Onset

Incubation period(typically 5-10 days;max 21 days)

Catarrhal stage(1-2 weeks)

Paroxysmal stage(1-6 weeks)

Convalescent stage(weeks to months)

Communicable period(onset to 3 weeks after start of paroxysmal cough)

3

Source: ACIP May 2012. Stacey Martin. http://www.cdc.gov/vaccines/ed/ciinc/Pertussis.htm

3

Trends Pertussis notifications, Ireland 1948- 2012*

*2012 data weeks 1-394

DTP replaced by DTaP

Tdap booster

Pertussis notifications, 2001-2012*

*2012 data weeks 1-39

114

229

372

5

Pertussis notifications by week, 2009-2012*

Pertussis outbreaks, Leitrim

NW -Late notifications 2011-2012

East and other

6

Pertussis notifications and rate per 100,000 population, by HSE area*

ERHA MHB MWHB NEHB NWHB SEHB SHB WHBNational 0

50

100

150

200

250

300

350

400

0.0

5.0

10.0

15.0

20.0

25.0

30.0

7.8

3.92.4

4.5

26.3

7.1

12.3

7.6 8.2

HSE area

Num

ber n

otific

ation

s

Rate

/100

,000

pop

ulati

on

*Data as of 4/10/2012 (n=376)7

Pertussis notifications, by HSE Area, Interpreted Overall Lab Result, 2012*

(n= 372)

*2012 data weeks 1-398

Pertussis notifications, ASIR (/100,000) 2012* (n=372)

*2012 data weeks 1-399

Pertussis notifications, 2001-2012*ASIR (/100,000)

*2012 data weeks 1-3910

Pertussis notifications by age group and vaccination status (n=372)*

0-5mo 6-11 mo 1-2 yrs 3-4 yrs 5-9 yrs 10-14 yrs

15-19 yrs

20-24 yrs

25-34 yrs

35-44 yrs

45-54 yrs

55-64 yrs

65+ yrs0

20

40

60

80

100

120

140

Unk blankUnvaccinatedIncompleteComplete

Age group (months/years)

Num

ber n

otific

ation

s

11*2012 data weeks 1-39

Pertussis cases <1 year of age, by age in weeks at onset date and number of doses of pertussis vaccine.

(n=138)

*2012 data weeks 1-39. Onset date available for 98 of 138 events < 1 year12

Reported fatalities, 2011-2012• 2012 – 2 infant deaths

• 2011 – 1 infant death

13

Pertussis notifications, England and Wales 2005-2012

14Source: HPA http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1317136496345

Year

Australia 1991-2011

Disease Watch. March 2012, Volume 16, Issue 1 » Ongoing pertussis epidemic in Western Australia

Summary

• Increase in pertussis in Ireland similar to that seen in other countries

• Waning immunity contributory factor• Additional control measures needed

– Booster doses for adolescents and HCWs• Antenatal vaccination • Cocooning strategy (difficult)

– Diagnosis, chemoprophylaxis of susceptible

16

Acknowledgements

• Departments of Public Health• Clinicians, microbiologists• Notifying GPs