Sheila de Oliveira Garcia Mateos
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Sheila de Oliveira Garcia Mateos has a total of 297 co-authors. Here are the top co-authors by number of shared publications:
- Ester Cerdeira Sabino
Faculdade de Medicina (FMUSP) and Instituto de Medicina Tropical, Universidade de São Paulo, São Paulo, Brazil
8 shared publications - Cesar de Almeida-Neto
Division of Research & Transfusion Medicine Pro‐Blood Foundation/Blood Center of São Paulo São Paulo Brazil
4 shared publications Ester C. Sabino
Affiliation Institute of Tropical Medicine, Faculdade de Medicina Universidade de São Paulo, São Paulo, São Paulo, Brazil
4 shared publications- Juliana Pereira
Faculdade de Medicina da Universidade de São Paulo
4 shared publications Brian Custer
Affiliation Vitalant Research Institute, San Francisco, California, United States of America
3 shared publications- Carlos Augusto Prete
Department of Electronic Systems Engineering, University of Sao Paulo
3 shared publications
Latest Publications
- Open Access
- 22 July 2026
- Published by MDPI AG in Diagnostics
- Vol. 16 (14) , 2288
Integrated TCRγ Clonality Workflow for Molecular Diagnosis in HTLV-1 Carriers and Adult T-Cell Leukemia/Lymphoma
Background/Objectives: T-cell receptor gamma (TCRγ) clonality testing by multiplex polymerase chain reaction (PCR) is an important ancillary method in the diagnostic evaluation of T-cell lymphoproliferative disorders. Interpretation is particularly challenging in HTLV-1 infection, in which persistent antigenic stimulation may produce clonal or oligoclonal T-cell expansions overlapping with non-neoplastic patterns. This study aimed to assess the diagnostic performance and interpretative contribution of two EuroClonality/BIOMED-2 assays (TCRγ-A and TCRγ-B), considered complementary components of the same analytical panel, and a single-tube multiplex PCR assay (TCRγ-O), and to develop an integrated workflow for TCRγ clonality interpretation. Methods: A total of 107 peripheral blood samples were analyzed, including 19 healthy donors, 75 HTLV-1 carriers, and 13 patients with adult T-cell leukemia/lymphoma (ATLL). TCRγ clonality was evaluated using three multiplex PCR assays followed by capillary electrophoresis. Profiles were classified as polyclonal, oligoclonal, or monoclonal. Diagnostic performance analysis was performed using healthy donors as the reference negative group and ATLL patients as the reference positive group. Results: The combined EuroClonality approach (TCRγ-A+B) showed the highest sensitivity (100%), whereas TCRγ-O showed the highest specificity (94.7%). TCRγ-A and TCRγ-B each showed a sensitivity of 76.9%, with specificities of 84.2% and 78.9%, respectively. Classification was highly concordant in healthy donors and ATLL patients employing both assays. However, among HTLV-1 carriers, classification varied across the assays. The integrated workflow was associated with a significant change in the distribution of molecular classification patterns in the HTLV-1 group compared with EuroClonality-based interpretation alone. (Stuart–Maxwell, p < 0.001). Conclusions: The EuroClonality/BIOMED-2 strategy provided greater sensitivity, whereas TCRγ-O showed greater specificity. Their integration supported a complementary and hierarchical approach to TCRγ clonality assessment, particularly in HTLV-1 infection. These findings support an exploratory integrated framework for TCRγ clonality interpretation in HTLV-1 infection and ATLL, requiring validation in larger independent cohorts.
- 22 July 2026
- Published by MDPI AG in Diagnostics
- Vol. 16 (14) , 2288
Open AccessIntegrated TCRγ Clonality Workflow for Molecular Diagnosis in HTLV-1 Carriers and Adult T-Cell Leukemia/Lymphoma
Background/Objectives: T-cell receptor gamma (TCRγ) clonality testing by multiplex polymerase chain reaction (PCR) is an important ancillary method in the diagnostic evaluation of T-cell lymphoproliferative disorders. Interpretation is particularly challenging in HTLV-1 infection, in which persistent antigenic stimulation may produce clonal or oligoclonal T-cell expansions overlapping with non-neoplastic patterns. This study aimed to assess the diagnostic performance and interpretative contribution of two EuroClonality/BIOMED-2 assays (TCRγ-A and TCRγ-B), considered complementary components of the same analytical panel, and a single-tube multiplex PCR assay (TCRγ-O), and to develop an integrated workflow for TCRγ clonality interpretation. Methods: A total of 107 peripheral blood samples were analyzed, including 19 healthy donors, 75 HTLV-1 carriers, and 13 patients with adult T-cell leukemia/lymphoma (ATLL). TCRγ clonality was evaluated using three multiplex PCR assays followed by capillary electrophoresis. Profiles were classified as polyclonal, oligoclonal, or monoclonal. Diagnostic performance analysis was performed using healthy donors as the reference negative group and ATLL patients as the reference positive group. Results: The combined EuroClonality approach (TCRγ-A+B) showed the highest sensitivity (100%), whereas TCRγ-O showed the highest specificity (94.7%). TCRγ-A and TCRγ-B each showed a sensitivity of 76.9%, with specificities of 84.2% and 78.9%, respectively. Classification was highly concordant in healthy donors and ATLL patients employing both assays. However, among HTLV-1 carriers, classification varied across the assays. The integrated workflow was associated with a significant change in the distribution of molecular classification patterns in the HTLV-1 group compared with EuroClonality-based interpretation alone. (Stuart–Maxwell, p < 0.001). Conclusions: The EuroClonality/BIOMED-2 strategy provided greater sensitivity, whereas TCRγ-O showed greater specificity. Their integration supported a complementary and hierarchical approach to TCRγ clonality assessment, particularly in HTLV-1 infection. These findings support an exploratory integrated framework for TCRγ clonality interpretation in HTLV-1 infection and ATLL, requiring validation in larger independent cohorts.
- Open Access
- 1 January 2026
- Published by FapUNIFESP (SciELO) in Revista do Instituto de Medicina Tropical de São Paulo
- Vol. 68, e30
Molecular biomarkers associated with ATLL and HAM progression in HTLV-1 infection: a systematic review
Human T-lymphotropic virus type 1 (HTLV-1) infects approximately five to 10 million individuals worldwide, although only a minority develop severe outcomes such as adult T-cell leukemia/lymphoma (ATLL) or HTLV-1-associated myelopathy (HAM). Proviral load (PVL), while widely used, shows limited sensitivity and specificity, reinforcing the need for complementary biomarkers. Omics-based approaches have emerged as promising tools to improve risk prediction. We conducted a systematic review following PRISMA guidelines, searching PubMed, Web of Science, Virtual Health Library (BVS), and CAPES Periodicals databases for studies published between May 2020 and May 2025. Eligible studies included original observational designs investigating genomic, proteomic, and metabolic biomarkers associated with progression to ATLL or HAM. Methodological quality was assessed using tools from the National Heart, Lung, and Blood Institute (NHLBI). In total, 35 studies met the inclusion criteria, most conducted in Brazil, Japan, and Iran. A total of 67 biomarkers were identified: 37 genomic, 27 proteomic, and three metabolic with potential clinical applications in risk stratification, prognosis, and therapeutic monitoring of HTLV-1 infection. PVL remained the most frequently investigated marker but lacked predictive power in isolation. Additional candidates with strong potential included IFN-γ, CXCL10, Neopterin, AnxA1, and sTNFR2. This review highlights the potential of integrated multiparametric panels—combining PVL with omics-derived biomarkers—as a promising strategy to improve risk stratification, prognosis, and therapeutic monitoring in people living with HTLV-1 (PLHTLV-1). However, further longitudinal and clinically validated studies are needed to confirm their applicability and support their translation into early intervention strategies, particularly during the asymptomatic phase.
- 1 January 2026
- Published by FapUNIFESP (SciELO) in Revista do Instituto de Medicina Tropical de São Paulo
- Vol. 68, e30
Open AccessMolecular biomarkers associated with ATLL and HAM progression in HTLV-1 infection: a systematic review
Human T-lymphotropic virus type 1 (HTLV-1) infects approximately five to 10 million individuals worldwide, although only a minority develop severe outcomes such as adult T-cell leukemia/lymphoma (ATLL) or HTLV-1-associated myelopathy (HAM). Proviral load (PVL), while widely used, shows limited sensitivity and specificity, reinforcing the need for complementary biomarkers. Omics-based approaches have emerged as promising tools to improve risk prediction. We conducted a systematic review following PRISMA guidelines, searching PubMed, Web of Science, Virtual Health Library (BVS), and CAPES Periodicals databases for studies published between May 2020 and May 2025. Eligible studies included original observational designs investigating genomic, proteomic, and metabolic biomarkers associated with progression to ATLL or HAM. Methodological quality was assessed using tools from the National Heart, Lung, and Blood Institute (NHLBI). In total, 35 studies met the inclusion criteria, most conducted in Brazil, Japan, and Iran. A total of 67 biomarkers were identified: 37 genomic, 27 proteomic, and three metabolic with potential clinical applications in risk stratification, prognosis, and therapeutic monitoring of HTLV-1 infection. PVL remained the most frequently investigated marker but lacked predictive power in isolation. Additional candidates with strong potential included IFN-γ, CXCL10, Neopterin, AnxA1, and sTNFR2. This review highlights the potential of integrated multiparametric panels—combining PVL with omics-derived biomarkers—as a promising strategy to improve risk stratification, prognosis, and therapeutic monitoring in people living with HTLV-1 (PLHTLV-1). However, further longitudinal and clinically validated studies are needed to confirm their applicability and support their translation into early intervention strategies, particularly during the asymptomatic phase.
- Open Access
- 26 September 2025
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 20 (9) , e0332305
Clinical, laboratory and genetic factors associated with smoking in a Brazilian Sickle Cell Disease (SCD) cohort
Background: Smoking is associated with increased morbidity among individuals with sickle cell disease (SCD). While genetic factors influencing smoking behavior have been identified in other populations, they have not been studied in individuals with SCD. This study aimed to assess the impact of smoking on clinical and laboratory parameters in a large SCD cohort and to identify genetic variants potentially associated with smoking behavior in this population. Methods: The Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) Brazil SCD cohort was established across six Brazilian cities to investigate clinical outcomes in individuals with SCD. Adult participants were interviewed and asked whether they had ever smoked more than 100 cigarettes in their lifetime. Those who responded “yes” were classified as ever smokers, while those who responded “no” were classified as never smokers. Clinical and laboratory data were compared between the two groups. All participants were genotyped using a customized array, and a genome-wide association study (GWAS) was conducted to identify single nucleotide variants (SNVs) associated with smoking status. Results: Of the 1,231 adults with available smoking data, 332 (27%) were classified as ‘ever smokers’ and 899 (73%) as ‘never smokers’. ‘Ever smoker’ status was associated with male sex, age ≥ 40 years, lower educational attainment, and hemoglobin levels above the 75th percentile. In the GWAS, no SNVs reached genome-wide significance (p < 5 × 10 ⁻ ⁸). However, several SNVs demonstrated nominal significance (p < 1 × 10 ⁻ ⁷), including rs11087854 and a variant at position 1059991 on chromosome 20 within the gene AL110114.1, as well as rs701023 in the NCOR2 gene, suggesting a potential association with smoking behavior. Conclusion: Biological sex, age, and educational level are associated with smoking status among adults with SCD, and tobacco use appears to correlate with elevated hemoglobin levels in this population. Although no genome-wide significant associations were identified, our findings highlight potential genetic loci—particularly within AL110114.1 and NCOR2—that warrant further investigation in relation to smoking behavior in individuals with SCD.
- 26 September 2025
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 20 (9) , e0332305
Open AccessClinical, laboratory and genetic factors associated with smoking in a Brazilian Sickle Cell Disease (SCD) cohort
Background: Smoking is associated with increased morbidity among individuals with sickle cell disease (SCD). While genetic factors influencing smoking behavior have been identified in other populations, they have not been studied in individuals with SCD. This study aimed to assess the impact of smoking on clinical and laboratory parameters in a large SCD cohort and to identify genetic variants potentially associated with smoking behavior in this population. Methods: The Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) Brazil SCD cohort was established across six Brazilian cities to investigate clinical outcomes in individuals with SCD. Adult participants were interviewed and asked whether they had ever smoked more than 100 cigarettes in their lifetime. Those who responded “yes” were classified as ever smokers, while those who responded “no” were classified as never smokers. Clinical and laboratory data were compared between the two groups. All participants were genotyped using a customized array, and a genome-wide association study (GWAS) was conducted to identify single nucleotide variants (SNVs) associated with smoking status. Results: Of the 1,231 adults with available smoking data, 332 (27%) were classified as ‘ever smokers’ and 899 (73%) as ‘never smokers’. ‘Ever smoker’ status was associated with male sex, age ≥ 40 years, lower educational attainment, and hemoglobin levels above the 75th percentile. In the GWAS, no SNVs reached genome-wide significance (p < 5 × 10 ⁻ ⁸). However, several SNVs demonstrated nominal significance (p < 1 × 10 ⁻ ⁷), including rs11087854 and a variant at position 1059991 on chromosome 20 within the gene AL110114.1, as well as rs701023 in the NCOR2 gene, suggesting a potential association with smoking behavior. Conclusion: Biological sex, age, and educational level are associated with smoking status among adults with SCD, and tobacco use appears to correlate with elevated hemoglobin levels in this population. Although no genome-wide significant associations were identified, our findings highlight potential genetic loci—particularly within AL110114.1 and NCOR2—that warrant further investigation in relation to smoking behavior in individuals with SCD.
- Open Access
- 24 October 2023
- Published by Cambridge University Press (CUP) in Antimicrobial Stewardship & Healthcare Epidemiology
- Vol. 3 (1) , e185
Thinking out of the box: revisiting health surveillance based on medical records
Despite the considerable advances in the last years, the health information systems for health surveillance still need to overcome some critical issues so that epidemic detection can be performed in real time. For instance, despite the efforts of the Brazilian Ministry of Health (MoH) to make COVID-19 data available during the pandemic, delays due to data entry and data availability posed an additional threat to disease monitoring. Here, we propose a complementary approach by using electronic medical records (EMRs) data collected in real time to generate a system to enable insights from the local health surveillance system personnel. As a proof of concept, we assessed data from São Caetano do Sul City (SCS), São Paulo, Brazil. We used the “fever” term as a sentinel event. Regular expression techniques were applied to detect febrile diseases. Other specific terms such as “malaria,” “dengue,” “Zika,” or any infectious disease were included in the dictionary and mapped to “fever.” Additionally, after “tokenizing,” we assessed the frequencies of most mentioned terms when fever was also mentioned in the patient complaint. The findings allowed us to detect the overlapping outbreaks of both COVID-19 Omicron BA.1 subvariant and Influenza A virus, which were confirmed by our team by analyzing data from private laboratories and another COVID-19 public monitoring system. Timely information generated from EMRs will be a very important tool to the decision-making process as well as research in epidemiology. Quality and security on the data produced is of paramount importance to allow the use by health surveillance systems.
- 24 October 2023
- Published by Cambridge University Press (CUP) in Antimicrobial Stewardship & Healthcare Epidemiology
- Vol. 3 (1) , e185
Open AccessThinking out of the box: revisiting health surveillance based on medical records
Despite the considerable advances in the last years, the health information systems for health surveillance still need to overcome some critical issues so that epidemic detection can be performed in real time. For instance, despite the efforts of the Brazilian Ministry of Health (MoH) to make COVID-19 data available during the pandemic, delays due to data entry and data availability posed an additional threat to disease monitoring. Here, we propose a complementary approach by using electronic medical records (EMRs) data collected in real time to generate a system to enable insights from the local health surveillance system personnel. As a proof of concept, we assessed data from São Caetano do Sul City (SCS), São Paulo, Brazil. We used the “fever” term as a sentinel event. Regular expression techniques were applied to detect febrile diseases. Other specific terms such as “malaria,” “dengue,” “Zika,” or any infectious disease were included in the dictionary and mapped to “fever.” Additionally, after “tokenizing,” we assessed the frequencies of most mentioned terms when fever was also mentioned in the patient complaint. The findings allowed us to detect the overlapping outbreaks of both COVID-19 Omicron BA.1 subvariant and Influenza A virus, which were confirmed by our team by analyzing data from private laboratories and another COVID-19 public monitoring system. Timely information generated from EMRs will be a very important tool to the decision-making process as well as research in epidemiology. Quality and security on the data produced is of paramount importance to allow the use by health surveillance systems.
- Open Access
- 26 April 2023
- Published by MDPI AG in Hematology Reports
- Vol. 15 (2) , 298-304
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.
- 26 April 2023
- Published by MDPI AG in Hematology Reports
- Vol. 15 (2) , 298-304
Open AccessComparison 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.
- Open Access
- 22 September 2022
- Published by eLife Sciences Publications, Ltd in eLife
- Vol. 11
SARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals: A serial cross-sectional study
Background: The COVID-19 situation in Brazil is complex due to large differences in the shape and size of regional epidemics. Understanding these patterns is crucial to understand future outbreaks of SARS-CoV-2 or other respiratory pathogens in the country.Methods: We tested 97,950 blood donation samples for IgG antibodies from March 2020 to March 2021 in 8 of Brazil’s most populous cities. Residential postal codes were used to obtain representative samples. Weekly age- and sex-specific seroprevalence were estimated by correcting the crude seroprevalence by test sensitivity, specificity, and antibody waning.Results: The inferred attack rate of SARS-CoV-2 in December 2020, before the Gamma variant of concern (VOC) was dominant, ranged from 19.3% (95% credible interval [CrI] 17.5–21.2%) in Curitiba to 75.0% (95% CrI 70.8–80.3%) in Manaus. Seroprevalence was consistently smaller in women and donors older than 55 years. The age-specific infection fatality rate (IFR) differed between cities and consistently increased with age. The infection hospitalisation rate increased significantly during the Gamma-dominated second wave in Manaus, suggesting increased morbidity of the Gamma VOC compared to previous variants circulating in Manaus. The higher disease penetrance associated with the health system’s collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI 2.43–3.53).Conclusions: These results highlight the utility of blood donor serosurveillance to track epidemic maturity and demonstrate demographic and spatial heterogeneity in SARS-CoV-2 spread.Funding: This work was supported by Itaú Unibanco ‘Todos pela Saude’ program; FAPESP (grants 18/14389-0, 2019/21585-0); Wellcome Trust and Royal Society Sir Henry Dale Fellowship 204311/Z/16/Z; the Gates Foundation (INV- 034540 and INV-034652); REDS-IV-P (grant HHSN268201100007I); the UK Medical Research Council (MR/S0195/1, MR/V038109/1); CAPES; CNPq (304714/2018-6); Fundação Faculdade de Medicina; Programa Inova Fiocruz-CE/Funcap - Edital 01/2020 Number: FIO-0167-00065.01.00/20 SPU N°06531047/2020; JBS – Fazer o bem faz bem.
- 22 September 2022
- Published by eLife Sciences Publications, Ltd in eLife
- Vol. 11
Open AccessSARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals: A serial cross-sectional study
Background: The COVID-19 situation in Brazil is complex due to large differences in the shape and size of regional epidemics. Understanding these patterns is crucial to understand future outbreaks of SARS-CoV-2 or other respiratory pathogens in the country.Methods: We tested 97,950 blood donation samples for IgG antibodies from March 2020 to March 2021 in 8 of Brazil’s most populous cities. Residential postal codes were used to obtain representative samples. Weekly age- and sex-specific seroprevalence were estimated by correcting the crude seroprevalence by test sensitivity, specificity, and antibody waning.Results: The inferred attack rate of SARS-CoV-2 in December 2020, before the Gamma variant of concern (VOC) was dominant, ranged from 19.3% (95% credible interval [CrI] 17.5–21.2%) in Curitiba to 75.0% (95% CrI 70.8–80.3%) in Manaus. Seroprevalence was consistently smaller in women and donors older than 55 years. The age-specific infection fatality rate (IFR) differed between cities and consistently increased with age. The infection hospitalisation rate increased significantly during the Gamma-dominated second wave in Manaus, suggesting increased morbidity of the Gamma VOC compared to previous variants circulating in Manaus. The higher disease penetrance associated with the health system’s collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI 2.43–3.53).Conclusions: These results highlight the utility of blood donor serosurveillance to track epidemic maturity and demonstrate demographic and spatial heterogeneity in SARS-CoV-2 spread.Funding: This work was supported by Itaú Unibanco ‘Todos pela Saude’ program; FAPESP (grants 18/14389-0, 2019/21585-0); Wellcome Trust and Royal Society Sir Henry Dale Fellowship 204311/Z/16/Z; the Gates Foundation (INV- 034540 and INV-034652); REDS-IV-P (grant HHSN268201100007I); the UK Medical Research Council (MR/S0195/1, MR/V038109/1); CAPES; CNPq (304714/2018-6); Fundação Faculdade de Medicina; Programa Inova Fiocruz-CE/Funcap - Edital 01/2020 Number: FIO-0167-00065.01.00/20 SPU N°06531047/2020; JBS – Fazer o bem faz bem.
- Open Access
Predicting SARS-CoV-2 Variant Spread in a Completely Seropositive Population Using Semi-Quantitative Antibody Measurements in Blood Donors
SARS-CoV-2 serologic surveys estimate the proportion of the population with antibodies against historical variants, which nears 100% in many settings. New approaches are required to fully exploit serosurvey data. Using a SARS-CoV-2 anti-Spike (S) protein chemiluminescent microparticle assay, we attained a semi-quantitative measurement of population IgG titers in serial cross-sectional monthly samples of blood donations across seven Brazilian state capitals (March 2021–November 2021). Using an ecological analysis, we assessed the contributions of prior attack rate and vaccination to antibody titer. We compared anti-S titer across the seven cities during the growth phase of the Delta variant and used this to predict the resulting age-standardized incidence of severe COVID-19 cases. We tested ~780 samples per month, per location. Seroprevalence rose to >95% across all seven capitals by November 2021. Driven by vaccination, mean antibody titer increased 16-fold over the study, with the greatest increases occurring in cities with the highest prior attack rates. Mean anti-S IgG was strongly correlated (adjusted R2 = 0.89) with the number of severe cases caused by Delta. Semi-quantitative anti-S antibody titers are informative about prior exposure and vaccination coverage and may also indicate the potential impact of future SARS-CoV-2 variants.
Open AccessPredicting SARS-CoV-2 Variant Spread in a Completely Seropositive Population Using Semi-Quantitative Antibody Measurements in Blood Donors
SARS-CoV-2 serologic surveys estimate the proportion of the population with antibodies against historical variants, which nears 100% in many settings. New approaches are required to fully exploit serosurvey data. Using a SARS-CoV-2 anti-Spike (S) protein chemiluminescent microparticle assay, we attained a semi-quantitative measurement of population IgG titers in serial cross-sectional monthly samples of blood donations across seven Brazilian state capitals (March 2021–November 2021). Using an ecological analysis, we assessed the contributions of prior attack rate and vaccination to antibody titer. We compared anti-S titer across the seven cities during the growth phase of the Delta variant and used this to predict the resulting age-standardized incidence of severe COVID-19 cases. We tested ~780 samples per month, per location. Seroprevalence rose to >95% across all seven capitals by November 2021. Driven by vaccination, mean antibody titer increased 16-fold over the study, with the greatest increases occurring in cities with the highest prior attack rates. Mean anti-S IgG was strongly correlated (adjusted R2 = 0.89) with the number of severe cases caused by Delta. Semi-quantitative anti-S antibody titers are informative about prior exposure and vaccination coverage and may also indicate the potential impact of future SARS-CoV-2 variants.
- Open Access
Predicting SARS-CoV-2 variant spread in a completely seropositive population using semi-quantitative antibody measurements in blood donors
Background: SARS-CoV-2 serologic surveys estimate the proportion of the population with antibodies against historical variants which nears 100% in many settings. New analytic approaches are required to exploit the full information in serosurvey data. Method: Using a SARS-CoV-2 anti-Spike (S) protein chemiluminescent microparticle assay, we attained a semi-quantitative measurement of population IgG titres in serial cross-sectional monthly samples of routine blood donations across seven Brazilian state capitals (March 2021-November 2021). In an ecological analysis (unit of analysis: age-city-calendar month) we assessed the relative contributions of prior attack rate and vaccination to antibody titre in blood donors. We compared blood donor anti-S titre across the seven cities during the growth phase of the Delta variant of concern (VOC) and use this to predict the resulting age-standardized incidence of severe COVID-19 cases. Results: On average we tested 780 samples per month in each location. Seroprevalence rose to >95% across all seven capitals by November 2021. Driven proximally by vaccination, mean antibody titre increased 16-fold over the study. The extent of prior natural infection shaped this process, with the greatest increases in antibody titres occurring in cities with the highest prior attack rates. Mean anti-S IgG was a strong predictor (adjusted R2 =0.89) of the number of severe cases caused by the Delta VOC in the seven cities. Conclusions: Semi-quantitative anti-S antibody titres are informative about prior exposure and vaccination coverage and can inform on the potential impact of future SARS-CoV-2 variants. Summary: In the face of near 100% SARS-CoV-2 seroprevalence, we show that average semi-quantitative anti-S titre predicted the extent of the Delta variant’s spread in Brazil. This is a valuable metric for future seroprevalence studies.
Open AccessPredicting SARS-CoV-2 variant spread in a completely seropositive population using semi-quantitative antibody measurements in blood donors
Background: SARS-CoV-2 serologic surveys estimate the proportion of the population with antibodies against historical variants which nears 100% in many settings. New analytic approaches are required to exploit the full information in serosurvey data. Method: Using a SARS-CoV-2 anti-Spike (S) protein chemiluminescent microparticle assay, we attained a semi-quantitative measurement of population IgG titres in serial cross-sectional monthly samples of routine blood donations across seven Brazilian state capitals (March 2021-November 2021). In an ecological analysis (unit of analysis: age-city-calendar month) we assessed the relative contributions of prior attack rate and vaccination to antibody titre in blood donors. We compared blood donor anti-S titre across the seven cities during the growth phase of the Delta variant of concern (VOC) and use this to predict the resulting age-standardized incidence of severe COVID-19 cases. Results: On average we tested 780 samples per month in each location. Seroprevalence rose to >95% across all seven capitals by November 2021. Driven proximally by vaccination, mean antibody titre increased 16-fold over the study. The extent of prior natural infection shaped this process, with the greatest increases in antibody titres occurring in cities with the highest prior attack rates. Mean anti-S IgG was a strong predictor (adjusted R2 =0.89) of the number of severe cases caused by the Delta VOC in the seven cities. Conclusions: Semi-quantitative anti-S antibody titres are informative about prior exposure and vaccination coverage and can inform on the potential impact of future SARS-CoV-2 variants. Summary: In the face of near 100% SARS-CoV-2 seroprevalence, we show that average semi-quantitative anti-S titre predicted the extent of the Delta variant’s spread in Brazil. This is a valuable metric for future seroprevalence studies.
- Open Access
- 9 March 2022
- Published by Frontiers Media SA in Frontiers in Medicine
- Vol. 9, 844265
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.
- 9 March 2022
- Published by Frontiers Media SA in Frontiers in Medicine
- Vol. 9, 844265
Open AccessPrevalence 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.
- Open Access
- 22 February 2022
- Published by Springer Nature in Research Square
SARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals
There are large differences in the shape and size of regional SARS-CoV-2 epidemics in Brazil. Here we tested monthly blood donation samples for IgG antibodies from March 2020 to March 2021 in eight of Brazil’s most populous cities. There was large variation in the inferred attack rate adjusted for seroreversion across cities, and seroprevalence was consistently smaller in women and donors older than 55 years. The age-specific infection fatality rate differed between cities and consistently increased with age. The infection hospitalisation rate (IHR) increased significantly during the gamma-dominated second wave in Manaus, suggesting increased morbidity of the Gamma VOC compared to previous variants circulating in Manaus. The higher disease penetrance associated with the health system’s collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI 2.43–3.53). These results demonstrate large heterogeneity in epidemic spread and highlight the utility of blood donor serosurveillance to monitor SARS-CoV-2 epidemics.
- 22 February 2022
- Published by Springer Nature in Research Square
Open AccessSARS-CoV-2 antibody dynamics in blood donors and COVID-19 epidemiology in eight Brazilian state capitals
There are large differences in the shape and size of regional SARS-CoV-2 epidemics in Brazil. Here we tested monthly blood donation samples for IgG antibodies from March 2020 to March 2021 in eight of Brazil’s most populous cities. There was large variation in the inferred attack rate adjusted for seroreversion across cities, and seroprevalence was consistently smaller in women and donors older than 55 years. The age-specific infection fatality rate differed between cities and consistently increased with age. The infection hospitalisation rate (IHR) increased significantly during the gamma-dominated second wave in Manaus, suggesting increased morbidity of the Gamma VOC compared to previous variants circulating in Manaus. The higher disease penetrance associated with the health system’s collapse increased the overall IFR by a minimum factor of 2.91 (95% CrI 2.43–3.53). These results demonstrate large heterogeneity in epidemic spread and highlight the utility of blood donor serosurveillance to monitor SARS-CoV-2 epidemics.