Natural vertical cotransmission of Dengue virus and Chikungunya virus from Aedes aegypti in Brumado, Bahia, Brazil

ABSTRACT Background: Arthropod-borne viruses have recently emerged and are pathogens of various human diseases, including dengue, zika, and chikungunya viruses. Methods: We collectedAedes aegyptilarvae (N = 20) from Brumado, Bahia, Brazil, and treated and individually preserved the specimens. We analyzed the samples for dengue, zika, and chikungunya viruses using molecular biology methods. Results: We found that 25% (N = 5) and 15% (N = 3) were positive exclusively for dengue and chikungunya viruses, respectively; 15% (N = 3) were coinfected with both. Conclusions: This is the first report of dengue and chikungunya virus coinfection in A. aegypti larvae.

Do climate changes alter the distribution and transmission of malaria? Evidence assessment and recommendations for future studies

Abstract Malaria, a mosquito-borne infectious disease, is considered a significant global health burden. Climate changes or different weather conditions may impact infectious diseases, specifically those transmitted by insect vectors and contaminated water. Based on the current predictions for climate change associated with the increase in carbon dioxide concentrations in the atmosphere and the increase in atmospheric temperature, the Intergovernmental Panel on Climate Change predicts that in 2050, malaria may threaten some previously unexposed areas worldwide and cause a 50% higher probability of malaria cases. Climate-based distribution models of malaria depict an increase in the geographic distribution of the disease as global environmental temperatures and conditions worsen. Researchers have studied the influence of changes in climate on the prevalence of malaria using different mathematical models that consider different variables and predict the conditions for malaria distribution. In this context, we conducted a mini-review to elucidate the important aspects described in the literature on the influence of climate change in the distribution and transmission of malaria. It is important to develop possible risk management strategies and enhance the surveillance system enhanced even in currently malaria-free areas predicted to experience malaria in the future.

Current vector control challenges in the fight against malaria in Brazil

Abstract In Brazil, malaria is an important public health problem first reported in 1560. Historically, fluctuations in malaria cases in Brazil are attributed to waves of economic development; construction of railroads, highways, and hydroelectric dams; and population displacement and land occupation policies. Vector control measures have been widely used with an important role in reducing malaria cases. In this review article, we reviewed the vector control measures established in the Brazilian territory and aspects associated with such measures for malaria. Although some vector control measures are routinely used in Brazil, many entomological and effectiveness information still need better evidence in endemic areas where Plasmodium vivax predominates. Herein, we outlined some of the needs and priorities for future research: a) update of the cartography of malaria vectors in Brazil, adding molecular techniques for the correct identification of species and complexes of species; b) evaluation of vector competence of anophelines in Brazil; c) strengthening of local entomology teams to perform vector control measures and interpret results; d) evaluation of vector control measures, especially use of insecticide-treated nets and long-lasting insecticidal nets, estimating their effectiveness, cost-benefit, and population acceptance; e) establishment of colonies of malaria vectors in Brazil, i.e., Anopheles darlingi, to understand parasite-vector interactions better; f) study of new vector control strategies with impacts on non-endophilic vectors; g) estimation of the impact of insecticide resistance in different geographical areas; and h) identification of the relative contribution of natural and artificial breeding sites in different epidemiological contexts for transmission.

Typology and distribution of antennal sensory organs of adults Haematobia irritans of the Midwest Region of Brazil / Tipologia e distribuição de órgãos sensilares de Haematobia irritans adultas do Centro-Oeste do Brasil

Considering the great economic and sanitarian importance of Haematobia irritans − the development of resistance of this species to the main chemical insecticides used in its control, in several other localities of the world; as well as that different strains of the same species frequently present different types and distribution patterns −, the present aim study was to investigate the typology and distribution of different types of sensillae of H. irritans adults, from populations of this fly present in Brazilian Midwest, with emphasis on olfactory sensillae. This study provides new data on the typology and sensillary distribution of antennal sensilla of this fly. In the antennal segments were found non-innervated spinules and ten subtypes of sensilla: long bristles sensillum, long basiconic sensillum, blunt coeloconic sensillum, clavate coeloconic sensilla − single-tip and double-tip subtypes −, grooved coeloconic sensillum, long grooved coeloconic sensillum, trichoid sensillum, coeloconic sensillum, and smaller basiconic sensillum. A slight sexual dimorphism was observed in the antennal sensillae of H. irritans. These results provide a morphological basis for future investigations on olfactory-mediated behavior of this species, and could assist future studies for the development of alternative measures to the monitoring and control of this fly populations, with less environmental impact.(AU)

Considerando a grande importância econômica e sanitária de Haematobia irritans, o desenvolvimento de resistência desta espécie aos principais inseticidas químicos utilizados em seu controle, em diversas outras localidades do mundo, bem como que diferentes cepas de uma mesma espécie frequentemente apresentam diferentes tipos e padrões de distribuição sensilares, objetivou-se no presente trabalho investigar a tipologia e a distribuição dos diferentes tipos e subtipos sensilares de adulttos de H. irritans, oriunda de populações desta mosca presentes no centro-oeste brasileiro, com ênfase nas sensilas olfatórias. Este estudo apresenta novos dados sobre a tipologia e distribuição sensilar da antenna desta mosca. Em seus segmentos antenais foram observados pilosidades não enervadas e dez subtipos de sensilas, sendo: long bristles sensillum, long basiconic sensillum, blunt coeloconic sensillum, clavate coeloconic sensilla - single-tip and double-tip subtypes -, grooved coeloconic sensillum, long grooved coeloconic sensillum, trichoid sensillum, coeloconic sensillum, e smaller basiconic sensillum. Leve dimorfismo sexual foi observado em relação às sensilas antenais de H. irritans. Estes resultados fornecem uma base morfológica para futuras investigações sobre o comportamento mediado pelo olfato desta espécie, e poderão fomentar futuros estudos para desenvolvimento de medidas alternativas de monitoramento e controle de populações dessa mosca, com menor impacto.(AU)

Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies.

An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.

Metagenomics, paratransgenesis and the Anopheles microbiome: a portrait of the geographical distribution of the anopheline microbiota based on a meta-analysis of reported taxa

Anophelines harbour a diverse microbial consortium that may represent an extended gene pool for the host. The proposed effects of the insect microbiota span physiological, metabolic and immune processes. Here we synthesise how current metagenomic tools combined with classical culture-dependent techniques provide new insights in the elucidation of the role of the Anopheles-associated microbiota. Many proposed malaria control strategies have been based upon the immunomodulating effects that the bacterial components of the microbiota appear to exert and their ability to express anti-Plasmodium peptides. The number of identified bacterial taxa has increased in the current “omics” era and the available data are mostly scattered or in “tables” that are difficult to exploit. Published microbiota reports for multiple anopheline species were compiled in an Excel® spreadsheet. We then filtered the microbiota data using a continent-oriented criterion and generated a visual correlation showing the exclusive and shared bacterial genera among four continents. The data suggested the existence of a core group of bacteria associated in a stable manner with their anopheline hosts. However, the lack of data from Neotropical vectors may reduce the possibility of defining the core microbiota and understanding the mosquito-bacteria interactive consortium.

A comparative study of fat body morphology in five mosquito species

The insect fat body plays major roles in the intermediary metabolism, in the storage and transport of haemolymph compounds and in the innate immunity. Here, the overall structure of the fat body of five species of mosquitoes (Aedes albopictus, Aedes fluviatilis, Culex quinquefasciatus, Anopheles aquasalis and Anopheles darlingi) was compared through light, scanning and transmission electron microscopy. Generally for mosquitoes, the fat body consists of lobes projecting into the haemocoel and is formed by great cell masses consisting of trophocytes and oenocytes. Trophocytes are rich in lipid droplets and protein granules. Interestingly, brown pigment granules, likely ommochromes, were found exclusively in the trophocytes located within the thorax and near the dorsal integument of Anopheles, which is suggestive of the role these cells play in detoxification via ommochrome storage. This study provides a detailed comparative analysis of the fat body in five different mosquito species and represents a significant contribution towards the understanding of the structural-functional relationships associated with this organ.

Insights into the transcriptome of oenocytes from Aedes aegypti pupae

Oenocytes are ectodermic cells present in the fat body of several insect species and these cells are considered to be analogous to the mammalian liver, based on their role in lipid storage, metabolism and secretion. Although oenocytes were identified over a century ago, little is known about their messenger RNA expression profiles. In this study, we investigated the transcriptome of Aedes aegypti oenocytes. We constructed a cDNA library from Ae. aegypti MOYO-R strain oenocytes collected from pupae and randomly sequenced 687 clones. After sequences editing and assembly, 326 high-quality contigs were generated. The most abundant transcripts identified corresponded to the cytochrome P450 superfamily, whose members have roles primarily related to detoxification and lipid metabolism. In addition, we identified 18 other transcripts with putative functions associated with lipid metabolism. One such transcript, a fatty acid synthase, is highly represented in the cDNA library of oenocytes. Moreover, oenocytes expressed several immunity-related genes and the majority of these genes were lysozymes. The transcriptional profile suggests that oenocytes play diverse roles, such as detoxification and lipid metabolism, and increase our understanding of the importance of oenocytes in Ae. aegypti homeostasis and immune competence.

Prevenção domiciliar da dengue: avaliação preliminar de tela protetora para pratos de vasos de planta / Prevención domiciliar de la dengue: evaluación preliminar de tela protectora para platos de macetas de planta / Dengue prevention at the household level: preliminary evaluation of a mesh cover for flowerpot saucers

Avaliou-se em laboratório a eficácia de um protótipo de capa de tela de poliéster (evidengue®) destinada a vedar o acesso de fêmeas do mosquito Aedes aegypti a pratos de vasos de planta. Dois pratos de vasos com água foram envolvidos individualmente com a capa e colocados com os seus respectivos vasos em duas gaiolas entomológicas, um em cada gaiola. Numa terceira gaiola foi colocado um conjunto idêntico de prato e vasos sem a capa. Cada gaiola recebeu 20 fêmeas copuladas do mosquito, alimentadas com sangue de camundongo. Os resultados mostram que a capa foi eficaz como barreira ao acesso de fêmeas. Novos testes são necessários para se avaliar a eficácia da capa como dispositivo de prevenção da ovipostura nos pratos.

The effectiveness of a polyester mesh cover (evidengue®), aimed at preventing the access of female Aedes aegypti mosquitoes to flowerpot saucers, was evaluated in laboratory. Two saucers of flowerpot with water were individually wrapped with the cover was placed with their respective pots in two entomological cages. One identical set of flowerpot and saucer was placed in a third cage. In each cage, 20 gravid females, fed on mouse blood, were released. Results show that the cover was effective to prevent access of females. Further tests are necessary to assess cover effectiveness as a device to prevent saucer oviposition.

Se evaluó en laboratorio la eficiencia de una cubierta de tela de polyester (evidengue®) con el objetivo de vedar el acceso de hembras del mosquito Aedes aegypti a platos de macetas de planta. Fueron utilizadas tres jaulas entomológicas, dos de ellas con evidengue® y una para control. En cada jaula fueron colocados dos conjuntos de macetas de planta y platos y 20 hembras copuladas, alimentadas con sangre de ratón. Los resultados muestran que la cubierta fue eficaz como barrera al acceso de hembras. Nuevas pruebas son necesarias para evaluar la eficiencia de la cubierta como dispositivo de prevención de la oviposición en los platos.

Padronização de condições para detecção de DNA de Leishmania spp. em flebotomíneos (Diptera, Psychodidae) pela reação em cadeia da polimerase / Standardization of conditions for PCR detection of Leishmania spp. DNA in sand flies (Diptera, Psychodidae)

A correta identificação dos agentes etiológicos em insetos vetores é de crucial importância aos estudos epidemiológicos. A pesquisa de flagelado nesses vetores, pela dissecção de seu trato digestivo, observação microscópica do seu conteúdo ou por isolamento dos parasitas provenientes de insetos em meios de cultura, tem-se mostrado operacionalmente inadequada e com baixa especificidade do diagnóstico, pois fêmeas de flebotomíneos também podem albergar outros flagelados como Trypanosoma e Endotrypanum. Acreditamos que por sua eficiência e especificidade, a amplificação de seqüências-alvo do DNA da Leishmania, por meio da reação em cadeia de polimerase, pode ser aplicada na investigação de sua presença em flebotomíneos, desde que estes estejam devidamente acondicionados e o DNA do parasita extraído a partir de metodologia adequada. Este trabalho descreve metodologias utilizadas na padronização da conservação dos espécimes de flebotomíneos e extração do DNA da Leishmania como uma alternativa mais prática que os métodos tradicionais.

The correct identification of etiological agents in vector insects is crucial for epidemiological studies. Identification of flagellates in such vectors, usually by dissection of the digestive tract and microscopic observation of the contents as well as attempts at parasite isolation from insects in culture media, have proven operationally inadequate and with poor diagnostic specificity, since female sand flies are also hosts for other flagellates like Trypanosoma and Endotrypanum. Due to the efficiency and specificity of DNA target sequence amplification by polymerase chain reaction (PCR), the latter could be used to investigate the presence of Leishmania in sand flies, although the insects need to be properly stored and the Leishmania DNA extracted using appropriate methodology. This paper describes methodologies to standardize sand fly storage and Leishmania DNA extraction in such specimens as a more practical method in field studies.

Effect of the Aedes fluviatilis saliva on the development of Plasmodium gallinaceum infection in Gallus (gallus) domesticus

Effect of Aedes fluviatilis saliva on the development of Plasmodium gallinaceum experimental infection in Gallus (gallus) domesticus was studied in distinct aspects. Chickens subcutaneously infected with sporozoites in the presence of the mosquito salivary gland homogenates (SGH) showed higher levels of parasitaemia when compared to those ones that received only the sporozoites. However, the parasitaemia levels were lower among chickens previously immunized by SGH or non-infected mosquito bites compared to the controls, which did not receive saliva. High levels of anti-saliva antibodies were observed in those immunized chickens. Moreover, 53 and 102 kDa saliva proteins were recognized by sera from immunized chickens. After the sporozoite challenge, the chickens also showed significant levels of anti-sporozoite antibodies. However, the ability to generate anti-sporozoites antibodies was not correlated to the saliva immunization. Our results suggest that mosquito saliva components enhance P. gallinaceum parasite development in naive chickens. However, the prior exposure of chickens to salivary components controls the parasitemia levels in infected individuals.

Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae)

DNA amplification by the polymerase chain reaction (PCR) was applied in the investigation of the presence of Leishmania (Kinetoplastida: Trypanosomatidae) parasites in single phlebotomine sandflies. Three phlebotomine/parasite pairs were used: Lutzomyia longipalpis/Leishmania chagasi, Lutzomyia migonei/Leishmania amazonensis and Lutzomyia migonei/Leishmania braziliensis, all of them incriminated in the transmission of visceral or cutaneous leishmaniasis. DNA extraction was performed with whole insects, with no need of previous digestive tract dissection or pooling specimens. The presence of either mouse blood in the digestive tract of the sandflies or the digestive tract itself did not interfere in the PCR. Infection by as few as 10 Leishmania sp. per individual were sufficient for DNA amplification with genus-specific primers. Using primers for L. braziliensis and L. mexicana complexes, respectively, it was possible to discriminate between L. braziliensis and L. amazonensis in experimentally infected vectors (L. migonei)

Tratamento cirúrgico da fratura-luxaçäo de Lisfranc / Surgical treatment of Lisfranc fracture dislocation

Os autores apresentam o estudo crítico de 16 pacientes (16 pTs) com fratura-luxaçäo da articulaçäo de Lisfranc tratados pelo método cruento através de incisöes longitudinais e fixaçäo com fios de Kirschner. Os deslocamentos da junta de Lisfranc säo ferimentos que apresentam grande potencial para incapacidade crônica quando näo diagnosticados e tratados de maneira correta. Discutem neste trabalho os aspectos clínicos, anatômicos e radiográficos para avaliaçäo do diagnóstico e detalhes da técnica cirúrgica, evoluçäo e complicaçöes. Obtiveram 80 por cento de bons resultados com o tratamento cruento. Os casos considerados como maus geralmente se associam a cominuiçäo da fratura, lesöes de partes moles ou reduçäo anatômica inadequada. Concluem que o melhor tratamento para as lesöes de Lisfranc é a reduçäo aberta com fixaçäo das fraturas por meios de fios de Kirschner ou parafusos.

Morphological changes induced by colchicine in neutrophilis interfere with the distribution of glycogen particles

A incubaçäo de neutrófilos na presença de colchicina induz a formaçäo de protuverâncias, onde usando-se a técnica do ácido periódico-tiossemicarbazida-proteinato de prata, uma concentraçäo de partículas caracterizada como glicogênio foi encontrada. Outras estruturas citoplasmáticas, tais como mitocôndrias e grânulos, näo estavam presentes nas protuberâncias. A microeletrônica de varredura revelou que a superfície das protuberâncias era mais lisa que a do restante do corpo celular

Structural observations on the attachment of promastigotes of Leishmania mexicana amazonensis to the surface of macrophages

Se analiza el proceso de interacción entre el parásito Leishmania mexicana amazonensis y los macrófagos, en experimentos en los cuales se emplea una alta relación parásito/macrófago, mediante el empleo de las microscopías de luz y electrónicas de barrido y transmisión. Los parásitos se adhieren al macrófago pero no son ingeridos por éste. la adherencia se realiza en los promastigotes vivos por el flagelo, pero cuando se emplean amastigotas o promastigotas fijados en glutaraldehido la adherencia se realiza sin orientación específica. la adherencia de los parásitos a la superficie del macrófago induce cambios en la organización estructural de periferia de éste pero no interfiere con la distribución de los sitios de unión de la concanavalina A. La incubación previa de los macrófagos en presencia de citocalasina B o ferritina cationizada no interfiere con la adherencia de los parásitos a la superficie del macrófago