Mapeamento dinâmico da probabilidade de infestação por vetores urbanos de arbovírus nos municípios do Rio Grande do Sul, 2016-2017 / Mapeo dinámico de la probabilidad de infestación por vectores urbanos de arbovirus en los municipios de Rio Grande do Sul, Brasil, 2016-2017 / Dynamic mapping of the probability of infestation by urban arbovirus vectors in the municipalities of Rio Grande do Sul state, Brazil, 2016-2017

Objetivo: Comparar o mapeamento oficial com um mapeamento probabilístico da infestação por Aedes spp. nos municípios do Rio Grande do Sul, Brasil. Métodos: Estudo ecológico com dados de amostras de criadouros em 2016-2017; obteve-se a classificação oficial em boletins epidemiológicos e estimou-se a probabilidade de infestação por município e semana, ajustando-se um modelo dinâmico de ocupação de sítios aos dados da vigilância epidemiológica municipal. Resultados: 187.245 amostras coletadas em 473 municípios originaram 10.648 detecções de Aedes aegypti e 8.414 de Aedes albopictus; o mapeamento oficial concorda com o probabilístico em municípios da região noroeste e oeste do RS; os mapeamentos discordam nas regiões leste, centro, nordeste e sul, revelando municípios oficialmente não infestados com alta probabilidade de infestação e notificação de arboviroses. Conclusão: A classificação oficial identificou infestação nos municípios infestados do noroeste e oeste, e não identificou infestação em municípios com possíveis falsos zeros e onde ela varia temporalmente.

Objetivo: Comparar el mapeo oficial con un mapeo probabilístico de infestación por Aedes spp. en los municipios de Rio Grande do Sul, Brasil. Métodos: Estudio ecológico analizando muestras colectadas en criaderos en 2016-2017; se obtuvo la clasificación oficial en boletines epidemiológicos, y la probabilidad de infestación por municipio y semana ajustando un modelo dinámico de ocupación de sitios a los datos de la vigilancia epidemiológica municipal. Resultados: 187.245 muestras de 473 municipios generaron 10.648 detecciones de Aedes aegypti y 8.414 detecciones de Aedes albopictus. El mapeo oficial está de acuerdo con el probabilístico en municipios del noroeste y oeste de RS; los mapeos no concuerdan en el este, centro, nordeste y sur, revelando municipios oficialmente no infestados con alta probabilidad de infestación y notificación de arbovirus. Conclusión: Mientras la clasificación oficial identifica municipios del noroeste y oeste infestados críticamente, no identifica infestación en municipios con posiblemente falsos ceros y en donde la infestación varía temporalmente.

Objective: To compare official mapping with probabilistic mapping of infestation by Aedes spp. in the municipalities of Rio Grande do Sul state, Brazil. Methods: This was an ecological study using data from samples of mosquito breeding sites collected in 2016-2017; official classification was obtained from epidemiological reports, and infestation per municipality and week was estimated by fitting a dynamic site-occupancy model to data from municipal epidemiological surveillance. Results: 187,245 samples collected in 473 municipalities returned 10,648 detections of Aedes aegypti, and 8,414 detections of Aedes albopictus; official mapping agrees with probabilistic mapping in municipalities in the northwestern and western regions of the state. The mappings are not in agreement in the eastern, central, northeastern and southern regions, revealing municipalities officially not infested but with high probability of infestation and notification of arbovirus infection. Conclusion: While official classification identified critically infested municipalities in the state's northwestern and western regions, it did not identify infestation in municipalities with possible false zero errors and where infestation varies over time.

Un acercamiento al conocimiento de los hábitats larvarios de Aedes (Stegomyia) aegypti (Diptera: Culicidae) en el entorno doméstico en Jarabacoa, República Dominicana / An approach to larval habitats of Aedes (Stegomyia) aegypti (Diptera: Culicidae) in the domestic environment of Jarabacoa, Dominican Republic

Introducción: A nivel mundial, Aedes aegypti es el culícido más importante en cuanto a la transmisión de arbovirus de impacto en salud pública. Objetivo: Profundizar en los conocimientos ecológicos de Ae. aegypti en República Dominicana, a través de los recipientes o contenedores que utiliza para desarrollar sus formas preimaginales. Métodos: El estudio se extendió desde octubre a diciembre de 2017. Se muestrearon aleatoriamente 100 viviendas, en las que se revisaron todos los recipientes con potencialidad para albergar larvas y/o pupas de mosquitos, dentro y fuera del domicilio. Se cuantificó el tipo y total de cada depósito positivo según su ubicación en cada vivienda, para calcular el porcentaje de representatividad, junto al Índice Pupal por Depósitos específicos (IPDe) para cada receptáculo con pupas. Resultados: Se detectó presencia de Ae. aegypti en el 41 por ciento de las casas visitadas. De los 419 recipientes analizados, 74 resultaron positivos a larvas y/o pupas (17,66 por ciento). Se clasificaron 28 tipos de depósitos atendiendo a su función y material. Cuantitativamente, los depósitos permanentes fueron los más representativos con un 54,05 por ciento. Las mayores capturas se realizaron en el peridomicilio. El tanque plástico fue el más relevante, pues aportó el 28,37 por ciento del total de depósitos positivos, así como un elevado IPDe. Conclusiones: Los resultados evidencian elevados niveles de infestación en los domicilios de Jarabacoa que deben ser controlados a fin de disminuir el riesgo en la transmisión de arbovirosis. El control de los recipientes artificiales, como los contenedores desechables, los neumáticos y sobre todo los tanques de agua, es la piedra angular de cualquier esfuerzo para prevenir estas enfermedades(AU)

Introduction: Aedes aegypti is the most important culicid worldwide in terms of transmission of arbovirus infections of a high impact on public health. Objective: Broaden ecological knowledge about Aedes aegypti in the Dominican Republic, particularly about the containers and other sites where immature development occurs. Methods: The study extended from October to December 2017. One hundred households were randomly surveyed, checking all the containers with a potential to host mosquito larvae and/or pupae both inside and outside the house. Quantification was made of the type and total of positive containers according to their location in each household, to estimate the percentage of representativeness and the pupal index per container identified (PICI) when pupae were found in them. Results: Aedes aegypti was found to be present in 41 percent of the houses visited. Of the 419 containers analyzed, 74 were positive for larvae and/or pupae (17.66 percent). Containers were classified into 28 types according to their function and material. Quantitatively, permanent containers were the best represented with 54.05 percent. The largest captures were made in the area around the house. Plastic water tanks were the most relevant, with 28.37 percent of the total positive containers and a high PICI. Conclusions: Results show high levels of infestation in Jarabacoa households. These should be controlled to reduce the risk of arbovirus infection transmission. Control of artificial breeding sites, such as disposable containers, tires and especially water tanks, is the cornerstone of any effort to prevent these diseases(AU)

Rodent-borne viruses survey in rural settlers from Central Brazil

Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.57%) were reactive for orthohantavirus and 3 (0.64%) for mammarenavirus. These rural settlers lived under unfavorable infrastructure, socioeconomic disadvantages, and unsanitary conditions, representing a risk for rodent-borne infections. Development of public policies towards the improvement of health, sanitation and awareness of rodent-borne diseases in improvised camps and settlements is imperative, in order to reduce morbidity and mortality caused by these diseases.

Snail transmitters of schistosomiasis and other mollusks of medical and economic importance at the simplício queda única hydroelectric plant, southeast Brazil

Abstract INTRODUCTION This paper presents the results of an extensive survey of freshwater mollusks in the Simplício Queda Única Hydroelectric Development area, Southeast Brazil. METHODS Mollusks were collected between 2008 and 2013. All specimens were examined for the presence of larval trematodes. RESULTS In total, 12,507 specimens classified into 16 genera were obtained. Known snail vectors of schistosomiasis and fascioliasis and exotic species were identified, and new records are reported. CONCLUSIONS No specimens parasitized by larval trematodes of medical interest were detected. However, the results reinforce the importance of surveillance in study areas vulnerable to the occurrence of schistosomiasis transmission.

Distribution of the members of the Pipiens Assemblage in the sympatric area from Argentina: which is where and when?

Given their medical and veterinary relevance, the members of the Pipiens Assemblage are a worldwide target of ecological research. The distribution of Culex pipiens s.s. and Cx. quinquefasciatus converge in Buenos Aires, Argentina, where hybrids have been detected. Each member of the assemblage exhibits a distinct eco-physiological behaviour that can affect its efficiency in pathogen transmission. Our aim was to identify the environmental drivers for the spatio-temporal distribution of each member, focusing on latitudinal and urbanisation gradients. Immatures of mosquitoes were surveyed in artificial containers found within 11 public cemeteries, raised up to the adult stage and identified by their male genitalia. The distribution of each member was associated with the environment in a Generalized Linear Model. The variable accounting for most of the heterogeneity was latitude; Cx. quinquefasciatus was collected more frequently at northern cemeteries, whereas Cx. pipiens and hybrids were more likely at the southern extreme. The urbanisation gradient was also associated with the occurrence of Cx. quinquefasciatus and hybrids at the high and low end, respectively. Other relevant variables were cemetery total area, the proportion with graves and the presence of plastic flowers in the containers. The spatial distribution of the members of the Pipiens Assemblage within the sympatric region in South America is driven by environmental features. The information presented herein provides essential baseline data for surveillance programs and control activities.

Triatominae (Hemiptera, Reduviidae) in the Pantanal region: association with Trypanosoma cruzi, different habitats and vertebrate hosts

ABSTRACTINTRODUCTION: The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection.METHODS: The fieldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at five selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads.RESULTS: In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher efficiency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests.CONCLUSIONS: Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruziin the Pantanal region.

Lymnaea cousini , huésped de Fasciola hepatica en el trópico alto andino de Colombia, y sus nuevos haplotipos, confirmados con el marcador mitocondrial del gen de la citocromo oxidasa I / Lymnaea cousini , intermediate host of Fasciola hepatica in the Colombian high tropical Andes, and its new haplotypes confirmed with the mitochondrial marker cytochrome oxidase I

Institución donde se ejecutó el trabajo: Programa de Estudio y Control de Enfermedades Tropicales, PECET, Unidad de Malacología Médica y Trematodos (UMMT), Sede de Investigación Universitaria, Universidad de Antioquia, Medellín, Colombia Introducción. La fasciolosis es la enfermedad transmitida por vectores con mayor distribución latitudinal, longitudinal y altitudinal, debido a la capacidad colonizadora del parásito Fasciola hepatica y de sus huéspedes intermediarios, los moluscos limneidos. Estos caracoles se investigan por su importancia epidemiológica, pero su identificación taxonómica es difícil por la similitud fenotípica entre especies. En este sentido, con respecto a Lymnaea cousini , un huésped de F. hepatica en Colombia, existe incertidumbre en razón de su similitud morfológica con L. meridensis , descrita recientemente en Venezuela. Objetivo. Confirmar con el marcador del gen de la citocromo oxidasa I en el ADN mitocondrial COI (ADNmt), el estatus taxonómico de ejemplares morfológicamente caracterizados como L. cousini provenientes de Nariño, Norte de Santander y Santander (Colombia), depositados en la Colección de Moluscos Vectores de la Universidad de Antioquia, VHET N° 37. Materiales y métodos. Para la amplificación del COI mitocondrial, se extrajo ADN total del pie de cada ejemplar con el estuche DNeasy Blood and Tissue (Qiagen ® ). Los productos amplificados se enviaron a secuenciar a Macrogen Inc., Corea. Las 27 secuencias generadas en esta investigación se compararon con secuencias publicadas en el GenBank, incluidas las secuencias de la localidad tipo de L. cousini. Resultados. Se encontraron dos nuevos haplotipos de L. cousini para Colombia. Los especímenes de Nariño correspondían al haplotipo A, referenciado en Ecuador, y los especímenes de Santander y Norte de Santander, a un nuevo haplotipo al que se denominó D. Conclusión. Mediante el marcador mitocondrial del COI , se confirmó que los especímenes pertenecían a la especie L. cousini . Con el hallazgo se duplicó el número de haplotipos conocidos de la especie en Colombia y se amplió su distribución geográfica al suroeste y nordeste de la región altoandina colombiana.

Introduction: Fasciolosis is the disease transmitted by vectors with the highest latitudinal, longitudinal, and altitudinal distribution due to the colonizing capacity of the parasite Fasciola hepatica and its intermediate hosts, Lymnaeidae mollusks. These snails are under research due to their epidemiological importance, but their taxonomic identification is difficult given their interspecific phenotypical similarity. For this reason, there is uncertainty regarding Lymnaea cousini -a host of F. hepatica in Colombia- due to the morphological similarity it has with Lymnaea meridensis , recently described for Venezuela. Objective: To confirm with the COI marker (ADNmt) the taxonomic status of individuals morphologically identified as L. cousini from Nariño, Norte de Santander, and Santander (Colombia), deposited in the Vector Mollusks Collection VHET No. 37 of Universidad de Antioquia. Materials and methods: The amplification of the mitochondrial COI required total DNA extraction of each individual´s foot using the DNeasy Blood and Tissue Kit (Qiagen®). Products amplified were sent for sequencing to Macrogen Inc., Korea. Twenty seven sequences generated in this research were compared to sequences published in the GenBank, including sequences of the type locality of L. cousini . Results: Two new haplotypes of L. cousini were obtained for Colombia. Specimens from Nariño correspond to haplotype A, referenced for Ecuador, and specimens from Santander and Norte de Santander belong to a new haplotype we called haplotype D. Conclusion : By using the mitochondrial COI marker, we confirmed that the species under study did correspond to L. cousini . The number of known haplotypes of the species for Colombia has been duplicated and its geographical distribution has been extended to the southwest and northeast of the Colombian high Andean region.

Detección molecular de virus de encefalitis de Saint Louis en mosquitos de Buenos Aires, Argentina

Durante el mes de marzo de 2013 una población de palomas torcazas (Zenaida auriculata) se instaló en una zona céntrica de la ciudad de Buenos Aires. Conociendo el rol que poseen estas aves como hospedadores competentes del virus de la encefalitis de Saint Louis (SLEV), fue colocada en el lugar una trampa de luz tipo CDC, a fin de realizar una vigilancia entomológica. Durante ese mes,fueron capturados 5 grupos de mosquitos (n = 48), 3 correspondieron a la especie Culex pipiens (n = 10) y 2 a Culex spp.(n = 38), no pudiéndose determinar en estos últimos con precisión la especie por encontrarse dañados. En un grupo de mosquitos Culex spp. se detectó el SLEV por técnicas moleculares. Posteriormente fue secuenciado y clasificado como perteneciente al genotipo III.

During March 2013 a population of eared doves (Zenaida auriculata) was established in the center of City of Buenos Aires. Considering the role of these birds as host competent for Saint Louis encephalitis virus (SLEV), a CDC light trap was put in place to perform entomologic surveillance. During this month 5 pools of mosquitoes (n = 48) were collected and taxonomically determined. Three of them were classified as Culex pipiens (n = 10) and the other two were Culex spp. (n = 38). In this case, the mosquitoes species could not be determined due to that individuals were damaged. One of the Culex spp. pool was found to be positive for Saint Louis encephalitis virus by molecular techniques. This was then sequenced and classified as genotype III.

A malacological survey in the Manso Power Plant, State of Mato Grosso, Brazil: new records of freshwater snails, including transmitters of schistosomiasis and exotic species

Introduction Schistosomiasis is a parasitic disease of public health concern in Brazil, and the construction of hydroelectric dams, in addition to increasing permanent human settlement and tourism, has created conditions suitable for the establishment of mollusks that can transmit schistosomiasis. Such areas require a number of actions to prevent the establishment of schistosomiasis. This paper reports on a freshwater malacological survey carried out in the geographical area of the Manso Power Plant. Methods Mollusks were collected in 18 municipalities in the State of Mato Grosso between February 2002 and February 2004 (qualitative study) and from April 2009 to February 2011 (quantitative study). Results Thirty-one species of mollusks were collected, including newly recorded species (Antillorbis nordestensis and Burnupia ingae). In addition, the geographic distributions of known species, including Biomphalaria straminea, a snail vector of Schistosoma mansoni, were expanded. A total of 4,507 specimens were collected in the APM Manso reservoir (Usina Hidrelétrica de Aproveitamento Múltiplo de Manso) during the quantitative study, and Biomphalaria amazonica was found in six of the 10 localities analyzed. The Afroasiatic species Melanoides tuberculata, introduced after February 2009, was the dominant species (relative abundance 94.96%). Conclusions The study area is epidemiologically important due to the occurrence of B. straminea and B. amazonica, which are vectors of schistosomiasis, and M. tuberculata, a snail host of Centrocestus formosanus, which is responsible for centrocestiasis transmission. Observations of M. tuberculata and the exotic freshwater clams Corbicula fluminea and Corbicula largillierti raise concerns about biodiversity. .

Freshwater gastropods of the Baixada Maranhense Microregion, an endemic area for schistosomiasis in the State of Maranhao, Brazil: I - qualitative study

Introduction: The Baixada Maranhense Microregion currently has the highest prevalence of schistosomiasis in the State of Maranhão, likely because this parasitosis is characterized as an occupational disease, and increased contact with water increases the risk of infection by Schistosoma mansoni. This paper reports the results of the first comprehensive freshwater malacological survey performed in the Baixada Maranhense Microregion. Methods: Freshwater mollusks were collected from the twenty-one municipalities of the Baixada Maranhense Microregion and from Bacurituba and Cajapió and were evaluated for infection by trematodes. Results: A total of 9,129 mollusks were collected (sixteen species), which included the first records of six species in the State of Maranhão: Gundlachia radiata, G. ticaga, Hebetancylus moricandi, Plesiophysa guadeloupensis, Pomacea bridgesii diffusa and Omalonyx sp. Biomphalaria glabrata was found in five municipalities, whereas B. straminea was found in nine. Biomphalaria glabrata and B. straminea were observed in syntopy in Pinheiro and São Bento. Of the 990 specimens of B. glabrata and the 2,109 specimens of B. straminea that were exposed to and/or analyzed for the presence of larval trematodes, only a single specimen of B. glabrata (0.1%) from São Bento shed S. mansoni. Other larval trematodes were first observed in mollusks from the State of Maranhão. Conclusions: These results indicate that the study area is epidemiologically important due to the presence of two natural vectors of schistosomiasis and the active transmission of schistosomiasis, which was confirmed in the infected specimen that was collected in this study. .

Atlas iconográfico dos triatomíneos do Brasil (vetores da doença de Chagas) / Iconographic atlas of triatomine Brazil (vectors of Chagas' disease)

O material conta com ilustrações e informações sobre a morfologia dos insetos, tamanho, habitat, ciclo de vida, além de mapas sobre a diversidade e distribuição geográfica das 66 espécies de barbeiros registradas até o momento...

Susceptibility of Argentinean Biomphalaria tenagophila and Biomphalaria straminea to infection by Schistosoma mansoni and the possibility of geographic expansion of mansoni schistosomiasis

Introduction Human migration and the presence of natural vectors (mollusks) of Schistosoma mansoni are the primary causes of the expansion of mansoni schistosomiasis into southern areas of South America. Water conditions are favorable for the expansion of this disease because of the extensive hydrographic network, which includes the basins of the Paraná and Uruguay rivers and favors mollusk reproduction. These rivers also aid agriculture and tourism in the area. Despite these favorable conditions, natural infection by S. mansoni has not yet been reported in Argentina, Uruguay, or Paraguay. Methods Two species of planorbid from Argentina, Biomphalaria straminea and B. tenagophila, were exposed to the miracidia of five Brazilian strains of S. mansoni. Results Biomphalaria tenagophila (Atalaya, Buenos Aires province) was infected with the SJS strain (infection rate 3.3%), confirming the experimental susceptibility of this Argentinian species. Biomphalaria straminea (Rio Santa Lucía, Corrientes province) was susceptible to two Brazilian strains: SJS (infection rate 6.7%) and Sergipe (infection rate 6.7%). Conclusions These results demonstrate that species from Argentina have the potential to be natural hosts of S. mansoni and that the appearance of foci of mansoni schistosomiasis in Argentina is possible. .

Ants in a hospital environment and their potential as mechanical bacterial vectors

Introduction We studied the richness and abundance of ant species, their bacteria and the bacteria isolated from patient clinical samples. Methods Ants were collected with baited traps at 64 sites in a public hospital in São Luis, State of Maranhão, Brazil. Results In total, 1,659 ants from 14 species were captured. The most frequent species were Crematogaster victima, Solenopsis saevissima, Tapinoma melanocephalum, Camponotus vittatus and Paratrechina fulva. Forty-one species of bacteria were isolated from the ants and 18 from patients. Conclusions Ants are potential vehicles for pathogenic and opportunistic bacteria, and they can represent a risk factor in nosocomial infections. .

Caracterização das espécies do gênero Rhodnius Stål, 1859 (Hemiptera, Reduviidae, Triatominae) pelo método do Código de Barras de DNA / Characterization of the genus Rhodnius Stål, 1859 (Hemiptera, Reduviidae, Triatominae) by the method of DNA Barcode

A doença de Chagas é uma infecção causada pelo agente etiológico o Trypanosoma cruzi, transmitida ao ser humano através das fezes infectadas dos triatomíneos. O gênero Rhodnius, composto por 18 espécies, é um dos mais estudados, não só pela sua importância epidemiológica, como também pela difícil diferenciação de suas espécies. A correta identificação destas é necessária, pois o controle da doença esta baseado no combate ao vetor. O sequenciamento de DNA vem sendo amplamente utilizado para identificação, determinação das relações de parentesco e inferências filogenéticas de triatomíneos. O método do Código de Barras de DNA é um sistema de identificação taxonômica universal, rápido e de livre acesso, baseado na variação de uma parte da sequência do gene mitocondrial citocromo oxidase subunidade I (COI)O objetivo do presente estudo foi caracterizar a identidade taxonômica de espécimes do gênero Rhodnius, por meio da taxonomia clássica e da amplificação fragmento do COI, avaliando a utilidade deste marcador para discriminar as espécies. Através da análise do COI foi possível caracterizar 13 espécies de Rhodnius, porém não foi possível inferir a filogenia deste grupo utilizando este marcador. As análises das distâncias indicam a existência do barcoding-gap para a maioria das espécies. Portanto, este estudo demonstra que a proposta do Código de Barras de DNA para caracterizar espécies do gênero Rhodnius é útil, porém sugere-se a utilização integrada de procedimentos adicionais de sistemática e taxonomia.

Chagas disease is an infection caused by the etiological agent Trypanosoma cruzi, transmitted to humans through the feces of infected triatomines. The genus Rhodnius, comprising 18 species, is one of the most studied, not only for its epidemiological importance, but also because of the difficult differentiation of these species. The correct identification is necessary, because the control of disease is based on vector combat. The DNA sequencing has been widely used for identification, determination of phylogenetic relationships and phylogenetic inferences of triatomines. The method of DNA Barcoding is a system of universal taxonomic identification, fast with free access, based on the variation of a part of the sequence of the mitochondrial gene cytochrome oxidase subunit I (COI). The objective of this study was to characterize the taxonomic identity of specimens of the genus Rhodnius, by classical taxonomy and amplification of COI fragment, evaluating its usefulness to discriminate species. By analysis of COI was possible to characterize 13 Rhodnius species, but it was not possible to infer the phylogeny of this group. The analysis of the distances indicates the existence of barcoding-gap for most species. Therefore, this study demonstrates that the proposed DNA Barcoding, to characterize the genus Rhodnius, is useful, but it is suggested to use additional procedures integrated systematic and taxonomy.

Hybridism between Biomphalaria cousini and Biomphalaria amazonica and its susceptibility to Schistosoma mansoni

Molecular techniques can aid in the classification of Biomphalaria species because morphological differentiation between these species is difficult. Previous studies using phylogeny, morphological and molecular taxonomy showed that some populations studied were Biomphalaria cousini instead of Biomphalaria amazonica. Three different molecular profiles were observed that enabled the separation of B. amazonica from B. cousini. The third profile showed an association between the two and suggested the possibility of hybrids between them. Therefore, the aim of this work was to investigate the hybridism between B. cousini and B. amazonica and to verify if the hybrids are susceptible to Schistosoma mansoni. Crosses using the albinism factor as a genetic marker were performed, with pigmented B. cousini and albino B. amazonica snails identified by polymerase chain reaction-restriction fragment length polymorphism. This procedure was conducted using B. cousini and B. amazonica of the type locality accordingly to Paraense, 1966. In addition, susceptibility studies were performed using snails obtained from the crosses (hybrids) and three S. mansoni strains (LE, SJ, AL). The crosses between B. amazonica and B. cousini confirmed the occurrence of hybrids. Moreover, hybrids can be considered potential hosts of S. mansoni because they are susceptible to LE, SJ and AL strains (4.4 percent, 5.6 percent and 2.2 percent, respectively). These results indicate that there is a risk of introducing schistosomiasis mansoni into new areas.

Malacological survey of Biomphalaria snails in municipalities along the Estrada Real in the southeast of the State of Minas Gerais, Brazil / Pesquisa malacológica de Biomphalaria em municípios da Estrada Real, situados no sudeste do Estado de Minas Gerais

INTRODUCTION: The increasing practice of ecotourism and rural tourism in the State of Minas Gerais, Brazil, highlights the importance of studies concerning the occurrence of potential intermediate hosts of Schistosoma mansoni. This study aimed to identify species of Biomphalaria snails in municipalities along the Estrada Real, an important Brazilian tourism project. METHODS: The specimens were collected in different water collections of 36 municipalities along the Estrada Real in the southeast of the State of Minas Gerais. Biomphalaria species were characterized using both morphological and molecular approaches. The research was conducted between August 2005 and September 2009 and all the sites visited were georeferenced using GPS. RESULTS: Six Biomphalaria species were found in 30 of the 36 municipalities studied: glabrata, tenagophila, straminea, peregrina, occidentalis and schrammi. The first three species of Biomphalaria, recognized as intermediate hosts of S. mansoni, were present in 33.3 percent, 47.2 percent and 8.3 percent of the municipalities studied, respectively. The mollusks were found in different types of water collections and no infection by S. mansoni was detected. The highest occurrence of Biomphalaria concentration was verified in the area covered by the Caminho Novo route (Diamantina/MG to Rio de Janeiro/RJ). CONCLUSIONS: Considering the occurrence of schistosomiasis in the State of Minas Gerais and the socioeconomic repercussions involved in the Estrada Real Project, this work focuses on the vulnerability of water collections due to the presence of Biomphalaria mollusks and emphasizes the need for epidemiological surveillance and sanitary and educational measures integrated with the local community and tourism sectors.

INTRODUÇÃO: O aumento das práticas de ecoturismo e turismo rural, em Minas Gerais, Brasil, evidencia a importância de se realizarem estudos sobre a ocorrência de hospedeiros intermediários do Schistosoma mansoni, no estado. O presente trabalho objetivou a busca e identificação das espécies de caramujos Biomphalaria encontrados em municípios mineiros pertencentes à Estrada Real, um importante projeto de turismo brasileiro. MÉTODOS: Os moluscos foram coletados em 36 municípios da Estrada Real, no sudeste de Minas Gerais. A pesquisa foi realizada de agosto de 2005 a setembro de 2009 e todos os locais visitados foram georreferenciados com o uso de GPS. RESULTADOS: Dos 36 municípios estudados, 30 apresentaram a ocorrência de pelo menos uma entre as seis espécies de Biomphalaria: glabrata, tenagophila, straminea, peregrina, occidentalis e schrammi. As três primeiras espécies citadas, reconhecidas como hospedeiras intermediárias do S. mansoni, estavam presentes em 33,3 por cento, 47,2 por cento e 8,3 por cento dos municípios estudados, respectivamente. Os moluscos foram encontrados em diferentes tipos de coleções hídricas e em nenhum deles foi detectada infecção pelo S. mansoni. Houve maior ocorrência de Biomphalaria na área referente ao Caminho Novo (Diamantina/MG ao Rio de Janeiro/RJ). CONCLUSÕES: Considerando-se a ocorrência da esquistossomose, no Estado de Minas Gerais, e as repercussões socioeconômicas que envolvem o projeto Estrada Real, este trabalho aponta para a vulnerabilidade das coleções hídricas devido à presença de moluscos Biomphalaria e enfatiza a necessidade de vigilância epidemiológica e medidas educativas e sanitárias integradas com a comunidade local e setores de turismo.

Evaluación de la persistencia de una formulación comercial de Bacillus sphaericus en criaderos naturales de anofelinos vectores de malaria en estado Bolívar, Venezuela / Evaluation of the persistence of a comercial formulation of Bacillus sphaericus in malaria vectors anopheline larval hábitats in Bolívar state, Venezuela

El municipio Sifontes del estado Bolívar es la principal área endémica a malaria de Venezuela. Durante los últimos cinco años se ha reportado en este municipio un promedio anual cercano a 15 mil casos, alcanzándose durante 2009 la cifra de 20.282, lo que constituye una situación de epidemia. En este municipio se evaluó la persistencia de una formulación comercial de Bacillus sphaericus Neide (Vectolex CG 7,5%) en criaderos naturales de Anopheles marajoara, An. triannulatus y An. braziliensis. Para ello se realizaron dos experimentos en los cuales se evaluaron las dosis de 2 y 3 gr/m2 durante 60 y 90 días. Los resultados indican que hay diferencias en la persistencia por tipo de criadero y especie de anofelino. La tendencia general para todas las especies indica que el porcentaje de reducción de la población larvaria fue de 100% durante la primera semana, luego disminuyó paulatinamente hasta más o menos 40% después de los 28 días, para luego recuperarse a alrededor de 60% a los 45 días, manteniéndose así hasta el día 90 con ambas dosis. Este comportamiento es más evidente para An. marajoara, mientras que con An. triannulatus la eficacia se mantiene alrededor de 80% durante 90 días con 3 gr/m2. Sobre An. braziliensis, la eficacia se mantiene en 100% hasta el día 14 con ambas concentraciones, para luego caer abruptamente sin recuperación. Es la primera vez que se evalúa B. sphaericus sobre estas especies de anofelinos en Venezuela, considerándose estos resultados muy prometedores para el control de vectores

Sifontes municipality in Bolivar state is the main malaria endemic area in Venezuela. During the last five years an annual average of 14,000 cases has been reported, reaching 13,450 during 2008, resulting in an epidemic situation. A commercial formulation of Bacillus sphaericus Neide (Vectolex CG 7.5%), was evaluated in larval habitats of Anopheles marajoara, An. triannulatus and An. braziliensis. Two experiments were carried out in a lagoon and a pasture inundated area, 2 and 3 gr/m2 doses were evaluated during 60 and 90 days. The results point out that there are differences in the persistence depending on the type of larval habitat and anopheline species. The general trend indicated that for all the species the persistence of the Vectolex, therefore the reduction of the larval population was 100% during the first week. However, it felt under 40% after day 28, then recovered by day 45, and remaining around 40% for 90 days with both doses. A similar pattern was observed for An. marajoara, whereas for An. triannulatus the efficacy remained around 80% during 90 days only at 3 gr/m2. With An. braziliensis there was 100% persistence until day 14 with both doses, for then felt abruptly without recovering. This is the first time that B. sphaericus was evaluated for these anopheline species in Venezuela, considering these results promissory for the malaria control program

O estudo da competência vetorial das populações de Aedes aegypti da cidade de Belo Horizonte, Minas Gerais, ao Dengue vírus 2

A Dengue é um dos principais problemas de saúde pública no mundo e a principalarbovirose que atinge o homem. A doença é encontrada em mais de 100 países eaproximadamente 2,5 bilhões de pessoas vivem em áreas endêmicas (WHO, 2008).Sendo assim, seu principal vetor nas Américas, o A. aegypti, tem sido objeto deinúmeros estudos por apresentar ampla variação na sua competência vetorial paraDENV dentro e entre populações por todo o mundo. A competência vetorial é definidacomo um mecanismo intrínseco do vetor para infecção, replicação e transmissão dovírus e está associada com o número de barreiras anatômicas que determinam aeficiência da infecção no vetor (Black IV et al., 2002). Este estudo é pioneiro no Brasile analisou a competência vetorial das populações de A. aegypti da cidade de BeloHorizonte, para o DENV-2. Um total de 300 fêmeas de A. aegypti, de cada uma dasregionais, foram submetidas a um repasto sanguíneo infectante com o DENV-2. Após14 dias, amostras de 40 mosquitos fêmeas representativas de cada uma das regionais,foram dissecadas a partir da separação da cabeça e do corpo. A presença do vírus nocorpo e na cabeça dos mosquitos foi verificada através da RT-PCR “One Step”utilizando iniciadores específicos para o DENV-2. Sendo assim, dentre as populaçõesanalisadas a com maior e menor barreira de infecção (MIB) foi a Pampulha (93%) e aNorte (18%), respectivamente. Já a população com maior e menor barreira de escape foia Venda Nova (50%) e a Centro-Sul (1%), respectivamente. Por fim, verificou-se que apopulação com maior competência vetorial foi a da regional Norte (70%) seguida pelaOeste (30%), Centro-Sul (25%), Barreiro (25%), Venda Nova (15%), Leste (13%),Noroeste (10%), Nordeste (5%) e a com menor foi a da Pampulha (3%). Com estesresultados, medidas de controle do vetor poderão ser reforçadas nas regionais quepossuem populações de A. aegypti com maior competência para transmitir o DENV.