Aspectos históricos e ecológicos da malária no Rio Grande do Sul, Brasil

A malária, também chamada de impaludismo, é uma doença antiga e de grande impacto na saúde pública, causando milhares de mortes anuais pelo mundo. No Brasil, sua ocorrência está relacionada a duas regiões, sendo a amazônica considerada endêmica e a região extra-amazônica, não endêmica. O bioma Mata Atlântica tem apresentado importância na transmissão de malária extra-amazônica, uma vez que propicia um ambiente para que ocorra todos os elementos necessários para sua manutenção: vetores anofelinos, parasitos do gênero Plasmodium e hospedeiros como o homem e os primatas-não-humanos. O Rio Grande do Sul teve endemismo de malária na região litorânea, onde possui grande área coberta por Mata Atlântica, apesar de ser considerada livre desta doença desde meados de 1960. Desta forma, o objetivo deste trabalho foi realizar a construção histórica de ocorrência da malária no Estado e relacionar aspectos ecológicos relacionados ao vetor Anopheles, uma vez que houve confirmação de um caso humano autóctone na região em 2014. Para tanto, foi realizada extensa busca documental e visitas a acervos e museus para reunir relatórios e materiais relativos ao impaludismo no RS. Dados do caso autóctone foram resgatados e analisados para definir a reemergência da malária no Rio Grande do Sul. Para as coletas de mosquitos, foram amostrados os municípios de Três Cachoeiras, Três Forquilhas, Eldorado do Sul e Morro Reuter, onde foram instaladas armadilhas do tipo CDC e Shannon, com capturas noturnas das 18h às 6h e das 18h às 22h, respectivamente. Os dados foram analisados estatisticamente para a associação com fatores abióticos. As ocorrências de mosquitos também foram relacionadas com NDVI em busca de uma associação com a vegetação. Como resultados, se discorre desde o primeiro relato de malária no RS, em 1900, passando pelos períodos da Primeira República (1889-1930), entre 1930 e 1960, entre 1960 e 2000, até chegar entre 2000 até 2019, passando por 2014 quando acontece a reemergência da doença. Por sua vez, esta foi determinada após análises de informações epidemiológicas. Com relação aos dados amostrais, foram realizadas 142 amostragens que, juntas, coletaram 266 indivíduos de Anopheles e 2.773 espécimes de outros grupos taxonômicos, totalizando 3.039 mosquitos. As espécies foram afetadas de forma diferente pelas condições abióticas, de acordo com a localidade amostrada, provavelmente porque o esforço amostral entre elas foi diferente. Não houve diferença significativa entre as estações do ano ou entre as localidades. O NDVI também não mostrou diferença significativa.Malaria, also called impaludism, is an ancient disease with great impact on public health, causing thousands of deaths annually worldwide. In Brazil, its occurrence is related to two types of regions, with the Amazon being considered endemic and the extra-Amazonian region, non-endemic. The Atlantic Forest biome has shown importance in the transmission of extra-Amazonian malaria, since it provides an environment for all the elements necessary for its maintenance: anopheline vectors, plasmodium parasites and hosts such as humans or non-human primates. Rio Grande do Sul was endemic for malaria in the coastal region, where it has a large area covered by Atlantic Forest, despite being considered free of this disease since the mid-1960s. Thus, the objective of this work was to carry out a historical rescue of malaria occurrence in the State and to relate ecological aspects related to the Anopheles vector, since there was confirmation of an autochthonous human case in the region in 2014. To this end, an extensive documentary search and visits to collections and museums were carried out to gather reports and materials related to impaludism in RS. Data from the autochthonous case were retrieved and analyzed to define the reemergence of malaria in Rio Grande do Sul. For mosquito collections, the municipalities of Três Cachoeiras, Três Forquilhas, Eldorado do Sul and Morro Reuter were sampled, where CDC and Shannon traps were installed, with night catches from 6:00 pm to 6:00 am and from 6:00 pm to 10:00 pm, respectively. Data were statistically analyzed for association with abiotic factors. Mosquito occurrences were also linked to NDVI in search of an association with vegetation. As a result, it goes from the first report of malaria in RS, in 1900, through the periods of the First Republic (1889-1930), between 1930 and 1960, between 1960 and 2000, until reaching between 2000 and 2019, passing through 2014 when disease reemergence. In turn, this was determined after analysis of epidemiological information. Regarding the sampling data, 142 samples were taken, which together collected 266 individuals of Anopheles and 2,773 specimens from other taxonomic groups, totaling 3,039 mosquitoes. Species were affected differently by abiotic conditions, according to the sampled locality, probably because the sampling effort between them was different. There was no significant difference between seasons or between locations. The NDVI also showed no significant difference

La coepidemia de dengue y COVID-19 en Brasil : entre los desafíos en su manejo y las consecuencias de la desigualdad socioeconómica

SARS-CoV-2, the etiological agent of COVID-19, spread worldwide, reaching pandemic status in March 2020. In this scenario, dengue epidemics continue to impact endemic countries. Taking into account an increase in dengue cases worldwide, the COVID-19 pandemic may signal a serious danger to global public health. In some countries the pandemic coincided with already installed dengue epidemics. Thus, understanding the collective constituents of arboviruses in pandemic times is fundamental for a significant analysis. The present work brings a narrative review elucidating important impacts resulting from the co-epidemic and its consequences in a broader perspective. Problems with the differential diagnosis of these infections are aggravating factors for the decision of clinical management and prognosis of infected individuals. In addition, socioeconomic characteristics and ethnicity are fundamental factors for both dengue transmission dynamics and COVID-19. It also stands out, a scenario that represents a high risk of collapse for health services in facing challenges for combating and managing resources. Therefore, we conclude that in order to overcome the crisis of simultaneous epidemics and their serious consequences, historical aspects and their relationship with the conditions of social vulnerability need to be taken into account, in addition to promoting specific actions for their combat.O SARS-CoV-2, agente etiológico da COVID-19, se espalhou pelo mundo, atingindo o status de pandemia em março de 2020. Neste cenário, as epidemias de dengue continuam a impactar os países endêmicos. Levando em consideração o aumento dos casos de dengue em todo o mundo, a pandemia de COVID-19 pode sinalizar um sério perigo para a saúde pública global. Em alguns países, a pandemia coincidiu com epidemias de dengue já instaladas. Assim, compreender os constituintes coletivos das arboviroses em tempos de pandemia é fundamental para uma análise significativa. O presente trabalho traz uma revisão narrativa elucidando impactos importantes decorrentes da co-epidemia e suas consequências em uma perspectiva mais ampla. Problemas com o diagnóstico diferencial dessas infecções são fatores agravantes para a decisão do manejo clínico e prognóstico dos indivíduos infectados. Além disso, as características socioeconômicas e etnia são fatores fundamentais tanto para a dinâmica de transmissão da dengue quanto para a COVID-19. Destaca-se também, um cenário que representa alto risco de colapso para os serviços de saúde no enfrentamento dos desafios para o combate e gestão de recursos. Conclui-se, portanto que, para superar a crise das epidemias simultâneas e suas graves consequências, devem ser considerados os aspectos históricos e sua relação com as condições de vulnerabilidade social, além da promoção ações específicas para o seu combate.El SARS-CoV-2, el agente etiológico de COVID-19, se propagó por todo el mundo y alcanzó el estado de pandemia en marzo de 2020. En este escenario, las epidemias de dengue continúan afectando a los países endémicos. Teniendo en cuenta un aumento de los casos de dengue en todo el mundo, la pandemia de COVID-19 puede indicar un grave peligro para la salud pública mundial. En algunos países, la pandemia coincidió con epidemias de dengue ya instaladas. Por lo tanto, comprender los componentes colectivos de los arbovirus en tiempos de pandemia es fundamental para un análisis significativo. El presente trabajo trae una revisión narrativa que aclara los impactos importantes resultantes de la co-epidemia y sus consecuencias en una perspectiva más amplia. Los problemas con el diagnóstico diferencial de estas infecciones son factores agravantes para la decisión de manejo clínico y pronóstico de los individuos infectados. Además, las características socioeconómicas y la etnia son factores fundamentales tanto para la dinámica de transmisión del dengue como para el COVID-19. También se destaca, escenario que representa un alto riesgo de colapso de los servicios de salud ante los desafíos de combate y gestión de recursos. Por tanto, concluimos que para superar la crisis de epidemias simultáneas y sus graves consecuencias, es necesario tener en cuenta los aspectos históricos y su relación con las condiciones de vulnerabilidad social, además de promover acciones específicas para su combate

Microbiota potentialized larvicidal action of imidazolium salts against Aedes aegypti (diptera: culicidae)

Mosquitoes are important vectors of pathogens due to their blood feeding behavior. Aedes aegypti (Diptera: Culicidae) transmits arboviruses, such as dengue, Zika, and Chikungunya. This species carries several bacteria that may be beneficial for its biological and physiological development. Therefore, studying the response of its microbiota to chemical products could result in vector control. Recently, imidazolium salts (IS) were identified as effective Ae. aegypti larvicides. Considering the importance of the mosquito microbiota, this study addressed the influence of IS on the bacteria of Ae. aegypti larvae. After exposition of larvae to different IS concentrations, the cultured microbiota was identified through culturomics and mass spectrometry, and the non-cultivated microbiota was characterized by molecular markers. In addition, the influence of the IS on axenic larvae was studied for comparison. There was an alteration in both cultivable species and in their diversity, including modifications in bacterial communities. The axenic larvae were less susceptible to the IS, which was increased after exposing these larvae to bacteria of laboratory breeding water. This highlights the importance of understanding the role of the larval microbiota of Ae. aegypti in the development of imidazolium salt-based larvicides. Such effect of IS towards microbiota of Ae. aegypti larvae, through their antimicrobial action, increases their larvicidal potential

Aedes-Chikungunya virus interaction : key role of vector midguts microbiota and its saliva in the host infection

Aedes mosquitoes are important vectors for emerging diseases caused by arboviruses, such as chikungunya (CHIKV). These viruses’ main transmitting species are Aedes aegypti and Ae. albopictus, which are present in tropical and temperate climatic areas all over the globe. Knowledge of vector characteristics is fundamentally important to the understanding of virus transmission. Only female mosquitoes are able to transmit CHIKV to the vertebrate host since they are hematophagous. In addition, mosquito microbiota is fundamentally important to virus infection in the mosquito. Microorganisms are able to modulate viral transmission in the mosquito, such as bacteria of the Wolbachia genus, which are capable of preventing viral infection, or protozoans of the Ascogregarina species, which are capable of facilitating virus transmission between mosquitoes and larvae. The competence of the mosquito is also important in the transmission of the virus to the vertebrate host, since their saliva has several substances with biological effects, such as immunomodulators and anticoagulants, which are able to modulate the host’s response to the virus, interfering in its pathogenicity and virulence. Understanding the Aedes vector-chikungunya interaction is fundamentally important since it can enable the search for new methods of combating the virus’ transmission

Reemergence of human malaria in Atlantic Forest of Rio Grande do Sul, Brazil

Unforeseen Plasmodium infections in the Atlantic Forest of Brazilian Extra-Amazonian region could jeopardise malaria elimination. A human malaria case was registered in Três Forquilhas, in the Atlantic Forest biome of Rio Grande do Sul, after a 45 years’ time-lapsed without any malaria autochthonous notification in this southern Brazilian state. This finding represents the expansion of the malaria distribution areas in Brazil and the southernmost human malaria case record in South America in this decade. The coexistence of the bromeliad-breeding vector Anopheles (Kerteszia) cruzii and non-human primates in the Atlantic Forest regularly visited by the patient claimed for the zoonotic origin of this infection. The reemergence of Atlantic Forest human malaria in Rio Grande do Sul was also discussed

Aedes–Chikungunya Virus Interaction: Key Role of Vector Midguts Microbiota and Its Saliva in the Host Infection

Aedes mosquitoes are important vectors for emerging diseases caused by arboviruses, such as chikungunya (CHIKV). These viruses’ main transmitting species are Aedes aegypti and Ae. albopictus, which are present in tropical and temperate climatic areas all over the globe. Knowledge of vector characteristics is fundamentally important to the understanding of virus transmission. Only female mosquitoes are able to transmit CHIKV to the vertebrate host since they are hematophagous. In addition, mosquito microbiota is fundamentally important to virus infection in the mosquito. Microorganisms are able to modulate viral transmission in the mosquito, such as bacteria of the Wolbachia genus, which are capable of preventing viral infection, or protozoans of the Ascogregarina species, which are capable of facilitating virus transmission between mosquitoes and larvae. The competence of the mosquito is also important in the transmission of the virus to the vertebrate host, since their saliva has several substances with biological effects, such as immunomodulators and anticoagulants, which are able to modulate the host’s response to the virus, interfering in its pathogenicity and virulence. Understanding the Aedes vector-chikungunya interaction is fundamentally important since it can enable the search for new methods of combating the virus’ transmission

Morpho-histochemical description of the tissues of the digestive system of Aedes aegypti larvae

Muitos trabalhos são desenvolvidos para identificar substâncias ou microrganismos capazes de controlar a população de insetos importantes para a saúde pública, sendo a identificação de lesões histológicas um critério para compreender o mecanismo de ação e eficácia do produto. As análises histopatológicas são baseadas na comparação entre tecidos de indivíduos controle e indivíduos expostos. Entretanto, são raros os trabalhos que referenciam o estado dos tecidos sadios. Neste trabalho caracterizou-se morfo-histoquimicamente os principais tecidos sadios do sistema digestório de larvas em 3º a 4º ínstar de Aedes aegypti, mostrando diversas imagens das variações que podem ser esperadas, além de apresentar as técnicas de processamento. Para isto, um total de trinta larvas foram fixadas, desidratadas e incluídas em historesina. Cortes foram realizados e corados com HE para morfologia e azul do Nilo, azul bromofenol, azul de toluidina e PAS para a caracterização histoquímica. Como resultados, o intestino das larvas se mostrou um tubo reto, formado por uma camada simples de células cúbicas, moderadamente acidófilas, com núcleo central e uma borda em escova voltada para o lúmen. Foram registradas variações celulares, uma vez que as células epiteliais também são secretivas das enzimas digestivas. Cortes sequenciais foram importantes para definir a morfologia, uma vez que o ângulo e altura de corte podem influenciar na sua aparência. O PAS revelou a presença de muitos grânulos de glicogênio por todos os tecidos, inclusive nas vesículas secretivas. Estas ainda possuem muitas proteínas e foram coradas fracamente para lipídios. Não foram registrados eventos de metacromasia na cor vermelha com o azul de toluidina, entretanto os tecidos parecem se corar diferentemente do tegumento.Many surveys are designed to identify substances or microorganisms capable of controlling the population of insects that are important to public health, and the identification of resulting histological injures is a criterion for understanding the mechanism of action and the efficacy of the product. The histopathological analyses are based on the comparison between tissues of control subjects and exposed subjects, but there are rare studies that mention the state of healthy tissues. This work characterized the main morpho-histochemically healthy tissues of the digestive system of larvae in the 3rd and the 4th instar of Aedes aegypti, showing several images of the variations that can be expected, as well as displaying processing techniques. For this, a total of thirty larvae were pinned, dehydrated and embedded in historesin. Sections were made and stained with hematoxylin for morphology and Blue Nile, bromophenol blue, toluidine blue and PAS staining for the immunohistochemical characterization. As a result, the intestines of the larvae showed an upright tube formed by a single layer of cuboidal cells, moderately acidophilic, with a central nucleus and a brush border facing the lumen. Cellular changes were recorded, since epithelial cells also secrete digestive enzymes. Sequential slices were important in defining the morphology, since the angle and height of the cut may affect its appearance. The PAS revealed the presence of many glycogen granules in all tissues, including the secretory vesicles. These still have protein and were weakly colored to lipids. There were no metachromasia events in red with toluidine blue, though the tissues seem to blush differently from the integument

Morpho-histochemical description of the tissues of the digestive system of Aedes aegypti larvae

Muitos trabalhos são desenvolvidos para identificar substâncias ou microrganismos capazes de controlar a população de insetos importantes para a saúde pública, sendo a identificação de lesões histológicas um critério para compreender o mecanismo de ação e eficácia do produto. As análises histopatológicas são baseadas na comparação entre tecidos de indivíduos controle e indivíduos expostos. Entretanto, são raros os trabalhos que referenciam o estado dos tecidos sadios. Neste trabalho caracterizou-se morfo-histoquimicamente os principais tecidos sadios do sistema digestório de larvas em 3º a 4º ínstar de Aedes aegypti, mostrando diversas imagens das variações que podem ser esperadas, além de apresentar as técnicas de processamento. Para isto, um total de trinta larvas foram fixadas, desidratadas e incluídas em historesina. Cortes foram realizados e corados com HE para morfologia e azul do Nilo, azul bromofenol, azul de toluidina e PAS para a caracterização histoquímica. Como resultados, o intestino das larvas se mostrou um tubo reto, formado por uma camada simples de células cúbicas, moderadamente acidófilas, com núcleo central e uma borda em escova voltada para o lúmen. Foram registradas variações celulares, uma vez que as células epiteliais também são secretivas das enzimas digestivas. Cortes sequenciais foram importantes para definir a morfologia, uma vez que o ângulo e altura de corte podem influenciar na sua aparência. O PAS revelou a presença de muitos grânulos de glicogênio por todos os tecidos, inclusive nas vesículas secretivas. Estas ainda possuem muitas proteínas e foram coradas fracamente para lipídios. Não foram registrados eventos de metacromasia na cor vermelha com o azul de toluidina, entretanto os tecidos parecem se corar diferentemente do tegumento.Many surveys are designed to identify substances or microorganisms capable of controlling the population of insects that are important to public health, and the identification of resulting histological injures is a criterion for understanding the mechanism of action and the efficacy of the product. The histopathological analyses are based on the comparison between tissues of control subjects and exposed subjects, but there are rare studies that mention the state of healthy tissues. This work characterized the main morpho-histochemically healthy tissues of the digestive system of larvae in the 3rd and the 4th instar of Aedes aegypti, showing several images of the variations that can be expected, as well as displaying processing techniques. For this, a total of thirty larvae were pinned, dehydrated and embedded in historesin. Sections were made and stained with hematoxylin for morphology and Blue Nile, bromophenol blue, toluidine blue and PAS staining for the immunohistochemical characterization. As a result, the intestines of the larvae showed an upright tube formed by a single layer of cuboidal cells, moderately acidophilic, with a central nucleus and a brush border facing the lumen. Cellular changes were recorded, since epithelial cells also secrete digestive enzymes. Sequential slices were important in defining the morphology, since the angle and height of the cut may affect its appearance. The PAS revealed the presence of many glycogen granules in all tissues, including the secretory vesicles. These still have protein and were weakly colored to lipids. There were no metachromasia events in red with toluidine blue, though the tissues seem to blush differently from the integument