Performance of parallel screening of Brazilian blood donors with two human immunodeficiency virus immunoassays: implications for sequential immunoassay testing algorithms in other countries

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The Retrovirus Epidemiology Donor Study (REDS) program was established in the United States in 1989 with the purpose of increasing blood transfusion safety in the context of the HIV/AIDS and human T-lymphotropic virus epidemics. REDS and its successor, REDS-II were at first conducted in the US, then expanded in 2006 to include international partnerships with Brazil and China. In 2011, a third wave of REDS renamed the Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) was launched. This seven-year research program focuses on both blood banking and transfusion medicine research in the United States of America, Brazil, China, and South Africa. The main goal of the international programs is to reduce and prevent the transmission of HIV/AIDS and other known and emerging infectious agents through transfusion, and to address research questions aimed at understanding global issues related to the availability of safe blood. This article describes the contribution of REDS-II to transfusion safety in Brazil. Articles published from 2010 to 2013 are summarized, including database analyses to characterize blood donors, deferral rates, and prevalence, incidence and residual risk of the main blood-borne infections. Specific studies were developed to understand donor motivation, the impact of the deferral questions, risk factors and molecular surveillance among HIV-positive donors, and the natural history of Chagas disease. The purpose of this review is to disseminate the acquired knowledge and briefly summarize the findings of the REDS-II studies conducted in Brazil as well as to introduce the scope of the REDS-III program that is now in progress and will continue through 2018.

© 2014 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. All rights reserved.

Undisclosed human immunodeficiency virus risk factors identified through a computer-based questionnaire program among blood donors in Brazil

BACKGROUND

Human immunodeficiency virus (HIV) risk factor screening among blood donors remains a cornerstone for the safety of blood supply and is dependent on prospective donor self-disclosure and an attentive predonation interview. Audio computer-assisted structured interview (ACASI) has been shown to increase self-reporting of risk behaviors.

STUDY DESIGN AND METHODS

This cross-sectional study was conducted between January 2009 and March 2011 at four Brazilian blood centers to identify the population of HIV-negative eligible blood donors that answered face-to-face interviews without disclosing risks, but subsequently disclosed deferrable risk factors by ACASI. Compared to the donor interview, the ACASI contained expanded content on demographics, sexual behavior, and other HIV risk factors questions.

RESULTS

A total of 901 HIV-negative blood donors were interviewed. On the ACASI, 13% of donors (n = 120) declared a risk factor that would have resulted in deferral that was not disclosed during the face-to-face assessment. The main risk factors identified were recent unprotected sex with an unknown or irregular partner (49 donors), sex with a person with exposure to blood or fluids (26 donors), multiple sexual partners (19 donors), and male-male sexual behavior (10 donors). Independent factors associated with the disclosure of any risk factor for HIV were age (≥40 years vs. 18-25 years; adjusted odds ratio [AOR], 0.45; 95% confidence interval [CI], 0.23-0.88) and blood center (Hemope vs. Hemominas; AOR, 2.51; 95% CI, 1.42-4.44).

CONCLUSION

ACASI elicited increased disclosure of HIV risk factors among blood donors. ACASI may be a valuable modality of interview to be introduced in Brazilian blood banks.

The National Heart, Lung, and Blood Institute retrovirus epidemiology donor studies (Retrovirus Epidemiology Donor Study and Retrovirus Epidemiology Donor Study-II): twenty years of research to advance blood product safety and availability

The Retrovirus Epidemiology Donor Study (REDS), conducted from 1989 to 2001, and the REDS-II, conducted from 2004 to 2012, were National Heart, Lung, and Blood Institute-funded, multicenter programs focused on improving blood safety and availability in the United States. The REDS-II also included international study sites in Brazil and China. The 3 major research domains of REDS/REDS-II have been infectious disease risk evaluation, blood donation availability, and blood donor characterization. Both programs have made significant contributions to transfusion medicine research methodology by the use of mathematical modeling, large-scale donor surveys, innovative methods of repository sample storage, and establishing an infrastructure that responded to potential emerging blood safety threats such as xenotropic murine leukemia virus-related virus. Blood safety studies have included protocols evaluating epidemiologic and/or laboratory aspects of human immunodeficiency virus, human T-lymphotropic virus 1/2, hepatitis C virus, hepatitis B virus, West Nile virus, cytomegalovirus, human herpesvirus 8, parvovirus B19, malaria, Creutzfeldt-Jakob disease, influenza, and Trypanosoma cruzi infections. Other analyses have characterized blood donor demographics, motivations to donate, factors influencing donor return, behavioral risk factors, donors' perception of the blood donation screening process, and aspects of donor deferral. In REDS-II, 2 large-scale blood donor protocols examined iron deficiency in donors and the prevalence of leukocyte antibodies. This review describes the major study results from over 150 peer-reviewed articles published by these 2 REDS programs. In 2011, a new 7-year program, the Recipient Epidemiology and Donor Evaluation Study-III, was launched. The Recipient Epidemiology and Donor Evaluation Study-III expands beyond donor-based research to include studies of blood transfusion recipients in the hospital setting and adds a third country, South Africa, to the international program.

Human immunodeficiency virus prevalence, incidence, and residual risk of transmission by transfusions at Retrovirus Epidemiology Donor Study-II blood centers in Brazil

BACKGROUND

In Brazil nationally representative donor data are limited on human immunodeficiency virus (HIV) prevalence, incidence, and residual transfusion risk. The objective of this study was to analyze HIV data obtained over 24 months by the Retrovirus Epidemiology Donor Study-II program in Brazil.

STUDY DESIGN AND METHODS

Donations reactive to third- and fourth-generation immunoassays (IAs) were further confirmed by a less-sensitive (LS) IA algorithm and Western blot (WB). Incidence was calculated for first-time (FT) donors using the LS-EIA results and for repeat donors with a model developed to include all donors with a previous negative donation. Residual risk was projected by multiplying composite FT and repeat donor incidence rates by HIV marker-negative infectious window periods.

RESULTS

HIV prevalence among FT donors was 92.2/10(5) donations. FT and repeat donor and composite incidences were 38.5 (95% confidence interval [CI], 25.6-51.4), 22.5 (95% CI, 17.6-28.0), and 27.5 (95% CI, 22.0-33.0) per 100,000 person-years, respectively. Male and community donors had higher prevalence and incidence rates than female and replacement donors. The estimated residual risk of HIV transfusion transmission was 11.3 per 10(6) donations (95% CI, 8.4-14.2), which could be reduced to 4.2 per 10(6) donations (95% CI, 3.2-5.2) by use of individual-donation nucleic acid testing (NAT).

CONCLUSION

The incidence and residual transfusion risk of HIV infection are relatively high in Brazil. Implementation of NAT will not be sufficient to decrease transmission rates to levels seen in the United States or Europe; therefore, other measures focused on decreasing donations by at-risk individuals are also necessary.

Number of recent sexual partners among blood donors in Brazil: associations with donor demographics, donation characteristics, and infectious disease markers

BACKGROUND

Brazilian blood centers ask candidate blood donors about the number of sexual partners in the past 12 months. Candidates who report a number over the limit are deferred. We studied the implications of this practice on blood safety.

STUDY DESIGN AND METHODS

We analyzed demographic characteristics, number of heterosexual partners, and disease marker rates among 689,868 donations from three Brazilian centers between July 2007 and December 2009. Donors were grouped based on maximum number of partners allowed in the past 12 months for each center. Chi-square and logistic regression analysis were conducted to examine associations between demographic characteristics, number of sex partners, and individual and overall positive markers rates for human immunodeficiency virus (HIV), human T-lymphotropic virus Types 1 and 2, hepatitis B virus, hepatitis C virus, and syphilis.

RESULTS

First-time, younger, and more educated donors were associated with a higher number of recent sexual partners, as was male sex in São Paulo and Recife (p<0.001). Serologic markers for HIV and syphilis and overall were associated with multiple partners in São Paulo and Recife (p<0.001), but not in Belo Horizonte (p=0.05, p=0.94, and p=0.75, respectively). In logistic regression analysis, number of recent sexual partners was associated with positive serologic markers (adjusted odds ratio [AOR], 1.2-1.5), especially HIV (AOR, 1.9-4.4).

CONCLUSIONS

Number of recent heterosexual partners was associated with HIV positivity and overall rates of serologic markers of sexually transmitted infections. The association was not consistent across centers, making it difficult to define the best cutoff value. These findings suggest the use of recent heterosexual contacts as a potentially important deferral criterion to improve blood safety in Brazil.