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BACKGROUND: Environmental disturbance, deforestation and socioeconomic factors all affect malaria incidence in tropical and subtropical endemic areas. Deforestation is the major driver of habitat loss and fragmentation, which frequently leads to shifts in the composition, abundance and spatial distribution of vector species. The goals of the present study were to: (i) identify anophelines found naturally infected with Plasmodium; (ii) measure the effects of landscape on the number of Nyssorhynchus darlingi, presence of Plasmodium-infected Anophelinae, human biting rate (HBR) and malaria cases; and (iii) determine the frequency and peak biting time of Plasmodium-infected mosquitoes and Ny. darlingi. METHODS: Anopheline mosquitoes were collected in peridomestic and forest edge habitats in seven municipalities in four Amazon Brazilian states. Females were identified to species and tested for Plasmodium by real-time PCR. Negative binomial regression was used to measure any association between deforestation and number of Ny. darlingi, number of Plasmodium-infected Anophelinae, HBR and malaria. Peak biting time of Ny. darlingi and Plasmodium-infected Anophelinae were determined in the 12-h collections. Binomial logistic regression measured the association between presence of Plasmodium-infected Anophelinae and landscape metrics and malaria cases. RESULTS: Ninety-one females of Ny. darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B were found to be infected with Plasmodium. Analysis showed that the number of malaria cases and the number of Plasmodium-infected Anophelinae were more prevalent in sites with higher edge density and intermediate forest cover (30-70%). The distance of the drainage network to a dwelling was inversely correlated to malaria risk. The peak biting time of Plasmodium-infected Anophelinae was 00:00-03:00 h. The presence of Plasmodium-infected mosquitoes was higher in landscapes with > 13 malaria cases. CONCLUSIONS: Nyssorhynchus darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B can be involved in malaria transmission in rural settlements. The highest fraction of Plasmodium-infected Anophelinae was caught from midnight to 03:00 h. In some Amazonian localities, the highest exposure to infectious bites occurs when residents are sleeping, but transmission can occur throughout the night. Forest fragmentation favors increases in both malaria and the occurrence of Plasmodium-infected mosquitoes in peridomestic habitat. The use of insecticide-impregnated mosquito nets can decrease human exposure to infectious Anophelinae and malaria transmission.
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Culicidae , Animales , Brasil/epidemiología , Culicidae/parasitología , Culicidae/fisiología , Ecosistema , Conducta Alimentaria , Humanos , Mordeduras y Picaduras de Insectos , Malaria/epidemiología , Malaria/transmisión , Mosquitos Vectores/parasitología , Mosquitos Vectores/fisiología , Plasmodium/aislamiento & purificación , PrevalenciaRESUMEN
We describe the alloglossiid trematode Magnivitellinum saltaensis n. sp., a parasite of the characiform fish Psalidodon endy, and its life cycle from Salta, northwest of Argentina. This is the first life cycle described for a species belonging to the genus Magnivitellinum. Cercariae emerged naturally from Biomphalaria tenagophila snails and infected experimentally exposed larvae of Diptera and Ephemeroptera as second intermediate hosts. These larvae in turn were exposed to commercially raised fish, and adults were recovered from characiform albino fish Gymnocorymbus ternetzi. Molecular analysis of natural and experimental adults showed the same genetic sequence for the partial region of 28S rDNA, thus confirming conspecificity. Comparison of these sequences with those published for M. simplex from Mexico showed 1.45% divergence, indicating that the specimens found in Salta belong to a different species, the third described of Magnivitellinum, in agreement with morphological data, geographical location, and host species composition. The new species is distinguished by its small body, vitelline follicles extending from the mid-level of the ventral sucker, Y-shaped excretory vesicle, and presence of papillae around the mouth.
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Biomphalaria/parasitología , Characidae/parasitología , Culicidae/parasitología , Enfermedades de los Peces/parasitología , Estadios del Ciclo de Vida , Trematodos/crecimiento & desarrollo , Infecciones por Trematodos/veterinaria , Animales , Argentina , Cercarias , Femenino , Larva/parasitología , Masculino , Metacercarias , Filogenia , ARN Ribosómico 28S/genética , Trematodos/anatomía & histología , Trematodos/clasificación , Trematodos/genética , Infecciones por Trematodos/parasitologíaRESUMEN
BACKGROUND: Understanding local anopheline vector species and their bionomic traits, as well as related human factors, can help combat gaps in protection. METHODS: In San José de Chamanga, Esmeraldas, at the Ecuadorian Pacific coast, anopheline mosquitoes were sampled by both human landing collections (HLCs) and indoor-resting aspirations (IAs) and identified using both morphological and molecular methods. Human behaviour observations (HBOs) (including temporal location and bed net use) were documented during HLCs as well as through community surveys to determine exposure to mosquito bites. A cross-sectional evaluation of Plasmodium falciparum and Plasmodium vivax infections was conducted alongside a malaria questionnaire. RESULTS: Among 222 anopheline specimens captured, based on molecular analysis, 218 were Nyssorhynchus albimanus, 3 Anopheles calderoni (n = 3), and one remains unidentified. Anopheline mean human-biting rate (HBR) outdoors was (13.69), and indoors (3.38) (p = 0.006). No anophelines were documented resting on walls during IAs. HBO-adjusted human landing rates suggested that the highest risk of being bitten was outdoors between 18.00 and 20.00 h. Human behaviour-adjusted biting rates suggest that overall, long-lasting insecticidal bed nets (LLINs) only protected against 13.2% of exposure to bites, with 86.8% of exposure during the night spent outside of bed net protection. The malaria survey found 2/398 individuals positive for asymptomatic P. falciparum infections. The questionnaire reported high (73.4%) bed net use, with low knowledge of malaria. CONCLUSION: The exophagic feeding of anopheline vectors in San Jose de Chamanga, when analysed in conjunction with human behaviour, indicates a clear gap in protection even with high LLIN coverage. The lack of indoor-resting anophelines suggests that indoor residual spraying (IRS) may have limited effect. The presence of asymptomatic infections implies the presence of a human reservoir that may maintain transmission.
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Culicidae/parasitología , Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Mosquitos Vectores/parasitología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Anopheles/parasitología , Niño , Preescolar , Estudios Transversales , Ecuador/epidemiología , Femenino , Humanos , Malaria Falciparum/parasitología , Malaria Vivax/parasitología , Masculino , Persona de Mediana Edad , Proyectos Piloto , Plasmodium falciparum/fisiología , Plasmodium vivax/fisiología , Prevalencia , Riesgo , Encuestas y Cuestionarios , Adulto JovenAsunto(s)
Erradicación de la Enfermedad/organización & administración , Erradicación de la Enfermedad/estadística & datos numéricos , Malaria/epidemiología , Malaria/prevención & control , Vigilancia de la Población , Argelia/epidemiología , Animales , Argentina/epidemiología , China/epidemiología , Culicidae/parasitología , Humanos , Malaria/transmisión , Control de Mosquitos/estadística & datos numéricos , Vigilancia de la Población/métodos , Riesgo , Sri Lanka/epidemiología , Organización Mundial de la SaludRESUMEN
Avian malaria is a mosquito-borne disease that affects multiple avian species and is caused by protozoans of the genus Plasmodium. An avian malaria infection caused by Plasmodium sp. in Magellanic penguins (Spheniscus magellanicus) with high mortality is described in a zoo in Southern Brazil. Clinically, three birds presented signs of inappetence, anorexia, pale mucosa, dyspnea, and opisthotonus, with death in a clinical course of 5-8 h. At the necropsy, all birds exhibited pale mucosa, marked splenomegaly and hepatomegaly, in addition to moderate leptomeningeal blood vessels ingurgitation in the brain. Microscopically, multiple exoerythrocytic meronts were observed in the cytoplasm of endothelial cells in the spleen, liver, heart, lungs, brain, kidneys, and pancreas. The spleen had a multifocal perivascular inflammatory infiltrate of lymphocytes, plasma cells, and macrophages, which also exhibited hemosiderosis and erythrophagocytosis. The liver had a multifocal periportal inflammatory infiltrate of lymphocytes, macrophages, and plasma cells, in addition to marked hemosiderosis in the hepatic sinusoids. Fragments of spleen, liver, brain, skeletal muscle, and lung were tested by the polymerase chain reaction technique for the detection of a fragment of the cytochrome B gene from haemosporidians, which resulted positive for Plasmodium spp. After sequencing, the samples were phylogenetically associated to Plasmodium sp. detected in Turdus albicollis (KU562808) in Brazil and matched to the lineage TURALB01 previously detected in T. albicollis. Avian malaria infections caused by Plasmodium sp. of lineage TURALB01 may occur in S. magellanicus with high mortality, and, thus, it is essential to detect and characterize the agent involved to obtain the differential diagnosis of the condition.
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Animales de Zoológico/parasitología , Enfermedades de las Aves/diagnóstico , Malaria Aviar/diagnóstico , Malaria Aviar/mortalidad , Plasmodium/aislamiento & purificación , Spheniscidae/parasitología , Animales , Enfermedades de las Aves/parasitología , Aves , Brasil , Culicidae/parasitología , Citocromos b/genética , Malaria Aviar/parasitología , Filogenia , Plasmodium/genéticaRESUMEN
Malaria is a deadly disease transmitted to human through the bite of infected female mosquitoes. The aim of this paper is to study the different vector-bias values between low and high transmission areas with the examples of Mexico (low) and Sudan, Democratic Republic of the Congo (Congo, DR) (high) during malaria transmission. We develop a malaria transmission model with vector-bias and investigate the basic reproduction number, the existence of equilibria and the corresponding globally asymptotically stable. Then, we simulate the reported cases of Mexico and Sudan, Democratic Republic of the Congo by World Health Organization (WHO) (WHO, 0000) and predict the direction of the disease. Our simulation results show that the most endemic country is Congo, DR with the highest vector-bias and R0 values, followed by Sudan and Mexico with less, respectively and that the disease will die out in Mexico and persist in Sudan and Congo, DR. Furthermore, we perform sensitivity analysis of R0 and give some useful comments on reducing the cases of the disease.
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Culicidae/parasitología , Malaria , Modelos Biológicos , Mosquitos Vectores/parasitología , Animales , República Democrática del Congo/epidemiología , Femenino , Malaria/epidemiología , Malaria/transmisión , México/epidemiología , Sudán/epidemiologíaRESUMEN
Malaria remains an important parasitic disease with a large morbidity and mortality burden. Plasmodium transmission-blocking (TB) compounds are essential for achieving malaria elimination efforts. Recent efforts to develop high-throughput screening (HTS) methods to identify compounds that inhibit or kill gametocytes, the Plasmodium sexual stage infectious to mosquitoes, have yielded insight into new TB compounds. However, the activities of these compounds against gametes, formed in the first minutes of mosquito infection, are typically not assessed, unless screened in a standard membrane feeding assay, a labor-intensive assay. We demonstrate here the generation of a Plasmodium model for drug screens against gametes and fertilization. The new P. berghei line, named Ookluc, was genetically and pharmacologically validated and scalable for HTS. Screening the Pathogen Box from the Medicines for Malaria Venture using the new model identified promising TB compounds. The use of Ookluc in different libraries of compounds may aid in the identification of transmission-blocking drugs not assessed in screens against asexual stages or gametocytes.
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Antimaláricos/farmacología , Malaria/tratamiento farmacológico , Plasmodium berghei/efectos de los fármacos , Animales , Culicidae/parasitología , Luciferasas/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Nanopartículas/administración & dosificaciónRESUMEN
Pythium insidiosum is a straminopilan pathogen causing life threatening infections in mammals inhabiting temperate, tropical and subtropical areas of the world. The concept that P. insidiosum could also infect mosquitoes was mentioned earlier by investigators conducting phylogenetic analysis on available P. insidiosum isolates deposited at different culture collections. However, an official report and details on its pathological features in mosquitoes are not available. We are reporting the isolation of P. insidiosum from infected mosquito larvae during a survey conducted in central Brazil. At least three oomycotan isolates were recovered during the survey. Due to their ability to infect mosquito larvae the isolates were deposited in the U.S. Department of Agriculture, Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF; Ithaca, New York) as putative Lagenidium species. The investigated isolates developed very well at 37⯰C, produced typical Pythium-like vesicles containing numerous biflagellate zoospores, hydrolyzed sucrose, and their cultured extracted proteins were recognized in serological analysis by anti-P. insidiosum antibodies. Phylogenetic analyses using ITS and partial COXII DNA sequences identified the isolates as P. insidiosum within the American Cluster I. This is the first official report of P. insidiosum recovered from infected mosquito larvae, indicating that this mammalian pathogen, in addition to plants, it could also use mosquito larvae to complete its life cycle in nature.
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Culicidae/parasitología , Pythium/aislamiento & purificación , Animales , Brasil , Larva/parasitología , Filogenia , Pythium/clasificación , Pythium/genética , Análisis de Secuencia de ADNRESUMEN
Though malaria control initiatives have markedly reduced malaria prevalence in recent decades, global eradication is far from actuality. Recent studies show that environmental and social heterogeneities in low-transmission settings have an increased weight in shaping malaria micro-epidemiology. New integrated and more localized control strategies should be developed and tested. Here we present a set of agent-based models designed to study the influence of local scale human movements on local scale malaria transmission in a typical Amazon environment, where malaria is transmission is low and strongly connected with seasonal riverine flooding. The agent-based simulations show that the overall malaria incidence is essentially not influenced by local scale human movements. In contrast, the locations of malaria high risk spatial hotspots heavily depend on human movements because simulated malaria hotspots are mainly centered on farms, were laborers work during the day. The agent-based models are then used to test the effectiveness of two different malaria control strategies both designed to reduce local scale malaria incidence by targeting hotspots. The first control scenario consists in treat against mosquito bites people that, during the simulation, enter at least once inside hotspots revealed considering the actual sites where human individuals were infected. The second scenario involves the treatment of people entering in hotspots calculated assuming that the infection sites of every infected individual is located in the household where the individual lives. Simulations show that both considered scenarios perform better in controlling malaria than a randomized treatment, although targeting household hotspots shows slightly better performance.
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Malaria/transmisión , Modelos Biológicos , Movimiento , Adolescente , Adulto , Animales , Niño , Preescolar , Simulación por Computador , Culicidae/parasitología , Empleo , Humanos , Incidencia , Lactante , Recién Nacido , Persona de Mediana Edad , Actividad Motora , Fotoperiodo , Plasmodium , Bosque Lluvioso , Ríos , Sueño , América del Sur , Adulto JovenRESUMEN
Magellanic penguins (Spheniscus magellanicus) are native to Argentina, Chile and the Falkland Islands. Magellanic penguins are highly susceptible to blood parasites such as the mosquito-borne Plasmodium spp., which have been documented causing high morbidity and mortality in zoos and rehabilitation centres. However, to date no blood parasites have been detected in wild Magellanic penguins, and it is not clear whether this is reflective of their true absence or is instead related to an insufficiency in sampling effort or a failure of the diagnostic methods. We examined blood smears of 284 Magellanic penguins from the Argentinean coast and tested their blood samples with nested polymerase chain reaction tests targeting Haemoproteus, Plasmodium, Leucocytozoon and Babesia. No blood parasites were detected. Analysing the sampling effort of previous studies and the climatogeography of the region, we found there is strong basis to conclude that haemosporidians do not infect wild Magellanic penguins on the Argentinean coast. However, at present it is not possible to determine whether such parasites occur on the Chilean coast and at the Falkland Islands. Furthermore, it is troubling that the northward distribution expansion of Magellanic penguins and the poleward distribution shift of vectors may lead to novel opportunities for the transmission of blood parasites.
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Apicomplexa/aislamiento & purificación , Enfermedades de las Aves/parasitología , Culicidae/parasitología , Insectos Vectores/parasitología , Infecciones Protozoarias en Animales/parasitología , Spheniscidae/parasitología , Animales , Argentina , Babesia/aislamiento & purificación , Clima , Geografía , Haemosporida/aislamiento & purificación , Parasitemia/veterinaria , Plasmodium/aislamiento & purificación , Estudios ProspectivosRESUMEN
BACKGROUND: Haemosporidian parasites of the genera Plasmodium and Haemoproteus can have detrimental effects on individual birds and populations. Despite recent investigations into the distribution and richness of these parasites and their vertebrate hosts, little is known about their dipteran vectors. The Neotropics has the highest diversity of mosquitoes in the world, but few studies have tried to identify vectors in this area, hampering the understanding of the ecology of avian malaria in the highly diverse Neotropical environments. METHODS: Shannon traps and active collection were used to capture 27,110 mosquitoes in a Seasonally Dry Tropical Forest in southeastern Brazil, a highly endangered ecosystem. RESULTS: We screened 17,619 mosquito abdomens from 12 different species and several unidentified specimens of Culex, grouped into 1,913 pools, for the presence of haemosporidians. Two pools (out of 459) of the mosquito Mansonia titillans and one pool (out of 29) of Mansonia pseudotitillans were positive for Plasmodium parasites, with the detection of a new parasite lineage in the former species. Detected Plasmodium lineages were distributed in three different clades within the phylogenetic tree revealing that Mansonia mosquitoes are potential vectors of genetically distant parasites. Two pools of Culex spp. (out of 43) were positive for Plasmodium gallinaceum and closely related lineages. We found a higher abundance of these putative vectors in pasture areas, but they were also distributed in areas at intermediate and late successional stages. One pool of the mosquito Psorophora discrucians (out of 173) was positive for Haemoproteus. CONCLUSIONS: The occurrence of different Plasmodium lineages in Mansonia mosquitoes indicates that this genus encompasses potential vectors of avian malaria parasites in Brazil, even though we did not find positive thoraces among the samples tested. Additional evidence is required to assign the role of Mansonia mosquitoes in avian malaria transmission and further studies will add information about evolutionary and ecological aspects of avian haemosporidia and untangle the diversity of their vectors in Brazil.
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Culicidae/parasitología , Transmisión de Enfermedad Infecciosa , Malaria Aviar/transmisión , Mosquitos Vectores/parasitología , Plasmodium/aislamiento & purificación , Animales , Aves , Brasil , Bosques , Análisis de Secuencia de ADNRESUMEN
In this study, a total of 4146 culicids collected in an Atlantic Forest area in Paraná state, southern Brazil were examined for the presence of mites. Forty larval Parasitengone mites (Arrenurus spp., Arrenuridae; Durenia spp., Trombellidae; Microtrombidium spp., Microtrombidiidae) parasitized 25 specimens of mosquitoes, with the intensity varying from one to nine mites attached. Most mites were found on Aedes serratus/nubilus, Culex vomerifer, Cx. pedroi and Cx. sacchettae. The overall percentage of parasitized mosquitoes was 0.6 %. The highest intensity of mites encountered was in an individual of Cx. pedroi with nine attached mites. Regarding the attachment site, most mite specimens were attached to the abdomen (n = 25), whereas 15 were located on the thorax. Specimens of Arrenurus spp. were only found on the abdomen of mosquitoes, and the same was observed for Microtrombidium spp., while Durenia spp. attached to both the thorax (n = 15) and abdomen (n = 4). This is the first record for the genus Durenia in Brazil. Additionally, some species of mosquitoes were, for the first time, reported as being parasitized by mites.
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Culicidae/parasitología , Interacciones Huésped-Parásitos , Ácaros/fisiología , Distribución Animal , Animales , Brasil , Femenino , Bosques , Larva/crecimiento & desarrollo , Larva/fisiología , Masculino , Ácaros/crecimiento & desarrolloRESUMEN
BACKGROUND: The merozoite surface protein 1 (MSP1) gene encodes the major surface antigen of invasive forms of the Plasmodium erythrocytic stages and is considered a candidate vaccine antigen against malaria. Due to its polymorphisms, MSP1 is also useful for strain discrimination and consists of a good genetic marker. Sequence diversity in MSP1 has been analyzed in field isolates of three human parasites: P. falciparum, P. vivax, and P. ovale. However, the extent of variation in another human parasite, P. malariae, remains unknown. This parasite shows widespread, uneven distribution in tropical and subtropical regions throughout South America, Asia, and Africa. Interestingly, it is genetically indistinguishable from P. brasilianum, a parasite known to infect New World monkeys in Central and South America. METHODS: Specific fragments (1 to 5) covering 60 % of the MSP1 gene (mainly the putatively polymorphic regions), were amplified by PCR in isolates of P. malariae and P. brasilianum from different geographic origin and hosts. Sequencing of the PCR-amplified products or cloned PCR fragments was performed and the sequences were used to construct a phylogenetic tree by the maximum likelihood method. Data were computed to give insights into the evolutionary and phylogenetic relationships of these parasites. RESULTS: Except for fragment 4, sequences from all other fragments consisted of unpublished sequences. The most polymorphic gene region was fragment 2, and in samples where this region lacks polymorphism, all other regions are also identical. The low variability of the P. malariae msp1 sequences of these isolates and the identification of the same haplotype in those collected many years apart at different locations is compatible with a low transmission rate. We also found greater diversity among P. brasilianum isolates compared with P. malariae ones. Lastly, the sequences were segregated according to their geographic origins and hosts, showing a strong genetic and geographic structure. CONCLUSIONS: Our data show that there is a low level of sequence diversity and a possible absence of allelic dimorphism of MSP1 in these parasites as opposed to other Plasmodium species. P. brasilianum strains apparently show greater divergence in comparison to P. malariae, thus P. malariae could derive from P. brasilianum, as it has been proposed.
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Variación Genética , Proteína 1 de Superficie de Merozoito/genética , Plasmodium/genética , Alelos , Animales , Brasil , Culicidae/parasitología , Humanos , Funciones de Verosimilitud , Filogenia , Plasmodium/aislamiento & purificación , Plasmodium malariae/genética , Polimorfismo GenéticoRESUMEN
RESUMO Objetivo: submeter à análise do conteúdo uma estratégia metacognitiva de avaliação indireta no pré-encontro com o cliente. Método: estudo metodológico. Utilizou-se o índice de concordância e confiabilidade entre juízes para os critérios de pertinência, adequação, clareza, concisão e precisão de uma tecnologia para raciocínio diagnóstico de enfermagem por iniciantes por meio de formulário eletrônico. Fizeram parte da amostra 13 juízes. Os dados foram analisados por estatística descritiva. Resultados: houve alta concordância e confiabilidade interavaliadores para 85 itens relacionados à etapa de coleta de dados e descrição da estratégia. Apenas cinco itens não alcançaram os critérios de validação e devem ser reformulados. Conclusão: a avaliação indireta no préencontro é pertinente ao processo de raciocínio diagnóstico, sendo possível desenvolver habilidades e competências diagnósticas no iniciante por meio de estratégias, propostas em uma tecnologia inovadora sob a forma de diagrama. .
RESUMEN Objetivo: analizar el contenido de una estrategia metacognitiva de la evaluación indirecta en la reunión previa con el cliente. Método: investigación metodológica; se utilizó el índice de concordancia y confiabilidad interevaluadores a los criterios de pertinencia, claridad adecuación, concisión y precisión de una tecnología para el razonamiento diagnóstico de enfermería para los principiantes a través de medios electrónicos. La muestra estuvo conformada por 13 jueces. Los datos fueron analizados utilizando estadística descriptiva. Resultados: alta confiabilidad interevaluadores de 85 artículos relacionados con la etapa de recolección de datos y la descripción de la estrategia. Sólo 05 artículos no alcanzaron los criterios de validación y deben ser modificados. Conclusión: se concluye que la evaluación indirecta en la reunión previa es relevante para el proceso de razonamiento de diagnóstico, es posible desarrollar habilidades y destrezas de diagnóstico a los principiantes a través de estrategias, propuestas sobre la tecnología innovadora en la forma de un diagrama. .
ABSTRACT Objective: to undergo a content analysis of a metacognitive strategy of indirect assessment in the pre-encounter with the client. Method: methodological study. Agreement and inter-rater reliability index for the criteria: relevance, adequacy, clarity, conciseness and accuracy of a technology to the nursing diagnosis reasoning for novices through an electronic form. The sample consisted of 13 raters. Data were analyzed using descriptive statistics. Results: high agreement and inter-rater reliability for 85 items related to data collection stage and the strategy description. Only fi ve items did not reach the validation criteria and must be rewritten. Conclusion: indirect assessment of the pre-encounter is relevant to the diagnostic reasoning process, being possible to develop competencies and diagnostic skills in the novice through strategies, proposals on innovative technology in the form of a diagram. .
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Humanos , Animales , Culicidae/microbiología , Culicidae/parasitología , Malaria Falciparum/prevención & control , Control Biológico de Vectores , Plasmodium falciparum/crecimiento & desarrollo , Wolbachia/fisiología , Interacciones Huésped-Parásitos , Malaria Falciparum/parasitologíaRESUMEN
Introdução:Fragmentos de mata inseridos no cenário urbano podem reunircondições favoráveis à reprodução de espécies de culicideos de importânciaepidemiológica, constituindo aspecto ecológico extraordinário na discussãode processos adaptativos e suas implicações para a saúde pública.Objetivo:Identificar a composição de espécies de mosquitos adultos, frequência,diversidade, dominância e constância. Pretendeu-se ainda verificar aassociação dos mosquitos com temperatura e pluviosidade e discutir suaimportância em saúde pública. Verificar o dimorfismo sexual e descrever avariação morfológica temporal alar de fêmeas da espécie de importânciaepidemiológica mais frequente. Métodos: Foram realizadas duascoletas/mês, em parque ecológico inserido em ambiente urbano domunicípio de Taubaté-SP, entre agosto de 2008 e agosto de 2009,utilizando-se as técnicas de aspiração, CDC e puçá. Foram empregados osíndices de diversidade, dominância e constância. Analisou-se a associaçãoentre temperatura e pluviosidade e abundância de mosquitos, além dasvariações morfológicas da espécie mais frequente com base na morfometriageométrica alar. Resultados: Foram coletados 2.733 exemplares adultos,sendo 1.412 fêmeas e 1.321 machos, distribuídos em seis gêneros e 23espécies. As mais frequentes e abundantes foram: Aedes scapularis(n=1063), Culex bidens (n=728), Culex nigripalpus (n=408), Ae. albopictus(n=130), Psorophora ferox (n=97) e Culex chidesteri (n=82),perfazendoaproximadamente 90% do total de espécimes coletados. Nove espéciesclassificaram-se como constantes, 5 acessórias e as demais acidentais. Os...
Introduction: Fragments of forest embedded in the urban scenario cancreate favorable conditions to the reproduction of culicidae species ofepidemiological importance, constituting an extraordinary ecological aspect inthe discussion of adaptable processes and its implications to the publichealth. Objective: Identify the composition of specimens of adultmosquitoes, analyzing its frequency, diversity, dominance, constancy, anddiscuss those ones of importance in public health. Verify association of theabundance of mosquitoes with abiotic factors, sexual dimorphism and thewing temporal morphological variation of females of the most frequentspecies of epidemiological importance. Methods: Two samples a monthwere collected, in an ecological park inserted in urban environment in themunicipality of Taubaté-SP, from August, 2008 to August 2009, usingtechniques of aspiration, CDC e insect net to capture. Indexes of diversity,dominance and constancy were used. The association of mosquitoabundance with temperature and rainfall was analyzed, besides themorphological variations of the most frequent species with basis in the winggeometric morphometrics. Results: 2.733 adult individuals were collected,being 1.412 females and 1.321 males, distributed in six genders and 23specimens. The most frequent and abundant were: Aedes scapularis(n=1063), Culex bidens (n=728), Cx. nigripalpus (n=408), Ae. albopictus(n=130), Psorophora ferox (n=97) e Cx. chidesteri (n=82), totalizingapproximately 90% of the total of specimens collected. Nine species wereclassified as constant, 5 as accessory and the other ones as accidental. The...
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Biodiversidad , Culicidae/parasitología , Ecología/estadística & datos numéricos , Insectos Vectores/parasitología , BrasilRESUMEN
Mosquitoes are responsible for the transmission of pathogens that cause devastating human diseases such as malaria and dengue. The current increase in mean global temperature and changing sea level interfere with precipitation frequency and some other climatic conditions which, in general, influence the rate of development of insects and etiologic agents causing acceleration as the temperature rises. The most common strategy employed to combat target mosquito species is the Integrated Vector Management (IVM), which comprises the use of multiple activities and various approaches to preventing the spread of a vector in infested areas. IVM programmes are becoming ineffective; and the global scenario is threatening, requiring new interventions for vector control and surveillance. Not surprisingly, there is a growing need to find alternative methods to combat the mosquito vectors. The possibility of using transgenic mosquitoes to fight against those diseases has been discussed over the last two decades and this use of transgenic lines to suppress populations or to replace them is still under investigation through field and laboratory trials. As an alternative, the available transgenic strategies could be improved by coupling suppression and substitution strategies. The idea is to first release a suppression line to significantly reduce the wild population, and once the first objective is reached a second release using a substitution line could be then performed. Examples of targeting this approach against vectors of malaria and dengue are discussed.
Asunto(s)
Animales Modificados Genéticamente , Culicidae/crecimiento & desarrollo , Insectos Vectores , Control de Mosquitos/métodos , Control Biológico de Vectores/métodos , Animales , Culicidae/parasitología , Culicidae/virología , Dengue/prevención & control , Femenino , Malaria/prevención & control , MasculinoRESUMEN
The susceptibility of two fish and four mosquito species to the Caiman yacare haemoparasite Hepatozoon caimani was experimentally investigated. Mosquitoes belonging to four species (Aedes fluviatilis, Aedes albopictus, Aedes aegypti and Culex quinquefasciatus) were blood-fed on two naturally infected C. yacare from the Central-West Region of Brazil that exhibited distinct levels of parasitaemia: caimans A (11.05%) and B (1.25%). None of the engorged A. fluviatilis, A. albopictus or A. aegypti mosquitoes fed on caiman A survived for the duration of the sporogonic cycle; the great majority of the engorged mosquitoes died within 48 h of the blood meal. All A. aegypti fed on caiman B were negative, whereas 91.3% of dissected C. quinquefasciatus fed on the same caiman contained oocysts. Characid fish-Metynnis sp. and Astyanax sp.-were individually fed with C. quinquefasciatus females previously engorged (21-23 days) on caiman B. No parasite was found in the Astyanax fish. By contrast, 100% of the Metynnis fish depicted numerous cysts harbouring cystozoites identical to those of H. caimani, even more than 8 months after the ingestion of the infected mosquitoes. The cysts were located near the veins of the liver and, in some cases, close to the tunica intima of these vessels. No inflammatory reaction was observed. Gametocytes were observed in the blood smears of juvenile caimans that had ingested infected fish 9-12 weeks earlier. The potential role of fish as paratenic vertebrate hosts of H. caimani in nature is discussed.
Asunto(s)
Caimanes y Cocodrilos/parasitología , Culicidae/parasitología , Eucoccidiida/crecimiento & desarrollo , Peces/parasitología , Aedes/parasitología , Animales , Brasil , Culex/parasitología , Femenino , OocistosRESUMEN
The aim of this study was to make the first report on canine heartworm disease in the state of Rondônia and confirm its transmission in this state. Blood samples were randomly collected from 727 dogs in the city of Porto Velho. The samples were analyzed to search for microfilariae and circulating antigens, using three different techniques: optical microscopy on thick blood smears stained with Giemsa; immunochromatography; and PCR. Mosquitoes were collected inside and outside the homes of all the cases of positive dogs and were tested using PCR to search for DNA of Dirofilaria immitis. Ninety-three blood samples out of 727 (12.8%) were positive according to the immunoassay technique and none according to the thick smear method. Among the 93 positive dogs, 89 (95.7%) were born in Porto Velho. No difference in the frequency of infection was observed between dogs raised indoors and in the yard. PCR on the mosquitoes resulted in only one positive pool. This result shows that the transmission of canine heartworm disease is occurring in the city of Porto Velho and that there is moderate prevalence among the dogs. The techniques of immunochromatography and PCR were more effective for detecting canine heartworm than thick blood smears. The confirmation of canine heartworm disease transmission in Porto Velho places this disease in the ranking for differential diagnosis of pulmonary nodules in humans in Rondônia.
O objetivo deste estudo foi de registrar pela primeira vez a dirofilariose canina no estado de Rondônia e confirmar sua transmissão neste estado. Amostras de sangue de 727 cães foram colhidas aleatoriamente na cidade de Porto Velho. As amostras foram analisadas em busca de microfilárias e antígenos circulantes usando três técnicas diferentes: microscopia ótica de gota espessa corada com Giemsa e imunocromatografia de fluxo lateral e PCR. Mosquitos foram colhidos no domicilio e peridomicílio de todos os casos de cães positivos, estes mosquitos foram testados pela PCR na detecção de DNA de Dirofilaria immitis. Noventa e três das 727 amostras de sangue foram positivas na técnica de imunoensaio (12,8%). Nenhuma amostra foi positiva na gota espessa. Entre os 93 cães positivos, 89 (95,7%) foram nascidos em Porto Velho. Nenhuma diferença na frequencia de infecção foi observada entre cães criados dentro da casa ou no quintal. O PCR dos mosquitos resultou em apenas um pool positivo. Este resultado mostra que a transmissão de dirofilariose canina está ocorrendo na cidade de Porto Velho e a frequência que ocorre nos cães é considerada moderada. As técnicas de imunocromatografia e PCR são mais eficazes na detecção de dirofilariose comparadas a gota espessa. A confirmação de transmissão de dirofilariose canina em Porto Velho, coloca esta doença no ranking de diagnóstico diferencial de nódulos pulmonares em seres humanos em Rondônia.