Epidemiology of Invasive Pneumococcal Disease in Adults in the United States

1
Epidemiology of Invasive Pneumococcal Disease in
Adults in the United States

• Cynthia Whitney
• Centers for Disease Control and Prevention
• Atlanta, GA

2

• Incidence and Case Fatality Ratio by Age Group
• Invasive Pneumococcal Disease
• ABCs 1998

3
Outline

• Changing epidemiology following conjugate vaccine
  introduction
• Factors associated with pneumococcal disease risk
  and high-risk populations

4
Outline

• Changing epidemiology following conjugate vaccine
  introduction
• Vaccine recommendations
• Effect in children
• Effect in adults
• Factors associated with pneumococcal disease risk
  and high-risk populations

5
Pneumococcal Conjugate Vaccine Introduction in
the U.S.
6
U.S. Recommendations for Use of Pneumococcal
Conjugate Vaccine

• All children lt2 years
• Children 2-4 years with
• Certain chronic illnesses
• Immunocompromising conditions
• Consider for all children 2-4 with priority to
  those
• 24-35 months
• Alaska Native, American Indian, African American
• Attending day care

Shortage
Advisory Committee on Immunization Practices.
MMWR 2000
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Active Bacterial Core Surveillance
(ABCs) Emerging Infections Program Network
Established
New

• Areas
• OR (3 counties)
• CA (1 county)
• MN (7 counties)
• GA (20 counties)
• MD (6 counties)
• CT (entire state)
• NY (7 counties)
• TN (10 counties)
• CO (8 counties)
• NM (entire state)

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ABCs Methods

• Case pneumococcus isolated from normally sterile
  site
• Active contact with clinical laboratories to
  identify cases
• Audits to ensure complete reporting
• Susceptibility testing and serotyping at
  reference laboratories
• Chart review for clinical information

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Invasive Pneumococcal Disease Rates by Age and
YearChildren lt5 Years, ABCs, 1998-2002
1 yr
2002 vs baseline
lt1 yr
- 80 (lt1 yr)
- 70 (1 yr)
2 yrs
- 72 (2 yr)
- 29 (3 yr)
3 yrs
4 yrs
- 39 (4 yr)
Source ABCs (August 2003), Observed
Rates Sites CA (SF co), CT, GA (20 co), MD (6
co), MN (7 co), NY (7 co), OR (3 co)
2002 data are preliminary
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Change in Invasive Disease Rates in Children lt2
Years by SerotypeABCs, 1998/1999 (Baseline) and
2002
Same serogroup as vaccine type Number of cases
63 in 1998, 42 in 1999, and 70 in 2002
2002 data are preliminary
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Transmission From Children to Adults

• Adults living with young children have higher
  carriage rates (Hendley et al)
• Adults with young children in household have
  higher risk of disease (Nuorti et al, Breiman et
  al)

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Invasive Pneumococcal Disease Rates by Age Group
and YearPersons ?5 Years, ABCs, 1998-2002
2002 vs baseline
65 years
- 29
40-64 yrs
- 20
20-39 yrs
- 46
5-19 yrs
- 23
Source ABCs (August 2003), Observed
Rates Sites CA (SF co), CT, GA (20 co), MD (6
co), MN (7 co), NY (7 co), OR (3 co)
2002 data are preliminary
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Change in Invasive Disease Rates by Serotype and
Age GroupABCs 1998/1999 average vs 2002
2002 data are preliminary
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Proportion of Invasive Pneumococcal Isolates With
Serotypes included in PCV-7 by Year Adults Aged
50 and Older, ABCs
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Adults Aged 50 Years with Invasive Pneumococcal
Disease Death Rates by Year Active Bacterial
Core Surveillance
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Rates of Invasive Pneumococcal Disease Caused by
Penicillin-Nonsusceptible Strains by Age
GroupABCs 1998/1999 and 2002
51 reduction
Source ABCs (August 2003), Observed
Rates Sites CA (SF co), CT, GA (20 co), MD (6
co), MN (7 co), NY (7 co), OR (3 co)
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Conclusions Changing Epidemiology

• Conjugate vaccine is working well in young
  children, in spite of shortage resulting in
  missed doses
• Replacement disease noted in children but
  magnitude of effect small not seen in adults
• Herd immunity effect in adults substantial and
  means fewer deaths and expensive
  hospitalizations also means remaining disease
  less likely conjugate vaccine types
• Vaccine use may be reversing the course of the
  pneumococcal resistance problem

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Remaining Questions

• How far will disease drop?
• Will replacement disease become a problem?
• Where will pneumococcal resistance go from here?

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Outline

• Changing epidemiology following conjugate vaccine
  introduction
• Factors associated with pneumococcal disease risk
  and high-risk populations
• Underlying conditions
• Demographics
• Other exposures
• Special populations

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Incidence of invasive pneumococcal disease in
adults with selected underlying conditions and
healthy adults United States, 2000
Preliminary results using data from CDCs Active
Bacterial Core Surveillance And the National
Health Interview Survey
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• Cases of IPD cases with ACIP indication for
  vaccination by race and age group
• ABCs 1998

Compares with Charleston County, 1986-7, 91
Baltimore, 1995-6, 62-72 Monroe County,
1985-89, 61.
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• Percent of IPD cases with reported underlying
  HIV/AIDS by race and age group, 1998
• Active Bacterial Core Surveillance

23

• Projected National Rates of
• Invasive Pneumococcal Disease by Age Group and
  Race
• ABCs, 1998

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Invasive Pneumococcal Disease in Navajo and White
Mountain Apache vs. White and Black Persons in
the General U.S. Population, 1997-8
J Watt et al, CID 2003 in press
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Adults Aged 65-74 Years Rates of Invasive
Pneumococcal Disease by Sex and Year Active
Bacterial Core Surveillance
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Independent Risk Factors for Invasive
Pneumococcal Disease in Immunocompetent Adults
18-64

• Factor OR (95 CI)
• Male sex 2.7 (1.7-4.3)
• Black race 3.4 (2.0-5.6)
• Chronic illness 2.6 (1.4-5.1)
• Smoking status
• Current 4.1 (2.4-7.3)
• Former 1.1 (0.5-2.2)
• Passive 2.5 (1.2-5.1)
• Never/no passive 1.0
• Level of education
• lthigh school 2.8 (1.3-5.9)
• High school 2.0 (1.2-3.4)
• College grad 1.0
• Children in household
• lt6 yo and in daycare 3.0 (1.5-6.2)
• lt6 yo not in daycare 1.0 (0.5-2.0)
• No children lt6 1.0

Nuorti et al. NEJM 2000342681-9.
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Risk of Invasive Pneumococcal Disease in
Residents in Long Term Care Facilities

• Compared risk in persons 65 years living in the
  community vs long-term care facilities data from
  U.S. census and ABCs
• Compared to community-dwellers, LTCF residents
  had
• 4-fold risk of invasive disease (194/100,000 vs
  45/100,000)
• 2-fold higher case-fatality rate (31 vs 16)
• More resistance to fluoroquinolones (6 vs 0.4)

Kupronis et al. J Am Geriatr Soc 2003 in press
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Pneumococcal Serotypes in High-Risk Populations

• Navajo adults
• 7-valent serotypes accounted for only 19.4 of
  invasive strains (before conjugate vaccine)
• Serotypes 1 and 5 27
• J Watt et al CID 2003 in press
• Certain serotypes (e.g., 6A, 6B, 9V, 18C, 19F,
  23F) more common in adults with HIV/AIDS or
  immunocompromising conditions A Fry et al CID
  2003

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Summary High Risk Groups and Risk factors

• Chronic medical conditions, especially
  immunocompromising conditions, increase risk of
  invasive disease
• Risk higher for certain demographic groups
  males, older persons, blacks, Native Americans
• Elderly in long-term care facilities at higher
  risk than elderly in community
• Serotype distribution can vary by high-risk group

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Conclusions

• Designers of efficacy trials for new pneumococcal
  vaccines need to account for changing serotype
  distribution and declining disease rates
• Vaccine trials could utilize high-risk groups to
  help obtain needed sample size, although in some
  high-risk groups (e.g., HIV) vaccines may be less
  effective

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Pneumococcal Disease
Upper respiratory tract infections
Invasive disease
Pneumonia
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Acknowledgements

• CDC
• Chris Van Beneden
• Anne Schuchat
• Elizabeth Zell
• Tamara Pilishvili
• Moe Kyaw
• Katherine Robinson
• Tami Skoff
• Carolyn Wright
• Brendan Noggle
• John Walls
• Dick Facklam
• LaShondra Shealey
• Dee Jackson

• ABCs sites
• Monica Farley
• Wendy Baughman
• David Stephens
• Nana Bennett
• Shelley Zansky
• Nancy Barrett
• Jim Hadler
• Lee Harrison
• Lauri Thompson Sanza
• Karen Stefonek
• Paul Cieslak
• Art Reingold
• Pam Daily
• Ruth Lynfield
• Catherine Lexau
• John Besser

Sue Johnson Pam Gahr Allen Craig Bill
Schaffner Brenda Barnes Matt Finke Ken
Gershman UTHSC San Antonio Jim Jorgensen Lettie
McElmeel Sharon Crawford Emory University Keith
Klugman