The sensitivity of an HIV P24 antigen and antibody assay used in paralel (3rd Generation) compared to HIV antigen/antibody combination assays (4th generation) to detect recent HIV infection in South African blood donors as identified through nucleic acid

Abstract: Introduction Although Nucleic Acid Testing has become the gold standard for the detection of HIV it remains an expensive technology. In Africa the use of sensitive serological assays might be a more viable option. HIV Combo assays have been on the market for several years and have been evaluated. Four cases of a 2nd diagnostic window period have been reported by the use of these assays. This raised questions regarding the sensitivity of these Combo assays compared to stand-alone serological assays for HIV detecting antigen and antibodies separately. In this study the sensitivity of three HIV Combo assays were compared to stand-alone assays by the use of 2 unique sample groups of early HIV infections as identified by NAT since 2005 by the South African National Blood Service (SANBS). Methods A retrospective study using two sample groups of archived plasma from HIV positive blood donors; A) 153 HIV NAT yield samples B) 87 low antibody ratio (Abbott Prism) recent HIV samples. These groups were tested by three HIV Combo assays (Abbott, Biorad and Roche) and one p24 antigen assay (Innogenetics). The Abbott Prism HIV O Plus assay results were already available as reference method for antibody detection. Sensitivity to detect HIV antigen and/or antibodies were evaluated. The significance of donor demographic indicators of donor group (new, re-joined or active) race, age, gender and region were analysed in relation to the presence/absence of p24 antigen between the two groups..

Cost-effectiveness analysis of introducing HTLV-1 testing in South Africa

We have previously reported a 2013 cross-sectional study of HTLV prevalence among 46,765 South African blood donors. Confirmed HTLV-1 prevalence was 0.16% in Black donors, 0.02% in both White and Coloured donors and 0% in south Asian donors, for an overall prevalence of 0.062% extrapolated to the current blood donor population. Using these data we estimated the cost effectiveness of potential HTLV screening strategies in preventing transfusion transmitted HTLV-1 infection (TTI). Five blood donor screening strategies were considered: no screening; HTLV testing of every donation; HTLV testing each donor one time only; HTLV testing of new donors only; and universal filter leukodepletion without HTLV testing

Cancer Incidence and Mortality in a Cohort of US Blood Donors: A 20-Year Study

Blood donors are considered one of the healthiest populations. This study describes the epidemiology of cancer in a cohort of blood donors up to 20 years after blood donation. Records from donors who participated in the Retroviral Epidemiology Donor Study (REDS, 1991–2002) at Blood Centers of the Pacific (BCP), San Francisco, were linked to the California Cancer Registry (CCR, 1991–2010). Standardized incidence ratios (SIR) were estimated using standard US 2000 population, and survival analysis used to compare all-cause mortality among donors and a random sample of nondonors with cancer from CCR. Of 55,158 eligible allogeneic blood donors followed-up for 863,902 person-years, 4,236 (7.7%) primary malignant cancers were diagnosed. SIR in donors was 1.59 (95% CI = 1.54,1.64). Donors had significantly lower mortality (adjusted HR = 0.70, 95% CI = 0.66–0.74) compared with nondonor cancer patients, except for respiratory system cancers (adjusted HR = 0.93, 95% CI = 0.82–1.05). Elevated cancer incidence among blood donors may reflect higher diagnosis rates due to health seeking behavior and cancer screening in donors. A “healthy donor effect” on mortality following cancer diagnosis was demonstrated. This population-based database and sample repository of blood donors with long-term monitoring of cancer incidence provides the opportunity for future analyses of genetic and other biomarkers of cancer

West Nile Virus Infections Projected from Blood Donor Screening Data, United States, 2003

Routine donor nucleic acid amplification testing is a valuable surveillance screening tool

Association between HLA Class I and Class II Alleles and the Outcome of West Nile Virus Infection: An Exploratory Study

BACKGROUND: West Nile virus (WNV) infection is asymptomatic in most individuals, with a minority developing symptoms ranging from WNV fever to serious neuroinvasive disease. This study investigated the impact of host HLA on the outcome of WNV disease. METHODS: A cohort of 210 non-Hispanic mostly white WNV(+) subjects from Canada and the U.S. were typed for HLA-A, B, C, DP, DQ, and DR. The study subjects were divided into three WNV infection outcome groups: asymptomatic (AS), symptomatic (S), and neuroinvasive disease (ND). Allele frequency distribution was compared pair-wise between the AS, S, and ND groups using χ2 and Fisher's exact tests and P values were corrected for multiple comparisons (Pc). Allele frequencies were compared between the groups and the North American population (NA) used as a control group. Logistic regression analysis was used to evaluate the potential synergistic effect of age and HLA allele phenotype on disease outcome. RESULTS: The alleles HLA-A*68, C*08 and DQB*05 were more frequently associated with severe outcomes (ND vs. AS, P(A*68) = 0.013/Pc = 0.26, P(C*08) = 0.0075/Pc = 0.064, and P(DQB1*05) = 0.029/Pc = 0.68), However the apparent DQB1*05 association was driven by age. The alleles HLA-B*40 and C*03 were more frequently associated with asymptomatic outcome (AS vs. S, P(B*40) = 0.021/Pc = 0.58 and AS vs. ND P(C*03) = 0.039/Pc = 0.64) and their frequencies were lower within WNV(+) subjects with neuroinvasive disease than within the North American population (NA vs. S, P(B*40) = 0.029 and NA vs. ND, P(C*03) = 0.032). CONCLUSIONS: Host HLA may be associated with the outcome of WNV disease; HLA-A*68 and C*08 might function as "susceptible" alleles, whereas HLA-B*40 and C*03 might function as "protective" alleles

Vasovagal reactions in whole blood donors at three REDS-II blood centers in Brazil

BACKGROUND: In Brazil little is known about adverse reactions during donation and the donor characteristics that may be associated with such events. Donors are offered snacks and fluids before donating and are required to consume a light meal after donation. For these reasons the frequency of reactions may be different than those observed in other countries. STUDY DESIGN AND METHODS: A cross-sectional study was conducted of eligible whole blood donors at three large blood centers located in Brazil between July 2007 and December 2009. Vasovagal reactions (VVRs) along with donor demographic and biometric data were collected. Reactions were defined as any presyncopal or syncopal event during the donation process. Multivariable logistic regression was performed to identify predictors of VVRs. RESULTS: Of 724,861 donor presentations, 16,129 (2.2%) VVRs were recorded. Rates varied substantially between the three centers: 53, 290, and 381 per 10,000 donations in Recife, Sao Paulo, and Belo Horizonte, respectively. Although the reaction rates varied, the donor characteristics associated with VVRs were similar (younger age [18-29 years], replacement donors, first-time donors, low estimated blood volume [EBV]). In multivariable analysis controlling for differences between the donor populations in each city younger age, first-time donor status, and lower EBV were the factors most associated with reactions. CONCLUSION: Factors associated with VVRs in other locations are also evident in Brazil. The difference in VVR rates between the three centers might be due to different procedures for identifying and reporting the reactions. Potential interventions to reduce the risk of reactions in Brazil should be considered