Effectiveness of Postpartum Tdap Immunization in California Hospitals by yurtgc548


									 Effectiveness of Postpartum
    Tdap Immunization in
     California Hospitals

K. Winter, K. Harriman, R. Schechter, J. Chang, J. Talarico
          California Department of Public Health
Background – Pertussis in infants

• Pertussis is an acute and prolonged cough illness
  caused by Bordetella pertussis
• Most severe disease occurs in infants <3 months
  of age
  § >60% of infected infants <1 year are hospitalized
  § All pertussis deaths in CA since 1998 have been in
    infants <3 months of age (n=43)
• Infants do not start DTaP series until 2 months of
  age and are not fully protected until 18 months
Pertussis hospitalizations in infants <1 year,
     by age in weeks – California, 2008
  Background – Postpartum Tdap

  • Source of pertussis infection in infants has been
    linked to parents, most often mothers, in 20%-
    55% of cases*
  • First pertussis vaccine for adolescents and
    adults licensed in 2005 (Tdap)
  • Advisory Committee for Immunization Practices
    recommended vaccination of close contacts of
    infants as part of ‘cocooning’ strategy in 2006
*Bisgard KM, et al. Infant pertussis: who was the source? Pediatr
Infect Dis J 2004; 23(11):985-989.
Wendelboe AM, et al. Transmission of Bordetella pertussis to young
infants. Pediatr Infect Dis J 2007; 26(4):293-299.
Background – Pertussis on the rise

• Pertussis is cyclical with peaks occurring every 3-
  5 years.
• Last peak occurred in 2005 when >3,000 cases
  were reported and 8 infants died in California
• Data suggests that 2010 will be another peak
  year in California
   § 3 times as many cases were reported from January 1-
     May 31, 2010 as the same period in 2009
   § 5 infants have died, all <3 months of age
• This year we have an intervention: Tdap
Epidemic curve of pertussis cases by month of report and
    deaths by month of onset– California, 2009-2010

                                                  X 2009 death
                                                  X 2010 death
     X    X                              X
Study Questions

• Is postpartum Tdap vaccination an effective
  strategy to reduce transmission of B. pertussis
  to young infants?
• How many birthing facilities in California have
  policies to administer Tdap vaccine to
  postpartum women?
• Distributed survey to Infection Preventionists and Labor and
  Delivery Managers at California hospitals with >50
  births/year (n=267)
   § Does facility have a postpartum Tdap policy?
   § When (month/year) was it implemented?
   § Also obtained a brief description of the policy and description of any
     barriers to implementation
• Attempted to identify birth hospital for all reported pertussis
  cases <4 months of age born 2006-2009 in California
   § For cases born 2006-2008: Matched pertussis cases to birth record
     (vital statistics) using name and DOB to identify birth hospital
   § For cases born 2009: Birth hospital reported on case report form
Methods, continued

• Calculated annual rate of pertussis among infants
  born in each facility (# cases/total births)
• Compared pertussis incidence before and after
  Tdap policy implementation
  § If month of implementation was unknown, assumed to
    be January
• Evaluated incidence over time in all hospitals
• 744 infants <4 months of age were infected with
  § 537 (72%) hospitalized
  § 10 (1%) died
  § Hospital of birth identified in 620 (83%)
• 214 of 267 (80%) facilities with >50 births
  responded to survey
  § 53 (25%) implemented a postpartum Tdap policy by
    the end of 2009
  § First Tdap policy was implemented in January 2007
  § 161 (controls) had no policy or were in process of
Results, continued
• Pertussis incidence after postpartum Tdap policy
   § Declined or remained at 0 in 42 (79%) facilities
   § Increased in 11 (21%) facilities
• Overall incidence in all facilities with a Tdap policy
  declined significantly after policy implementation
   § Before Tdap policy: 41.7 cases/100,000 births
     (95% CI 34.4-49.0)
   § After Tdap policy: 19.2 cases/100,000 births       (95%
     CI 12.7-25.6)
Results, continued
• Pertussis incidence over time also declined significantly
  in hospitals with a postpartum Tdap vaccination policy
  from 2006 (when no postpartum Tdap policies existed)
  to 2009 (when 53 policies existed)
• Increase in incidence was observed in control hospitals
                                 2006                2009
       Hospitals with Tdap
             policy (n=48)   46.8 (34.1-59.5)   23.8 (14.7-33.0)
    Hospitals with no Tdap
            policy (n=145)   29.7 (23.7-35.8)   35.7 (29.0-42.3)
Overall pertussis incidence in infants <4 months of age statewide
  and in facilities with and without a postpartum Tdap policy –
                       California, 2006-2009

• Decline in pertussis incidence observed in
  facilities with a postpartum Tdap vaccination
  policy suggests that vaccinating new mothers
  may reduce transmission to infants.
• Although recommended in 2006, only ¼ of
  birthing hospitals had implemented a
  postpartum Tdap policy by 2009. Additional
  efforts are needed to encourage facilities to
  adopt cocooning policies.
Data limitations

• Pertussis incidence for infants born late in 2009
  incomplete (onset in 2010)
• Vaccine uptake in facilities with a Tdap policy was
• Maternal vaccination status for infant cases

• To increase postpartum Tdap uptake, CDPH is
  now recommending no minimum interval
  between Td and Tdap
• CDPH also providing a limited quantity of free
  Tdap vaccine to birthing facilities to help
  establish cocooning programs
• Include hospital of birth on case report form for
  infants <1 year of age
  § Identify hospitals with highest rates of pertussis and
    encourage to adopt postpartum Tdap policies

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