detection of dengue virus rna in blood donors from honduras and brazil with a prototype...
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Detection of Dengue Virus RNA in Blood Donors from Honduras and Brazil with a
Prototype Transcription-Mediated Amplification Assay
Dengue
• Over 2.5 billion people live in risk areas for dengue infection
• WHO estimates that in 2004 there were 50-100 million cases of DF, 500,000 cases of dengue hemorrhagic shock syndrome (DHS) and 20,000 consequent deaths
• Epidemic is expanding due to global warming, expanding vectors and trafficking of subtypes
• Dengue the most important arboviral disease of humans
Expanding global epidemic of Dengue
Number of dengue fever cases reported per month, Brazil.
A) 1986–1993, B) 1994–2003. Dark bars represent January.A) 1986–1993, B) 1994–2003. Dark bars represent January.
Curvas epidémicas del 2002, 2003,2004 Y 2005*Casos Sospechosos de Dengue Clásico
Honduras , *Semana 41
0
500
1000
1500
2000
2500
3000
3500
4000
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51SEMANAS DEL AÑO
CAS
OS
2002 2003 2004 2005
* AÑO EPIDÉMICO 1995 EXCLUÍDO
2003 (16,559 casos)
FUENTE: Telegrama Epidemiológico.
2002 (32,269 casos)
2004 (19,971 casos)
2005 (16,037 casos)*
Analytical sensitivity of the prototype dengue TMA assay
• DEN 1, 2, 3 and 4 diluted to 1 PFU/mL
Serotype Mean RLU STDEV %Positive DEN1 596067 643944 100 (8/8)DEN2 1189318 376157 100 (8/8)DEN3 710402 396623 100 (8/8)DEN4 1526021 180112 100 (8/8)
Negatives 8922 5032 0 (0/4)
Sources of Donor Plasma from Sources of Donor Plasma from Dengue Endemic RegionsDengue Endemic Regions
Sources of Donor Plasma from Sources of Donor Plasma from Dengue Endemic RegionsDengue Endemic Regions
Country Honduras Brasil Australia
Region TequciqalpaSan Pedro
SulaSao Paulo
Cairins
Townsville
Brisbane
Cairins & Townsvill
e
Period08/31/04-01/24/05
09/06/04-01/13/05
Feb. 2003-Apr. 2003
2003 2003 2003 2005
Total by Region
1187 1819 3239 3220 1071 1444 2500
Total by Country
2994 3239 8235
12 IR, 9 RR 11 confirmed
8 IR, 3 IR confirmation
pending
in progress
Dengue TMA Results from Dengue TMA Results from Honduran Blood DonorsHonduran Blood Donors
(n = 2994)(n = 2994)
Dengue TMA Results from Dengue TMA Results from Honduran Blood DonorsHonduran Blood Donors
(n = 2994)(n = 2994)Specimen ID
Initial TMA
Results
Repeat TMA
Results
BSRI Genotyping
CDC Genotypin
g
Growth in culture (CDC)
Duplicate Viral Load Testing
(PFU/100 uL of plasma)
DV-00033 ReactiveNonreactiv
eDEN-1 Negative Negative <0.001 <0.001
DV-00164 Reactive Reactive DEN-4 DEN-4 DEN-4 0.44 0.44
DV-00220 Reactive Reactive DEN-4 DEN-4 DEN-4 13.07 13.07
DV-00477 Reactive Reactive DEN-4 DEN-4 DEN-4 51.84 51.84
DV-00545 Reactive Reactive DEN-1 DEN-1 DEN-1 1.38 1.38
DV-00766 ReactiveNonreactiv
eNegative Negative Negative Neg Neg
DV-00802 Reactive Reactive DEN-4 Negative Negative 0.25 0.25
DV-01110 Reactive Reactive DEN-1 DEN-1 Negative 0.54 0.54
DV-01328 Reactive Reactive DEN-1 DEN-1 Negative 20.00 20.00
DV-02221 ReactiveNonreactiv
eDEN-3 Negative Negative 0.002 0.002
DV-02837 Reactive Reactive DEN-2 DEN-2 Negative 0.01 0.01
DV-02921 Reactive Reactive DEN-3 Negative Negative 0.002 0.002
Planned studies of TT-Dengue
• Transmission study in Honduras with BSF and Gen-Probe funding
• Transmission study in Brazil under REDS-II funding
• Collaborations with Australia, Hong Kong and Singapore blood banks
Dengue Transmission Study Approach
• It is mandatory in Brazil to save donor serum samples for 6 months after the transfusion
• Phase 1: Prevalence Study– Dengue TMA on 10,000 unlinked donor samples to
determine prevalence• Phase 2: Transmission Study
– collect recipient samples ~1 week after transfusion.– capture donor samples in routine repository.– Dengue TMA on both samples.– sequence virus to confirm linkage
AcknowledgementsJ Linnen, A Broulik, C Collins, DP Kolk, C Giachetti, L Mimms Gen-Probe Incorporated, San Diego, CA;
E Vinelli Honduran Red Cross, Tegucigalpa, Honduras;
E Sabino, Blood Center of Sao Paulo, Sao Paulo, Brazil;
R Lanciotti, CDC, Fort Collins, CO;
C Hyland, Australian Red Cross, Brisbane, Australia;
L Tobler, MP BuschBlood Systems Research Institute, San Francisco, CA;