Seroprevalence of IgG and IgM anti-SARS-CoV-2 among voluntary blood donors in Rio de Janeiro, Brazil

Background: In Brazil, mathematical models for deriving estimates and projections of COVID-19 cases have been developed without data on asymptomatic SARS-CoV-2 infection. We estimated the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the State of Rio de Janeiro. Methods: Data were collected on 2,857 blood donors from April 14 to 27, 2020. We report the crude prevalence of antibodies to SARS-CoV-2, the weighted prevalence by the total state population, and adjusted prevalence estimates for test sensitivity and specificity. To establish the correlates of SARS-CoV-2 prevalence, we used logistic regression models. The analysis included period and site of blood collection, sociodemographic characteristics, and place of residence. Results: The proportion of SARS-Cov-2 positive tests without any adjustment was 4.0% (95% CI 3.3-4.7%), and the weighted prevalence was 3.8% (95% CI 3.1-4.5%). Further adjustment by test sensitivity and specificity produced lower estimates, 3.6% (95% CI 2.7-4.4%) and 3.3% (95% CI 2.6-4.1%), respectively. The variable most significantly associated with the crude prevalence was the period of blood collection: the later the period, the higher the prevalence. Regarding socio-demographic characteristics, the younger the blood donors, the higher the prevalence, and the lower the educational level, the higher the odds of a positive SARS-Cov-2 antibody. Similar results were found for the weighted prevalence. Discussion: Although our findings resulted from a convenience sample, they match some basic premises: the increasing trend over time, since the epidemic curve in the state is still on the rise; the higher prevalence among the youngest who are more likely to circulate; and the higher prevalence among the less educated as they have more difficulties in following the social distancing recommendations. Despite the study limitations, it is possible to infer that protective levels of natural herd immunity to SARS-CoV-2 are far from being reached in Rio de Janeiro

10-year analysis of human immunodeficiency virus incidence in first-time and repeat donors in Brazil

INTRODUÇÃO: A incidência em doadores de sangue de primeira vez e de repetição é uma medida importante do risco de infecção por HIV transmitido por transfusão. Entretanto, no Brasil pouco se sabe sobre a tendência da incidência do HIV em doadores de sangue ao longo do tempo, e sobre o risco residual nas doações de sangue. Ao mesmo tempo, o entendimento e o monitoramento da incidência é de grande relevância, pois os fatores de risco para uma unidade doada estar em janela infecciosa ou imunológica são desconhecidos e, principalmente, os dados de tendências de incidência do HIV não estão disponíveis em relação à população geral do Brasil. Para tentar ajudar a preencher essa lacuna, este estudo avaliou a incidência do HIV ao longo do tempo em quatro grandes hemocentros no Brasil. MÉTODOS: As doações foram testadas e os resultados confirmados por meio de testes sorológicos para HIV de 2007 a 2016 e, adicionalmente, foram realizados testes para a detecção de ácido nucleico a partir de 2011. O teste de avidez do antígeno limitante (LAg) foi realizado em amostras positivas para HIV em doadores de primeira vez para classificar se uma infecção foi adquirida recentemente. Foi calculada a incidência em doadores de primeira vez usando a duração média da infecção recente, e em doadores de repetição usando métodos clássicos. As tendências temporais e demográficas foram avaliadas por meio da regressão de Poisson. RESULTADOS: No período de 10 anos compreendido pelo estudo, a incidência estimada de HIV em doadores de primeira vez se mostrou maior em Recife (45,1 casos por 100.000 pessoas-ano), seguido por São Paulo (32,2 casos por 100.000 pessoas-ano) e por Belo Horizonte (23,3 casos por 100.000 pessoasano). Em doadores de repetição a incidência também foi maior em Recife (33,2 casos novos de HIV por 100.000 pessoas-ano), seguido por Belo Horizonte (27,5 casos novos de HIV por 100.000 pessoas-ano) e por São Paulo (17,0 casos novos por 100.000 pessoas-ano). Já no Rio de Janeiro os resultados entre doadores de primeira vez foram estimados em 35,9 casos por 100.000 pessoasano de 2013 a 2016; e entre os doadores de repetição a incidência foi estimada em 29,2 casos por 100.000 pessoas-ano de 2011 a 2016. A incidência de HIV foi maior em doadores espontâneos do que em doadores de reposição, e entre os doadores mais jovens que comparecem ao hemocentro mais vezes para doar. O risco residual de transmissão de HIV por transfusão foi de 5,46 e 7,41 por milhão de unidades de concentrado de hemácias e de plasma fresco congelado transfundidas, respectivamente. CONCLUSÃO: Não foram evidenciadas alterações no padrão da incidência de HIV ao longo dos 10 anos de estudo. Reduzir a doação feita por indivíduos com infecção por HIV recentemente adquirida é a forma mais segura de reduzir o risco de infecção transmitida por transfusão, e atenção especial é necessária para os doadores de repetição, para determinados grupos etários e para as regiões com maior incidência de HIVBACKGROUND: Incidence in first-time and repeat blood donors is an important measure of transfusion-transmitted HIV infection risk. In Brazil, little is known about the trend in the incidence of HIV in blood donors over time and about the residual risk in blood donations. Understanding and monitoring incidence is of great importance, as the risk factors related to transfusion transmission are unknown and, mainly, data on incidence trends are not available in relation to the general population of Brazil. To try to help fill this gap, this study assessed HIV incidence over time at four large blood centers in Brazil. MATERIALS AND METHODS: Donations were screened and confirmed using serological assays for HIV from 2007 to 2016, and additionally screened by nucleic acid testing from 2011 forward. Limiting antigen (LAg) avidity testing was conducted on HIV seroreactive samples from first-time donors to classify whether an infection was recently acquired. We calculated incidence in first-time donors using the mean duration of recent infection and in repeat donors using classical methods. Time and demographic trends were assessed using Poisson regression. RESULTS: Over the 10-year period, HIV incidence in first-time donors was highest in Recife (45.1/100.000 person-years (105 py)) followed by São Paulo (32.2/105 py) and then Belo Horizonte (23.3/105 py), and in repeat donors was highest in Recife (33.2/105 py), Belo Horizonte (27.5/105 py) and São Paulo (17.0/105 py). Results from Rio de Janeiro were available from 2013 to 2016 with incidence in first-time donors of 35.9/105 py, and from 2011 to 2016 with incidence of 29.2/105 py in repeat donors. The incidence of HIV was higher in community donors than in replacement donors, and among younger donors who attend the blood center more often to donate. Incidence varied by other donor demographics. When incidence was considered in 2-year intervals, no significant trend was evident. Overall residual risk of transfusion-transmitted HIV infection was 5.46 and 7.41 per million units of packed red blood cell (pRBC) and fresh frozen plasma (FFP) transfused, respectively. CONCLUSION: HIV incidence in both first time and repeat donors varied by region in Brazil. Clear secular trends were not evident. Reducing donation among donors with newly acquired HIV infection is the safest way to reduce the risk of transfusiontransmitted infection, and special attention is needed for repeat donors, age groups and regions with the highest HIV incidenc

Comparison of Two Methods of Capillary Sampling in Blood Pre-Donation Anemia Screening in Brazil

Background: The laboratory tests most used by blood banks to diagnose anemia are the hemoglobin (Hb) and microhematocrit (Hct) tests, measured from capillary samples. Objective: To analyze the two capillary screening methods for pre-donation anemia by comparing their agreement in diagnosing anemia. Method: A cross-sectional study in a population of 15,521 blood donation candidates for whom information was available on Hb and Hct, performed from capillary blood samples. Hb was determined using the HemoCue® test and Hct by the centrifugation method. The Kappa coefficient was calculated to assess the agreement between the methods. Pearson’s correlation tests and gender-adjusted linear regression were used to assess the change in the response variable (Hb) as a function of the explanatory variable (Hct). Results: The majority of the study population were men (70.4%), aged between 18 and 44 years (72.1%), who declared themselves white or mixed skin color (85.6%), and had undergone at least 11 years of complete education (72.4%). The Kappa coefficient found was 92.7 and 99.2 for women and men, respectively. Pearson’s correlation showed a correlation coefficient of 0.98 and the linear regression graph showed an adequate relationship between the tests with R2 = 0.97. Conclusions: Comparing the Hb and Hct capillary tests, it was found that Hct can be safely used to screen for anemia in pre-blood donation

Association of HIV infection with clinical and laboratory characteristics of sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is a multisystem disorder characterized by a wide spectrum of clinical manifestations and severity. Studies investigating potential effects of co-morbid human immunodeficiency virus (HIV) and SCD have produced conflicting results, and additional investigations are needed to elucidate whether the interaction between the two disease states might impact both HIV and SCD clinical outcomes. The association of HIV infection with clinical and laboratory characteristics of patients with SCD was assessed. METHODS: This nested case-control study included individuals with SCD with HIV treated at six Brazilian SCD centers. Clinical and laboratory data were abstracted from medical records. HIV positive participants were compared to age, gender, center, and SCD genotype matched HIV negative participants (ratio 1:4). Individual clinical outcomes as well as a composite outcome of any SCD complication and a composite outcome of any HIV-related complication were compared between the two groups. RESULTS: Fifteen HIV positive participants were included, 12 (80%) alive and 3 (20%) deceased. Most of the HIV positive patients had HbSS (60%; n = 9), 53% (n = 8) were female, and mean age was 30 ± 13 years. The frequency of individual SCD complications of acute chest syndrome/pneumonia, sepsis/bacteremia, pyelonephritis, ischemic stroke, hemorrhagic stroke, abnormal transcranial Doppler (TCD), and pulmonary hypertension was higher in HIV positive participants when compared to HIV negative, although analyzed individually none were statistically significant. HIV positive participants had significantly higher risk of any SCD complication and of a composite HIV-related complication compared to the HIV negative group (HR = 4.6; 95%CI 1.1-19.6; P = 0.04 and HR = 7.7; 95%CI 1.5-40.2; P = 0.02, respectively). There was a non-significant trend towards higher risk of any infections in participants with HIV positive (HR = 3.5; 95%CI 0.92-13.4; P = 0.07). Laboratory parameters levels were not significantly different in individuals with and without HIV. CONCLUSIONS: In summary, our study in SCD patients shows that those with HIV have an increased risk of any SCD complication and HIV-related complications, as well as a suggestive but not significantly increased risk of infections

Seroprevalence of anti-SARS-CoV-2 among blood donors in Rio de Janeiro, Brazil

OBJECTIVE: To estimate the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the state of Rio de Janeiro, Brazil. METHODS: Data were collected on 2,857 blood donors from April 14 to 27, 2020. This study reports crude prevalence of antibodies to SARS-CoV-2, population weighted prevalence for the state, and prevalence adjusted for test sensitivity and specificity. Logistic regression models were used to establish the correlates of SARS-CoV-2 prevalence. For the analysis, we considered collection period and site, sociodemographic characteristics, and place of residence. RESULTS: The proportion of positive tests for SARS-Cov-2, without any adjustment, was 4.0% (95%CI 3.3–4.7%), and the weighted prevalence was 3.8% (95%CI 3.1–4.5%). We found lower estimates after adjusting for test sensitivity and specificity: 3.6% (95%CI 2.7–4.4%) for the non-weighted prevalence, and 3.3% (95%CI 2.6–4.1%) for the weighted prevalence. Collection period was the variable most significantly associated with crude prevalence: the later the period, the higher the prevalence. Regarding sociodemographic characteristics, the younger the blood donor, the higher the prevalence, and the lower the education level, the higher the odds of testing positive for SARS-Cov-2 antibody. We found similar results for weighted prevalence. CONCLUSIONS: Our findings comply with some basic premises: the increasing trend over time, as the epidemic curve in the state is still on the rise; and the higher prevalence among both the youngest, for moving around more than older age groups, and the less educated, for encountering more difficulties in following social distancing recommendations. Despite the study limitations, we may infer that Rio de Janeiro is far from reaching the required levels of herd immunity against SARS-CoV-2.

Prevalence and Risk Factors for Human T-Cell Lymphotropic Virus (HTLV) in Blood Donors in Brazil-A 10-Year Study (2007-2016).

It is unknown whether HTLV-1/2 prevalence has been stable or changing with time in Brazil. We present a 10-year (2007-2016) analysis of HTLV-1/2 infection in first-time blood donors from four blood banks in Brazil. The Brazilian blood centers participating in this multicenter Recipient Epidemiology and Donor Evaluation Study (REDS) are located in Recife in the Northeast and in São Paulo, Rio de Janeiro and Belo Horizonte located in the Southeast of the country. A previous REDS study using the same database from 2007 to 2009 showed that the prevalence per 100,000 donors was 222 in Recife, 83 in Belo Horizonte and 101 in São Paulo. From 2007 to 2016, HTLV-1/2 prevalence was calculated by year, blood center and birth cohort. Covariates included age, gender, schooling, self-reported skin color and type of donation. From 1,092,174 first-blood donations, in the general analysis, HTLV-1/2 infection predominated in females, donors over 50 years of age, black skin color and less educated. The average prevalence was 228 per 100,000 donors in Recife, 222 in Rio de Janeiro, 104 in Belo Horizonte and 103 in São Paulo. In the 10-year analysis, HTLV-1/2 prevalence was stable, but a trend was observed toward an increase in HTLV-1/2 infection among younger people (p < 0.001), males (p = 0.049), those with white skin color (p < 0.001), and higher education (p = 0.014). Therefore, this 10-year surveillance of the infection showed stable HTLV-1/2 prevalence overall but a trend toward increased prevalence among the younger and more educated donors despite Brazilian policies to control sexually transmitted infections being in place for more than 10 years

Strategies and performance of the CMS silicon tracker alignment during LHC Run 2

The strategies for and the performance of the CMS silicon tracking system alignment during the 2015–2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios