Human T-lymphotropic virus 2 (HTLV-2) prevalence of blood donors in the state of Pará, Brazil.

INTRODUCTION: The present study had the objective to describe the molecular prevalence and epidemiological aspects of the human T-lymphotropic virus 2 (HTLV-2) infection in the blood donor population of the Pará state. METHODS: The present study is a descriptive, retrospective, and cross-sectional review of epidemiological, serological, and molecular data on inapt blood donors in the State Center for Hematology and Hemotherapy from January 2015 to December 2021. The data were digitalized to create a database using the Statistical Package for Social Sciences program. The prevalence of HTLV-2 was calculated based on the total number of donations during the study period. Descriptive frequency was used to analyze the qualitative data. RESULTS: A total of 665,568 blood donations were made. Out of these, 1884 (0.2%) samples presented serological detection to HTLV and further were evaluated using molecular confirmatory tests. Out of these, 36 samples were positive for HTLV-2 using qPCR Taqman assay based on pol gene region (0.005%). The HTLV-2 was found to be more prevalent in women (63.9%); aged between 39 and 59 years (55.6%); residents of the metropolitan region of Belém (80.6%); with self-declared race as brown (80.6%); individuals who had completed high school (58.6%); and first-time donors (58.3%) CONCLUSION: The present study identified the presence of HTLV-2 (1 HTLV-2 case/20,000 donations; 0.005%) in the specific population of blood donors in Pará state. These findings can contribute to the existing literature on the subject both for specific population groups under study and for understanding the prevalence of HTLV-2 in the general population.

Frequency of antigen Dia on the blood donor population of the Hemocenter coordinator of the Hemopa Foundation

ABSTRACT Introduction: Erythrocyte phenotyping is a very important test in the adoption of prophylactic measures to reduce transfusion reactions/alloimmunizations in polytransfused patients. The blood group Diego, in its current, form has 22 antigens, of which 4 are immunogenic, being Dia/Dib and Wra/Wrb, while the others are less expressive. The antigen Dia is of low incidence among whites and blacks, however, it is common in the South American indigenous and Asian Mongolian populations. It is also considered a system of clinical importance for its immunogenicity. Method: The present study aimed to carry out a retrospective and descriptive survey of the frequency of the Dia antigen in the blood donor population at the HEMOPA Foundation Coordinating Blood Center from 12/2018 to 1/2000. The data obtained were from the HEMOPA Foundation SBS Progress and SBS WEB Systems databases. Results: During this period, 941,744 blood bags were collected and, of these, 930 bags were phenotyped for the Dia antigen, of which 842 were negative and 88 (9.7%) positive. The research showed that, among the positive donors for the antigen Dia, 88.6% were brown, 3.4%, black and 8%, white. In the statistical analysis, the frequency observed was higher in browns. Conclusion: In the present investigation, we concluded that our region has a relatively higher frequency of the Dia antigen, when compared to the rest of Brazil, and it occurs more often in browns.

Results of a sample-to-cutoff ratio using Abbott Architect rHTLV-I/II assay allow to predict detection of HTLV-1 and HTLV-2 proviral DNA by real-time PCR / Resultados da razão sinal da amostra sobre o cutoff da reação no ensaio Abbott Architect rHTLV-I/II permite prever a detecção de DNA proviral por PCR em tempo real

The present study aims to correlate the sample-to-cutoff ratios (S/CO) distributions of reactive results for HTLV-1/2 antibodies with the detection of proviral DNA in a population of blood donor candidates. It was carried out a retrospective data search of 632 HTLV-1/2 reactive samples, submitted to confirmatory testing from January 2015 to December 2019. Serological screening was performed by chemiluminescent microparticle immunoassay Architect rHTLV-I/II, whereas confirmatory testing was performed by in-house real-time polymerase chain reaction method. 496 out of 632 samples (78%) had undetectable HTLV-1/2 proviral DNA and 136 (22%) had detectable proviral DNA. HTLV infection was not confirmed in any individual for whom the S/CO ratio value was <4, and proviral DNA detection rates gradually escalated as S/CO ratio values increased. The sensitivity and predictive positive value found for the Architect rHTLV-I/II was 100% and 22%, respectively. The receiver operating characteristic (ROC) curve analysis showed that the optimal S/CO ratio value for predicting the presence of HTLV-1/2 was 18.11. High S/CO ratios were more associated with the detection of proviral DNA. The S/CO ratio value <4 suggests excluding true HTLV infection and the risk of blood transmission (AU).

O estudo tem como objetivo correlacionar às distribuições das razões sample-to-cutoff (S/CO) de resultados reagentes para anticorpos HTLV-1/2 com a detecção de DNA proviral em uma população de candidatos à doação de sangue. Realizou-se uma busca retrospectiva de dados de 632 amostras reagentes para HTLV-1/2 submetidas à testagem confirmatória entre janeiro de 2015 a dezembro de 2019. A triagem sorológica foi realizada pelo imunoensaio quimioluminescente de micropartículas Architect rHTLV-I/II, enquanto o teste confirmatório foi realizado pelo método de PCR em tempo real in-house. 496 de 632 amostras (78%) apresentaram DNA proviral indetectável e 136 (22%) apresentaram DNA proviral detectável. A infecção por HTLV não foi confirmada em nenhum indivíduo com valor de S/CO <4 e as taxas de detecção de DNA proviral escalonaram gradualmente à medida que as razões S/CO aumentaram. A sensibilidade e valor preditivo positivo encontrados para o Architect rHTLV-I/II foram 100% e 22%, respectivamente. Utilizando análise de curva ROC, o valor de razão S/CO ideal para predizer a presença de DNA proviral foi de 18,11. Razões S/CO elevadas foram mais associadas à detecção de DNA proviral. Em suma, o valor de S/CO <4 sugere a exclusão de infecção por HTLV e o risco de transmissão pelo sangue (AU).

Frequency of antigen Dia on the blood donor population of the Hemocenter coordinator of the Hemopa Foundation.

INTRODUCTION: Erythrocyte phenotyping is a very important test in the adoption of prophylactic measures to reduce transfusion reactions/alloimmunizations in polytransfused patients. The blood group Diego, in its current, form has 22 antigens, of which 4 are immunogenic, being Diª/Dib and Wra/Wrb, while the others are less expressive. The antigen Diª is of low incidence among whites and blacks, however, it is common in the South American indigenous and Asian Mongolian populations. It is also considered a system of clinical importance for its immunogenicity. METHOD: The present study aimed to carry out a retrospective and descriptive survey of the frequency of the Diª antigen in the blood donor population at the HEMOPA Foundation Coordinating Blood Center from 12/2018 to 1/2000. The data obtained were from the HEMOPA Foundation SBS Progress and SBS WEB Systems databases. RESULTS: During this period, 941,744 blood bags were collected and, of these, 930 bags were phenotyped for the Diª antigen, of which 842 were negative and 88 (9.7%) positive. The research showed that, among the positive donors for the antigen Diª, 88.6% were brown, 3.4%, black and 8%, white. In the statistical analysis, the frequency observed was higher in browns. CONCLUSION: In the present investigation, we concluded that our region has a relatively higher frequency of the Diª antigen, when compared to the rest of Brazil, and it occurs more often in browns.

Prevalence of Dengue, Chikungunya and Zika Viruses in Blood Donors in the State of Pará, Northern Brazil: 2018-2020.

Arboviruses have been reported over the years as constant threats to blood transfusion recipients, given the high occurrence of asymptomatic cases and the fact that the presence of viremia precedes the onset of symptoms, making it possible that infected blood from donors act as a source of dissemination. This work aims to identify the prevalence of dengue virus (DENV), Zika virus (ZIKV) and Chikungunya virus (CHIKV) infection in blood donors during epidemic and non-epidemic periods; classify the donor as symptomatic or asymptomatic; and verify the need to include DENV, CHIKV and ZIKV in the nucleic acid test (NAT) platform in northern Brazil. We investigated 36,133 thousand donations in two years of collection in Northern Brazil. One donor was positive for DENV and one for CHIKV (0.002% prevalence). As the prevalence for arboviruses was low in this study, it would not justify the individual screening of samples from donors in a blood bank. Thus, DENV- and CHIKV-positive samples were simulated in different amounts of sample pools, and both were safely detected by molecular biology even in a pool of 14 samples, which would meet the need to include these three viruses in the routine of blood centers in endemic countries such as Brazil.

Epidemiological and molecular profile of blood donors infected with HTLV-1/2 in the state of Pará, northern Brazil.

BACKGROUND: The Human T-lymphotropic virus (HTLV) is a retrovirus of the genus Deltaretrovirus, which belongs to the family Retroviridae. The most important types are HTLV-1 and HTLV-2. It is estimated that between five and 10 million individuals are infected with HTLV-1, worldwide. Studies in the state of Pará indicate that it has the third highest prevalence of HTLV infections of any Brazilian state. The present study describes the epidemiological, serological, and molecular profile of blood donors from the state of Pará that were classified as unfit due to infection by HTLV-1 and 2. METHODS: The present study is based on a descriptive, retrospective, and cross-sectional review of the epidemiological, serological, and molecular data on blood donations, between January 2015 and December 2019. The data were obtained from the blood bank system and were digitalized to form a database in the Statistical Package for Social Sciences program, version 20. Descriptive statistics were used to determine the absolute and relative frequencies of the qualitative variables. For the quantitative variables, the mean, standard deviation, and minimum and maximum values were calculated. A p < 0.05 significance level was adopted for all analyses. RESULTS: A total of 632 samples were analyzed, of which 496 (78%) had no detectable proviral DNA and 136 (22%) had detectable HTLV. The HTLV-1 was detected in most (78%; 106/136) of these samples, while only 30 (22%) were detected for HTLV-2. The HTLV proviral DNA was detected primarily in females (69.1%), with a mean age of 40 years, with the highest frequencies of detection being recorded in single individuals (66.2%), first-time donors (74.3%), and individuals that had graduated high school (44.1%). The molecular confirmation of HTLV showed that three-quarters (78%) of the serologically reactive individuals were negative for either types 1 or 2, so the epidemiological profile of these individuals was significantly different from their detectable profile. CONCLUSIONS: The HTLV is neglected in Brazil; there is thus a clear need for further research in the area of regional hemotherapy and hematology services, in order to contribute to the definition of regional infection profiles, that will be fundamental to the development of effective prophylactic practices for the prevention of the infection and the dissemination of knowledge on the dangers of HTLV in the community.

Prevalence, incidence and residual risk of transfusion-transmitted HBV infection before and after the implementation of HBV-NAT in northern Brazil.

BACKGROUND: Nucleic acid testing (NAT) for virus detection during blood screening has helped to prevent transfusion-transmitted infections worldwide. In northern Brazil, NAT was implemented in 2012 for HIV and HCV and more recently, in January 2015, the screening for HBV was included and currently used concomitant with serological tests (HBsAg and anti-HBc). This study aims to evaluate the prevalence and the incidence of HBV infection among voluntary blood donors at ten regional blood centers of HEMOPA Foundation in Pará state and to compare the residual risk of transfusion-transmitted HBV infection before and after the Brazilian HBV-NAT implementation. METHODS: The prevalence (restricted to first time donors- FT) and seroconversion rate (restricted to repeat donors- RP) of HBV were calculated based on rates of confirmed positive samples. Residual risk was based on the incidence and window period (WP) model described by Schreiber and coauthors. Logistic and Poisson regression were used in the statistical analysis by SPSS v20.0. A p value <0.05 was considered statistically significant. RESULTS: HBV prevalence in the periods before and after the implementation of HBV-NAT were 247 and 251 per 100,000 donations, respectively. Seroconversion rates were 114 and 122 per 100,000 donations in the two periods, respectively. The residual risk (RR) for HBV decreased significantly in the posterior period to the HBV-NAT implementation, when compared to RR before implementation, with a reduction of 1:144,92 to 1:294,11 donations (p <0,001). CONCLUSIONS: The RR to HBV decreased after the implementation of HBV-NAT, increasing significantly the transfusional security in the North region of Brazil at HEMOPA Foundation.