Pertussis

C. Mary Healy, M.D. Center for Vaccine Awareness and Research,

Texas Children’s HospitalBen Taub General Hospital

Baylor College of Medicine, Houston, Texas

Disclosures

Research Grant : Sanofi Pasteur

Advisory Board for Novartis Vaccines

Pertussis:The “pernicious” or “100 day” cough Recognized since the middle ages –

“The kink” or “kindhoest” 1640: Clinical description of the 1578 Paris

epidemic 1905: Bordetella pertussis isolated 1925: Vaccine protection reported

Incubation Period 7-10 days (4-21)

Catarrhal Stage“Cold”

Paroxysmal Stage“Whooping”

Convalescent Stage“weeks to months”

Lancet 2006; 367: 1926-36

Attach to ciliae; important immunogen; activates cAMP, histamine sensitizing factor, lymphocyte promoting factor

and islet-activating protein; stimulates IL-4 and IgE; interferes with phagocytosis; hemolytic; may be neurotoxic

Dermal necrosis and vasoconstriction

Ciliostasis; inhibitsDNA synthesis; killscilial epithelial cells

Activates cAMP; interfereswith leucocytes; hemolytic

Causes feverAdhesion and

immunomodulation

OMP that mediates

adherenceand resists

complement

Adhesion andimmunogen

Pertussis Vaccination: A Success Story

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DTaPDTaP

Pre-vaccination• > 180,000 cases• 4000 deaths

Vaccination reduced number of cases and deaths by >95%

CDC

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Incidence of Pertussis, U.S.N

o. o

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CDC

Pertussis in Texas

13.5 cases/100,000 pop

www.dshs.state.tx.us

Pertussis in Texas : not the whole story

www.wcchd.org

Pertussis in Texas : not the whole story

www.wcchd.org

Why Pertussis is a Problem Pertussis is highly contagious Pertussis vaccine protection

wears off after age 10 years There is an epidemic of

pertussis in the U.S. in adolescents and adults

Pertussis may be atypical or asymptomatic in adolescents and young adults who then spread the infection widely

Pertussis may be severe and fatal in young infants

Pertussis: an evolving story

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<6 mos6-11 mos1-4 yrs5-9 yrs10-19 yrs 20+ yrs

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CDC

Pertussis Threatens Infants Infants too young to be immunized (< 6 months)

have up to 20 times higher risk of pertussis Two thirds of these are admitted to hospital

Pneumonia, seizures, brain damage Pertussis causes ~ 20 deaths per year, almost all

in very young infants Infants of Hispanic ethnicity are at increased risk

Normal Chest x-ray Baby with Pertussis

Pertussis in Texas

4 deaths in 2008; 3 in 2009 All occurred in infants < 3 mo of age

Haleigh Throgmorton; age 6 weeksPersonal Communication: Texas Dept Health

California 2010 7-fold increase in the pertussis

incidence rate compared with 2009 Highest number of cases in 50 years Highest rate of disease in Hispanic

infants < 6 months (172 cases/100,000) 9 deaths

All in infants too young to complete have completed their immunizations

7 of Hispanic ethnicity Emergency interventions in place

Personal Communication, CDPH

Prevention of Infant Pertussis Treatment and Antimicrobial Prophylaxis

Azithromycin or Erythromycin (all age groups) Clarithromycin or TMP-SMX (not for young infants)

Tdap vaccine (tetanus, diphtheria, acellular pertussis) Natural and vaccine induced immunity wanes One time dose for adolescents and adults Part of pre-conceptual health

Targeted immunization-cocooning Postpartum women before hospital discharge Immunize all contacts of infants < 1 year Immunize healthcare providers No outcome data but estimated to have a strong

indirect effect:70% in 0 - 3 mo old cases

Red Book: 2009 Report of COID, pp. 504-19 MMWR 2008; 57(RR-4):1-51

Global Pertussis Initiative Vaccine 2007:2634-42 Vaccine 2007:2634-42

Who Infects Infants?

7%

8%

19%

16%

33%

% 10% 20% 30% 40% 50%

Other

Grandparents

Sibling

Father

Mother

Pediatr Infect Dis J. 2004;23:985-9.Pediatr Infect Dis J. 2007;26:293-9.

Household contacts in > 75% of cases

“Cocooning” Infants

Interrupt Transmission

to Infants

In 2006, CDC recommended Tdap booster vaccine for contacts of young infants: All postpartum women before hospital

discharge All contacts of infants < 1 year Healthcare providers for infants < 1 year

N Engl J Med 2005;352:1215-1222MMWR 2008; 57:1-51; Vaccine 2007:2634-42

Challenges with Cocooning

Pertussis awareness Healthcare providers Population at large

New immunization platform No infrastructure in place

Need to target two populations Postpartum women Families

New immunization providers Reimbursement

Implementation of Cocooning

Parents of infants in NICU (N=598)

Immunized 72% of all parents 86.9% of parents who had been screened Uptake higher in infants with stays > 3 days No adverse reactions observed

Doctor’s Office, North Carolina (N=200)

Approached parents attending for routine neonatal care

51.2% of parents immunized 40% of those immunized consented to Tdap on

the second visitDylag et al. Pediatrics 2008;122:e;550-5Walter et al. Acad Pediatr 2009; 9:344-7

The Cocoon Strategy: Aim: the phased implementation of

pertussis cocooning at Ben Taub General Hospital (BTGH), Houston, Texas Phase 1: postpartum immunization Phase 2: immunization of household contacts

Ben Taub General Hospital One of two public, tax-supported hospitals in

Harris County Hospital District ~5000 deliveries per year Predominantly Hispanic (>90%), medically

underserved and underinsured population High risk for pertussis illness No infrastructure for cocooning in place

Raising Awareness Healthcare Providers (HCP) educated by Grand

Rounds and small group in-services Obstetricians, Family Practitioners Midwives, Nursing Personnel Translators

Posters and literature in antenatal and postnatal areas

Pertussis information packets for families

Information on other means to access low or no-cost vaccines

Available to answer questions

Phase 1: Postpartum Women

Phase 1: Starting January 2008,

standing order for postpartum Tdap unless maternal contraindication is present*

Tdap administered on hospital discharge concurrent with rubella vaccine (if needed)

* 2 year minimum interval since prior tetanus-containing vaccine observed Jan 2008-May 2009; no minimum interval required June 2009-Jan 2010

Phase 1: Postpartum women 150 HCPs completed pertussis in-service Since Jan 7th, 2008 through Sept 20th,

2010, 10,450 postpartum women received Tdap prior to discharge Well-accepted No adverse events reported

June 2009 - Jan 2010 92% of postpartum women

are protected 86% immunized by us 6% previously had Tdap

87% of those by our programwith a prior baby

Healy et al. National Immunization Conference, 2010

Starting June 2009, contacts of newborn infants offered Tdap

Where possible, postpartum women were interviewed to ascertain the number of additional contacts eligible and recommended to receive Tdap

Pertussis education was provided

Consenting eligible contacts were immunizedon-site in the “Tdap Cocoon Clinic”

(Mon-Fri; 10am-7pm)

Phase 2: Household Contacts

Phase 2: Household Contacts Two Thirds of Mothers Interviewed Average of 3 contacts

per infant eligible for Tdap (range 1-11)

Average of 2 contacts per infant received Tdap (range 0-10)

58% of families had ≥ 1 contact immunized 1860 contacts immunized Timing of immunization

91% before or the day of infant discharge 8% day 1-7 post infant discharge Healy et al. National Immunization

Conference, 2010

Contact Relationship to Infant

0%

10%

20%

30%

40%

50%

60%

70%Father

Sibling

Grandmother

Grandfather

Aunt

Uncle

Great-grandparent

Caregiver

• 87% lived in the infant’s household• 98% would be in daily contact with infant

Healy et al. National Immunization Conference, 2010

Challenges Identified Education

Start early and often Takes time and effort, different groups have

different perceptions Convenient, out of hours service Readily accessible immunization records Financial constraints

Vaccine costs Requires multiple personnel

Multi-disciplinary approach Prepare for the unexpected !

Other Texas Initiatives Texas Medical Association

Postpartum immunization program in Williamson County hospitals

Strongly encourage contacts to avail of vaccines at a variety of locations

Educational initiatives Pamphlets, Webinar

Texas Pediatric Society Educational initiatives

Immunization Partnership Adopted promotion of pertussis cocooning

as a goal for current year

For the Future Maternal Immunization

Anecdotal evidence from pre-vaccine eraAnecdotal evidence from pre-vaccine era Studies in the 1940s - 1950s demonstrated Studies in the 1940s - 1950s demonstrated

infant protection infant protection High levels of maternal antibody did not High levels of maternal antibody did not

interfere with infant response to DTaP interfere with infant response to DTaP Transfer of pertussis antibodies from mother Transfer of pertussis antibodies from mother

to infants occursto infants occurs and antibody persistand antibody persist

Neonatal Immunization Variable results Interfered with response to other vaccines Disease may precede immune response

In Summary: The disease burden from pertussis is

considerable and very young infants are at high risk of life-threatening illness

Pertussis immunity wears off within 10 years of vaccination and booster Tdap vaccine is required

Targeted immunization strategies such as cocooning are recommended to prevent infants becoming infected with pertussis by family and household contacts

In Summary: Cocooning needs initial and sustained

educational efforts and novel initiatives to build this new immunization platform

All immunization providers in a variety of settings should work together to form the “protective cocoon” around the vulnerable infants

Finally, let us remember why this is important ……….

Protect Our Infants

AcknowledgementsCenter for Vaccine Awareness and ResearchCarol J. Baker, MDJulie A. Boom, MDAmy B. Middleman, MDBetsy H. Mayes, RN

Baylor College of MedicineMarcia A. Rench, RN

Baylor Methodist Community Health Fund

Harris County Hospital District Foundation

Williamson County Health Dept.

Ben Taub General HospitalKenneth Mattox, MDHarold Miller, MDAmy Young, MDJoseph Garcia Prats, MDFrancis Kelly, RNSara Ruppelt, PharmD

City of Houston Health Dept.

Immunization Partnership Sanofi Pasteur

Texas Dept of Health

All HCPs who care for pregnant women and their newborn infants