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.
Curvas epidémicas del 2002, 2003,2004 Y 2005* Casos Sospechosos de Dengue Clásico Honduras , *Semana 41
4000 3500 3000 2500
CASOS
2002 (32,269 casos)
2003 (16,559 casos)
2004 (19,971 casos)
2005 (16,037 casos)*
2000 1500 1000 500 0
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 51
SEM ANAS DEL AÑO
2002
* AÑO EPIDÉMICO 1995 EXCLUÍDO FUENTE: Telegrama Epidemiológico.
2003
2004
2005
Analytical sensitivity of the prototype dengue TMA assay
• DEN 1, 2, 3 and 4 diluted to 1 PFU/mL
Serotype Mean RLU DEN1 596067 DEN2 1189318 DEN3 710402 DEN4 1526021 Negatives 8922 STDEV 643944 376157 396623 180112 5032 %Positive 100 (8/8) 100 (8/8) 100 (8/8) 100 (8/8) 0 (0/4)
Sources of Donor Plasma from Dengue Endemic Regions
Country Honduras San Pedro Sula 09/06/0401/13/05
1819
Brasil Cairin s
2003 3220
Australia Brisban e
2003 1444
Region Period
Tequciqalpa
Sao Paulo
Townsville 2003 1071
Cairins & Townsville
2005 2500
08/31/0401/24/05
1187
Feb. 2003Apr. 2003
3239
Total by Region
Total by Country
2994
3239
8235
12 IR, 9 RR 11 confirmed
8 IR, 3 IR confirmation pending
in progress
Dengue TMA Results from Honduran Blood Donors (n = 2994)
Specimen ID
Initial TMA Results Reactive Reactive Reactive Reactive Reactive Reactive Reactive Reactive Reactive Reactive Reactive Repeat TMA Results Nonreactiv e Reactive Reactive Reactive Reactive Nonreactiv e Reactive Reactive Reactive Nonreactiv e Reactive
BSRI Genotyping
CDC Genotypin g Negative DEN-4 DEN-4 DEN-4 DEN-1 Negative Negative DEN-1 DEN-1 Negative DEN-2
Growth in culture (CDC)
Duplicate Viral Load Testing (PFU/100 uL of plasma) <0.001 0.44 13.07 51.84 1.38 Neg 0.25 0.54 20.00 0.002 0.01 <0.001 0.44 13.07 51.84 1.38 Neg 0.25 0.54 20.00 0.002 0.01
DV-00033 DV-00164 DV-00220 DV-00477 DV-00545 DV-00766 DV-00802 DV-01110 DV-01328 DV-02221 DV-02837
DEN-1 DEN-4 DEN-4 DEN-4 DEN-1 Negative DEN-4 DEN-1 DEN-1 DEN-3 DEN-2
Negative DEN-4 DEN-4 DEN-4 DEN-1 Negative Negative Negative Negative Negative Negative
Planned studies of TT-Dengue
• Transmission study in Honduras with BSF and Gen-Probe funding • Transmission study in Brazil under REDSII 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
Acknowledgements
J 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 Busch Blood Systems Research Institute, San Francisco, CA;