333. Why Vaccinate against Group A Streptococci?  The Disease Burden in a High Risk Community
Session: Poster Abstract Session: Challenges in Vaccinology and Vaccine Exploration
Friday, October 21, 2011
Room: Poster Hall B1
Background: 

Of serious bacterial diseases, those caused by group A streptococci (GAS) remain orphans when considering vaccine prevention.  In certain populations a GAS vaccine could be a valuable adjunct.

Methods:

Ongoing active surveillance of group A streptococci‑associated diseases continues in Auckland.  Previous publications (with case definitions) have highlighted concern1,2Emm typing is ongoing3.  Methods include:

  • Population‑based regional rheumatic fever register referrals (1998 to present) to assess acute rheumatic fever (ARF) burden (Auckland).
  • Prospective national 2 year NZ Paediatric Surveillance Unit study of Acute Post Streptococcal Glomerulonephritis (APSGN) (2007-2009)3,4.
  • Laboratory‑based surveillance of invasive GAS disease (sterile cavity isolates) including toxic shock syndrome and necrotising fasciitis (2005-2006) (Auckland)5.
  • Estimate of GAS pharyngitits in Auckland population at very high risk of ARF (1998‑2001)6.

Results: 

  • ARF incidence (5-14y) (1998-2007)

          –     all Auckland:                                          25.3/100,000 (n=468)

          –     South Auckland                                      43/100,000 (n=299)

                (all ethnicities)

  • Hospitalised APSGN (NZ, 0-14y):  all ethnicities 10.1/100,000; indigenous Maori 16.7/100,000; Pacific 47/100,000; 112/190 cases in Auckland region4.
  • ·Invasive GAS ( 0-14y)                                   1984-1987 1/100,000 (N=3 per year)2

                                                                                                      2005-2007 6.1/100,000 (n=18 per year)5

  • GAS culture‑positive pharyngititis (1998-2001) in high risk school‑aged children (5‑19y):  0.4 per child year6.

Conclusion: 

In this well defined (0‑14y) population (~300,000), using M protein‑based vaccine covering all emm types relevant to our population and vaccinating the birth cohort with a vaccine efficacy ≥ 80% and with long term protection, up to 100 serious GAS cases could be potentially prevented annually.  Primary prevention of ARF by GAS pharyngitis treatment (cost ˜NZ$100/child/year for 50,000 high risk Auckland children (5-12y) ~NZ$5,000,000/year) could be much reduced if vaccine protection for the birth cohort were long lasting.

References:

  1. Lennon D et al, NZMJ 1988; 101:396
  2. Harnden A et al, PIDJ 1988; PIDJ 7:714
  3. Martin D et al, PIDJ 1994; 13:264
  4. Crone S et al, Paediatric Society of New Zealand, Annual Scientific Meeting 2010 (abstract).
  5. Safar A et al, EID 2011; 17:983
  6. Lennon D et al, PIDJ 2009; 28:787

Subject Category: I. Adult and Pediatric Vaccines

Diana R. Lennon, MB, ChB1, Joanna Stewart, MSc2, Catherine Jackson, MBChB, MPH3, William Wong, MBChB4, Sonja Crone, MBChB4 and Atheer Safar, MBChB4, (1)Population Child and Youth Health, University of Auckland, Auckland, New Zealand, (2)The University of Auckland, Auckland, New Zealand, (3)Counties Manukau District Health Board, Auckland, New Zealand, (4)Starship Children's Hospital, Auckland District Health Board, Auckland, New Zealand

Disclosures:

D. R. Lennon, None

J. Stewart, None

C. Jackson, None

W. Wong, None

S. Crone, None

A. Safar, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.