Resumo A hidradenite supurativa é uma doença inflamatória crónica associada a múltiplas comorbilidades e a sua associação com doenças linfoproliferativas tem sido, recentemente, um tema de debate. No entanto, é controverso se esse risco pode ser atribuído à própria doença ou se tem relação com o tratamento imunossupressor. Descrevemos o caso de um doente com hidradenite supurativa perianal grave tratada com metotrexato e infliximab, cuja exacerbação com persistência de sintomas graves refratários ao tratamento adequado levou ao diagnóstico de linfoma não-Hodgkin difuso de grandes células B. Optou-se pela realização de colostomia para melhoria da sépsis perianal e início de imunoquimioterapia.

Abstract Hidradenitis suppurativa is a chronic inflammatory disease associated with multiple comorbidities, and its association with lymphoma has recently been a topic of debate. However, it is still controversial whether this risk can be attributed to the disease itself or whether it has any relationship with immunosuppressive treatment. Here, we describe the case of a patient with severe perianal hidradenitis suppurativa treated with methotrexate and infliximab, whose exacerbation with persistence of severe symptoms refractory to adequate treatment led to the diagnosis of diffuse large non-Hodgkin B-cell lymphoma. It was decided to perform a colostomy to improve perianal sepsis, and immunochemotherapy was proposed.

Resumo Mancha-de-Bipolaris é uma das mais importantes doenças foliares do milho. Estratégias de manejo adequadas e o uso de cultivar resistente permitem o controle da doença, mas para tanto, conhecer os aspectos associados ao patógeno e a resposta do hospedeiro é necessário para traçar estratégias eficientes para seleção de genótipos resistentes a essa doença. Neste sentido, objetivou-se realizar a caracterização do isolado de Bipolaris maydis avaliando a patogenicidade em diferentes linhagens de milho-pipoca e os sintomas gerados no hospedeiro a partir da inoculação. A caracterização do isolado consistiu na avaliação macromorfológica das colônias e micromofológica dos conídios em meio nutritivo BDA. Para avaliação da patogenicidade do isolado foi conduzido um experimento em casa de vegetação utilizando 20 linhagens endogâmicas de milho-pipoca, com delineamento em blocos casualizados, com quatro repetições. A inoculação foi realizada por meio de pulverização em folhas, com uma suspensão contendo 1,0 x 104 conídios.ml-1 do isolado CF/UENF 501 de B. maydis. Foi realizada uma avaliação de incidência e três avaliações de severidade dos sintomas da doença, com o intervalo de sete dias para cada avaliação. Os dados da caracterização morfológica do isolado foram analisados por meio da estatística descritiva e para severidade da doença foi aplicado o modelo de regressão linear de primeiro grau. Realizou-se a análise de variância para o coeficiente linear e angular obtido para cada tratamento e quando constatada diferença aplicou-se o agrupamento de médias de Scott-knott a 5% de significância. O isolado apresentou colônias com coloração cinza esverdeado, aspecto algodonoso e forma irregular. As linhagens L353 e L354 e L624 estão entre as linhagens que apresentaram maior resistência no inicio e ao longo das avaliações. A elevada virulência do isolado CF/UENF 501 possibilitou diferenciar as linhagens quanto a intensidade da doença, bem como o padrão dos sintomas apresentados.

Abstract Southern corn leaf blight (SCLB) is one of the most important corn leaf diseases. Appropriate management strategies and the use of resistant cultivars allow disease control. Therefore, knowing the aspects related to the pathogen and the response of hosts makes it possible to design efficient strategies for selecting genotypes resistant to this disease. In this sense, the objective was to carry out the Bipolaris maydis isolate characterization, evaluating the pathogenicity in different popcorn lines and the symptoms generated in the host after inoculation. The isolate characterization consisted of the macromorphological evaluation of the colonies and the micromorphological evaluation of the conidia in the PDA medium. An experiment was carried out in a greenhouse to evaluate the pathogenicity of the isolate, using 20 inbred lines of popcorn in a randomized block design with four replicates. Inoculation was carried out by spraying leaves, with a suspension containing 1.0 x 104 conidia.ml-1 of the CF/UENF 501 isolate of B. maydis. An incidence assessment and three assessments of disease symptom severity were performed, with seven days intervals between evaluations. The morphological characterization data of the isolate were analyzed using descriptive statistics, and for disease severity, the linear regression model was applied the first-degree model. The variance analysis was performed for the linear and angular coefficients obtained for each treatment. When a difference was found, the Scott-Knott clustering algorithm at 5% significance was applied. The isolate had gray-green colonies, a cottony appearance, and an irregular shape. The lines L353, L354, and L624 show more resistance at the beginning and throughout the evaluations. The high virulence of the CF/UENF 501 isolate made it possible to differentiate the lines in terms of disease intensity and the pattern of symptoms presented.

Resumo O Brasil é o maior produtor de figos da América do Sul, porém o cultivo comercial brasileiro da figueira baseia-se na plantação de uma única cultivar, o Roxo-de-Valinhos, resultando em sérios problemas relativos a pragas e doenças. Uma vez que há variações epigenéticas na interação planta-patógeno, principalmente por meio da regulação gênica, o presente trabalho objetiva realizar a caracterização in vivo de acessos de figo, por meio da análise de incidência natural de nematoides formadores de galha e de incidência natural de ferrugem, correlacionada ao seu perfil epigenômico, a fim de subsidiar trabalhos de conservação, melhoramento genético e produção da cultura. A análise dos componentes principais dos dados da caracterização dos acessos foi realizada por meio da matriz de correlação residual obtida pela análise de variância conjunta utilizando o programa GENES. Pôde-se constatar que todas as plantas foram atacadas por este patógeno, evidenciando que são suscetíveis ao mesmo. Já a análise conjunta dos dados demonstrou que a metilação e a incidência de ferrugem em folhas, quando observadas na mesma fase fenológica da planta, se correlacionam, apresentando evidências iniciais de mesmas cargas fatoriais de pressão nos genótipos, com a premissa de comportamento semelhante nos mesmos, indicando que, além do fator genético, fatores abióticos também são responsáveis pelas alterações no fenótipo das plantas, evidenciando a plasticidade fenotípica das mesmas.

Abstract Commercial fig tree cultivation in Brazil involves a single cultivar, ‘Roxo-de-Valinhos’. The use of a single cultivar results in serious diseases and related problems. The aim of this study was to characterize fig accessions by analyzing the natural root-knot nematode and leaf rust incidence in relation to the epigenomic profile of the plant, since epigenetic variations affect plant–pathogen interactions. All plants were attacked by nematodes, indicating susceptibility; Meloidogyne incognita was the root-knot nematode species involved. Joint analysis of data showed that methylation and leaf rust incidence were correlated when observed in the same phenological phase, presenting initial evidence of the same factorial pressure loads in genotypes, suggesting similar behavior within these genotypes.

Abstract This article constitutes the second part of the lithic technographic analysis of Middle Holocene sites in a vast macro-region, the central portion of South America: it includes the groups of sites B, C and D. A common element in all the analyzed sets is the presence of the techno-functional category B tools. In reference to the production mode, it is observed that the principle of debitage predominates in the area of analysis. However, its application was diverse; there are assemblages in which there was a predetermination about the making of flakes, others in which the cores were reintroduced as blanks or presented edges and there are other places in which façonnage confection flakes were reintroduced as blanks for tools. Other production principles have also been recorded: the principles of affordance (both in the exclusive productional expression and in its productional and functional expression) and shaping are observed in sites in groups A, C and D. Recognizing the different production modes is the starting point for thinking about how groups with different technical traditions have occupied different spaces in the region.

Resumen Este artículo conforma la segunda parte del análisis de las tecnografías líticas de los sitios del Holoceno medio en una extensa macrorregión, el sector central de América del Sur: abarca los agrupamientos B, C y D de los sitios. Un elemento común en todos los conjuntos analizados en la presencia de herramientas de la categoría tecno-funcional B. En referencia a los modos de producción se observa que el principio de debitagem predomina en el área de análisis. No obstante su aplicación es diversa; hay conjuntos donde existió una predeterminación sobre la confección de lascas, otros donde los núcleos son reintroducidos como soportes o presentando filos y otros sitios en donde se reintrodujeron lascas de confección de façonage como herramientas de soporte. El resto de los principios de producción también fueron registrados: el de afordancia (tanto en la producción instrumental como en su expresión produccional) y el de façonage se observan en sitios de los agrupamientos A, C y D. El reconocimiento de los diferentes modos de producción, es el punto de inicio para pensar como grupos con tradiciones técnicas diferentes, ocuparon espacios diversos en la región.

This study evaluated the pollutant levels (NO2, SO2, CO, and O3), air quality index (AQI) and the influence of meteorological variables and coronavirus disease (COVID-19) pandemic on the air quality in Rio de Janeiro. The data set used comprises periods before (March-April, 2019) and during pandemic (March-April, 2020). According to the AQI results, on most days, the air quality was ranked as “good”. Brazilian air quality standards for SO2, O3, and NO2 were not exceeded in any of the monitoring stations during partial lockdown, while CO exceeded in all periods in one site due to industrial emission. Comparing both periods, descriptive statistics for the meteorological parameters presented no differences, which suggests similar conditions. However, when evaluated week by week in 2020, weather conditions presented some differences that probably affected pollutant concentrations. The correlations between O3 and NO2 and some meteorological parameters indicate that variations in both favored ozone formation, since it is a photochemical process favored by temperature and solar radiation and that, in Rio de Janeiro, low NO2 concentrations lead to increased O3. The improvements on air quality during the partial lockdown may be attributed mainly to a reduction on emission sources rather than weather conditions.

This study aims to analyze Tetragonisca angustula honey from southwestern Bahia for its physicochemical characteristics, phenolic compounds and glioma cell inhibitory effect, in samples from different periods of the year, dry (DP) and rainy (RP) period. The analyses showed that samples obtained in the DP and RP are statistically different for the physicochemical profile (p < 0.05). DP honey has a darker color, greater acidity, content of reducing sugars and ash and lower moisture, when compared to RP. The content of total phenolics and flavonoids was determined spectrometrically, using the Folin-Ciocalteu method and reaction with aluminum chloride, respectively, and there was no statistical difference between the samples (p > 0.05). For the extraction of phenolic compounds, dispersive liquid-liquid microextraction was used, besides analysis by high-performance liquid chromatography with ultraviolet detection (HPLC-UV), which identified chlorogenic acid and quantified caffeic acid and rutin (1.7723 and 0.9384 μg 100 mg-1 honey, respectively). Glioma cell inhibition effect lines were observed for DP at concentrations 1000 ng mL-1 of honey. Principal component analysis (PCA) proposes the physicochemical parameters as the main distinguishing factors between the DP and RP samples. DP samples showed similarity for the parameters ash content, acidity and reducing sugars and the samples of the RP had consonance between pH and moisture.

Resumen. Existen tres razas de Fusarium oxysporum f. sp. cubense (Foc) que afectan a bananos y plátanos, los cultivares de banano grupo Cavendish son resistentes a Foc raza 1 (FocR1) y Foc raza 2 (FocR2). Sin embargo, no existen métodos de control efectivos para la Raza 4 Tropical (R4T). Lo anterior, hace necesario generar estrategias de control biológico utilizando a FocR2 como modelo fúngico que está presente en México, y que coadyuven ante la posible introducción de FocR4T al país. Se evaluó la inhibición in vitro de las cepas bacterianas Bacillus subtilis (BASU), B. velezensis (BAVE), B. sonorensis (BASO) contra tres aislamientos de FocR2 (MIC17188, MIC17191 y MIC17192) obtenidos de muestras vegetales colectadas en tres sitios de producción de plátano de Puebla, Michoacán y Oaxaca. A los 14 días, la cepa BASU tuvo en promedio, mayor inhibición (55.1%) con respecto a BAVE y BASO (45.8 y 21.7%, respectivamente) contra las tres cepas fúngicas antes mencionadas. También se evaluó la inhibición in vitro de las bacterias Paenibacillus sp. (BSP 1.1) y Serratia sp. (AC35) en tres tiempos de pre-inoculación bacteriana. La cepa BSP1.1 presentó mayor inhibición (80.1%) cuando se pre-inoculó de manera individual, siete días antes del hongo y durante siete días de confrontación.

Abstract There are three races of Fusarium oxysporum f. sp. cubense (Foc) that affect bananas and plantains, though the Cavendish group banana cultivars are resistant to Foc race 1 (FocR1) and Foc race 2 (FocR2). However, there are no effective control methods for the Tropical Race 4 (R4T). The foregoing makes it necessary to generate biological control strategies for FocR2 fungal model that is present in Mexico, forecasting the potential introduction of FocR4T into our country. In vitro inhibition was evaluated of bacterial strains Bacillus subtilis (BASU), B. velezensis (BAVE), and B. sonorensis (BASO) against three isolates of FocR2 (MIC17188, MIC17191 and MIC17192), obtained from plant samples collected in three banana production sites in the states of Puebla, Michoacán and Oaxaca. At 14 days, the strain BASU had in average high inhibition (55.1%) in comparison to BAVE and BASO strains (45.8 and 21.7%, respectively) against the three fungal strains mentioned before. In addition, the in vitro inhibition of Paenibacillus sp. (BSP 1.1) and Serratia sp. (AC35) was also evaluated by considering three pre-inoculation timings; the strain BSP1.1 showed high inhibition (80.1%) when pre-inoculated individually seven days before the fungus and at seven days of confrontation.

Ursolic acid (UA) is being investigated due to its anti-inflammatory potential, and structural modifications can enhance its biological activities. The aim of this study was to evaluate the immunomodulatory effect of the ursolic acid derivatives (UAD) in macrophages and in the carrageenan-induced paw edema model. RAW264.7 cells were cultured in the presence or absence of UA or UAD (1-18). Nitric oxide (NO), nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF), and cellular viability were measured. 30 min before the carrageenan-induced paw edema, the UAD1 and UAD2 (200 mg kg-1) were administered intraperitoneally. The results showed that UAD2-4, UAD7, UAD9-11 had half maximal inhibitory concentration (IC50) greater than 90 µM and were able to reduce NO, NF-κB and TNF production. Moreover, UAD1 and UAD2 reduced paw edema and IL-6 production. In conclusion, the results obtained demonstrated a variation in the response between the derivatives due to the chemical modifications, showing potential to reduce the inflammatory mediators, deserving further investigations.

Abstract Feline herpesvirus type 1 (HVF-1) is the infectious agent of feline viral rhinotracheitis. The main clinical signs are cough, nasal and eye discharge, fever, conjunctivitis and sneezing. Although the occurrence of the virus is known in some regions of Brazil, in Campo Grande, Mato Grosso do Sul (MS), there is no epidemiological information about its frequency. Thus, this study aimed to determine the frequency of feline herpesvirus type 1 in the region, and to evaluate its possible association with clinical and epidemiological factors. Ocular, nasal and oropharyngeal swabs, and blood were collected from 152 animals and analyzed through PCR and sequencing. In addition, epidemiological and clinical data were obtained through clinical examination and anamnesis. FHV-1 was detected in samples from 84 (55.26%) animals. There was no association between infection and age or sex. However, there was a significant association between infection and nasal (p < 0.0001) and ocular (p = 0.014) discharge and sneezing (p = 0.001). The results demonstrate the occurrence of the virus in domestic cats in the region with a high frequency of infection. Thus, FHV-1 should be considered as a potential causal agent of upper respiratory tract disease in domestic cats from Campo Grande, MS, Brazil.

At present, the friendly recycling of paper industry effluent sludge has gained great prominence due to the ecological and economic benefits. The aim of this work is to evaluate the influence of the incorporation of paper industry effluent sludge into a red wall tile formulation (BIII group), replacing natural limestone material by up to 10 wt.%. For this purpose, five red wall tile formulations were developed by the dry process, pressed at 47 MPa, and fired at 1170 ºC by using a fast-firing cycle. The wall tile formulations were characterized in terms of chemical analysis, thermal analysis (DTA-TG), and dilatometric analysis. The influence of paper industry effluent sludge on the technical properties (apparent density, water absorption, and flexural strength) and sintered microstructure was investigated. The results showed that red wall tiles containing up to 10 wt.% of paper industry effluent sludge have very good usable final properties, indicating their suitability for the wall tile industrial production (BIII group - ABNT NBR ISO 13006). Such results emphasize the feasibility of ecological and economic recycling of paper industry effluent sludge for the production of red wall tiles.

ABSTRACT The genus Bartonella encompasses 38 validated species of Gram-negative, facultative intracellular bacteria that colonize the endothelial cells and erythrocytes of a wide spectrum of mammals. To date, 12 Bartonella species have been recorded infecting humans, causing diseases of long historical characterization, such as cat scratch fever and trench fever, and emerging bartonellosis that mainly affect animal health professionals. For this reason, this study aimed to report a documented case of Bartonella bovis infecting a veterinarian from Mexico by the amplification, sequencing and phylogenetic reconstruction of the citrate synthase (gltA) and the RNA polymerase beta-subunit (rpoB) genes, and to report the natural course of this infection. To our knowledge, this work is the first to report the transmission of B. bovis via needlestick transmission to animal health workers in Latin America.

Abstract This study evaluated the antimicrobial efficacy of a new intracanal drug based on Pentaclethra macroloba extract, a plant of Amazonian origin, against Enterococcus faecalis using macrodilution test and intratubular evaluation with Confocal Laser Scanning Microscopy (CLSM). The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the pure extract of Pentaclethra macroloba andits association with calcium hydroxide and ultracall were determined. Then, thirty-three dentin cylinders were prepared and inoculated with E. faecalis, to evaluate the antimicrobial effect of the medications on the dentinal tubules with CLSM. The data was analyzed using the Kruskal-Wallis and Dunn tests. The extract in association with calcium hydroxide showed a lower CBM, and in the intratubular test all tested medications were effective against E. faecalis (P >0.05). The new intracanal drug based on P. macroloba extract has an antimicrobial effect against E. faecalis and further studies are needed for its clinical use.

Resumo Este estudo avaliou a eficácia antimicrobiana de uma nova droga intracanal à base de extrato de Pentaclethra macroloba, uma planta de origem amazônica, contra Enterococcus faecalis por meio do teste de macrodiluição e avaliação intratubular em Microscopia Confocal de Varredura a Laser (CLSM). Foram determinadas a concentração inibitória mínima (CIM) e a concentração bactericida mínima (CBM) do extrato puro de Pentaclethra macroloba, sua associação com hidróxido de cálcio e ultracall. Em seguida, trinta e três cilindros de dentina foram preparados e inoculados com E. faecalis, para avaliar o efeito antimicrobiano de medicamentos nos túbulos dentinários em CLSM. Os dados foram analisados por meio dos testes de Kruskal-Wallis e Dunn. O extrato em associação com hidróxido de cálcio apresentou menor CBM. E no teste intratubular, todas as medicações testadas foram efetivas contra E. faecalis (P >0,05). A nova droga intracanal à base de extrato de P. macroloba tem efeito antimicrobiano contra E. faecalis e mais estudos são necessários para seu uso clínico.

Abstract A new species of cloud fish of the genus Hypsolebias is described from a temporary pool in the rio Trairi basin, Rio Grande do Norte State, Brazil. It is the first record of the genus Hypsolebias for the basin. The new speciesbelongs to the H. flammeus species-group, which is composed of the species H. alternatus, H. brunoi, H. delucai, H. fasciatus, H. longignatus, H. marginatus, H. multiradiatus, and H. flammeus. The new species differs from all other species of the group, except H. flammeus, H. multiradiatus,and H. brunoi, by male color pattern and the presence of a metallic blue sheen surrounding the black spots of females. It differs from H. flammeus, H. multiradiatus and H. brunoi by dorsal and anal fin shape (both rounded vs. pointed) and by the orientation of the reddish-brown bars on the body and anal fin of males (diagonal vs. vertical). The new species differs from its congeners of Northeast Brazil mainly by the higher number of dorsal fin rays in males and the higher number of scales in the longitudinal series.

Resumo Uma nova espécie de peixe das nuvens, gênero Hypsolebias, é descrita de uma poça temporária localizada na bacia do rio Trairi, Estado do Rio Grande do Norte, Brasil. É a primeira ocorrência do gênero Hypsolebias na bacia do rio Trairi. A nova Hypsolebias pertence ao grupo de espécies H. flammeus que é composto pelas espécies H. alternatus, H. brunoi, H. delucai, H. fasciatus, H. flammeus, H. longignatus, H. marginatus e H. multiradiatus. A nova espécie difere de todas as espécies desse grupo, exceto H. flammeus, H. multiradiatus e H. brunoi, pelo padrão de coloração do macho e pela presença de um brilho azul metálico envolvendo as manchas pretas na fêmea. Difere de H. flammeus, H. multiradiatus e H. brunoi pela forma das nadadeiras dorsal e anal (arredondada vs. pontiaguda) e pela orientação das barras castanhas avermelhadas no corpo e na nadadeira anal nos machos (diagonal vs. vertical). A nova espécie difere de outras congêneres do Nordeste do Brasil principalmente pelo elevado número de raios na nadadeira dorsal nos machos e pelo maior número de escamas na série longitudinal.

Resumen La interacción entre la capa freática salina y somera y la agricultura intensiva da lugar a un frágil equilibrio entre la acumulación y lixiviación de sales en los suelos de marisma recuperada del sector de riego B-XII, en el suroeste de España. Evaluamos el potencial de la tomografía de inducción electromagnética (EMI) e imágenes de NDVI de Sentinel 2 para el seguimiento de la salinidad del suelo a escala de parcela en esta zona, usando mediciones de la conductividad eléctrica aparente (ECa) del suelo realizadas en 2017 y 2020. Las estimaciones de la conductividad eléctrica (EC) obtenidas mediante inversión de la ECa mostraron una fuerte correlación (R≈0,90) con la conductividad del extracto de pasta saturada (ECe) y la relación de absorción de sodio (SAR), lo que dio lugar a ecuaciones de calibración lineales con R2≈0,80 para ambos años y resultados de validación cruzada de exclusión (LOOCV) fiables para los horizontes subsuperficiales de 0,55 < R2 < 0,81. El patrón espacial de EC mostró correlación inversa con el del NDVI para tomate para industria, algodón y remolacha cultivados entre los años 2017 y 2019, alcanzando valores R de -0,64, -0,87 y -0,73, respectivamente.

Abstract The presence of a shallow saline water table in combination with intensive agriculture in the reclaimed marshes of the B-XII irrigation district, in SW Spain, may disrupt the fragile balance between salt accumulation and leaching in the root zone. We evaluate the potential of electromagnetic induction tomography (EMI) and the use of Sentinel 2 NDVI imagery for field-scale soil salinity monitoring using soil apparent electrical conductivity (ECa) measured in 2017 and 2020. Depth-specific electrical conductivity (EC), obtained from the inversion of ECa, showed a strong correlation (R≈0.90) with laboratory-analysed saturated paste extract conductivity (ECe) and sodium adsorption ratio (SAR), resulting in linear calibration equations with R2≈0.80 for both years and reliable cross-validation of exclusion (LOOCV) results for the subsoil (0.55 < R2 < 0.81). The spatial pattern of EC showed inverse correlation with NDVI for processed tomato, cotton and sugar beet, cropped between 2017 and 2019, reaching R values of -0.64, -0.87 and -0.73, respectively.

ABSTRACT Introduction: viral hepatitis is a health problem world public, being one of the diseases that affect man. Objective: to know the seroprevalence of the surface antigen of the hepatitis B in blood donors. Methods: a study was conducted retrospective in order to determine the seroprevalence of the hepatitis B virus in 93,440 donors, in the Blood Bank Provincial “Renato Guitart Rosell” of Santiago de Cuba. The term studied ranged from October 2015 to May 2016. Results: there was a slight decrease in the prevalence of hepatitis B surface antigen carriers during the three years studied. The highest reactivity to this marker was in the group aged 41 to 50 years and the male sex predominated. It was found that 0.30% were seropositive for hepatitis B virus. Conclusions: the fulfillment of the established procedures for the adequate selection of the blood donor and the quality and safety of the results in the laboratory determinations of the prevalence of hepatitis B surface antigen carriers, together with the recruitment of voluntary, altruistic and non-remunerated blood donors, has allowed achieving a low seroprevalence in the Province of Santiago de Cuba.

RESUMEN Introducción: las hepatitis virales son un problema en la salud pública mundial y son una de las enfermedades que afectan al hombre. Objetivo: conocer la seroprevalencia del antígeno de superficie de la hepatitis B en donantes de sangre. Métodos: se realizó un estudio retrospectivo con el objetivo de determinar la seroprevalencia del virus de la hepatitis B en 93 440 donantes en el Banco de sangre provincial “Renato Guitart Rosell” de Santiago de Cuba. El período estudiado estuvo comprendido de octubre de 2015 a mayo de 2016. Resultados: se mostró un ligero decrecimiento de la prevalencia de portadores de antígeno de superficie de la hepatitis B a través de los tres años estudiados. La mayor reactividad a este marcador estuvo en el grupo de 41 a 50 años y predominó el sexo masculino. Se encontró que el 0,30% resultó seropositivo al virus de la hepatitis B. Conclusiones: el cumplimiento de los procedimientos establecidos para la adecuada selección del donante de sangre y la calidad y la seguridad de los resultados en las determinaciones de laboratorio de la prevalencia de portadores de antígeno de superficie de la hepatitis B, unido al reclutamiento de donantes de sangre voluntarios, altruistas no remunerados, ha permitido que se logre una baja seroprevalencia en la Provincia de Santiago de Cuba.