Streptococcus pneumoniae (Pneumococcus) and Disease Prevention by Immunization 2001

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Streptococcus pneumoniae(Pneumococcus) and
Disease Prevention by Immunization2001

• Richard D. Clover, M.D.
• Dept. of Family and Community Medicine
• University of Louisville

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PNEUMOCOCCAL CARRIER STATE

• Disease occurs in persons who are already
  asymptomatic carriers
• Carrier rates
• 38-60 in preschool children
• 29-35 in grammar school children
• 9-25 in junior high school students
• 18-29 in adults with children at home
• 6 in adults with no children at home
• Virtually all children lt2 of age become
  carriers

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LOWER RESPIRATORY TRACT INFECTIONS

• S. pneumoniae is the most common cause of
  community-acquired bacterial pneumonia
• gt500,000 cases annually
• 25-35 require hospitalization
• 10-25 have concomitant bacteremia

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DISSEMINATED INVASIVE INFECTIONS INCIDENCE OF
BACTEREMIA

• No. cases per 100,000 Total no. cases
• Overall 15-30 39,000-79,500
• gt65 yrs 50-83 25,000-26,560
• Children lt2 yrs 163 3260
• Black Adults 49-58
• Certain Native 156
• Americans
• Children lt2 yrs 2396

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S. pneumoniae MORTALITY

• 40,000 deaths annually due to pneumococcal
  infection
• More deaths than any other vaccine-preventable
  disease half preventable with vaccination
• Case-fatality rates for bacteremia 30-40
  elderly 15-20 adults
• Highest mortality in the elderly and in patients
  with underlying medical conditions
• S.pneumoniae and influenza together are the 6th
  leading cause of death more deaths than BC and
  AIDS combined

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DRUG-RESISTANT S.pneumoniae

• Mortality associated with S. pneumoniae dropped
  with advent of penicillin in the 1940s
• During the 1960s, isolates of S.pneumoniae
  moderately resistant to penicillin appeared
• Isolates with high-level resistance emerged in
  the 1970s
• 60-fold increase in 1992 vs 1987
• Prevalence of drug-resistant strains continues to
  increase -- up to 35 in some communities

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1996 NURSING HOME OUTBREAK OF MULTIDRUG-RESISTANT
S. pneumoniae DISEASE

• First such outbreak documented in adult
  population
• 11 cases of pneumonia among 84 residents
• 3 deaths
• Multidrug-resistant S. pneumoniae, serotype 23F,
  isolated from blood, sputum, and nasopharyngeal
  specimens of 74 residents and employees
• Only 3 residents had received pneumococcal
  vaccine
• No further cases after residents received vaccine
  and prophylactic antibiotics

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PNEUMOCOCCAL POLYSACCHARIDE VACCINE

• 14-valent pneumococcal vaccine licensed in 1977
• 23-valent preparation licensed in 1983
• 23-valent vaccines cover 85-90 of serotypes
  that cause invasive pneumococcal infections
• 23-valent vaccines contain serotypes 1, 2, 3, 4,
  5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B,
  17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F
• 6 serotypes most frequently associated with
  drug-resistant infection 6B, 9V, 14, 19A, and 23F

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EFFECTIVENESS IN CASE-CONTROLLED STUDIES

• Study, yr Type of infection Efficacy
• (95 CI)
• Shapiro 1984 Invasive infection 67 (13-87)
• Sims 1988 Invasive infection 70 (37-86)
• Shapiro 1991 Invasive infection
• All pts 56 (42-67)
• Immunocompromised pts 21 (lt0-60)
  Immunocompetent pts 61 (47-72) Persons aged
  65-74 yrs 80 (51-92)
• Farr 1995 Bacteremia 81 (34-94)
• Forrester 1987 Bacteremia lt0 (lt0-55)
• Only case-controlled study that failed to
  demonstrate effectiveness against bacteremic
  disease.
• Methodologic concerns have been raised regarding
  this trial.

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ADVERSE REACTIONS TO PNEUMOCOCCAL VACCINE

• Low incidence of adverse reactions
• 50 of patients experience mild, local
  reactions, usually lasting lt48 hours
• More severe local reactions, moderate systemic
  reactions, and severe systemic reactions are rare
• 33 of 7531 vaccine recipients had local
  reactions and none had severe febrile or
  anaphylactic reactions
• CDC. MMWR.February 19893864-68, 73-76
• CDC. MMWR. April 199746(RR-8)1-24
• Fine et al. Arch Intern Med. 19941542666-2677

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CONTRAINDICATIONS TO VACCINATION

• Allergy to any vaccine component, including
  thimerosal
• Acute febrile illness

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COST-EFFECTIVENESS OF PNEUMOCOCCAL VACCINE IN
PREVENTING BACTEREMIA IN THE ELDERLY

• Vaccination is cost saving in preventing
  bacteremia alone
• With prevention of pneumonia, meningitis, and
  other complications added, vaccination is even
  more cost effective
• Cost saving of more than 8 per person vaccinated
• Vaccination of 23 million gt65 years in 1993 would
  have saved 194 million
• Sisk etr al. JAMA. 19972781333-1339.

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COST-EFFECTIVENESS OF PNEUMOCOCCAL VACCINE IN
ELDERLY AND HIGH-RISK PATIENTS

• Pneumococcal pneumonia - 78 of the annual cost
  of CAP
• Vaccinating seniors, high-risk groups lt65 years,
  and HIV patients is cost effective
• Net saving/person gt50 years of age (in U.S.) is
  225
• LMS Alert Vaccines. 1998 No. 5

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CDC RECOMMENDATIONS

• All adults gt65 years
• Immunocompetent persons gt2 years with
• Chronic cardiovascular disease
• Chronic pulmonary disease
• Diabetes mellitus
• Alcoholism
• Chronic liver disease
• CSF leaks

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CDC RECOMMENDATIONS

• Immunocompromised persons gt2 years with
• Functional or anatomic asplenia
• HIV, AIDS
• Leukemia, lymphoma, Hodgkins disease, multiple
  myeloma
• Generalized malignancy
• Chronic renal failure, nephrotic syndrome
• Receiving immunosuppressive chemotherapy,
  radiation
• Organ and bone marrow transplant patients

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CDC RECOMMENDATIONS

• Persons gt2 years living in special environments
  or social settings, such as
• Nursing homes
• Chronic-care facilities
• Alaskan Natives
• Certain Native American populations

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CDC RECOMMENDATIONS

• Uncertain vaccination status
• All persons who have unknown vaccination status
  should receive one dose of pneumococcal vaccine
• When in doubt, vaccinate

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DURATION OF PROTECTION

• Full antibody response occurs in 2-3 week
• Antibody levels remain elevated for at least 5
  years
• May decrease to preimmunization levels within 10
  years
• May decline within 3-5 years in children, within
  5-10 years in elderly, splenectomy and renal
  dialysis patients, transplant recipients
• Duration of protection suggests revaccination for
  some patients
• CDC.MMWR.February 19893864-68, 73-76

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REVACCINATION GUIDELINES

• Revaccinate persons who
• Are gt65 years of age, if vaccinated gt5 years
  earlier and aged lt65 years when first vaccinated
• Are 2-64 years and at high risk for serious
  pneumococcal infection
• Are at high risk and have shown a rapid decline
  in antibody levels, if first vaccinated gt5 years
  earlier
• Revaccination is not routinely recommended for
  most
• patients

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ADVERSE REACTIONS FOLLOWING REVACCINATION

• Revaccination after intervals of gt5 years is
  associated with an increased incidence of adverse
  side effects
• 3 after first dose
• 11 after second dose
• This increased risk is not a contraindication to
  revaccination
• Jackson et al.JAMA.1999281243-248

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REVACCINATION OF THE ELDERLY

• Protection by pneumococcal polysaccharide vaccine
  may not be lifelong
• One-time revaccination after gt5 years is
  recommended for persons gt65 years vaccinated at
  lt65 years
• Jackson et al. JAMA. 1999281243-248