PREVALÊNCIA DE MARCADORES SOROLÓGICOS DO VÍRUS DA HEPATITE B (HBV) NOS MUNICÍPIOS DE URBANO SANTOS, AXIXÁ, HUMBERTO DE CAMPOS, MORROS E ICATU: RESULTADOS PARCIAIS DE UM ESTUDO DE BASE POPULACIONAL

As hepatites virais são doenças que apresentam distribuição universal. No Brasil, há grande variação regional na prevalência de cada hepatite. A prevalência da infecção pelo vírus da hepatite B (HBV) nas capitais do Nordeste é de 0,5%. Não há informações sobre a prevalência desta infecção no estado do Maranhão. Em estudo realizado no ano de 2010 com pacientes do Maranhão observou-se que muitos portadores do HBV eram provenientes dos municípios de Urbano Santos, Axixá, Morros, Icatu e Humberto de Campos. Esta maior frequência também já vinha sendo observada pelo Programa de Hepatites Virais da Secretaria Estadual de Saúde. Essas observações sugerem que esta é uma região onde a prevalência do HBV pode ser maior que a descrita para a região Nordeste do Brasil. Este trabalho objetiva identificar os indivíduos com sorologia positiva para os marcadores do HBV (HBsAg, anti-HBc total e anti-HBs). Trata-se de um estudo de prevalência com base em uma população definida. A amos-tra é composta por 4.000 pessoas residentes nos municípios citados. Os pacientes foram entrevistados mediante um questionário epidemiológico, demográfico e clínico. Posteriormente foram coletadas amos-tras de sangue para realização dos exames sorológicos e moleculares. Das 871 amostras testadas até o momento, a prevalência do HBsAg foi de 2.99%. As prevalências de anti-HBc total e anti-HBs foram 32.53% e 40.34%, respectivamente. Anti-HBs isoladamente positivo esteve presente em 19.63%. Esta prevalência do HBsAg identificada até o momento sugere que aquela região tenha uma endemicidade intermediária para infecção crônica pelo HBV.Palavras-chave: Hepatite. Prevalência. Maranhão.  PREVALENCE OF SEROLOGIC MARKERS OF HEPATITIS B VIRUS (HBV) IN THE TOWNS OF URBANO SANTOS, AXIXÁ, HUMBERTO DE CAMPOS, MORROS AND ICATÚ: PARTIAL RESULTS OF A POPULATIONAL SURVEY ABSTRACT: Viral hepatitis is a disease that presents universal distribution. In Brazil there is substantial regional variation in the prevalence of each hepatitis. The prevalence of infection with hepatitis B virus (HBV) in the capitals of the Northeast is 0.5%. There is no information about the prevalence of this infec-tion in the state of Maranhão. In a study conducted in 2010 patients with Maranhão be noted that many HBV carriers were from the cities of Urbano Santos, Axixá, Morros, Icatu and Humberto de Campos. This increased frequency also was already being observed by the State Department of Health Viral Hepatitis Program. These observations suggest that this is a region where the prevalence of HBV may be greater than that described for the Northeast region of Brazil. This paper intends to identify individuals with positive serology for HBsAg markers, anti-HBc and anti-HBs in HBV. This is a prevalence study based on a defined population. The sample consists of 4,000 people living in that cities. Patients were interviewed using an epidemiological, demographic and clinical questionnaire. Subsequently, blood samples were collected to measure the serological and molecular tests. Among 871 samples examined so far, the prevalence of HB-sAg was 2.99% so far. The prevalence of anti-HBc and anti-HBs were 32.53% and 40.34%, respectively. Positive isolated anti-HBs was present in 19.63%. This prevalence of HBV infection, detected so far in the study, identifies this region as intermediate endemicity.KEYWORDS: Hepatitis. Prevalence. Maranhão State PREVALENCIA DE MARCADORES SEROLÓGICOS DEL VIRUS DE HEPATITIS B (HBV) EN LOS MUNICIPIOS DE URBANO SANTOS, AXIXÁ, HUMBERTO DE CAMPOS, MORROS E ICATÚ: RESULTADOS PARCIALES DE UN ESTUDIO CON BASE EN LA POBLACIÓN.RESUMEN: Las hepatitis virales son enfermedades que presentan distribución universal. En Brasil, hay gran variación regional en la prevalencia de cada hepatitis. La prevalencia de la infección por el virus de hepatitis B (HBV) en las capitales del Nordeste es de 0,5%. No hay informaciones sobre la prevalencia de esta infección en el Estado de Maranhão. En estudio realizado en el año de 2010 con pacientes de Maranhão se observó que muchos portadores de HBV eran provenientes de los municipios de Urbano Santos, Axixá, Morros, Icatú y Humberto de Campos. Esta mayor frecuencia también ya estaba siendo observada por el Programa de Hepatitis Virales de la Secretaría Estadual de Salud. Estas observaciones sugieren que esta es una región donde la prevalencia de la HBV puede ser mayor que la descrita para la región Nordeste de Brasil. Este trabajo busca identificar a los individuos con serología positiva para los marcadores HBsAg, anti-HBc total y anti-HBs de la HBV. Se trata de un estudio de prevalencia con base en una población definida. La muestra es compuesta por 4.000 personas residentes en los municipios de Urbano Santos, Axixá, Humberto de Campos, Morros e Icatú. Los pacientes fueron entrevistados me-diante un cuestionario epidemiológico, demográfico y clínico. Posteriormente fueron recogidas muestras de sangre para realización de los exámenes serológicos y moleculares. De las 871 serologías realizadas, la prevalencia de HBsAg fue de 2.99%. Las prevalencias de anti-HBc Total y anti-HBs fueron 32.53% y 40.34%, respectivamente. Anti-HBs aisladamente positivo estuvo presente en 19.63%. La prevalencia de2.99% de la infección por la HBV, detectada hasta el momento por el estudio, identifica esta región como de endemicidad intermediaria.PALABRAS CLAVE: Hepatitis. Prevalencia. Maranhão

High prevalence of hepatitis B virus and low vaccine response in children and adolescents in Northeastern Brazil

Children have an increased likelihood of becoming carriers of the chronic hepatitis B virus. A total of 1,381 children and adolescents were assessed in five municipalities of Maranhao State, Brazil, for detection of anti-HBc, HBsAg and anti-HBs serologic markers and sociodemographic and behavioral features. Among those who were HBsAg negative and anti-HBc negative, the proportion of anti-HBs positives was calculated after the individuals had completed the vaccination schedule. The robust variance of the Poisson’s regression model was used in order to have adjusted tables and calculate the prevalence ratio. Multivariate analysis was performed to identify the factors associated with the prevalence of anti-HBc with or without HBsAg and the vaccine response. It was observed that 163 children were anti-HBc positive and nine individuals were HBsAg positive. The factors associated with the infection were: municipality of residence (residing in Morros municipality or Humberto de Campos municipality), residence in a rural area, aged between 13 and 15 years old, and illicit drug use. The percentage of individuals who were anti-HBc negative and received all three doses of the vaccine was 48.5%. Among these, only 276 (38.9%) had antibodies at protective concentrations. In an adjusted analysis, Morros municipality presented an increased positivity of vaccine response (p < 0.001), and the age ranging between 6 and 10 years old presented a reduced frequency of response. This study reveals a high prevalence of current and past HBV infection within the targeted age group which, in addition to the low vaccination coverage and serological responses, raises concerns about the management of prevention measures, especially the quality of vaccination in these locations

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle

Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E$^{-2}$ shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E$^{-2}$ be able to explain the observations

Investigating multiple elves and halos above strong lightning with the fluorescence detectors of the Pierre Auger Observatory

ELVES are being studied since 2013 with the twenty-four FD Telescopes of the Pierre Auger Observatory, in the province of Mendoza (Argentina), the world’s largest facility for the study of ultra-high energy cosmic rays. This study exploits a dedicated trigger and extended readout. Since December 2020, this trigger has been extended to the three High levation Auger Telescopes (HEAT), which observe the night sky at elevation angles between 30 and 60 degrees, allowing a study of ELVES from closer lightning. The high time resolution of the Auger telescopes allows us to upgrade reconstruction algorithms and to do detailed studies on multiple ELVES. The origin of multiple elves can be studied by analyzing the time difference and the amplitude ratio between flashes and comparing them with the properties of radio signals detected by the ENTLN lightning network since 2018. A fraction of multi-ELVES can also be interpreted as halos following ELVES. Halos are disc-shaped light transients emitted at 70-80 km altitudes, appearing at the center of the ELVES rings, due to the rearrangement of electric charges at the base of the ionosphere after a strong lightning event