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Braz. j. biol ; 83: e248122, 2023. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1355851


Abstract Being vector of West Nile Virus and falariasis the control of Culex quinquefasciatus is likely to be essential. Synthetic insecticide treatment is looking most effective for vectors mosquito control. However, these products are toxic to the environment and non-target organisms. Consequently, ecofriendly control of vectors mosquito is needed. In this regard botanical insecticide is looking more fruitful. Therefore, the present research aimed to investigate the effectiveness of methanolic extract and various fractions, including, n-hexane, ethyl-acetate, chloroform, and aqueous fraction, obtained from methanolic extract of Ailanthus altissima, Artemisia scoparia, and Justicia adhatoda using separating funnel against larval, pupal, and adult stages of Culex quinquefasciatus. The larvae and pupae of Culex quinquefasciatus were exposed to various concentrations (31.25-1000 ppm) of methanolic extract and its fractions for 24 hours of exposure period. For knock-down bioassay (filter paper impregnation bioassay) different concentration of the methanolic extract and its various fractions (i.e. 0.0625, 0.125, 0.25, 0.5 and 1mg/mL) were applied for 1 hour exposure period. The results were statistically analysed using standard deviation, probit analysis, and linear regression. The R2 values of larvae, pupae, and adult range from 0.4 to 0.99. The values of LC50 (concentration causing 50% mortality) for late 3rd instar larvae after 24 hours exposure period range from 93-1856.7 ppm, while LC90 values range from 424 -7635.5ppm. The values of LC50for pupae range form 1326.7-6818.4ppm and and values of LC90 range from 3667.3-17427.9ppm, respectively. The KDT50 range from 0.30 to 2.8% and KDT90 values range from1.2 to 110.8%, respectively. In conclusion, Justicia adhatoda may be effective for controlling populations of vector mosquito.

Resumo Por ser o vetor do vírus do Nilo Ocidental e da falaríase, o controle de Culex quinquefasciatus Say é provavelmente essencial. O tratamento com inseticida sintético parece ser mais eficaz para o controle dos mosquitos vetores. No entanto, esses produtos são tóxicos para o meio ambiente e organismos não visados. Consequentemente, o controle ecológico dos mosquitos vetores é necessário. Nesse sentido, o inseticida botânico parece mais produtivo. Portanto, a presente pesquisa teve como objetivo investigar a eficácia do extrato metanólico e de várias frações, incluindo n-hexano, acetato de etila, clorofórmio e fração aquosa, obtidos do extrato metanólico de Ailanthus altissima (Mill.) Swingle, Artemisia scoparia Waldst. & Kit. e Justicia adhatoda L. usando funil de separação contra os estágios larval, pupal e adulto de C. quinquefasciatus. As larvas e pupas de C. quinquefasciatus foram expostas a várias concentrações (31,25-1000 ppm) de extrato metanólico, e suas frações por 24 horas de período de exposição. Para o bioensaio knock-down (bioensaio de impregnação de papel de filtro), diferentes concentrações do extrato metanólico e suas várias frações (ou seja, 0,0625, 0,125, 0,25, 0,5 e 1 mg / mL) foram aplicadas por um período de exposição de 1 hora. Os resultados foram analisados ​​estatisticamente usando desvio padrão, análise Probit e regressão linear. Os valores de R2 de larvas, pupas e adultos variaram de 0,4 a 0,99. Os valores de LC50 (concentração que causa 50% de mortalidade) para larvas de terceiro estádio tardio após 24 horas de período de exposição variaram de 93-1856,7 ppm, enquanto os valores de LC90 variaram de 424-7635,5ppm. Os valores de LC50 para pupas variaram de 1326,7-6818,4 ppm e os valores de LC90 variaram de 3667,3-17427,9 ppm, respectivamente. O KDT50 variou de 0,30 a 2,8% e os valores de KDT90 variaram de 1,2 a 110,8%, respectivamente. Por fim, a espécie J. adhatoda pôde ser eficaz para controlar populações de mosquitos vetores.

Animals , Culex , Insecticides/pharmacology , Anopheles , Plant Extracts/pharmacology , Plant Leaves , Mosquito Vectors , Larva
Braz. j. biol ; 82: e241338, 2022. tab
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1278470


Abstract Mosquito-borne diseases result in the loss of life and economy, primarily in subtropical and tropical countries, and the emerging resistance to insecticides is increasing this threat. Botanical insecticides are promising substitutes for synthetic insecticides. This study evaluated the larvicidal and growth index of Culex pipiens of four solvent extracts of Terminalia chebula, Aloe perryi, and Peganum harmala against Cx. pipiens. None of the 12 extracts exhibited larvicidal potential against third instars except the ethyl acetate extract of P. harmala. After 24 h of exposure, the LC50 value was 314.88 ppm, and the LC90 value was 464.19 ppm. At 320 ppm, the hatchability was 25.83%, and it resulted in 100% mortality. In addition, the eggs treated with the EtOAc extract of P. Harmala exhibited a long larval period compared with the control. The larval period continued for 12 days, and the pupal period took three days in the treatment groups. The growth index data also exhibited a decrease (0.00-7.53) in the treated groups compare with 8.5 in the control. The transformation of eggs into adults decreased with increasing concentrations. This paper is the first report on the development and growth index of Cx. pipiens potential using P. harmala seeds.

Resumo As doenças transmitidas por mosquitos resultam na perda de vidas e economia, principalmente em países subtropicais e tropicais, e a resistência emergente aos inseticidas está aumentando essa ameaça. Os inseticidas botânicos são substitutos promissores dos inseticidas sintéticos. Este estudo avaliou o índice larvicida e de crescimento de Culex pipiens de quatro extratos solventes de Terminalia chebula, Aloe perryi e Peganum harmala contra Cx. pipiens. Nenhum dos 12 extratos exibiu potencial larvicida contra o terceiro ínstar, exceto o extrato de acetato de etila de P. harmala. Após 24 horas de exposição, o valor LC50 era 314,88 ppm e o valor LC90 era 464,19 ppm. A 320 ppm, a eclodibilidade foi de 25,83% e resultou em 100% de mortalidade. Além disso, os ovos tratados com o extrato de EtOAc de P. harmala exibiram um longo período larval em comparação com o controle. O período larval continuou por 12 dias, e o período pupal durou três dias nos grupos de tratamento. Os dados do índice de crescimento também exibiram uma diminuição (0,00-7,53) nos grupos tratados em comparação com 8,5 no controle. A transformação de ovos em adultos diminuiu com o aumento das concentrações. Este artigo é o primeiro relatório sobre o índice de desenvolvimento e crescimento de Cx. potencial de pipiens usando sementes de P. harmala.

Animals , Aedes , Culex , Peganum , Insecticides , Anopheles , Seeds , Plant Extracts/pharmacology , Larva
Rev. Soc. Bras. Med. Trop ; 54: e00922020, 2021. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1143892


Abstract INTRODUCTION: Despite their widespread usage, synthetic insecticides and larvicides are harmful for controlling disease-causing mosquitoes owing to the development of resistance. The leaves of Eugenia astringens, Myrrhinium atropurpureum, and Neomitranthes obscura were collected from Marambaia and Grumari restingas. The safety and larvicidal efficacy of their extracts were tested against Aedes (Stegomyia) aegypti L. and Simulium (Chirostilbia) pertinax Kollar. METHODS: The dry leaves were subjected to static maceration extraction using 90% methanol. A. aegypti and S. pertinax larvae were exposed to 7.5, 12.5, and 25.0 µL/mL of the extracts (n= 30). The larvicidal activity after 24 h and 48 h, and the mortality, were determined. The median lethal concentration (CL50) was estimated by a Finney's probit model. RESULTS: M. atropurpureum and E. astringens extracts exhibited the strongest larvicidal effects against A. aegypti. M. atropurpureum extracts (25 µL/mL) caused mortalities of over 50% and 100% after 24 h and 48 h, respectively (CL50 = 11.10 and 9.68 ppm, respectively). E. astringens extracts (25 µL/mL) caused mortalities of 50% and 63.33% after 24 h and 48 h, respectively. High concentrations of N. obscura extracts induced a maximum mortality of 46.66% in A. aegypti larvae after 48 h (CL50= 25 ppm). The larvae of S. pertinax showed 100% mortality following exposure to all the plant extracts at all the tested concentrations after 24 h. CONCLUSIONS: The extracts of M. atropurpuerum exhibited the strongest larvicidal activity against A. aegypti. The larvae of S. pertinax were sensitive to all the extracts at all the tested concentrations.

Animals , Simuliidae , Aedes , Culex , Myrtaceae , Insecticides/pharmacology , Anopheles , Plant Extracts/pharmacology , Plant Leaves , Larva
Mem. Inst. Oswaldo Cruz ; 116: e210064, 2021. graf
Article in English | LILACS | ID: biblio-1279459


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.

Animals , Malaria/epidemiology , Anopheles , Brazil/epidemiology , Forests , Mosquito Vectors
Mem. Inst. Oswaldo Cruz ; 116: e200497, 2021. graf
Article in English | LILACS | ID: biblio-1154873


BACKGROUND Flight tones play important roles in mosquito reproduction. Several mosquito species utilise flight tones for mate localisation and attraction. Typically, the female wingbeat frequency (WBF) is lower than males, and stereotypic acoustic behaviors are instrumental for successful copulation. Mosquito WBFs are usually an important species characteristic, with female flight tones used as male attractants in surveillance traps for species identification. Anopheles darlingi is an important Latin American malaria vector, but we know little about its mating behaviors. OBJECTIVES We characterised An. darlingi WBFs and examined male acoustic responses to immobilised females. METHODS Tethered and free flying male and female An. darlingi were recorded individually to determine their WBF distributions. Male-female acoustic interactions were analysed using tethered females and free flying males. FINDINGS Contrary to most mosquito species, An. darlingi females are smaller than males. However, the male's WBF is ~1.5 times higher than the females, a common ratio in species with larger females. When in proximity to a female, males displayed rapid frequency modulations that decreased upon genitalia engagement. Tethered females also modulated their frequency upon male approach, being distinct if the interaction ended in copulation or only contact. MAIN CONCLUSIONS This is the first report of An. darlingi flight acoustics, showing that its precopulatory acoustics are similar to other mosquitoes despite the uncommon male:female size ratio, suggesting that WBF ratios are common communication strategies rather than a physical constraint imposed by size.

Animals , Male , Female , Mosquito Vectors , Malaria/transmission , Anopheles , Reproduction
Article in Spanish | LILACS, BDNPAR | ID: biblio-1293251


Las mutaciones KDR en el gen del canal del sodio (VGSC) han sido ya detectadas en al menos 13 especies de mosquitos Anopheles en su mayoría especies de África, pero aún resta por determinar los cebadores específicos para la detección en especies de Latinoamérica. En nuestro país la especie Anopheles darlingi es el vector principal de la malaria, y el A. albitarsis, el vector secundario. Se emplearon muestras de mosquitos Anoheles de las especies A. strodei, A. albitarsis, A. fluminensis, A. evansae, A. nuneztovari, A. nyssorhynchela lutzi y A. oswaldoi capturadas en los departamentos de Caaguazú y Alto Paraná en Paraguay. Para la amplificación y secuenciación se usaron cebadores reportados para el gen VGSC de A. albimanus en Guatemala, que resultaron ser específicos solo para la especie A. strodei. La secuencia revela el codón TTA que codifica para una Leucina como la secuencia TTG, reportada para la versión susceptible en la posición L1014. El fragmento amplificado es de aproximadamente 225 pares de bases. A nuestro entender, esta es la primera caracterización del gen VGSC en mosquitos Anopheles del Paraguay y para la especie A. strodei

KDR mutations in the sodium channel gene (VGSC) have already been detected in at least 13 species of Anopheles mosquitoes, mostly African species, but the molecular techniques for detection in Latin American species have yet to be determined. In our country, Anopheles darlingi species is the main vector of Malaria, and A. albitarsis, the secondary vector. We used samples of Anoheles from the species A. strodei, A. albitarsis, A. fluminensis, A. evansae, A. nuneztovari, A. nyssorhynchela lutzi and A. oswaldoi collected at the departments of Caaguazú and Alto Paraná in Paraguay. For the amplification and sequentiation, primers reported for the VGSC gen of A. strodei in Guatemala were used and were specific only for A. strode in this case. The sequence revealed the TTA codon that codifies for a leucine as the TTG sequence, reported for the susceptible version at position L1014. The amplified fragment is approximately 225 base pairs. To our knowledge, this is the first characterization of the VGSC gene in Anopheles mosquitoes in Paraguay and for the species A. strodei

Animals , Polymerase Chain Reaction , Anopheles , Sodium Channels , Mosquito Vectors
Mem. Inst. Oswaldo Cruz ; 115: e200070, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135278


BACKGROUND Nyssorhynchus deaneorum is a potential malaria vector because it has been shown to be competent to transmit Plasmodium vivax and Plasmodium falciparum, and because it exhibits antropophilic and endophilic behaviors in some regions of the Amazon. This profile makes Ny. deaneorum a useful mosquito for experiments that model Plasmodium-vector interactions in the Amazon. OBJECTIVE Herein we describe how a free-mating colony of Ny. deaneorum has been established using an automated light stimulation system. METHODS Mosquitoes were captured in São Francisco do Guaporé, Rondônia. The F1 generation was reared until adult emergence at which point copulation was induced using an automatic copulation induction system (ACIS). FINDINGS After four generations, natural mating and oviposition began to occur without light stimulation. The number of pupae and adult mosquitoes increased from the F5 to F10 generations. The new Ny. deaneorum colony exhibited susceptibility to P. vivax. MAIN CONCLUSIONS Automated light stimulation is an effective method for establishing an Ny. deaneorum colony under laboratory conditions as it produces enough adults to create a stenogamic colony. The establishment of a stable, P. vivax-susceptible colony of Ny. deaneorum makes it possible to model parasite-vector interactions and to test novel drug therapies that target parasite development in mosquitoes.

Animals , Female , Oviposition , Copulation/physiology , Mosquito Vectors/parasitology , Insect Vectors/growth & development , Malaria , Anopheles/parasitology , Plasmodium falciparum , Plasmodium vivax , Brazil , Insect Vectors/physiology , Anopheles/physiology
Mem. Inst. Oswaldo Cruz ; 115: e200043, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135250


BACKGROUND The number of malaria cases in Roraima nearly tripled from 2016 to 2018. The capital, Boa Vista, considered a low-risk area for malaria transmission, reported an increasing number of autochthonous and imported cases. OBJECTIVES This study describes a spatial analysis on malaria cases in an urban region of Boa Vista, which sought to identify the autochthonous and imported cases and associated them with Anopheles habitats and the potential risk of local transmission. METHODS In a cross-sectional study at the Polyclinic Cosme e Silva, 520 individuals were interviewed and diagnosed with malaria by microscopic examination. Using a global positional system, the locations of malaria cases by type and origin and the breeding sites of anopheline vectors were mapped and the risk of malaria transmission was evaluated by spatial point pattern analysis. FINDINGS Malaria was detected in 57.5% of the individuals and there was a disproportionate number of imported cases (90.6%) linked to Brazilian coming from gold mining sites in Venezuela and Guyana. MAIN CONCLUSIONS The increase in imported malaria cases circulating in the west region of Boa Vista, where there are positive breeding sites for the main vectors, may represent a potential condition for increased autochthonous malaria transmission in this space.

Humans , Animals , Male , Female , Adult , Plasmodium/isolation & purification , Travel , Miners/statistics & numerical data , Mosquito Vectors/parasitology , Malaria/diagnosis , Malaria/transmission , Anopheles/parasitology , Plasmodium/classification , Urban Population , Venezuela , Brazil/epidemiology , Cross-Sectional Studies , Geographic Information Systems , Spatial Analysis , Gold , Guyana , Malaria/parasitology , Malaria/epidemiology , Anopheles/classification , Middle Aged
Mem. Inst. Oswaldo Cruz ; 115: e190431, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135241


BACKGROUND Long lasting insecticide-treated nets (LLINs) may be effective for vector control of cutaneous leishmaniasis (CL). Their efficacy, however, has not been sufficiently evaluated. OBJECTIVE To evaluate the large-scale efficacy of LLINs on Lutzomyia longiflocosa entomological parameters up to two years post-intervention in the sub-Andean region of Colombia. METHODS A matched-triplet cluster-randomised study of 21 rural settlements, matched by pre-intervention L. longiflocosa indoor density was used to compare three interventions: dip it yourself (DIY) lambda-cyhalothrin LLIN, deltamethrin LLIN, and untreated nets (control). Sand fly indoor density, feeding success, and parity were recorded using CDC light trap collections at 1, 6, 12, and 24 months post-intervention. FINDINGS Both LLINs reduced significantly (74-76%) the indoor density and the proportion of fully engorged sand flies up to two years post-intervention without differences between them. Residual lethal effects of both LLINs and the use of all nets remained high throughout the two-year evaluation period. CONCLUSIONS Both LLINs demonstrated high efficacy against L. longiflocosa indoors. Therefore, the deployment of these LLINs could have a significant impact on the reduction of CL transmission in the sub-Andean region. The DIY lambda-cyhalothrin kit may be used to convert untreated nets to LLINs increasing coverage.

Animals , Mosquito Control/methods , Leishmaniasis, Cutaneous/prevention & control , Insecticide-Treated Bednets , Insect Vectors/drug effects , Insecticides/administration & dosage , Anopheles/drug effects , Rural Population , Insecticide Resistance , Leishmaniasis, Cutaneous/parasitology , Colombia , Mosquito Vectors
Rio de Janeiro; Fiocruz; 2020. 228 p. il, fots, mapas^c23 cm.(Coleção história e saúde).
Monography in Portuguese | LILACS | ID: biblio-1369911


Mostra uma trajetória ampliada do Anopheles gambiae no Brasil. evidencia a importância de compreender seu percurso desde sua chegada em 1930, considerando o processo histórico que o fez ser inicialmente entendido como um problema emergencial local, tratado de maneira paleativa para, posteriormente, ser enquadrado em um experimento de demonstração em saúde pública tendo em vista sua erradicação

Vector Control , Disease Eradication , Malaria/epidemiology , Anopheles , Brazil
Rev. Soc. Bras. Med. Trop ; 53: e20190211, 2020. tab, graf
Article in English | LILACS | ID: biblio-1057287


Abstract INTRODUCTION Anopheles stephensi is the main malaria vector in Southeast Asia. Recently, plant-sourced larvicides are attracting great interests. METHODS: The essential oil was extracted from the leaf of Cinnamomum camphora (L.), and a bioassay was conducted to determine the larvicidal efficacy. The chemical composition of the essential oil was determined by GC-MS analysis. RESULTS: The oil showed strong, dose-dependent larvicidal activities. The onset of larvicidal efficiency was rapid. The LC50 and LC95 were determined as 0.146% and 1.057% at 1 h, 0.031% and 0.237% at 12 h, 0.026% and 0.128% at 24 h, respectively. The oil contains 32 compounds. CONCLUSIONS The essential oil of C. camphora leaf has an excellent larvicidal potential for the control of A. stephensi.

Animals , Oils, Volatile/pharmacology , Cinnamomum camphora/chemistry , Mosquito Vectors/drug effects , Insecticides/pharmacology , Larva/drug effects , Anopheles/drug effects , Biological Assay , Oils, Volatile/isolation & purification , Mosquito Vectors/classification , Insecticides/isolation & purification , Lethal Dose 50 , Anopheles/classification
Rev. Soc. Bras. Med. Trop ; 53: e20190018, 2020. graf
Article in English | LILACS | ID: biblio-1092184


Abstract INTRODUCTION: The larvicidal potential of Saussurea costus (Falc.) Lipsch. was studied against the early 4th instar larvae of Anopheles stephensi Liston., Aedes aegypti Linn.,and Culex quinquefasciatus Say. because of the emergence of mosquito resistance to conventional synthetic insecticides. METHODS: At concentrations of 12.5-200 ppm, larvicidal activities were studied under laboratory conditions. RESULTS: After 24 h of exposure, the methanol extract of the roots recorded the highest larvicidal activity against An. stephensi, with LC50 and LC90values of 7.96 and 34.39 ppm, respectively. CONCLUSIONS: We are developing potent larvicidal compound(s) from S. costus for controlling the mosquito larval population.

Animals , Plant Extracts/pharmacology , Aedes/drug effects , Culex/drug effects , Saussurea/chemistry , Insecticides/pharmacology , Larva/drug effects , Anopheles/drug effects , Insecticides/isolation & purification
São Paulo; s.n; 2020. 125 p.
Thesis in Portuguese | LILACS | ID: biblio-1120501


Mudanças antropogênicas no ambiente podem ser um fator poderoso na evolução das espécies. A fragmentação de áreas naturais devido às interferências humanas é associada à diminuição na riqueza e aumento na abundância de espécies de mosquitos adaptadas a ambientes urbanos. A Mata Atlântica brasileira tem passado por um processo intenso de fragmentação e desmatamento devido às alterações antropogênicas no ambiente. Esse bioma é um importante local de transmissão de malária, no qual o principal vetor de patógenos que causam a malária humana e simiana é o Anopheles cruzii. Desse modo, é possível que alterações antropogênicas no meio ambiente possam modular o fenótipo e genótipo de An. cruzii. Neste estudo, foram usados a geometria alar e marcadores moleculares SNPs para acessar a estrutura micro-geográfica de populações de An. cruzii coletadas em uma área hipoendêmica de malária na cidade de São Paulo, Brasil. Nesta região, as modificações antropogênicas suprimem a Mata Atlântica a fragmentos, fazendo com que An. cruzii, Plasmodium e seres humanos vivam em simpatria. Diferentes hipóteses para ambos os marcadores foram usadas em um desenho de estudo transversal e longitudinal para acessar se estruturação simpátrica e processos microevolutivos estão modulando as populações de An. cruzii. No geral, as hipóteses testadas foram divididas em: há estrutura entre populações de An. cruzii de copa e solo, há estrutura entre populações de An. cruzii em áreas com diferentes níveis de modificações antropogênicas e há estrutura populacional em relação ao tempo em An. cruzii. Portanto, foram investigadas a variação alar e genética em populações de An. cruzii coletadas em áreas silvestre, periurbana e urbana durante um período de três anos. Os principais resultados da análise de geometria da asa mostraram que as populações de copa e solo do ambiente urbano são distintas de acordo com a análise de variáveis canônicas. Os resultados também mostraram uma sutil, mas significativa variação fenotípica nas populações das três áreas durante os três anos de estudo. As variações temporal e simpátrica do formato alar foram maiores no ambiente urbano, sugerindo que mudanças antropogênicas no ambiente podem modular a variação no formato alar de An. cruzii. Os resultados da análise de 1.235 SNPs considerados neutros e independentes mostraram baixa estruturação genética entre as populações de An. cruzii no geral. Porém, as análises sugeriram que as populações de copa e solo da área urbana são significativamente estruturadas. A população do solo da área urbana apresentou maior diversidade genética que a de copa, corroborando os resultados da morfometria alar. Esses resultados indicam que modificações antropogênicas no ambiente levando à fragmentação de áreas naturais podem estar modulando a acrodendrofilia de An. cruzii e mantendo estrutura e diversidade genética na população de solo da área urbana.

Anthropogenic changes in the environment can be a powerfull aspect in the evolution of the species. Fragmentation of natural areas due to human interference has been associated with the decrease of species richness and increase in the abundance of species that are adapted to these environments. The Brazilian Atlantic Forest has been undergoing an intense process of fragmentation and deforestation due to anthropogenic alterations in the environment. This biome is an important hotspot of malaria transmission, in which the main vector of simian and human malaria is the mosquito Anopheles cruzii. We hypothesized that anthropogenic alterations in the environment are an important driver for the phenotypic and genetic structure and diversity of An. cruzii. We tested five different hypotheses using both a cross-sectional and longitudinal design to assess the sympatric structure and microevolution process driving An. cruzii populations. We used both wing geometry and SNPs to assess the microgeographical genetic structure of An. cruzii populations in a malaria hypo-endemic area in the city of São Paulo, Brazil. In this region, anthropogenic modifications in the environment suppress the Atlantic Forest into fragments, resulting in mosquitoes An. cruzii, Plasmodium and humans living in simpatry. Our results show a slight but significant phenotypic variation in all three populations over the study period. Time was a more powerful driver for wing variation than geographic distance. Temporal wing-shape variation appears to be positively associated with urbanization, suggesting that anthropogenic changes in the environment may be a strong driver for wing-shape variation in An. cruzii. After filtering and removal of outlier loci, 1,235 SNPs were considered independent and neutral, and therefore, suitable to perform the analyses. The results showed an overall weak genetic structure among populations with a significant sympatric structure between ground and tree canopies populations from the urban area, with the population from ground level showing higher genetic diversity. Our findings indicate that anthropogenic modifications leading to habitat fragmentation could be driving the acrodendrophily of An. cruzii and maintaining genetic diversity and structure in populations from ground level.

Genetic Variation , Diptera , Malaria , Anopheles , Culicidae
Hist. ciênc. saúde-Manguinhos ; 26(3): 823-839, jul.-set. 2019.
Article in Portuguese | LILACS | ID: biblio-1039955


Resumo O artigo analisa a chegada e identificação do mosquito africano Anopheles gambiae no Brasil em 1930 e as primeiras reações de cientistas e autoridades de saúde pública contra as epidemias de malária causadas por essa espécie. Apesar de ter sido reconhecido como perigoso vetor da malária, sua presença em território nacional foi negligenciada a partir de 1932, após ações emergenciais na capital do Rio Grande do Norte, favorecendo um alastramento silencioso que resultou em uma grande epidemia de malária em 1938. São abordadas questões científicas e políticas que contribuíram para que o combate ao mosquito fosse colocado em segundo plano nas articulações entre a Divisão Sanitária Internacional da Fundação Rockefeller e autoridades brasileiras até 1937.

Abstract The article analyzes the arrival and identification of the African mosquito Anopheles gambiae in Brazil in 1930, and the initial reactions of scientists and public health authorities against the epidemics of malaria caused by this species. Although this mosquito was recognized as a dangerous vector of malaria, its presence in Brazil was neglected after initial emergency actions in the city of Natal in 1932; this encouraged it to spread silently, resulting in a major malaria epidemic in 1938. This article examines scientific and political issues which caused the fight against mosquitoes to be pushed into the background until 1937 in cooperative efforts between the Rockefeller Foundation's International Health Division and the Brazilian authorities.

Humans , History, 20th Century , Mosquito Control/history , Epidemics/history , Mosquito Vectors , Malaria/history , Anopheles , Brazil/epidemiology , Mosquito Control/methods , Federal Government/history , Epidemics/prevention & control , Foundations/history , Malaria/epidemiology
Safety and Health at Work ; : 122-124, 2019.
Article in English | WPRIM | ID: wpr-761327


Simian malaria is a zoonotic disease caused by Plasmodium knowlesi infection. The common natural reservoir of the parasite is the macaque monkey and the vector is the Anopheles mosquito. Human cases of P. knowlesi infection has been reported in all South East Asian countries in the last decade, and it is currently the most common type of malaria seen in Malaysia and Brunei. Between 2007–2017, 73 cases of P. knowlesi infection were notified and confirmed to the Ministry of Health in Brunei. Of these, 15 cases (21%) were documented as work-related, and 28 other cases (38%) were classified as probably related to work (due to incomplete history). The occupations of those with probable and confirmed work related infections were border patrol officers, Armed Forces and security personnel, Department of Forestry officers, boatmen and researchers. The remaining cases classified as most likely not related to work were possibly acquired via peri-domestic transmission. The risk of this zoonotic infection extends to tourists and overseas visitors who have to travel to the jungle in the course of their work. It can be minimised with the recommended use of prophylaxis for those going on duty into the jungles, application of mosquito/insect repellants, and use of repellant impregnated uniforms and bed nets in jungle camp sites.

Anopheles , Arm , Asian Continental Ancestry Group , Brunei , Culicidae , Forestry , Haplorhini , Humans , Macaca , Malaria , Malaysia , Occupations , Parasites , Plasmodium knowlesi , Plasmodium , Zoonoses
Rev. Soc. Bras. Med. Trop ; 52: e20190308, 2019. graf
Article in English | LILACS | ID: biblio-1057242


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.

Animals , Climate Change , Mosquito Vectors/parasitology , Malaria/transmission , Anopheles/parasitology , Population Dynamics , Models, Biological
São Paulo; s.n; 2019. 153 p.
Thesis in Portuguese | LILACS | ID: biblio-1026004


Introdução - Nyssorhynchus darlingi e outros mosquitos da subfamília Anophelinae atuam como vetores dos parasitos da malária humana. Alterações na paisagem podem alterar a distribuição, abundância e comportamento desses mosquitos. Bactérias presentes no intestino médio de vetores de Plasmodium são capazes de modular a infecção por Plasmodium spp. no mosquito. Objetivos - Ampliar o conhecimento sobre os mosquitos que atuam na dinâmica de transmissão da malária em áreas rurais e periurbanas da Amazônia brasileira e investigar a diversidade bacteriana associada ao abdômen de Ny. darlingi e Nyssorhynchus braziliensis. Métodos - Capturas de mosquitos foram realizadas em áreas rurais e periurbanas da Amazônia brasileira. Testes de detecção de Plasmodium spp. foram realizados nos mosquitos. Análises de correlação e de regressão foram realizadas entre métricas de paisagem e as variáveis: incidência acumulada de malária, número de Ny. darlingi, mosquitos infectados e taxa de picada humana. Sequenciamento da região V4 do gene 16S rRNA foi realizado para explorar a diversidade bacteriana associada ao abdômen de Ny. braziliensis e de Ny. darlingi naturalmente infectado e não infectado por Plasmodium spp. Resultados - Nyssorhynchus darlingi, Nyssorhynchus rangeli, Nyssorhynchus benarrochi B e Nyssorhynchus konderi B foram encontrados infectados com Plasmodium. Plasmodium vivax e Plasmodium falciparum foram as espécies do parasito encontradas nos vetores. Foram encontradas correlações positivas entre incidência acumulada de malária e as variáveis taxa de picada humana, densidade de borda e número de Ny. darlingi. Porcentagem de cobertura florestal e taxa de picada humana apresentaram correlação negativa. O período entre 0 h:00 e 3 h:00 foi o que apresentou maior número de mosquitos infectados. Não houve diferença estatística entre a diversidade bacteriana de Ny. darlingi infectado e não infectado. Asaia e Serratia estavam presentes em ambas as espécies de Nyssochynchus. Enterobacter foi encontrado apenas em abdômen de Ny. darlingi não infectado e Pseudomonas foi o gênero mais abundante. Conclusão - Este estudo reporta pela primeira vez a infecção natural por Plasmodium em Ny. konderi B e Ny. benarrochi B em regiões da Amazônia brasileira. Os resultados obtidos sugerem que mudanças na paisagem podem favorecer a ocorrência de novos vetores e consequentemente, aumentar o número de casos de malária em regiões endêmicas. O encontro de maior número de mosquitos infectados após a meia-noite contribui para as medidas de controle do vetor e confirma a importância do uso de mosquiteiros impregnados com inseticida. A presença de Asaia e Serratia em ambas as espécies de Nyssorhynchus e a alta prevalência de Pseudomonas em Ny. darlingi indicam a necessidade de outros estudos sobre a possível utilização destas bactérias no controle da malária através da paratransgênese. A presença do gênero Enterobacter apenas em abdômen de Ny. darlingi não infectado sugere que bactérias deste gênero possam oferecer proteção a infecção por Plasmodium e outros estudos devem ser realizados para verificar essa hipótese.

Introduction - Nyssorhynchus darlingi and other mosquitoes of the subfamily Anophelinae act as vectors of human malaria parasites. Landscape changes can alter the distribution, abundance and behavior of these mosquitoes. Bacteria present in the midgut of Plasmodium vectors are able to modulate infection by Plasmodium spp. in the mosquito. Objectives - To broaden the knowledge about mosquitoes that act on the dynamics of malaria transmission in rural and peri-urban areas of the Brazilian Amazon and to investigate the bacterial diversity associated with abdomen of Ny. darlingi and Nyssorhynchus braziliensis. Methods - Mosquito collections were carried out in rural and peri-urban areas of the Brazilian Amazon. Detection tests for Plasmodium spp. mosquitoes were carried out. Correlation and regression analyzes were performed between landscape metrics and the following variables: cumulative incidence of malaria, number of Ny. darlingi, infected mosquitoes, and human biting rate. Sequencing of the V4 region of the 16S rRNA gene was performed to explore the bacterial diversity associated with abdomen of Ny. braziliensis and Ny. darlingi naturally infected and not infected by Plasmodium spp. Results - Nyssorhynchus darlingi, Nyssorhynchus rangeli, Nyssorhynchus benarrochi B and Nyssorhynchus konderi B were found infected with Plasmodium. Plasmodium vivax and Plasmodium falciparum were the parasite species found in the vectors. Positive correlations were found between cumulative incidence of malaria and the variables human biting rate, edge density and number of Ny. darlingi. Percentage of forest cover and human biting rate presented negative correlation. The period from 0 h: 00 to 3 h: 00 was the one with the highest number of infected mosquitoes. There was no statistical difference between bacterial diversity in Ny. darlingi infected and uninfected. Asaia and Serratia were present in both species of Nyssochynchus. Enterobacter was found only in abdomen of Ny. darlingi uninfected and Pseudomonas was the genus most abundant. Conclusion - This study reports for the first time the natural infection by Plasmodium in Ny. konderi B and Ny. benarrochi B in regions of the Brazilian Amazon. The results suggest that changes in the landscape can favor the occurrence of new vectors and, consequently, increase the number of malaria cases in endemic regions. The finding of a greater number of infected mosquitoes after midnight contributes to vector control measures and confirms the importance of insecticide-treated nets. The presence of Asaia and Serratia in both species of Nyssorhynchus and the high prevalence of Pseudomonas in Ny. darlingi indicate the need for further studies on the possible use of these bacteria in the control of malaria through paratransgenesis. The presence of the Enterobacter only in abdomen Ny. darlingi uninfected suggests that bacteria of this genus can offer protection to Plasmodium infection and other studies should be performed to verify this hypothesis.

Plasmodium , Rural Areas , Amazonian Ecosystem , Malaria , Anopheles
Mem. Inst. Oswaldo Cruz ; 114: e180598, 2019. tab, graf
Article in English | LILACS | ID: biblio-1040630


Anopheles bellator is a primary malaria vector in the Atlantic Forest. Partial sequences of timeless and Clock genes were used to assess the genetic differentiation of five Brazilian populations, which showed strong population structure (e.g. high F ST values and fixed differences) in all pairwise comparisons between Bahia sample and the others from Paraná, São Paulo and Rio de Janeiro states. Also, the resulting phylogenetic trees clearly grouped the sequences from Bahia in a different cluster with high bootstrap values. Among southern and southeastern populations low levels of genetic differentiation were found suggesting a general stability of the genetic structure.

Animals , Genetic Variation/genetics , Mosquito Vectors/genetics , Anopheles/genetics , Phylogeny , Brazil , Forests , Sequence Analysis, DNA , Mosquito Vectors/classification , Malaria/transmission , Anopheles/classification
Rev. Soc. Bras. Med. Trop ; 52: e20190159, 2019. graf
Article in English | LILACS | ID: biblio-1041542


Abstract INTRODUCTION: The lack of highly-productive Nyssorhynchus darlingi laboratory colonies limits some studies. We report the first well-established laboratory colony of Ny. darlingi in Brazil. METHODS: Mosquitoes were collected from Porto Velho and were reared at the Laboratory of Fiocruz/RO. After induced mating by light stimulation in the F1 to F6, the subsequent generations were free mating. Larvae were reared in distilled water and fed daily until pupation. RESULTS: In 11 generations, the colony produced a high number of pupae after the F5 generation. CONCLUSIONS: These results demonstrate the potential for permanently establishing Ny. darlingi colonies for research purposes in Brazil.

Animals , Mosquito Vectors/growth & development , Anopheles/growth & development , Oviposition , Reproduction , Brazil , Mosquito Vectors/physiology , Malaria , Anopheles/physiology