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1.
J Biomed Biotechnol ; 2010: 439174, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20011070

RESUMO

The interaction between Leishmania and sand flies has been demonstrated in many Old and New World species. Besides the morphological differentiation from procyclic to infective metacyclic promastigotes, the parasite undergoes biochemical transformations in its major surface lipophosphoglycan (LPG). An upregulation of beta-glucose residues was previously shown in the LPG repeat units from procyclic to metacyclic phase in Leishmania (Viannia) braziliensis, which has not been reported in any Leishmania species. LPG has been implicated as an adhesion molecule that mediates the interaction with the midgut epithelium of the sand fly in the Subgenus Leishmania. These adaptations were explored for the first time in a species from the Subgenus Viannia, L. (V.) braziliensis with its natural vectors Lutzomyia (Nyssomyia) intermedia and Lutzomyia (Nyssomyia) whitmani. Using two in vitro binding techniques, phosphoglycans (PGs) derived from procyclic and metacyclic parasites were able to bind to the insect midgut and inhibit L. braziliensis attachment. Interestingly, L. braziliensis procyclic parasite attachment was approximately 11-fold greater in the midgut of L. whitmani than in L. intermedia. The epidemiological relevance of L. whitmani as a vector of American Cutaneous Leishmaniasis (ACL) in Brazil is discussed.


Assuntos
Leishmania braziliensis/patogenicidade , Psychodidae/parasitologia , Animais , Sistema Digestório/metabolismo , Sistema Digestório/parasitologia , Glicoesfingolipídeos/química , Glicoesfingolipídeos/isolamento & purificação , Glicoesfingolipídeos/metabolismo , Interações Hospedeiro-Parasita/fisiologia , Estágios do Ciclo de Vida , Microscopia de Fluorescência
2.
J Med Entomol ; 46(5): 1125-30, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19769044

RESUMO

This no-choice, laboratory study focuses on the feeding of dried, ground, homogeneous powdered, unprocessed fruit and leaves of Azadirachta indica and Melia azedarach to Lutzomyia longipalpis larvae to determine the effects on their mortality and metamorphosis. A. indica and M. azedarach fruit and leaves significantly increased larval mortality in comparison to larvae fed the untreated, standard diet. A. indica fruit and leaves blocked the molting of the larvae to the fourth instar, resulting in them remaining as third instars until the end of the experiment. M. azedarach fruit also blocked the molting of larvae, which remained permanently in the fourth instar. Feeding M. azedarach leaves resulted in greater molt inhibition. All insects in this group stopped their development as second-instar larvae. No antifeedant effect was detected for any experimental treatment. The results indicate that nontoxic, unprocessed materials obtained from A. indica and M. azedarach are potent development inhibitors of L. longipalpis larvae.


Assuntos
Azadirachta , Melia azedarach , Metamorfose Biológica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Psychodidae/efeitos dos fármacos , Animais , Frutas , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Folhas de Planta , Psychodidae/crescimento & desenvolvimento
3.
Mem Inst Oswaldo Cruz ; 103(8): 760-7, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19148413

RESUMO

Studies were undertaken on the phlebotomines in the municipalities of Bujari, Xapuri and Rio Branco in the state of Acre. The abundance of species on the ground and in the tree canopy was estimated by Standardized Index of Species Abundance. Of the 52 species identified, Lutzomyia (N.) antunesi, Lutzomyia (N.) whitmani, Lutzomyia (P.) davisi, Lutzomyia migonei, Lutzomyia (N.) umbratilis, Lutzomyia (N.) flaviscutellata, Lutzomyia (T.) ubiqui-talis, Lutzomyia (P.) hirsuta hirsuta, Lutzomyia (P.) paraensis and Lutzomyia (P.) ayrozai are known to be vectors of Leishmania, the causative agent of American cutaneous leishmaniasis. Lutzomyia (T.) auraensis, Lu. (N.) antunesi, Lu. (N.) whitmani and Lu. (P.) davisi accounted for 66.95% of the specimens collected. Lu. (N.) whitmani was the most abundant species, followed by Lu. (N.) antunesi and Lu. (P.) davisi. Lu. (N.) antunesi was the most abundant species in the soil as well as in the canopy. Lu. (N.) umbratilis occurred in all three municipalities and was the fifth most abundant species in the Chico Mendes Municipal Park in Rio Branco. It was collected on both the ground level as well as in the canopy; however, it was more frequently collected in the tree canopy. The present study suggests the existence of three transmission cycles of Leishmania in Acre, including the transmission of Leishmania (V.) guyanensis by Lu. (N.) umbratilis south of the Amazon River.


Assuntos
Insetos Vetores/classificação , Psychodidae/classificação , Animais , Brasil/epidemiologia , Ecossistema , Feminino , Humanos , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/transmissão , Densidade Demográfica
4.
J Vector Ecol ; 43(1): 168-178, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29757525

RESUMO

In southeast Amazon, Lutzomyia (Nyssomyia) flaviscutellata is the incriminated vector of Leishmania (Leishmania) amazonensis, a causative agent of zoonotic cutaneous leishmaniasis (CL). The optimal methods for surveying Lu. flaviscutellata were investigated in the Bragança region, northeast Pará State, Brazil, selected for the presence of Le. amazonensis. The performances of modified Disney traps and CDC light traps were compared in four ecotopes within and around four village transects during the wet and dry seasons. The physiological age of female sand flies was estimated and natural infection by flagellates was evaluated by dissection. Disney traps were better for detecting the presence of Lu. flaviscutellata, while CDC traps performed well for detecting Lutzomyia (Nyssomyia) antunesi, suspected vector of Leishmania lindenbergi. The former was more abundant during the wet season, when female flies were naturally infected with Le. amazonensis. These findings identified the environments of local transmission. In order to improve surveys of Lu. flaviscutellata as part of integrated epidemiological surveillance of CL, our recommendations include focusing vector surveys with Disney traps on forest fragments where people work, during the seasonal peak of the vector. Further field studies are required to make model-based predictions of seasonal variations in the vectorial capacity of vector populations.


Assuntos
Insetos Vetores/parasitologia , Insetos Vetores/patogenicidade , Leishmaniose Cutânea/transmissão , Psychodidae/parasitologia , Psychodidae/patogenicidade , Animais , Brasil , Entomologia , Leishmania/patogenicidade , Leishmaniose Cutânea/parasitologia , Estações do Ano
5.
Cad Saude Publica ; 23(3): 725-30, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17334585

RESUMO

The sand fly fauna in Itatiaia National Park, Rio de Janeiro, Brazil, was investigated in different habitats ranging from sylvatic areas to those altered by human activity related to ecotourism, specifically identifying species that have been suggested as potential leishmaniasis vectors. Sand flies were captured from June 2002 to March 2004, using CDC light traps and Shannon traps. A total of 1,256 sand fly specimens were captured, from species belonging to genera Lutzomyia and Brumptomyia: Brumptomyia guimaraesi, B. troglodytes, Lutzomyia (Lutzomyia) amarali, L. lanei, L. migonei, L. sallesi, L. edwardsi, L. tupynambai, L. (Pintomyia) pessoai, L. (P.) bianchigalatie, L. rupicola, L. (Psathyromyia) shannoni, L. pascalei, L. (Psychodopygus) matosi, L. (P.) davisi, L. (P.) hirsuta hirsuta, L. (P.) ayrozai, L. peresi, L. monticola, and L. misionensis. Worthy of special attention were four species that are considered potential vectors for cutaneous leishmaniasis in Brazil: L. ayrozai, L. hirsuta hirsuta, L. migonei, and L. davisi, representing 19.19% of the specimens captured in this study.


Assuntos
Ecossistema , Insetos Vetores/classificação , Leishmaniose Cutânea/transmissão , Psychodidae/classificação , Animais , Brasil , Humanos , Insetos Vetores/fisiologia , Psychodidae/fisiologia , Especificidade da Espécie
6.
Parasit Vectors ; 10(1): 157, 2017 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-28340594

RESUMO

BACKGROUND: Before 1996 the phlebotomine sand fly Lutzomyia neivai was usually treated as a synonym of the morphologically similar Lutzomyia intermedia, which has long been considered a vector of Leishmania braziliensis, the causative agent of much cutaneous leishmaniasis in South America. This report investigates the likely range changes of both sand fly species in response to a stabilisation climate change scenario (RCP4.5) and a high greenhouse gas emissions one (RCP8.5). METHODS: Ecological niche modelling was used to identify areas of South America with climates currently suitable for each species, and then the future distributions of these climates were predicted based on climate change scenarios. Compared with the previous ecological niche model of L. intermedia (sensu lato) produced using the GARP algorithm in 2003, the current investigation modelled the two species separately, making use of verified presence records and additional records after 2001. Also, the new ensemble approach employed ecological niche modelling algorithms (including Maximum Entropy, Random Forests and Support Vector Machines) that have been widely adopted since 2003 and perform better than GARP, as well as using a more recent climate change model (HadGEM2) considered to have better performance at higher resolution than the earlier one (HadCM2). RESULTS: Lutzomyia intermedia was shown to be the more tropical of the two species, with its climatic niche defined by higher annual mean temperatures and lower temperature seasonality, in contrast to the more subtropical L. neivai. These different latitudinal ranges explain the two species' predicted responses to climate change by 2050, with L. intermedia mostly contracting its range (except perhaps in northeast Brazil) and L. neivai mostly shifting its range southwards in Brazil and Argentina. This contradicts the findings of the 2003 report, which predicted more range expansion. The different findings can be explained by the improved data sets and modelling methods. CONCLUSIONS: Our findings indicate that climate change will not always lead to range expansion of disease vectors such as sand flies. Ecological niche models should be species specific, carefully selected and combined in an ensemble approach.


Assuntos
Mudança Climática , Insetos Vetores , Psychodidae/crescimento & desenvolvimento , Animais , Modelos Teóricos , América do Sul , Análise Espacial , Especificidade da Espécie
7.
J Med Entomol ; 43(2): 262-6, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16619609

RESUMO

The effects of azadirachtin A added to the standard diet on the development, mortality, and metamorphosis of Lutzomyia longipalpis Lutz & Neiva, 1912 were studied. Concentrations of 0.1, 1.0, and 10.0 microg of azadirachtin/mg of diet significantly increased larval mortality in comparison with nontreated insects. Concentrations 0.1 and 1.0 microg blocked the molt of larvae, which remained as third instars until the end of the experiment. The 10 microg/mg concentration resulted in greater molt inhibition. In this group, all insects stopped their development as second instars. Simultaneous addition of ecdysone (1 microg/mg) to the standard diet containing azadirachtin counteracted the effects of azadirachtin on mortality and inhibition of ecdysis. These results indicate that azadirachtin is a potent growth inhibitor of L. longipalpis.


Assuntos
Ecdisona/farmacologia , Inseticidas , Limoninas/farmacologia , Psychodidae/efeitos dos fármacos , Análise de Variância , Animais , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Metamorfose Biológica/efeitos dos fármacos , Muda/efeitos dos fármacos , Mortalidade , Psychodidae/crescimento & desenvolvimento , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Fatores de Tempo
8.
J Med Entomol ; 42(6): 986-92, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16465739

RESUMO

The phlebotomine sand flies Lutzomyia (Nyssomyia) intermedia (Lutz & Neiva) and Lutzomyia (Nyssomyia) whitmani (Coutinho & Antunes) are important vectors of Leishmania (Vianna) braziliensis, the etiological agent of American cutaneous leishmaniasis. In some areas, both species occur in sympatry, and their relative roles as vectors in these areas are not clear. We studied the nocturnal activity and biting rhythms of both species in Posse, a locality in Rio de Janeiro State, Brazil. Our results show differences between the activity patterns of Lu. intermedia and Lu. whitmani that might be epidemiologically important. Although the activity profiles vary between seasons and microhabitats (peridomestic versus forest), the two species show marked differences in their tendencies to bite humans in the early morning (0400-0600 hours), with Lu. whitmani showing higher feeding rates than Lu. intermedia.


Assuntos
Ciclos de Atividade/fisiologia , Insetos Vetores/fisiologia , Psychodidae/fisiologia , Estações do Ano , Temperatura , Árvores , Animais , Brasil , Feminino , Humanos , Leishmaniose Cutânea/transmissão , Masculino , Especificidade da Espécie
9.
PLoS One ; 10(11): e0143282, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26619186

RESUMO

Vector borne diseases are susceptible to climate change because distributions and densities of many vectors are climate driven. The Amazon region is endemic for cutaneous leishmaniasis and is predicted to be severely impacted by climate change. Recent records suggest that the distributions of Lutzomyia (Nyssomyia) flaviscutellata and the parasite it transmits, Leishmania (Leishmania) amazonensis, are expanding southward, possibly due to climate change, and sometimes associated with new human infection cases. We define the vector's climatic niche and explore future projections under climate change scenarios. Vector occurrence records were compiled from the literature, museum collections and Brazilian Health Departments. Six bioclimatic variables were used as predictors in six ecological niche model algorithms (BIOCLIM, DOMAIN, MaxEnt, GARP, logistic regression and Random Forest). Projections for 2050 used 17 general circulation models in two greenhouse gas representative concentration pathways: "stabilization" and "high increase". Ensemble models and consensus maps were produced by overlapping binary predictions. Final model outputs showed good performance and significance. The use of species absence data substantially improved model performance. Currently, L. flaviscutellata is widely distributed in the Amazon region, with records in the Atlantic Forest and savannah regions of Central Brazil. Future projections indicate expansion of the climatically suitable area for the vector in both scenarios, towards higher latitudes and elevations. L. flaviscutellata is likely to find increasingly suitable conditions for its expansion into areas where human population size and density are much larger than they are in its current locations. If environmental conditions change as predicted, the range of the vector is likely to expand to southeastern and central-southern Brazil, eastern Paraguay and further into the Amazonian areas of Bolivia, Peru, Ecuador, Colombia and Venezuela. These areas will only become endemic for L. amazonensis, however, if they have competent reservoir hosts and transmission dynamics matching those in the Amazon region.


Assuntos
Distribuição Animal , Mudança Climática , Ecossistema , Modelos Estatísticos , Psychodidae/fisiologia , Animais , Vetores de Doenças , América do Sul
10.
J Med Entomol ; 39(4): 587-600, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12144289

RESUMO

We analyzed 64 quantitative and qualitative morphological characters in different populations of Lutzomyia (Nyssomyia) umbratilis Ward & Fraiha from Venezuela (Gran Sabana, Bolívar/BO) and Brazil (Serra do Navio, Amapá/AP Manaus, Amazonas/AM, Monte Dourado, Pará/ PA, and Peixoto de Azevedo, Mato Grosso/MT). Based on an analysis of qualitative characters, no differences were observed that could distinguish between the populations. Parametric tests were used to verify differences between sample means and variance homogeneity. The analysis-of-variance (ANOVA) test showed the existence of differences between character means in the five populations. In the graphic representation of the Student-Newman-Keuls test (Student-Newman-Keuls), we observed that 77% of the analyzed characters displayed disjunctions between the Venezuelan and Brazilian populations. Considering only the Brazilian population averages, we concluded that they are statistically different. When the Student-Newman-Keuls test was applied, no pattern was found that could separate them. However, in part, the phenetic analysis showed some evidences of heterogeneity in MT population.


Assuntos
Psychodidae/anatomia & histologia , Animais , Brasil , Feminino , Masculino , Psychodidae/classificação , Venezuela
11.
PLoS One ; 6(12): e27721, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22163271

RESUMO

BACKGROUND: Although leishmaniases are regarded as serious public health issues in the State of Tocantins, as consequence of the impact of environmental changes, small advances in taxonomic and ecological studies of Phlebotominae fauna are taking place in this state. The present study aimed to improve the knowledge about the sand flies, as well as about the aspects of the bioecology of leishmaniases vectors from Porto Nacional, a city that was directly impacted by the construction of Luís Eduardo Magalhães Hydroelectric Plant (HEP-Lajeado). METHODOLOGY/PRINCIPAL FINDINGS: Sand flies were collected monthly using CDC light traps and Shannon traps for a period of 40 consecutive months, at different monitoring stations, where 7162 specimens were collected and 48 species were detected. Among the species found, 22 are first records in the state and seven are considered important vectors of leishmaniases. Lutzomyia longipalpis, the vector of American Visceral Leishmaniasis (AVL) showed higher frequency in urban compared to rural areas, and Nyssomyia whitmani, the vector of American Cutaneous Leishmaniasis (ACL), predominated in rural areas. The frequency and habits of sand fly vectors are discussed considering environmental characteristics and climatic factors. CONCLUSIONS/SIGNIFICANCE: The construction of dams requires a great amount of labor, therefore attracting people from elsewhere. Increased migration, without adequate structure, leads to bad living conditions in new and unplanned settlements. It also leads to deforestation associated with environmental impacts, which can facilitate the spread of leishmaniases. This study discusses the importance of Lu. longipalpis and Ny. whitmani on the transmission cycles of leishmaniases in Porto Nacional and the record of Bi. flaviscutellata in periurban area of the city.


Assuntos
Leishmaniose Cutânea/transmissão , Leishmaniose Visceral/transmissão , Psychodidae/fisiologia , Animais , Brasil , Cidades , Meio Ambiente , Monitoramento Ambiental , Feminino , Humanos , Insetos Vetores , Masculino , Modelos Estatísticos , Densidade Demográfica , Estações do Ano
12.
Acta Trop ; 120(3): 273-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21939631

RESUMO

In order to determine natural Leishmania (Viannia) infection in Lutzomyia (Pintomyia) fischeri, a multiplex PCR methodology coupled to non-isotopic hybridization was adopted for the analysis of sand fly samples collected by CDC light traps in an endemic area of American Cutaneous Leishmaniasis (ACL) in the periurban region of the municipality of Porto Alegre, Rio Grande do Sul State, Brazil. We analyzed by PCR methodology 560 specimens of Lutzomyia (Pintomyia) fischeri (520 females and 40 males). The wild sand flies were grouped into 56 pools (52 females and 4 males) of 10 each, and positive results were detected in 2 of the 52 female pools, representing a minimum infection rate of 0.38% based on the presence of at least 1 infected insect in the pool. This result associated with some local evidence such as anthopophily, spatial distribution in accordance with the transmission area and human case incidence, suggests that L. (P.)fischeri may be considered as a secondary vector of ACL in the studied locality.


Assuntos
Vetores de Doenças , Leishmania/isolamento & purificação , Leishmaniose Cutânea/transmissão , Psychodidae/parasitologia , Animais , Brasil , DNA de Protozoário/genética , Feminino , Masculino , Reação em Cadeia da Polimerase Multiplex/métodos
13.
Am J Trop Med Hyg ; 80(4): 593-5, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19346382

RESUMO

To identify Lutzomyia (Nyssomyia) neivai naturally infected by Leishmania a multiplex polymerase chain reaction (PCR) was used for the analysis of 450 specimens (270 females, 180 males) collected in an endemic periurban area of cutaneous leishmaniasis in Porto Alegre, Brazil. Insects were grouped into pools of 10 and positive results were achieved in 3/27 Lu. (N.) neivai female pools. Infection by L. (Viannia) braziliensis was confirmed after hybridizing PCR products with a subgenus-specific biotinylated probe. Considering the detection of three positive pools with at least one infected insect in each, an infection rate of 1.1% was estimated. Our results associated with epidemiologic data suggest a potential ability of Lu. (N.) neivai in transmitting L. braziliensis in Porto Alegre, where the first notifications of autochthonous cutaneous leishmaniasis in humans occurred in 2002, with an increase in the number of cases in recent years possibly as a consequence of deforestation and agricultural activities in the area.


Assuntos
Leishmania braziliensis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Psychodidae/parasitologia , Animais , Brasil , DNA de Protozoário/análise , Demografia , Feminino , Leishmania braziliensis/genética , Masculino
14.
Cad Saude Publica ; 24(12): 2948-52, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19082287

RESUMO

The article discusses habits related to the vectorial competence of Lutzomyia longipalpis, along with evidence confirming the importance of this sand fly species in the epidemiological chain of visceral leishmaniasis in Brazil. A new epidemiological profile for visceral leishmaniasis is also postulated, associated with domestic environments and the role of Lu. longipalpis in this process, its sylvatic origin, and its capacity to adapt to a wide range of habitats. Another sand fly species, Lu. cruzi, is mentioned as a vector of visceral leishmaniasis in some municipalities in Central Brazil, based on studies in endemic areas of the country.


Assuntos
Insetos Vetores/fisiologia , Leishmaniose Visceral/transmissão , Psychodidae/fisiologia , Animais , Brasil/epidemiologia , Humanos , Insetos Vetores/classificação , Leishmaniose Visceral/epidemiologia , Psychodidae/classificação , Urbanização
15.
Neotrop Entomol ; 37(5): 597-601, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19061048

RESUMO

The bacterial community associated with the midgut of three Brazilian Lutzomyia longipalpis (Lutz & Neiva) populations, two from endemic areas for visceral leishmaniasis (Jacobina, Bahia State and São Luís, Maranhão State) and one from a non-endemic area (Lapinha Cave, Minas Gerais State), was identified. Five groups, 35 females each, from each population were separated; a total of 175 females per collecting area were analyzed. The species identification was based on molecular and traditional bacteriological methods. All bacteria were either affiliated to non-Enterobacteriaceae, such as Acinetobacter, Burkholderia, Flavimonas, Pseudomonas and Stenotrophomonas, or and to Enterobacteriaceae, such as Citrobacter, Enterobacter, Escherichia, Klebsiella, Serratia, Pantoea, Morganella and Weeksella. Stenotrophomonas was found to be associated with all three populations studied. In addition, Serratia spp., which are well documented as laboratory contaminant of insects, were detected only in the Jacobina population. We also discuss the impact of the colonization of insect gut by bacteria on the development and transmission of pathogens.


Assuntos
Psychodidae/microbiologia , Animais , Brasil
16.
Mem Inst Oswaldo Cruz ; 102(2): 149-53, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17426877

RESUMO

The aim of the present study, in view of the widespread geographical distribution of Lutzomyia (Nyssomyia) whitmani s.l. in Brazil, in close association with the regions of transmission of Leishmania (Viannia) braziliensis and L. (V.) shawi, is to investigate the distribution of this sand fly species and American cutaneous leishmaniasis (ACL) in relationship to vegetation and landscape ecology throughout Brazil. Thematic maps were elaborated by the MapInfo programme, giving information on the spatial distribution of L. whitmani s.l., in accordance with types of vegetation and foci of ACL. With regards to the known areas of transmission of ACL in Brazil, it is notable that L. (N.) whitmani s.l. occurs in most of them, where it has been implicated as a possible vector of L. (V.) braziliensis. The presence of L. whitmani s.l. has been registered in 26 states, the one exception being Santa Catarina; in some states such as Roraima, Acre, Tocantins, and Mato Grosso do Sul this sand fly species has been recorded in a large number of municipalities. L. whitmani s.l. has been found in association with a variety of vegetation types, including the Amazonian forest, savanna ("campos cerrados"), and northeastern savanna ("caatingas nordestinas" or "savana estépica").


Assuntos
Insetos Vetores/fisiologia , Leishmania braziliensis , Leishmaniose Cutânea/epidemiologia , Psychodidae/fisiologia , Animais , Brasil/epidemiologia , Ecossistema , Geografia , Humanos , Insetos Vetores/parasitologia , Leishmaniose Cutânea/transmissão , Dinâmica Populacional , Psychodidae/parasitologia , Árvores
17.
Mem Inst Oswaldo Cruz ; 101(8): 851-6, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17293978

RESUMO

Lutzomyia longipalpis females received single and mixed infections with Endotrypanum and Leishmania. Two biological parameters were analyzed: the percentage of infected females and the distribution of flagellates in the gut of the females. The principal comparisons were performed between (1) two strains of Endotrypanum, (2) cloned versus primary sample of one strain of Endotrypanum, (3) Endotrypanum versus Leishmania guyanensis, and (4) the pattern of flagellates behaviour by optical microscopy in females with single or mixed infection versus the identification of parasites isolated from digestive tracts by isoenzyme electrophoresis. Flagellates of Endotrypanum showed distinct patterns of infection suggesting that there is variation between and within strains. The distribution of Endotrypanum and L. guyanensis differed significantly in relation to the colonization of the stomodeal valve. In co-infection with L. guyanensis, a large number of flagellates were seen to be plentifully infecting the stomodeal valve in significantly more specimens than in females infected by Endotrypanum only. However, the electrophoretic profiles of isoenzymes of parasites recovered from all co-infected specimens corresponded to Endotrypanum. This suggests that the mere correlation sand fly infection-biochemical analysis of isolates may induce parasitological incorrect consideration.


Assuntos
Leishmania guyanensis/patogenicidade , Psychodidae/parasitologia , Trypanosomatina/patogenicidade , Animais , Sistema Digestório/parasitologia , Eletroforese em Gel de Ágar , Feminino , Citometria de Fluxo , Interações Hospedeiro-Parasita , Isoenzimas/análise , Leishmania guyanensis/enzimologia , Leishmania guyanensis/isolamento & purificação , Trypanosomatina/enzimologia , Trypanosomatina/isolamento & purificação
18.
Mem Inst Oswaldo Cruz ; 100(8): 811-27, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16444411

RESUMO

An historical review is given of American visceral leishmaniasis (AVL), with particular reference to the eco-epidemiology of the disease in Brazil. Following the first records of AVL in this country, in 1934, the sandfly Lutzomyia longipalpis (Lutz and Neiva, 1912) was incriminated as the principal vector. It is now generally accepted, however, that there exist a number of cryptic species under the name of Lu. longipalpis s.l. and that variations in the quantity of the vasodilatory peptide maxadilan in the saliva of flies from different populations of Lu. longipalpis s.l., may account for the variable clinical manifestations of AVL seen in different geographic regions. Distribution of AVL has been shown to extend throughout most of South and Central America, with the domestic dog serving as the principal reservoir of infection for man. However, while one hypothesis suggests that the causative parasite is Leishmania infantum, imported from Europe with the Portuguese and Spanish colonists, the demonstration of a high rate of benign, inapparent infection in foxes in Amazonian Brazil raised an opposing suggestion that the parasite is indigenous to the Americas. Recent reports of similar infections in native marsupials, and possibly rodents, tend to support this view, particularly as Lu. longipalpis is primordially a silvatic sandfly. Although effective control measures in foci of the disease will diminish the number of canine and human infections, the presence of such an enzootic in a variety of native animals will render the total eradication of AVL unlikely.


Assuntos
Doenças Endêmicas , Insetos Vetores/parasitologia , Leishmania donovani , Leishmaniose Visceral/epidemiologia , Psychodidae/parasitologia , Animais , Brasil/epidemiologia , Cães , Ecossistema , Feminino , Humanos , Proteínas de Insetos/fisiologia , Insetos Vetores/classificação , América Latina/epidemiologia , Leishmania donovani/classificação , Leishmaniose Visceral/transmissão , Masculino , Psychodidae/classificação , Proteínas e Peptídeos Salivares/fisiologia
19.
Mem Inst Oswaldo Cruz ; 100(1): 39-42, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15867961

RESUMO

Lutzomyia intermedia (Lutz & Neiva, 1912) and L. whitmani (Antunes & Coutinho, 1939) (Diptera: Psychodidae: Phlebotominae), two important vectors of American cutaneous leishmaniasis in Brazil, occur in sympatry in the locality of Posse county, Petropolis municipality, state of Rio de Janeiro, Brazil. We investigated the influence of the lunar cycle on the frequency of specimens of the two species caught while attempting to bite the collectors and in CDC light traps. Analysis of the numbers of sand flies captured in different lunar phases for two consecutive years in the peridomestic site and forest shows that there is a significant positive correlation between moonlight intensity and the numbers of L. intermedia and L. whitmani females collected while blood-feeding, whereas the opposite was observed for the CDC traps.


Assuntos
Comportamento Alimentar/fisiologia , Insetos Vetores/fisiologia , Luz , Lua , Psychodidae/fisiologia , Animais , Brasil , Feminino , Humanos , Leishmaniose Cutânea/transmissão , Estações do Ano
20.
Mem Inst Oswaldo Cruz ; 97(6): 759-65, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12386692

RESUMO

Lutzomyia intermedia and Lutzomyia whitmani occur sympatrically in the district of Posse, municipality of Petrópolis, in the State of Rio de Janeiro (114 km from the city of Rio de Janeiro), where sand flies were captured weekly for three consecutive years in both the peridomicile and forest, in two first years from 18:00 to 22:00 h, using a Shannon trap and CDC light traps. The anthropophilic habit was assessed by recording the specimens that bit the human captors. Considering the different capture types and sites, the following species were identified: Brumptomyia brumpti, B. cardosoi, B. guimaraesi, Lutzomyia amarali, L. longipalpis, L. microps, L. costalimai, L. edwardsi, L. firmatoi, L. migonei, L. termitophila, L. tupynambai, L. fischeri, L. pessoai, L. lutziana, L. shannoni, L. barrettoi, L. intermedia, L. whitmani, L. lloydi, and L. minasensis. L. intermedia (38.3%) and L. whitmani (38.6%) predominated. L. intermedia predominated in the peridomicile, where it displayed more intense anthropophily, while L. whitmani displayed greater density in the banana plantations and forest, preferential sites for biting humans. Studies on seasonality showed that while L. intermedia displayed greater density in the hottest months of the year (December, January, and February), L. whitmani was abundant in the coolest months (June, July, and August), although both occurred throughout the year.


Assuntos
Insetos Vetores , Leishmaniose Cutânea/transmissão , Psychodidae , Estações do Ano , Animais , Brasil , Feminino , Habitação , Humanos , Masculino , Saúde da População Rural , Árvores
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