Detection of dengue virus in sera of Brazilian blood donors

BACKGROUND: Dengue is the most important arboviral disease in the world. Dengue viruses (DENVs) have produced huge outbreaks in Brazil in the past 25 years with more than 5 million reported cases. During these epidemics, asymptomatic individuals infected with DENV could donate blood and serve as a source of virus dissemination in the community. Here, we studied the circulation of DENV in healthy individuals during an epidemic outbreak. STUDY DESIGN AND METHODS: The study included 500 serum samples from healthy blood donors collected at the Hemotherapy Center of Ribeirao Preto, Brazil, during a dengue outbreak. The presence of DENV RNA in the serum samples was screened by real-time reverse transcriptionpolymerase chain reaction (PCR). The virus serotype was determined by a heminested PCR procedure. A partial fragment of the NS5 gene sequence was used for phylogenetic analysis. RESULTS: DENV RNA was detected in the serum sample of 2 of 500 (0.4%) individuals. Both of them were infected with DENV-3 Genotype III, a virus that has been circulating in Brazil in the past decade. CONCLUSION: Individuals with asymptomatic DENV infection can be blood donors and serve as a source of virus dissemination in the community. Further studies are needed to determine the risk of recipient infection by DENV as a result of transfusion in Brazil, especially during epidemic periods.

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.

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 Sao Paulo and Recife (p < 0.001). Serologic markers for HIV and syphilis and overall were associated with multiple partners in Sao 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.

Antimicrobial activity of two techniques for arm skin disinfection of blood donors in Brazil

Objective: Evaluation of the antimicrobial effect of skin disinfection techniques is essential to avoid the transmission of infectious agents during blood transfusion. The aim of this study was to examine the effectiveness of two methods of arm skin disinfection used in blood donors at a Hemotherapy Center in Brazil that represents an important centre for distributing haemocomponents to many cities in the country. Methods: Two skin disinfection techniques in 50 blood donors were evaluated. For the first arm, 10% povidone-iodine/two-stage technique was used. On the opposite arm, 0.5% chlorhexidine digluconate alcohol solution/one-stage technique was used. The swabs were seeded on three culture media: blood agar, mannitol salt agar and Mac Conkey agar. Automated bacterial classification based on biochemical tests/specific substrates was performed. Donor characteristics were collected using the computerised system of the Hemotherapy Center. Results: We found that microbial reduction was significantly higher for 10% povidone-iodine technique (98.57-98.87%) when compared with 0.5% chlorhexidine technique (94.38-95.06%). The species Leuconostoc mesenteroides and Staphylococcus hominis showed resistance to both disinfection techniques. We did not find statistically significant relationships between donor characteristics and microbial reduction. Conclusions: Arm skin disinfection with 10% povidone-iodine produced better antimicrobial activity. We must acknowledge that 10% povidone-iodine technique has the limitation of being a two-stage method. However, prevention of adverse events due to bacterial contamination and transfusion reactions should be prioritised. Production of hypoallergenic and stronger antiseptics that allowed a safe one-stage disinfection technique should be encouraged in health systems, not only in Brazil but also around the world.

Single Center Experience With Elective Surgical Patients as Living Kidney Donors

Purpose. To report a single center experience with elective surgical patients as living kidney donors. Methods. We retrospectively analyzed a prospective database of 458 living kidney donors from September 2005 to May 2011. Fifteen (3.2%) of them were elective surgical patients simultaneously undergoing living donor nephrectomy. We reviewed age, gender, operative time, intraoperative blood transfusion, intra- and postoperative complications, as well as length of hospital stay. Recipients were evaluated for delayed graft function. Four hundred forty-three patients undergoing living donor nephrectomy alone composed the control group. Results. Among the elective surgical patients group, the mean (range) operative time was 155 (90 to 310) minutes and mean (range) length of hospital stay was 3 (2 to 9) days. One (6.7%) recipient displayed delayed graft function. Among the regular living kidney donors group, the mean (range) operative time was 100 (70 to 150) minutes, mean (range) length of hospital stay was 3 (2 to 5) days, and delayed graft function was observed in 5.6% of recipients. Only operative time (P = .03) was significantly different between the groups. Conclusions. Elective surgical patients are potential donors who may be treated at the same time as the living donor nephrectomy.

Molecular and phylogenetic analyses of human Parvovirus B19 isolated from Brazilian patients with sickle cell disease and beta-thalassemia major and healthy blood donors

Human Parvovirus B19 (B19V) is a recognized cause of life-threatening conditions among patients with hemoglobinopathies. This study investigates B19V infection in patients with sickle cell disease and beta-thalassemia using different experimental approaches. A total of 183 individuals (144 with sickle cell disease and 39 with beta-thalassemia major) and 100 healthy blood donors were examined for B19V using anti-B19V IgG enzyme immunoassay, quantitative PCR, DNA sequencing, and phylogenetic analysis. Viremia was documented in 18.6% of patients and 1% of donors, and was generally characterized by low viral load (VL); however, acute infections were also observed. Anti-B19V IgG was detected in 65.9% of patients with sickle cell disease and in 60% of donors, whereas the patients with thalassemia exhibited relatively low seroreactivity. The seroprevalence varied among the different age groups. In patients, it progressively increased with age, whereas in donors it reached a plateau. Based on partial NS1 fragments, all isolates detected were classified as subgenotype 1A with a tendency to elicit genetically complex infections. Interestingly, quasispecies occurred in the plasma of not only patients but also donors with even higher heterogeneity. The partial NS1 sequence examined did not exhibit positive selection. Quantitation of B19V with a conservative probe is a technically and practically useful approach. The extensive spread of B19V subgenotype 1A in patients and donors and its recent introduction into the countryside of the Sao Paulo State, Brazil were demonstrated; however, it is difficult to establish a relationship between viral sequences and the clinical outcomes of the infection. J. Med. Virol. 84:16521665, 2012. (c) 2012 Wiley Periodicals, Inc.

Prevalence of celiac disease among blood donors in Sao Paulo - the most populated city in Brazil

OBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immune-mediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. Sao Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of Sao Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundacao Pro-Sangue Blood Center of Sao Paulo, Sao Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1: 286 among supposedly healthy blood bank volunteers in Sao Paulo, Brazil.

HTLV-1/2 seroprevalence and coinfection rate in Brazilian first-time blood donors: an 11-year follow-up

The seroprevalence and geographic distribution of HTLV-1/2 among blood donors are extremely important to transfusion services. We evaluated the seroprevalence of HTLV-1/2 infection among first-time blood donor candidates in Ribeirão Preto city and region. From January 2000 to December 2010, 1,038,489 blood donations were obtained and 301,470 were first-time blood donations. All samples were screened with serological tests for HTLV-1/2 using enzyme immunoassay (EIA). In addition, the frequency of coinfection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), Chagas disease (CD) and syphilis was also determined. In-house PCR was used as confirmatory test for HTLV-1/2. A total of 296 (0.1%) first-time donors were serologically reactive for HTLV-1/2. Confirmatory PCR of 63 samples showed that 28 were HTLV-1 positive, 13 HTLV-2 positive, 19 negative and three indeterminate. Regarding HTLV coinfection rates, the most prevalent was with HBV (51.3%) and HCV (35.9%), but coinfection with HIV, CD and syphilis was also detected. The real number of HTLV-infected individual and coinfection rate in the population is underestimated and epidemiological studies like ours are very informative.

Performance of six diagnostic tests to screen for Chagas disease in blood banks and prevalence of Trypanosoma cruzi infection among donors with inconclusive serology screening based on the analysis of epidemiological variables

OBJECTIVE: The frequent occurrence of inconclusive serology in blood banks and the absence of a gold standard test for Chagas'disease led us to examine the efficacy of the blood culture test and five commercial tests (ELISA, IIF, HAI, c-ELISA, rec-ELISA) used in screening blood donors for Chagas disease, as well as to investigate the prevalence of Trypanosoma cruzi infection among donors with inconclusive serology screening in respect to some epidemiological variables. METHODS: To obtain estimates of interest we considered a Bayesian latent class model with inclusion of covariates from the logit link. RESULTS: A better performance was observed with some categories of epidemiological variables. In addition, all pairs of tests (excluding the blood culture test) presented as good alternatives for both screening (sensitivity > 99.96% in parallel testing) and for confirmation (specificity > 99.93% in serial testing) of Chagas disease. The prevalence of 13.30% observed in the stratum of donors with inconclusive serology, means that probably most of these are non-reactive serology. In addition, depending on the level of specific epidemiological variables, the absence of infection can be predicted with a probability of 100% in this group from the pairs of tests using parallel testing. CONCLUSION: The epidemiological variables can lead to improved test results and thus assist in the clarification of inconclusive serology screening results. Moreover, all combinations of pairs using the five commercial tests are good alternatives to confirm results.

Factors associated with failure of clinical screening among blood donors who have altered serological results in the Centro Regional de Hemoterapia de Ribeirão Preto

OBJECTIVE: This study aimed to investigate the frequency of positive results for hepatitis B and C, HIV and syphilis in blood donations at the Centro Regional de Hemoterapia de Ribeirão Preto, to describe donors with positive results according to some demographic and socioeconomic variables, to identify risk factors associated to these donors and the reasons that they were not detected during clinical screening. METHODS: A descriptive study was performed between July 1st 2005 and July 31st 2006 by interviewing 106 donors after medical consultations where they were informed of positive results for hepatitis B, hepatitis C, HIV or syphilis. RESULTS: There was a predominance of first-time donors, males, under 50-year olds, married individuals, from Ribeirão Preto, with elementary education, low economic status and of people who donated at the request of friends or relatives. Hepatitis C was the most frequently detected infection (56.6%), followed by hepatitis B (20.7%), HIV (12.3%) and syphilis(10.4%). About 40% of donors had omitted risk factors for different reasons: because they trusted the results of serological tests, did not feel comfortable about talking of risk factors or did not consider them relevant. Other justifications were the duration of the interview, the interviewer was unskilled, embarrassment and doubts about confidentiality. CONCLUSION: The results indicate the need for changes in the approach to clinical screening and a review of methods to attract and guide potential donors.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immunemediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.