T follicular helper cells: Their development and importance in the context of helminthiasis.

The development of T follicular helper cells (Tfh) is a multifactorial process that occurs in multiple stages. After their activation the Tfh cells interact with the B cells to complete their differentiation. During this process, the Tfh cells begin to express canonical molecules such as the transcription factor B-cell lymphoma 6 protein, the CXC chemokine receptors type 5, and the inducible T-cell costimulator, as well as secreting other molecules such as IL-21. This whole process is regulated positively and negatively by several factors so that the best response is offered in the face of diseases of various origins, among them helminthiasis. In this context, the role of circulating Tfh, IL-4 and IgG subtypes is essential for an effective response against these pathogens. In this review, the migration process and the differentiation of Tfh, the regulation, their cell subtypes and the role of Tfh in the context of helminth infections will be addressed.

Aspects related to positivity for schistosomiasis: a cross-sectional study in a low prevalence area in Alagoas, Brazil, 2020. / Aspectos relacionados com a positividade para a esquistossomose: estudo transversal em área de baixa prevalência em Alagoas, 2020.

OBJECTIVE: To analyze aspects related to schistosomiasis positivity in an area of low prevalence in Brazil. METHODS: This was a cross-sectional study, carried out in the first half of 2020, where we analyzed the proportion of positivity, according to the number of Kato-Katz slides, the diagnostic performance of the test and positivity estimates based on data from the Schistosomiasis Surveillance and Control Program Information System (SISPCE). RESULTS: 2,088 slides from 348 individuals were analyzed, with proportion of positivity of 11.8%, 26.7% and 31.0% for 1, 4 and 6 slides analyzed, respectively. There was excellent agreement (Kappa = 0.91) between the readings of 4 and 6 slides. The SISPCE data was estimated to be underreported by up to 2.1 times. CONCLUSION: Increasing the number of slides increased Kato-Katz positivity, which can contribute to maximizing the control of the disease as a Public Health problem.

Aspects related to positivity for schistosomiasis: a cross-sectional study in a low prevalence area in the state of Alagoas, Brazil, 2020 / Aspectos relacionados con la positividad para la esquistosomiasis: un estudio transversal en un área de baja prevalencia en el estado de Alagoas, Brasil, 2020 / Aspectos relacionados com a positividade para a esquistossomose: estudo transversal em área de baixa prevalência do estado de Alagoas, 2020

Objective: To analyze aspects related to positivity for schistosomiasis in an area of ​​low prevalence in Brazil. Methods: Cross-sectional study, carried out in the first half of 2020, where proportion of positivity was analyzed according to the number of Kato-Katz slides, the diagnostic performance of the test and the creation of a positivity estimation factor from the data of the Information from the Schistosomiasis Surveillance and Control Program (SISPCE). Results: 2,088 slides from 348 individuals were analyzed, with proportion of positivity of 11.8%, 26.7% and 31.0% for 1, 4 and 6 slides analyzed, respectively. There was excellent agreement (Kappa = 0.91) between the reading of 4 and 6 slides. An underreporting of 2.1 times was estimated in the SISPCE data. Conclusion: Increasing the number of blades increased the positivity of Kato-Katz, which can contribute to maximize the control of the disease as a public health problem.

Objetivo: Analisar aspectos relacionados com a positividade para esquistossomose em área de baixa prevalência, no Brasil. Métodos: Estudo transversal, realizado no primeiro semestre de 2020, quando foram analisadas a proporção de positividade, em função do número de lâminas de Kato-Katz, o desempenho diagnóstico do teste e a estimação da positividade a partir dos dados do Sistema de Informação do Programa de Vigilância e Controle da Esquistossomose (SISPCE). Resultados: Foram analisadas 2.088 lâminas de 348 indivíduos, sendo a proporção de positividade de 11,8%, 26,7% e 31,0% para 1, 4 e 6 lâminas analisadas, respectivamente. Houve concordância excelente (índice Kappa = 0,91) na comparação entre as leituras de 4 e 6 lâminas. Foi estimada subnotificação de 2,1 vezes nos dados do SISPCE. Conclusão: Ampliar o número de lâminas aumentou a positividade do Kato-Katz, o que pode contribuir para maximizar o controle da doença enquanto problema de Saúde Pública.

Aspectos relacionados com a positividade para a esquistossomose: estudo transversal em área de baixa prevalência em Alagoas, 2020 / Aspectos relacionados con la positividad para la esquistosomiasis: un estudio transversal en un área de baja prevalencia en Alagoas, Brasil, 2020 / Aspects related to positivity for schistosomiasis: a cross-sectional study in a low prevalence area in Alagoas, Brazil, 2020

Objetivo: Analisar aspectos relacionados com a positividade para esquistossomose em área de baixa prevalência, no Brasil. Métodos: Estudo transversal, realizado no primeiro semestre de 2020, quando foram analisadas a proporção de positividade, em função do número de lâminas de Kato-Katz, o desempenho diagnóstico do teste e a estimação da positividade a partir dos dados do Sistema de Informação do Programa de Vigilância e Controle da Esquistossomose (SISPCE). Resultados: Foram analisadas 2.088 lâminas de 348 indivíduos, sendo a proporção de positividade de 11,8%, 26,7% e 31,0% para 1, 4 e 6 lâminas analisadas, respectivamente. Houve concordância excelente (índice Kappa = 0,91) na comparação entre as leituras de 4 e 6 lâminas. Foi estimada subnotificação de 2,1 vezes nos dados do SISPCE. Conclusão: Ampliar o número de lâminas aumentou a positividade do Kato-Katz, o que pode contribuir para maximizar o controle da doença enquanto problema de Saúde Pública.

Objetivo: Analizar aspectos relacionados con la positividad para esquistosomiasis en área de baja prevalencia en Brasil. Métodos: Estudio transversal, realizado en el primer semestre de 2020, donde se analizó la proporción de positividad según el número de portaobjetos de Kato-Katz, el rendimiento diagnóstico de la prueba y la creación de un factor de estimación de positividad a partir de los datos del Sistema de Información del Programa de Vigilancia y Control de la Esquistosomiasis (SISPCE). Resultados: Se analizaron 2.088 láminas de 348 individuos, con proporción de positividad del 11,8%, 26,7% y 31,0% para 1, 4 y 6 láminas analizadas, respectivamente. Hubo una excelente concordancia (Kappa = 0,91) en la comparación entre la lectura de 4 y 6 láminas. Se estimó un subregistro de 2,1 veces en los datos del SISPCE. Conclusión: Aumentar el número de muestras aumentó la positividad de Kato-Katz, lo que puede contribuir a maximizar el control de la enfermedad como problema de Salud Pública.

Objective: To analyze aspects related to schistosomiasis positivity in an area of low prevalence in Brazil. Methods: This was a cross-sectional study, carried out in the first half of 2020, where we analyzed the proportion of positivity, according to the number of Kato-Katz slides, the diagnostic performance of the test and positivity estimates based on data from the Schistosomiasis Surveillance and Control Program Information System (SISPCE). Results: 2,088 slides from 348 individuals were analyzed, with proportion of positivity of 11.8%, 26.7% and 31.0% for 1, 4 and 6 slides analyzed, respectively. There was excellent agreement (Kappa = 0.91) between the readings of 4 and 6 slides. The SISPCE data was estimated to be underreported by up to 2.1 times. Conclusion: Increasing the number of slides increased Kato-Katz positivity, which can contribute to maximizing the control of the disease as a Public Health problem.

New epidemiological profile of schistosomiasis from an area of low prevalence in Brazil.

INTRODUCTION: Schistosomiasis, caused by infection from Schistosoma mansoni, is a disease that represents an important public health problem for Brazil, especially for states in the Northeast region. Thus, the aim of this study is to present a new epidemiological profile for the disease in a municipality with low prevalence in the state of Alagoas, Brazil. METHODS: A cross-sectional study was conducted through a coproparasitological and malacological survey. A structured questionnaire was applied to the study participants to survey possible risk factors and a spatial analysis (kernel density) was used to measure the risk of infection. RESULTS: Of the 347 participants, 106 (30.5%) were infected by Schistosoma mansoni, most of them from the urban area of the municipality (68.9%; 73/106). A 3-fold risk of infection was found for individuals living in the urban area and a risk of 2.15 times for self-declared farmers. Biomphalaria glabrata and B. straminea were the species found in the municipality, but no animals were diagnosed as infected by the parasite. Spatial analysis showed a random distribution of vectors and human cases of the disease, and the formation of two clusters of human cases in the urban area was seen. CONCLUSIONS: A new epidemiological profile for schistosomiasis from S. mansoni infection was presented in a municipality of low endemicity: a high proportion of positive individuals in the urban area; presence of snails without positive diagnosis for S. mansoni infection; random distribution of vectors and human cases; and absence of association between classical risk factors and human infection.

Spatiotemporal clusters of schistosomiasis mortality and association with social determinants of health in the Northeast region of Brazil (1980-2017).

The Northeast region of Brazil includes the states with the highest prevalence for schistosomiasis mansoni (SM). This study aimed to evaluate the spatiotemporal patterns of SM mortality and to analyze this association with social determinants in health. We conducted an ecological time series study (1980-2017), using spatial analysis tools. Time trend analysis was performed by joinpoint regression. Maps representing mortality rates for SM were constructed and Moran Index was calculated to analyze spatial autocorrelation. A total of 13,720 deaths from SM were reported in this period. The states of Pernambuco (PE) (50.62%) and Alagoas (AL) (22.09%) had the highest mortality percentages. The mortality rate decreased from 1.28 to 0.63 along the time. Although most states showed a stable trend, Sergipe (SE) and Bahia (BA) showed increasing trends in the latest years. Additionally, the spatial analysis showed the concentration of municipalities that presented high risk in the coastal region of the states of PE, AL, SE, and BA. Lastly, mortality rates were correlated with social and educational indicators and hospitalizations for diarrhea. Altogether, these results demonstrate that some states showed stable or increasing trends of SM mortality in the last period of the studied time interval.

Influence of food type and calcium supplementation on growth, oviposition and survival parameters of Biomphalaria glabrata and Biomphalaria straminea

Schistosomiasis is a parasitic disease caused by Schistosoma mansoni whose intermediate host is the snail of the genus Biomphalaria. This snail is geographically widespread, making the disease a serious public health problem. The purpose of this study was to analyze the growth, reproductive rates and mortality of B. glabrata and B. straminea in different calcium concentrations and food types. Freshly hatched snails stored in aquariums under different dietary and calcium supplementation programs were studied. Under these conditions, all planorbids survived, so there was no mortality rate and 79,839 eggs of B. straminea and 62,558 eggs of B. glabrata were obtained during the 2 months of oviposition. The following conditions: lettuce + fish food and lettuce + fish food + powdered milk resulted in the highest reproductive rates. In addition, supplementation with calcium carbonate and calcium sulfide in three different concentrations did not significantly influenced the amount of eggs or ovigerous masses. Thus, this study shows that changes in diet are crucial for the survival/oviposition of these planorbids, being an important study tool for population control. Calcium is also a key factor in these conditions, but more work is necessary to better assess its effect on snail survival.

New epidemiological profile of schistosomiasis from an area of low prevalence in Brazil

Abstract INTRODUCTION: Schistosomiasis, caused by infection from Schistosoma mansoni, is a disease that represents an important public health problem for Brazil, especially for states in the Northeast region. Thus, the aim of this study is to present a new epidemiological profile for the disease in a municipality with low prevalence in the state of Alagoas, Brazil. METHODS: A cross-sectional study was conducted through a coproparasitological and malacological survey. A structured questionnaire was applied to the study participants to survey possible risk factors and a spatial analysis (kernel density) was used to measure the risk of infection. RESULTS: Of the 347 participants, 106 (30.5%) were infected by Schistosoma mansoni, most of them from the urban area of the municipality (68.9%; 73/106). A 3-fold risk of infection was found for individuals living in the urban area and a risk of 2.15 times for self-declared farmers. Biomphalaria glabrata and B. straminea were the species found in the municipality, but no animals were diagnosed as infected by the parasite. Spatial analysis showed a random distribution of vectors and human cases of the disease, and the formation of two clusters of human cases in the urban area was seen. CONCLUSIONS: A new epidemiological profile for schistosomiasis from S. mansoni infection was presented in a municipality of low endemicity: a high proportion of positive individuals in the urban area; presence of snails without positive diagnosis for S. mansoni infection; random distribution of vectors and human cases; and absence of association between classical risk factors and human infection.