Blood Centers In Brazil Research Articles

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

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. 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. 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). 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.

Comment on: "Clinical and functional evaluation of the joint status of hemophiliac adults at a Brazilian blood center"

In this issue of the Revista Brasileira de Hematologia e Hemoterapia, Ferreira et al. present a study entitled Clinical and functional evaluation of the joint status of hemophiliac adults at a Brazilian blood center(1). The authors are to be commended for presenting their paper on the outcomes of the clinical and functional evaluation of adults with hemophilia from a Hemophilia Centre in Brazil. The findings identify the importance of evaluating this specific group of patients with hemophilia in order to develop a deep understanding of their physical status and the problems that this can pose for the individuals concerned. The findings will also provide evidence to begin to address the issues raised in the study and it is hoped that this will ultimately improve patient outcomes. The use of standardized measures is essential in this regard and the authors have used two well established tools to assess the adults in the study. This scientific comment will make three observations on the findings outlined in the paper - The importance of primary prophylaxis - The use of standardized measures - The lack of engagement with physiotherapy

Clinical and functional evaluation of the joint status of hemophiliac adults at a Brazilian blood center.

BackgroundHemophilia is a potentially disabling condition as hemophilic arthropathy develops early in life and is progressive, especially in patients treated in an on-demand regime. ObjectiveThis study aimed to describe the structural joint status and the functional independence score of hemophiliac adults and correlate structural damage with the functional deficits found in these patients. MethodsHemophiliacs at the Juiz de Fora Regional Blood Center - HEMOMINAS Foundation, aged 18 years and over and treated in an on-demand regime, were clinically evaluated in respect to structural joint damage using the World Federation of Hemophilia Physical Examination Scale (WFH-PE) and functional deficits using the Functional Independence Score in Hemophilia (FISH). The Spearman rank test was used to evaluate the correlation between the two scores. ResultsThirty-nine patients were evaluated. The mean age was 36.8 years. Target joints were detected in 69.2% of patients studied. The mean Physical Examination Scale and Functional Independence Score were 16.87 and 25.64, respectively. Patients with mild hemophilia showed no significant joint involvement. Patients with severe or moderate hemophilia had similar results regarding structural damage (p-value < 0.001) and functional deficits (p-value = 0.001). There was statistical significance in the correlation between the two scores (r = -0.850; p-value = 0.01). ConclusionsThe World Federation of Hemophilia Physical Examination Scale and Functional Independence Score in Hemophilia may be useful to clinically assess structural joint damage and functional deficits in hemophiliacs as the tools are inexpensive and easy to administer and may be able to detect hemophilic arthropathy, which results from recurrent hemarthrosis and is common in the population studied.

Health-related quality of life in hemophilia: results of the hemophilia-Specific quality of life index (Haem-a-Qol) at a Brazilian blood center

BackgroundStudies on health-related quality of life are based on the increasingly evident need for medical care not to be limited to preventing death, but to focus instead on the value of health. ObjectiveThis study aimed to measure the health-related quality of life in hemophilia, using the Hemophilia- Specific Quality of Life (Haem-A-QoL) questionnaire and describe the socioeconomic characteristics and health conditions of these patients. MethodsThe Brazilian version of the Hemophilia-Specific Quality of Life questionnaire was administered to hemophiliac adults, treated in an on-demand regime at the Juiz de Fora Regional Blood Center - HEMOMINAS Foundation. The patients were interviewed about demographic and socioeconomic data and their understanding of the questionnaire. Clinical data were collected from medical records. The Mann-Whitney U test was used for statistical analysis. The level of significance was set for p-values < 0.05. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS, version 15.0). ResultsThirty-nine patients were evaluated. The mean age was 36.8 years. 84.6% had hemophilia A; 20.5% of the patients had hemophilia classified as mild, 41% as moderate and 38.5% as severe. The records of 10.5% of the patients registered seropositivity for anti-HIV and 57.9% for anti-HCV. Target joints were detected in 69.2%. The mean total Hemophilia-Specific Quality of Life score was 35.55. 'Sports and leisure'and 'Physical health'were the most impaired dimensions and the dimension 'Relationship and partners'was the least impaired. The Hemophilia-Specific Quality of Life scores showed good discriminant validity for hemophilia severity (p-value = 0.001), HIV-infection (p-value = 0.02), HCV-infection (p-value = 0.01) and the presence of target joints (p-value < 0.001). ConclusionHealth-related quality of life in hemophilia, measured by the Hemophilia-Specific Quality of Life questionnaire, was influenced by the presence of arthropathy and infectious diseases transmitted by blood products. Rehabilitation measures should be encouraged in order to improve the quality of life of these patients.

Comment on: "Temporal distribution of blood donations in three Brazilian blood centers and its repercussion on the blood supply"

As pointed out by Lorenzo Oliveira et al., the primary role of a blood center is the provision of a safe, economical and adequate blood supply(1). However, different factors govern the provision and the use of blood. An adequate supply of blood is based upon the availability of willing donors, while its usage depends upon medical need. It is clear that the concept of need only stimulates donors when dramatic circumstances such as natural disasters occur. It is frequently the case that modern disasters do not actually need a great deal of blood and indeed, the generosity of donors may be wasted. In view of this, a more effective system of communication and blood resource sharing in emergency situations has been developed in the United States. However, it is well-recognized that seasonal variation in the supply of blood is a pervasive problem. In the USA, there are times of the year when local or national appeals for blood donors may well be anticipated - for example during the summer or the Christmas/New Year holiday season. Careful inspection of Figure 1 shows the general reduction in collections during the middle part of the year (summer in the Northern hemisphere). Less apparent is the fact that the demographic structure of the donor population changes seasonally, unexpectedly affecting (for example) the prevalence if infectious disease markers. We have noted more first-time donors in the summer, and as might be expected, fewer donors in schools and colleges. This is, to a large extent, a consequence of the practice of collecting blood in locations away from the blood center itself, along with an increasing focus on younger blood donors. Figure 1 Blood collections by week, American Red Cross. Week 1 starts on the first Sunday in the calendar year: weeks zero and 52 may therefore be truncated. Certainly in the USA, a great deal of effort is put into recruitment of donors and such efforts are managed in the context of awareness of the drivers of blood shortages. Consequently, analysis of the number of blood units collected does not tell us as much as we may anticipate, because the data are a result of more or less successful efforts to overcome predictable shortages. Nevertheless, prompted by the accompanying paper, we analyzed weekly blood collection data for the American Red Cross, which collects about 40% of the 14 million blood donations in the USA (Figure 1). Clearly evident are repeated decrements around Weeks 21-22 (end of May), 26-27 (early July), 34-36 (beginning of September) and 46-47 (mid-late November). Also, as might be expected, there is a decline in the first and last weeks of the year, although it should be noted that the analysis is based upon each week starting on a Sunday, so the steep decline for week 52 is, in part, an artefact due to the truncation of this 'week'. The periods noted correspond to national holiday periods: Memorial Day, Independence Day, Labor Day, Thanksgiving and Christmas/New Year, respectively. Memorial and Labor days are held on a Monday, Independence Day is always July 4th (but observed on a weekday if falling on the weekend) and Thanksgiving is the fourth Thursday in November (many individuals are also on leave the following Friday). There are other holidays within the year, but they do not enjoy universal celebration, so do not clearly impact the collection data. On the whole, it is evident that blood collection organizations can adjust to predictable reductions in collections, but some logistic difficulties will be apparent for platelets, with a 5-day shelf-life. However, modeling studies suggest that unexpected surges in blood use, or shortages due to severe weather, an outbreak of influenza, etc. may have severe impacts upon blood availability. Where feasible, such events may be ameliorated by carefully organized resource sharing - that is, blood components may be shopped from locations that are less affected. However, in the absence of such mechanisms, local plans for donor mobilization should be developed and in place as part of emergency planning.

Temporal distribution of blood donations in three Brazilian blood centers and its repercussion on the blood supply

BackgroundSeasonal distribution of blood donation hinders efforts to provide a safe and adequate blood supply leading to chronic and persistent shortages. This study examined whether holidays, geographical area and donation type (community versus replacement) has any impact on the fluctuation of donations. MethodsThe numbers of blood donations from 2007 through 2010 in three Brazilian Retrovirus Epidemiological Donor Study II (REDS-II) participating centers were analyzed according to the week of donation. The weeks were classified as holiday or non-holiday. To compare donations performed during holiday versus non-holiday weeks, tabulations and descriptive statistics for weekly donations by blood center were examined and time series analysis was conducted. ResultsThe average weekly number of donations varied according to the blood center and type of week. The average number of donations decreased significantly during Carnival and Christmas and increased during the Brazilian National Donor Week. The fluctuation was more pronounced in Recife and Belo Horizonte when compared to São Paulo and higher among community donors. ConclusionNational bank holidays affect the blood supply by reducing available blood donations. Blood banks should take into account these oscillations in order to plan local campaigns, aiming at maintaining the blood supply at acceptable levels.

Temporal distribution of blood donations in three Brazilian blood centers and its repercussion on the blood supply

Temporal distribution of blood donations in three Brazilian blood centers and its repercussion on the blood supply

Difficult blood donor choices: dance, feast or donate blood?

Difficult blood donor choices: dance, feast or donate blood?

Comment on: One window-period donation in two years of individual donor-nucleic acid test screening for hepatitis B, hepatitis C and human immunodeficiency virus

Since 1999 blood transfusion services around the world have been implementing nucleic acid amplification tests (NAAT) to screen for hepatitis C (HCV) RNA, human immunodeficiency virus (HIV) RNA and hepatitis B (HBV) DNA to improve the safety of the blood supply. Initially HCV RNA and HIV RNA NAAT screening was implemented and more recently HBV DNA NAAT screening commenced. In the beginning mini pools (MP) of 98 were used due to the manual complex systems available which were not suitable for high throughput because of the stringent laboratory requirements(1). Over the years the pool sizes have decreased to either 16 as used in the USA(2) or even smaller such as 6 as used by many European and Asian countries(3-5). South Africa, in 2005, was the first country in the world to implement individual donation (ID) screening for all three viruses of all donations(6). NAAT screening in parallel with serological screening has allowed the classification of HIV positive donations as window period, concordant and elite controller infections. HCV positive donations can be classified as window period, concordant and resolved infections and HBV positive donations can be classified as Window period, HBsAg only, acute concordant, occult and anti-HBc only infections. Since the implementation of NAAT for HBV DNA screening, vaccine breakthrough infections have also been recognized(7). The article in this issue of the Revista Brasileira de Hematologia e Hemoterapia (RBHH) entitled One window-period donation in two years of individual donor-nucleic acid test screening for hepatitis B, hepatitis C and human immunodeficiency virus by Levi et al. describes the first two years of screening for HIV RNA, HCV RNA and HBV DNA using ID NAAT in a small Brazilian blood center(8). From a total of 24,441 donations, no additional yield was obtained for HIV and HCV and they showed a 35% clearance rate for HCV and no elite controllers for HIV. The primary objective of the paper is to describe an unusual HBV yield case. This case tested HBsAg and anti-HBc negative and had an anti-HBs titer of 18 IU/mL. On follow up, the anti-HBs rose to 109 IU/mL, however in four samples over seven months no HBsAg or anti-HBc reactivity occurred. Sequencing confirmed the donation as a genotype A2 vaccine breakthrough infection. This is unusual as most documented breakthrough infections have been of the non-A2 genotype due to the vaccine comprising an A2 virus(7). The authors also showed 19 cases of HBsAg positive with no other HBV marker reactivity. It would be interesting to understand whether the authors viewed these donations as true or false infections in light of the investigations being done in the USA in the context of potentially removing HBsAg screening if HBV NAAT and anti-HBc screening is performed. Although this paper describes a small number of donations screened by ID-NAAT, if extrapolated to the larger Brazilian donor base and the prevalence and incidence is similar to that presented by Levi et al., then ID-NAAT could have a large impact on the safety of the blood supply particularly for HBV and HIV due to the high prevalence and incidence of the diseases, respectively.

Greater Need for FVIII Replacement in Patients of Type Non-O Blood Groups with Moderate Hemophilia A

AbstractAbstract 4390Hemophilia A is a bleeding disorder of variable expressivity caused by mutations in clotting factor 8 gene located on Xq28 chromosome. In Brazil, treatment of such patients consists of replacement therapy with FVIII concentrate derived from human plasma, which is administered either to control an episode of hemorrhage or prophylactically in order to prevent bleeding and its consequences, such as arthropathy. Recent studies have demonstrated that the half-life of FVIII administered to patients of the type O blood group with severe hemophilia A is shorter than that in patients of Type non-O groups. A likely explanation for this fact would be the greater plasma concentration of von Willebrand factor (vWF) in individuals with type non-O blood. In this study, was investigated the association between the blood group and the annual consumption of FVIII concentrate (UI/Kg/year) in the last three years among 99 patients (68 with moderate and 31 with mild hemophilia A) treated at the two blood centers in Brazil (Hemocentro do Pará and Hemocentro/UNICAMP). Most cases were treated for episodes of hemorrhage. Determinations of antigen levels of von Willebrand factor (vWF:Ag), activity of ristocetin cofactor (vWF:RiCof) and FVIII clotting activity (FVIII:C) were performed to investigate the correlation between these variables and immunophenotypes of the ABO blood system. The Mann-Whitney test was used for the comparison of FVIII consumption (UI/Kg/year) between O type and non-O type hemophiliacs, with the level of significance set to 5% (p<0.05). Unexpectedly, significantly greater FVIII consumption was found among patients of the non-O type group (p=0.017). In the evaluation of patients with moderate hemophilia A, plasma levels of vWF:RiCof were significantly higher in non-O type patients in comparison to those with type O blood (p=0.045). No significant differences were found between blood groups in the evaluation of patients with mild hemophilia A. The present findings lead one to conclude that the higher level of plasma vWF:RiCof (which could exert an influence on the increased half-life of FVIII) in patients of the non-O type group with moderate hemophilia A was not enough to impede the need for greater FVIII replacement and lessen the frequency of bleeding in this group. The authors hypothesize that other variables, such as mutations in moderate hemophilia A, affect the stability of the FVIII molecule, which has antigen A and B determinants in individuals of non-O type groups. Further studies involving a larger sample are needed to corroborate the findings of the present investigation. Disclosures:No relevant conflicts of interest to declare.

Motivation and social capital among prospective blood donors in three large blood centers in Brazil

Studies analyzing motivation factors that lead to blood donation have found altruism to be the primary motivation factor; however, social capital has not been analyzed in this context. Our study examines the association between motivation factors (altruism, self-interest, and response to direct appeal) and social capital (cognitive and structural) across three large blood centers in Brazil. We conducted a cross-sectional survey of 7635 donor candidates from October 15 through November 20, 2009. Participants completed self-administered questionnaires on demographics, previous blood donation, human immunodeficiency virus testing and knowledge, social capital, and donor motivations. Enrollment was determined before the donor screening process. Among participants, 43.5 and 41.7% expressed high levels of altruism and response to direct appeal, respectively, while only 26.9% expressed high levels of self-interest. More high self-interest was observed at Hemope-Recife (41.7%). Of participants, 37.4% expressed high levels of cognitive social capital while 19.2% expressed high levels of structural social capital. More high cognitive and structural social capital was observed at Hemope-Recife (47.3 and 21.3%, respectively). High cognitive social capital was associated with high levels of altruism, self-interest, and response to direct appeal. Philanthropic and high social altruism were associated with high levels of altruism and response to direct appeal. Cognitive and structural social capital and social altruism are associated with altruism and response to direct appeal, while only cognitive social capital is associated with self-interest. Designing marketing campaigns with these aspects in mind may help blood banks attract potential blood donors more efficiently.

The impact of policies to restrict the use of plasma containing products and apheresis platelets from female donors to mitigate transfusion related acute lung injury (TRALI) in Brazil

Background and ObjectivesAlthough the incidence of TRALI is unknown in Brazil, some blood centers have adopted strategies to prevent TRALI. We evaluated the impact of three policies to mitigate TRALI on the supply of blood products: to divert the production of whole blood-derived plasma from female donors; to defer all female donors from apheresis platelet collections, and to defer only multiparous female donors from apheresis platelet collections. Materials and MethodsData from allogeneic whole blood and apheresis platelet donations from April 2008 to December 2009 were collected in three Brazilian blood centers and the impact of the aforementioned strategies was evaluated. ResultsOf 544,814 allogeneic blood donations, 30.8% of whole blood plasma and 24.1% of apheresis platelet donations would be reduced if only male donor plasma was issued for transfusion and all female donors were deferred from apheresis donation, respectively. If only multiparous donors were deferred from apheresis donation, there would be a 5% decrease of all apheresis platelet collections. ConclusionRestricting the use of whole blood derived plasma to male-only donors and deferring all female apheresis platelet donors would impact two out of three Brazilian blood centers. A deferral policy on multiparous apheresis platelet donors may be acceptable as a temporary measure, but may cause more stress on a system that is already working at its limit.

Human T-Lymphotropic Virus Type 1 and Type 2 Seroprevalence, Incidence, and Residual Transfusion Risk Among Blood Donors in Brazil During 2007–2009

Human T-lymphotropic virus type 1/2 (HTLV-1/2) infection is endemic in Brazil but representative donor prevalence and incidence data are lacking. All blood donations (2007-2009) from three blood centers in Brazil were studied. Samples reactive on one HTLV screening test (EIA) were retested with a different EIA; dual EIA reactivity correlated strongly with a confirmatory Western blot. Prevalence, incidence, and residual transfusion risk were calculated. Among 281,760 first-time donors, 363 were positive for HTLV on both EIAs (135 per 10(5), 95% CI 122-150). Prevalence differed considerably by region, from 83 to 222 per 10(5). Overall incidence rate was 3.6/10(5) person-years and residual transfusion risk was 5.0/10(6) per blood unit transfused. The logistic regression model showed significant associations with: age [adjusted odds ratio (aOR)=5.23 for age 50+ vs. <20], female sex (aOR=1.97), black (aOR=2.70 vs. white), and mixed skin colors (aOR=1.78 vs. white), and inversely with education (aOR=0.49, college vs. less than high school). HTLV testing with a dual-EIA strategy is feasible and can be useful in areas with low resources. Incidence and residual risk of HTLV-1 transmission by transfusion were relatively high and could be reduced by improving donor recruitment and selection in high prevalence areas. Blood center data may contribute to surveillance for HTLV infection.

Promoting safe and effective use of blood products

Promoting safe and effective use of blood products

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

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. 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. 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, São 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. 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.

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

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. 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. 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). 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.

Interdonation intervals and patterns of return among blood donors in Brazil

In Brazil, most donations come from repeat donors, but there are little data on return behavior of donors. Donors who made at least one whole blood donation in 2007 were followed for 2 years using a large multicenter research database. Donation frequency, interdonation intervals, and their association with donor demographics, status, and type of donation were examined among three large blood centers in Brazil, two in the southeast and one in the northeast. In 2007, of 306,770 allogeneic donations, 38.9% came from 95,127 first-time donors and 61.1% from 149,664 repeat donors. Through December 31, 2009, a total of 28.1% of first-time donors and 56.5% of repeat donors had donated again. Overall, the median interdonation interval was approximately 6 months. Among men it was 182 and 171 days for first-time and repeat donors, and among women, 212 and 200 days. Predictors of return behavior among first-time donors were male sex (odds ratio [OR], 1.17; 95% confidence interval [CI], 1.13-1.20), community donation (OR, 2.26; 95% CI, 2.20-2.33), and age 24 years or less (OR, 0.62-0.89 for donors ≥ 25 years). Among repeat donors predictors were male sex (OR, 1.35; 95% CI, 1.32-1.39), age 35 years or more (OR, 1.08-1.18 vs. ≤ 24 years), and community donation (OR, 2.39; 95% CI, 2.33-2.44). Differences in return by geographic region were evident with higher return rates in the northeast of Brazil. These data highlight the need to develop improved communication strategies for first-time and replacement donors to convert them into repeat community donors.

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

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. 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. 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). 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.

O controle da transmissão transfusional

The high prevalence of chagasic blood donors in blood centers in Brazil (6.9%) and in Latin America (6.5%) in the 60's and 70's, together with the combat to the vector since the 70's have made transfusion Chagas disease the main mechanism of the disease transmission in the 80's. However, the highly favorable results achieved to eliminate the vector and the serologic screening of blood donors, reduced the prevalence of serum positivity to 0.2% and 1.3%, respectively and the rate of annual transmission through blood transfusion from 20.000 to 13 in four decades in Brazil. Nevertheless, despite outstanding advancements in endemic countries, Chagas disease reached, via migration, non-endemic countries in North America and Europe besides Japan and Australia, placing their blood recipients at risk and turning Chagas disease into a worldwide health problem. Transfusion safety through serologic selection raised another big issue i.e. high proportion of inconclusive reactions as well as two great challenges: the meaning of such exams and what guidelines to provide the donor. However, the strategies adopted by non-endemic countries and the advancements achieved by endemics so far forecast the highly wished vector and transfusion control of Chagas disease.

Enhanced classification of Chagas serologic results and epidemiologic characteristics of seropositive donors at three large blood centers in Brazil

A major problem in Chagas disease donor screening is the high frequency of samples with inconclusive results. The objective of this study was to describe patterns of serologic results among donors to the three Brazilian REDS-II blood centers and correlate with epidemiologic characteristics. The centers screened donor samples with one Trypanosoma cruzi lysate enzyme immunoassay (EIA). EIA-reactive samples were tested with a second lysate EIA, a recombinant-antigen based EIA, and an immunfluorescence assay. Based on the serologic results, samples were classified as confirmed positive (CP), probable positive (PP), possible other parasitic infection (POPI), and false positive (FP). In 2007 to 2008, a total of 877 of 615,433 donations were discarded due to Chagas assay reactivity. The prevalences (95% confidence intervals [CIs]) among first-time donors for CP, PP, POPI, and FP patterns were 114 (99-129), 26 (19-34), 10 (5-14), and 96 (82-110) per 100,000 donations, respectively. CP and PP had similar patterns of prevalence when analyzed by age, sex, education, and location, suggesting that PP cases represent true T. cruzi infections; in contrast the demographics of donors with POPI were distinct and likely unrelated to Chagas disease. No CP cases were detected among 218,514 repeat donors followed for a total of 718,187 person-years. We have proposed a classification algorithm that may have practical importance for donor counseling and epidemiologic analyses of T. cruzi-seroreactive donors. The absence of incident T. cruzi infections is reassuring with respect to risk of window phase infections within Brazil and travel-related infections in nonendemic countries such as the United States.