110 likes | 121 Views
GBV-C, WNV & Dengue V in Ghanaian donors, women & children . C Li, D Candotti, JP Allain National Blood Service & University of Cambridge. Testing algorithm. Screening with Triplex NAT; probes labeled with: CY5 GBV-C, FAM WNV, HEX Dengue Confirmation with virus specific nested RT-PCR
E N D
GBV-C, WNV & Dengue V in Ghanaian donors, women & children C Li, D Candotti, JP Allain National Blood Service & University of Cambridge
Testing algorithm • Screening with Triplex NAT; probes labeled with: • CY5 GBV-C, FAM WNV, HEX Dengue • Confirmation with virus specific nested RT-PCR • Confirmed positive quantified by single virus QPCR for VL • Genotyping by sequencing E2 region and phylogenetic analysis • Antibody testing with Panbio kits
Quantification of GBV-C RNA load RNA from 200 l of plasma Reference high + plasma: last + dilution defines arbitrary unit GBV-C reference curve 40Ct = 1 AU/ml
Distribution of GBV-C markers in blood donors and pregnant women (Li et al. AIDS 2006, 20:379-386) Blood donations Pregnant women HIV-1 status Neg Pos Neg Pos N samples 140 96 140 86 % RNA+ 12.91 21.9 25 27.9 % anti-E2 + 3.8 14.5 18 17.3 % total markers 16.5 36.4 39.8 38.62 1. P<0.01 ; 2. Total is lower than RNA+Ab as some samples carry both
35 30 25 20 % of total 15 10 5 0 >102 102 103 104 105 106 ≥107 Distribution of HIV-1 RNA loads (IU/ml) Distribution of HIV-1 RNA load according to GBV-C RNA status GBV-C- GBV-C+ (P< 0.01)
GBV-C RNA positive (RNA load range, AU/ml) HIV RNA status Mothers Cord blood Positive 21 (1.1E3 - 5.6E5) 0 - Negative 34 (1.7E0 - 5.6E5) 2 (5.9%) - pair 1458 pair 1473 1.2E5 3.7E5 2.6E3 2.8E1 Screening for GBV-C RNA in HIV-1 RNA positive and negative mothers and paired cord blood samples
N= 157 44 91 125 105 71 68 18 16 14 12 10 % of total RNA IgG 8 6 4 2 0 <1 1-5 6-11 12-23 24-35 36-47 48-70 Age (months) Prevalence of GBV-C markers with age
50 40 % of total reactive 30 20 10 51-65y 6-11m 16-20y 21-25y 26-30y 31-35y 36-40y 41-45y 46-50y 12-23m 24-35m 36-47m 48-70m Age distribution (months or years) Age distribution of IgG antibody to West Nile Virus
Conclusions • GBV-C prevalence is high (16-40%) and genotype 1 is dominant • GBV-C viraemia is twice as frequent as neutralising antibodies • HIV-1 RNA load is lower in GBV-C viraemic patients • GBV-C vertical transmission is rare and horizontal transmission appears predominant in West Africa (related to genotype?) • Most WNV infections occur early in life, absence of viraemia, short window period --> minimal risk of transmission by transfusion • Dengue virus does not seem prevalent in Ghana
Acknowledgements KATH Blood Bank, Department of Medicine, Komfo Anokye Teaching Hospital, Kumasi, Ghana: Francis Sarkodie, Shirley Owusu-Ofori INTS Paris, France: Jean-Jacques Lefrere, M Mariotti Dept of Health & Human Services, F D A, USA: Indira Hewlett Roche, USA: Jim Gallarda National Institute for Biological Standards and Control, UK: Sally Baylis University of Malaysia, Sarawak: Jane Cardosa