Triatomine (Hemiptera: Reduviidae) populations and Trypanosoma cruzi genotyping in peridomestic and sylvatic environments in the semiarid region of Sergipe, Northeastern, Brazil.

We assessed the diversity of triatomines, the rates of natural infection, and the discrete typing units (DTUs) of Trypanosoma cruzi isolated from them in two municipalities in the state of Sergipe, Brazil. Active searches for triatomines were conducted in the peridomicily and wild enviroments of 10 villages within the two municipalities. Triatomines were taxonomically identified and their feces were extracted using the abdominal compression method. Parasite detection was performed using optical microscopy. For Trypanosoma cruzi genotyping via PCR-FFLB, 151 samples of the subspecies Triatoma brasiliensis macromelasoma and Triatoma brasiliensis were isolated from both municipalities. In total, 505 triatomines were collected, with Triatoma brasiliensis macromelasoma being the most frequent species (58.81 %). Triatoma b. brasiliensis was the only species in both peridomestic and wild environments. Regarding the other species, T. pseudomaculata was found only in the peridomestic environment; and T. b. macromelasoma and Psammolestes tertius were found in the wild environment. Three Discrete Typing Units were identified: TcI (87.51 %) detected in T. b. brasiliensis and T. b. macromelasoma, TcI+TcIII (10.41 %) in T. b. macromelasoma, and TcI+Trypanosoma rangeli (2.08 %) in T. b. macromelasoma. It is concluded that T. b. macromelasoma is the species collected most frequently in the studied region and the one that presents the highest rates of natural infection, highlighting its epidemiological importance for the vectorial transmission of Chagas disease in Sergipe.

Flying to the moon: Impactful accounts of triatomines invasion from the 2nd to the 13th floor of an urban residential building in the municipality of Rio Branco, Acre, Brazil.

BACKGROUND: Vectorial transmission through hematophagous triatomine insects remains the primary mode of Chagas Disease contagion. These insects have become increasingly common in urban environments. Therefore, this study aimed to report an encounter of triatomines with trypanosomatid infection in a vertical residential condominium in Rio Branco, the capital of the state of Acre, in the western Brazilian Amazon. METHODS: Triatomines were collected from residents and sent to the municipality's Entomological Surveillance sector. Trypanosomatid positivity was evaluated using optical microscopy, followed by species and genotype identification using molecular biology techniques. RESULTS: Twenty-five adult triatomine specimens were collected from two of three condominium buildings invading apartments from the 2nd to 13th floors. Six specimens were identified as Rhodnius sp. and 19 as R. montenegrensis. Among these, molecular tests were conducted on seven specimens, with five testing positive for Trypanosoma cruzi, all belonging to genotype TcI. CONCLUSIONS: These findings underscore the need for further studies to better understand the invasive capacity of these insects in these environments and the mechanisms involved in this process.

Chagas Disease Vectors of Alagoas, Brazil: First Report of Panstrongylus geniculatus (Latreille, 1811) (Hemiptera, Triatominae) in the Brazilian State and Update of the Dichotomous Key Based on Cytogenetic Data.

Panstrongylus geniculatus is the most widely distributed species of Panstrongylus in Brazil and merits attention from vector control programs due to its potential for domiciliation. Specimens infected with Trypanosoma cruzi have already been reported in both peridomiciliary and domiciliary environments. Building on these findings, we report, for the first time, the presence of P. geniculatus in the state of Alagoas and provide an updated dichotomous key (based on cytogenetic data) for species in Alagoas. Panstrongylus geniculatus has been identified in Boca da Mata, Joaquim Gomes, and Novo Lino. In light of the recent notification of Rhodnius domesticus and this record of P. geniculatus, we present an updated identification key enabling the differentiation of all species in Alagoas. Emphasis is placed on the importance of correctly identifying triatomine species because it is crucial for the development of effective control measures, thereby aiding in the mitigation of Chagas disease.

Enhancing the epidemiological surveillance of SARS-CoV-2 using Sanger sequencing to identify circulating variants and recombinants.

Since the emergence of SARS-CoV-2 in December 2019, more than 12,000 mutations in the virus have been identified. These could cause changes in viral characteristics and directly impact global public health. The emergence of variants is a great concern due to the chance of increased transmissibility and infectivity. Sequencing for surveillance and monitoring circulating strains is extremely necessary as the early identification of new variants allows public health agencies to make faster and more effective decisions to contain the spread of the virus. In the present study, we identified circulating variants in samples collected in Belo Horizonte, Brazil, and detected a recombinant lineage using the Sanger method. The identification of lineages was done through gene amplification of SARS-CoV-2 by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). By using these specific fragments, we were able to differentiate one variant of interest and five circulating variants of concern. We were also able to detect recombinants. Randomly selected samples were sequenced by either Sanger or Next Generation Sequencing (NGS). Our findings validate the effectiveness of Sanger sequencing as a powerful tool for monitoring variants. It is easy to perform and allows the analysis of a larger number of samples in countries that cannot afford NGS.

A model for bimodal rates and proportions.

The beta model is the most important distribution for fitting data with the unit interval. However, the beta distribution is not suitable to model bimodal unit interval data. In this paper, we propose a bimodal beta distribution constructed by using an approach based on the alpha-skew-normal model. We discuss several properties of this distribution, such as bimodality, real moments, entropies and identifiability. Furthermore, we propose a new regression model based on the proposed model and discuss residuals. Estimation is performed by maximum likelihood. A Monte Carlo experiment is conducted to evaluate the performances of these estimators in finite samples with a discussion of the results. An application is provided to show the modelling competence of the proposed distribution when the data sets show bimodality.

Flying to the moon: Impactful accounts of triatomines invasion from the 2nd to the 13th floor of an urban residential building in the municipality of Rio Branco, Acre, Brazil

ABSTRACT Background: Vectorial transmission through hematophagous triatomine insects remains the primary mode of Chagas Disease contagion. These insects have become increasingly common in urban environments. Therefore, this study aimed to report an encounter of triatomines with trypanosomatid infection in a vertical residential condominium in Rio Branco, the capital of the state of Acre, in the western Brazilian Amazon. Methods: Triatomines were collected from residents and sent to the municipality's Entomological Surveillance sector. Trypanosomatid positivity was evaluated using optical microscopy, followed by species and genotype identification using molecular biology techniques. Results: Twenty-five adult triatomine specimens were collected from two of three condominium buildings invading apartments from the 2nd to 13th floors. Six specimens were identified as Rhodnius sp. and 19 as R. montenegrensis. Among these, molecular tests were conducted on seven specimens, with five testing positive for Trypanosoma cruzi, all belonging to genotype TcI. Conclusions: These findings underscore the need for further studies to better understand the invasive capacity of these insects in these environments and the mechanisms involved in this process.

First report of Rhodnius stali Lent, Jurberg & Galvão, 1993 (Hemiptera: Reduviidae: Triatominae), vector of Trypanosoma cruzi (TcI) and Trypanosoma rangeli (TrA), in Rondônia, Southwestern Brazilian Amazonia.

Triatomines are hematophagous insects of epidemiological importance as they are vectors of Chagas disease. The first report of Rhodnius stali Lent, Jurberg & Galvão, 1993 in Rondônia, Brazil, is described. The insects were captured on palm trees of the genus Oenocarpus sp. Two adult male specimens of R. stali were identified and were found to be infected with Trypanosoma cruzi and Trypanosoma rangeli. The confirmation of this Rhodnius species in Rondônia increases the number of triatomines from nine to ten species in this state.

The unit generalized half-normal quantile regression model: formulation, estimation, diagnostics, and numerical applications.

In this paper, we propose and derive a new regression model for response variables defined on the open unit interval. By reparameterizing the unit generalized half-normal distribution, we get the interpretation of its location parameter as being a quantile of the distribution. In addition, we can evaluate effects of the explanatory variables in the conditional quantiles of the response variable as an alternative to the Kumaraswamy quantile regression model. The suitability of our proposal is demonstrated with two simulated examples and two real applications. For such data sets, the obtained fits of the proposed regression model are compared with that provided by a Kumaraswamy regression model.

Monitoring the Establishment of VOC Gamma in Minas Gerais, Brazil: A Retrospective Epidemiological and Genomic Surveillance Study.

Since its first identification in Brazil, the variant of concern (VOC) Gamma has been associated with increased infection and transmission rates, hospitalizations, and deaths. Minas Gerais (MG), the second-largest populated Brazilian state with more than 20 million inhabitants, observed a peak of cases and deaths in March-April 2021. We conducted a surveillance study in 1240 COVID-19-positive samples from 305 municipalities distributed across MG's 28 Regional Health Units (RHU) between 1 March to 27 April 2021. The most common variant was the VOC Gamma (71.2%), followed by the variant of interest (VOI) zeta (12.4%) and VOC alpha (9.6%). Although the predominance of Gamma was found in most of the RHUs, clusters of Zeta and Alpha variants were observed. One Alpha-clustered RHU has a history of high human mobility from countries with Alpha predominance. Other less frequent lineages, such as P.4, P.5, and P.7, were also identified. With our genomic characterization approach, we estimated the introduction of Gamma on 7 January 2021, at RHU Belo Horizonte. Differences in mortality between the Zeta, Gamma and Alpha variants were not observed. We reinforce the importance of vaccination programs to prevent severe cases and deaths during transmission peaks.

Reason for referrals to neurology: a community-based study in Brazil / Motivos de derivación a neurología: un estudio de base comunitaria en Brasil / Motivos de encaminhamentos para neurologia: um estudo de base comunitária no Brasil

Objective:to quantify the reasons for referrals of primary care physicians to neurology in Belo Horizonte, Brazil. Method:cross-sectional study evaluating referrals from Primary Care to the specialty of Neurology in Belo Horizonte, registered in the NOVO SISREG regulatory system, from March 2019 to July 2020. Neurologists or family physicians from the Regula Mais Brasil project, with experience in referral protocols for neurology, carried out the evaluation of the main diagnoses. Results:13,844 referrals to neurology were identified, with an average of 814.35 referrals per month. Headache, epilepsy and cerebrovascular disorders were the most common reasons, accounting for 55.5% of referrals. Other neurological conditions identified less frequently were parkinsonism, tremor, syncope and vertigo, responsible for 10.9% of referrals. Conclusion:most referrals did not prioritize only neurology expertise. It is possible that cultural aspects and the routine of physicians, health services and the community itself determined these referrals, raising awareness about the high demand, waiting time and possible clinical conditions that are soon ceasing to be managed by other specialties that also share these skills.

Objetivo:cuantificar los motivos de derivación de médicos de atención primaria a neurología en Belo Horizonte, Brasil. Método:estudio transversalque evaluó las derivaciones de la Atención Primaria a la especialidad de Neurología en Belo Horizonte, registradas en el sistema regulatorio NOVO SISREG, de marzo de 2019 a julio de 2020. Neurólogos o médicos de familia del proyecto Regula Mais Brasil, con experiencia en protocolos de derivación para neurología, realizó la evaluación de los principales diagnósticos. Resultados:se identificaron 13.844 derivaciones a neurología, con una media de 814,35 derivaciones al mes. La cefalea, la epilepsia y los trastornos cerebrovasculares fueron los motivos más frecuentes, representando el 55,5% de las derivaciones. Otras condiciones neurológicas identificadas con menor frecuencia fueron parkinsonismo, temblor, síncope y vértigo, responsables del 10,9% de las derivaciones. Conclusión: la mayoría de las referencias no priorizaron solo la experiencia en neurología. Es posible que los aspectos culturales y la rutina de los médicos, los servicios de salud y la propia comunidad determinaran estas derivaciones, concientizando sobre la alta demanda, tiempo de espera y posibles cuadros clínicos que pronto están dejando de ser manejados por otras especialidades que también comparten estas habilidades.

Objetivo:quantificar os motivos de encaminhamentos de médicos da Atenção Primária para neurologia em Belo Horizonte, Brasil. Método:estudo transversal com avaliação de encaminhamentos da Atenção Básica para especialidade de Neurologia em Belo Horizonte, registrados no sistema de regulação NOVO SISREG, no periodo de março de 2019 a julho de 2020. Neurologistas ou médicos de família do projeto Regula Mais Brasil, com experiência em protocolos de encaminhamentos para neurologia, realizaram a avaliação dos principais diagnósticos. Resultados:foram identificados 13.844 encaminhamentos para neurologia, com uma média de 814,35 encaminhamentos por mês. Cefaleia, epilepsia e distúrbios cerebrovasculares foram os motivos mais comuns, representando 55,5% dos encaminhamentos. Outras condições neurológicas identificadas em menor frequência foram o parkinsonismo, tremor, síncope e vertigem, responsáveispor 10,9% dos encaminhamentos. Conclusão:a maioria dos encaminhamentos não priorizou somente a expertise da neurologia. É possível que aspectos culturais e a rotina de médicos, serviços de saúde e da própria comunidade determinaram esses encaminhamentos, ascendendo alerta quanto a alta demanda, tempo de espera e possíveis condições clínicas que estão deixando de ser brevemente manejadas por outras especialidades que também compartilham dessas competências.

Molecular characterization of a new SARS-CoV-2 recombinant cluster XAG identified in Brazil.

Recombination events have been described in the Coronaviridae family. Since the beginning of the SARS-CoV-2 pandemic, a variable degree of selection pressure has acted upon the virus, generating new strains with increased fitness in terms of viral transmission and antibody scape. Most of the SC2 variants of concern (VOC) detected so far carry a combination of key amino acid changes and indels. Recombination may also reshuffle existing genetic profiles of distinct strains, potentially giving origin to recombinant strains with altered phenotypes. However, co-infection and recombination events are challenging to detect and require in-depth curation of assembled genomes and sequencing reds. Here, we present the molecular characterization of a new SARS-CoV-2 recombinant between BA.1.1 and BA.2.23 Omicron lineages identified in Brazil. We characterized four mutations that had not been previously described in any of the recombinants already identified worldwide and described the likely breaking points. Moreover, through phylogenetic analysis, we showed that the newly named XAG lineage groups in a highly supported monophyletic clade confirmed its common evolutionary history from parental Omicron lineages and other recombinants already described. These observations were only possible thanks to the joint effort of bioinformatics tools auxiliary in genomic surveillance and the manual curation of experienced personnel, demonstrating the importance of genetic, and bioinformatic knowledge in genomics.

First report of Rhodnius montenegrensis (Hemiptera: Reduviidae: Triatominae) in Bolivia.

BACKGROUND: The subfamily Triatominae, which comprises 157 species, carries the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. This short communication reports for the first time the occurrence of Rhodnius montenegrensis in Bolivia. METHODS: Active searches were carried out on palm trees of the genus Oenocarpus in Beni district, Bolivia. RESULTS: Fifteen R. montenegrensis specimens were collected from a rural area of the Beni district, Bolivia, and tested positive for T. cruzi. CONCLUSIONS: This new report expands the geographic distribution of the species in Latin America. Due to their ability to transmit trypanosomatids, the species deserves the attention of vector control programs.

Tracking the turnover of SARS-CoV-2 VOCs Gamma to Delta in a Brazilian state (Minas Gerais) with a high-vaccination status.

The emergence and global dissemination of Severe Acute Respiratory Syndrome virus 2 (SARS-CoV-2) variants of concern (VOCs) have been described as the main factor driving the Coronavirus Disease 2019 pandemic. In Brazil, the Gamma variant dominated the epidemiological scenario during the first period of 2021. Many Brazilian regions detected the Delta variant after its first description and documented its spread. To monitor the introduction and spread of VOC Delta, we performed Polymerase Chain Reaction (PCR) genotyping and genome sequencing in ten regional sentinel units from June to October 2021 in the State of Minas Gerais (MG). We documented the introduction and spread of Delta, comprising 70 per cent of the cases 8 weeks later. Comparing the viral loads of the Gamma and Delta dominance periods, we provide additional evidence that the latter is more transmissible. The spread and dominance of Delta did not culminate in the increase in cases and deaths, suggesting that the vaccination may have restrained the epidemic growth. Analysis of 224 novel Delta genomes revealed that Rio de Janeiro state was the primary source for disseminating this variant in the state of MG. We present the establishment of Delta, providing evidence of its enhanced transmissibility and showing that this variant shift did not aggravate the epidemiological scenario in a high immunity setting.

An overview on parametric quantile regression models and their computational implementation with applications to biomedical problems including COVID-19 data.

Quantile regression allows us to estimate the relationship between covariates and any quantile of the response variable rather than the mean. Recently, several statistical distributions have been considered for quantile modeling. The objective of this study is to provide a new computational package, two biomedical applications, one of them with COVID-19 data, and an up-to-date overview of parametric quantile regression. A fully parametric quantile regression is formulated by first parameterizing the baseline distribution in terms of a quantile. Then, we introduce a regression-based functional form through a link function. The density, distribution, and quantile functions, as well as the main properties of each distribution, are presented. We consider 18 distributions related to normal and non-normal settings for quantile modeling of continuous responses on the unit interval, four distributions for continuous response, and one distribution for discrete response. We implement an R package that includes estimation and model checking, density, distribution, and quantile functions, as well as random number generators, for distributions using quantile regression in both location and shape parameters. In summary, a number of studies have recently appeared applying parametric quantile regression as an alternative to the distribution-free quantile regression proposed in the literature. We have reviewed a wide body of parametric quantile regression models, developed an R package which allows us, in a simple way, to fit a variety of distributions, and applied these models to two examples with biomedical real-world data from Brazil and COVID-19 data from US for illustrative purposes. Parametric and non-parametric quantile regressions are compared with these two data sets.

First report of Rhodnius montenegrensis (Hemiptera: Reduviidae: Triatominae) in Bolivia

ABSTRACT Background: The subfamily Triatominae, which comprises 157 species, carries the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. This short communication reports for the first time the occurrence of Rhodnius montenegrensis in Bolivia. Methods: Active searches were carried out on palm trees of the genus Oenocarpus in Beni district, Bolivia. Results: Fifteen R. montenegrensis specimens were collected from a rural area of the Beni district, Bolivia, and tested positive for T. cruzi. Conclusions: This new report expands the geographic distribution of the species in Latin America. Due to their ability to transmit trypanosomatids, the species deserves the attention of vector control programs.

A collection of parametric modal regression models for bounded data.

Modal regression is an alternative approach for investigating the relationship between the most likely response and covariates and can hence reveal important structure missed by usual regression methods. This paper provides a collection of parametric mode regression models for bounded response variable by considering some recently introduced probability distributions with bounded support along with the well-established Beta and Kumaraswamy distribution. The main properties of the distributions are highlighted and compared. An empirical comparison between the considered modal regression is demonstrated through the analysis of three data sets from health and social science. For reproducible research, the proposed models are freely available to users as an R package unitModalReg.

A parametric quantile regression approach for modelling zero-or-one inflated double bounded data.

Over the last decades, the challenges in applied regression have been changing considerably, and full probabilistic modeling rather than predicting just means is crucial in many applications. Motivated by two applications where the response variable is observed on the unit-interval and inflated at zero or one, we propose a parametric quantile regression considering the unit-Weibull distribution. In particular, we are interested in quantifying the influence of covariates on the quantiles of the response variable. The maximum likelihood method is used for parameters estimation. Monte Carlo simulations reveal that the maximum likelihood estimators are nearly unbiased and consistent. Also, we define a residual analysis to assess the goodness of fit.

COVID-19 in long-term care facilities for the elderly: laboratory screening and disease dissemination prevention strategies. / COVID-19 nas instituições de longa permanência para idosos: estratégias de rastreamento laboratorial e prevenção da propagação da doença.

An infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the 2019 Novel Coronavirus Disease (COVID-19) pandemic has unveiled a hitherto hidden reality: the vulnerability of the population living in long-term care facilities for the elderly (LTCF). To date, several scientific publications have revealed a concentration of up to 60% of deaths attributed to COVID-19 in such institutions. Most LTFC residents share the primary risk factors currently associated with increased morbimortality due to the COVID-19 infection. It is crucial to define actions to prevent SARS-CoV-2 spread in this environment, besides the usual measures of social distancing and isolation of the carriers of this disease. This paper proposes strategies for the investigation of this infection in LTCF residents and workers using laboratory tests available in Brazil. The early identification of individuals with SARS-CoV-2, who may actively and continuously spread the virus, allows adopting measures aimed at interrupting the local transmission cycle of this infection.

First report of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in Amazonas, Brazil.

INTRODUCTION: Triatomines are hematophagous insects of epidemiological importance because they are vectors of Chagas disease. We present here the first report of Rhodnius montenegrensis in Amazonas, Brazil. METHODS: Triatomines were collected from Attalea butyracea palm trees in the municipality of Guajará. RESULTS: Two adult female R. montenegrensis specimens were identified. CONCLUSIONS: The present study confirms that the number of triatomine species within the Amazon has increased from 10 to 11, and the number of Brazilian states with R. montenegrensis has increased from two to three.

First report of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in Amazonas, Brazil

Abstract INTRODUCTION: Triatomines are hematophagous insects of epidemiological importance because they are vectors of Chagas disease. We present here the first report of Rhodnius montenegrensis in Amazonas, Brazil. METHODS: Triatomines were collected from Attalea butyracea palm trees in the municipality of Guajará. RESULTS: Two adult female R. montenegrensis specimens were identified. CONCLUSIONS: The present study confirms that the number of triatomine species within the Amazon has increased from 10 to 11, and the number of Brazilian states with R. montenegrensis has increased from two to three.