Update: vCJD Epidemiology and Transfusion-Transmission

1
Update vCJD Epidemiology and Transfusion-Transmis
sion

• TSE Advisory Committee
• September 18, 2006
• Dorothy Scott, M.D.
• OBRR/CBER

2
vCJD Cases Worldwidewww.cjd.ed.ac.uk/vcjdworld.ht
m

• Total number of cases worldwide (deceased
  alive) 196
• UK 162
• France 20
• Republic of Ireland 4
• 1-2 cases each Italy, USA, Canada, Saudi Arabia,
  Japan, Netherlands, Portugal, Spain

3
Rate of vCJD Deaths Declining in
UK(www.cjd.ed.ac.uk/figures.htm and
www.cjd.ed.ac.uk/vcjdworldwide.htm)

• Deaths from Definite and Probable vCJD in the UK
  (2000 present)
• 2000 (peak) 28
• 2001 20
• 2002 17
• 2003 18
• 2004 9
• 2005 5
• 2006 3 (as of 9/4/2006)
• (6 patients still living)

4
UK Transfusion-Transmitted vCJD in recipients of
non-leukoreduced red cell concentrates from
donors who developed vCJD

• 2 cases of clinical vCJD
• Donors developed clinical vCJD 18 to 42 mos.
  after donation
• Recipients (2) developed clinical vCJD 6.5 -8
  years after transfusion
• One infected, asymptomatic recipient died of
  unrelated illness 5 years post-transfusion
  (autopsy - PrpTSE in spleen, lymph nodes)
• M/V heterozygous at Prp codon 129

5
UK Tissue Survey tonsil and appendix
samplesHilton et al J. Path 2004 203733-9
Ironside et al BMJ 2006 332 1186-8
Genotype not Tested (trans- mission study)
V/V

• surgery 1996-1999
• patients age 20-29
• 3/12,674 positive
• All s from appendix

V/V
6
Summary

• vCJD clinical cases declining in UK
• 3 transfusion-transmission infections reported in
  UK (most recent in 2/2006)
• 3/18 identified living recipients (gt 5 years
  post-transfusion) of blood from vCJD donors have
  proven infection (efficient transmission)
• All three Prp genotypes at codon 129 (M/M, M/V,
  V/V) are susceptible to infection
• No clinical vCJD cases with M/V or V/V genotypes
  to date
• Continued possibility of silent/asymptomatic
  infection risk of iatrogenic transmission