Human leishmaniasis in Brazil: A general review / Leishmaniose humana no Brasil: uma revisão geral

Summary Leishmaniasis is a disease with ample clinical spectrum and epidemiological diversity and is considered a major public health problem. This article presents an overview of the transmission cycles, host-parasite interactions, clinical, histological and immunological aspects, diagnosis and treatment of various forms of the human disease.

Resumo A leishmaniose representa um complexo de doenças com amplo espectro clínico e diversidade epidemiológica, sendo considerada um grande problema de saúde pública. O presente artigo apresenta uma revisão geral sobre os ciclos de transmissão, as interações parasito-hospedeiro, os aspectos clínicos, histopatológicos e imunológicos, o diagnóstico e o tratamento das diversas formas da doença humana.

Aspectos ecoepidemiológicos, detección natural e identificación molecular de Leishmania spp. en Lutzomyia reburra, Lutzomyia barrettoi majuscula y Lutzomyia trapidoi / Eco-epidemiological aspects, natural detection and molecular identification of Leishmania spp. in Lutzomyia reburra, Lutzomyia barrettoi majuscula and Lutzomyia trapidoi

Resumen Introducción. La provincia de Pichincha, Ecuador, es un área endémica de leishmaniasis cutánea, en donde se han determinado como vectores los flebotomíneos antropofílicos con infección natural por Leishmania spp. Sin embargo, no se ha evaluado el papel en la transmisión de las especies zoofílicas. Objetivo. Evaluar la infección natural por Leishmania en dos especies de flebotomíneos zoofílicos, Lutzomyia reburra y Lu. barrettoi majuscula, y en una antropofílica, Lu. trapidoi, así como la endofagia y la sinantropía de estas especies en el noroccidente de Pichincha. Materiales y métodos. Los flebotomíneos se recolectaron en trampas de luz CDC colocadas en diferentes hábitats y altitudes en sitios que son focos de leishmaniasis cutánea. La infección con Leishmania spp. se detectó en el ADN genómico de hembras de las especies de flebotomíneos de interés. Se amplificó el gen espaciador interno de la transcripción del ARN ribosómico, unidad I (ITS1), y los genes de las topoisomerasas mitocondrial II (mtTOPOII) y nuclear II (TopoII). Se determinaron los porcentajes de positividad para Leishmania a escala espaciotemporal, la proporción de endofagia y el índice de sinantropía. Resultados. Se determinó la presencia de infección natural por Le. amazonensis en Lu. reburra (9,5 %) y Lu. b. majuscula (23,8 %); en Lu. trapidoi se detectaron Le. amazonensis, Le. brazilienis y Le. naiffilainsoni. Los flebotomíneos eran asinantrópicos y con baja endofagia. Conclusión. Se registró por primera vez la presencia de infección natural en Lu. reburra y Lu. barrettoi majuscula por Le. amazonensis, y se demostró la importancia de los flebotomíneos zoofílicos en el mantenimiento del ciclo de transmisión de Leishmania spp. en focos endémicos.

Abstract Introduction: The province of Pichincha in Ecuador is an endemic area of cutaneous leishmaniasis, where anthropophilic sand flies with natural infection by Leishmania, have been reported as vectors. However, the role in transmission of zoophilic species has not been evaluated. Objective: To evaluate natural infection by Leishmania in two zoophilic phlebotomine sand fly species, Lutzomyia reburra and Lu. barrettoi majuscula, and one anthropophilic species, Lu. trapidoi, as well as the endophagy and synanthropism of these species in the northwest of Pichincha. Materials and methods: Phlebotomines were collected using CDC light traps in different habitats and altitudes with presence of cutaneous leishmaniasis. Leishmania infection was detected using genomic DNA from females of the collected sand flies. We amplified the internal transcribed spacer gene of ribosomal RNA I (ITS1), the mitochondrial topoisomerase II gene (mtTOPOII), and the nuclear topoisomerase II gene (TopoII). Percentages of positivity for Leishmania, at spatio-temporal scale, proportion of endophagy and synanthropism index were calculated. Results: Natural infection was determined for Le. amazonensis in Lu. reburra (9.5%) and Lu. b. majuscula (23.8%), while in Lu. trapidoi we detected Le. amazonensis, Le. brazilienis and Le. naiffilainsoni. Phlebotomines were asynanthropic and with low endophagy. Conclusion: Natural infection with Le. amazonensis was recorded for the first time in Lu. reburra and Lu. b. majuscula, demonstrating the importance of zoophilic phlebotomines in the maintenance of the Leishmania transmission cycle in endemic foci.

Effect of Leishmania spp infection on the survival, life expectancy, fecundity and fertility of Lutzomyia longipalpiss.l. and Lutzomyia pseudolongipalpis

We evaluated the effects of Leishmaniaspp infection on several population parameters of Lutzomyia longipalpis sensu lato andLutzomyia pseudolongipalpis, vectors of visceral leishmaniasis in Venezuela, under experimental conditions during the first post-feeding period. Females of both species were allowed to feed and engorge on a suspension of fresh washed human red blood cells in foetal calf serum. These blood cells were either non-infected or infected with one of the fourLeishmaniaspp strains and were offered through a chicken skin membrane. The longevity, life expectancy and the fecundity of uninfected flies were similar in both species, but the fertility was significantly lower in uninfected Lu. longipalpis females. In all cases, the infection of Lu. longipalpis and Lu. pseudolongipalpis by the Leishmaniastrains resulted in significant detrimental effects, which exerted a fitness cost expressed by reduced survival and life expectancy, as well as decreased fertility and fecundity compared with the control groups. Nevertheless, differences in these parameters were observed between these vector species depending on whether they were infected with the autochthonous Venezuelan Leishmania infantum strain (NESA) or the Brazilian reference strain (PP75). The experimental data obtained agree with field data on the natural infection of these vector species and the significance of this scenario is discussed.

Peripheral blood fibrocytes: new information to explain the dynamics of Leishmania infection

Fibrocytes are important for understanding the progression of many diseases because they are present in areas where pathogenic lesions are generated. However, the morphology of fibrocytes and their interactions with parasites are poorly understood. In this study, we examined the morphology of peripheral blood fibrocytes and their interactions with Leishmania (L.) amazonensis . Through ultrastructural analysis, we describe the details of fibrocyte morphology and how fibrocytes rapidly internalise Leishmania promastigotes. The parasites differentiated into amastigotes after 2 h in phagolysosomes and the infection was completely resolved after 72 h. Early in the infection, we found increased nitric oxide production and large lysosomes with electron-dense material. These factors may regulate the proliferation and death of the parasites. Because fibrocytes are present at the infection site and are directly involved in developing cutaneous leishmaniasis, they are targets for effective, non-toxic cell-based therapies that control and treat leishmaniasis.

Protease inhibitors in potential drug development for leishmaniasis.

Leishmaniasis is a deadly protozoan parasitic disease affecting millions of people worldwide. The treatment strategy of Leishmania infection depends exclusively on chemotherapy till date. But the treatment of the disease is greatly hampered due to high cost, toxicity of the available drugs and more importantly emergence of drug resistance. Hence the potential new drugs are highly needed to combat this disease. The first and foremost step of the drug discovery process is to search and select the putative target in a specific biological pathway in the parasite that should be either unambiguously absent in the host or considerably different from the host homolog. Importantly, Leishmania genome sequences enrich our knowledge about Leishmania and simultaneously reinforce us to identify the ideal drug targets that distinctly exist in the parasite as well as to develop the effective drugs for leishmaniasis. Though the leishmanial research has significantly progressed during the past two decades, the identification of suitable drug targets or development of effective drugs to combat leishmaniasis is far from satisfactory. Enzymatic systems of Leishmania metabolic and biochemical pathways are essential for their survival and infection. Concurrently, it is noteworthy that Leishmania proteases, especially the cysteine proteases, metalloproteases and serine proteases have been extensively investigated and found to be indispensable for the survival of the parasites and disease pathogenesis. Herein, we have discussed the importance of few enzymes, particularly the Leishmania proteases and their inhibitors as promising candidates for potential development of anti-leishmanial drugs.

Desorganização da polpa branca esplênica está associada com a apresentação clínica mais grave da leishmaniose visceral em cães naturalmente infectados / Disorganization of the splenic white pulp is associated with more severe clinical presentation of visceral leishmaniasis in naturally infected dogs

O baço é o maior órgão linfoide secundário em seres humanos e em cães. Em ambos, a ausência do baço está associada com um risco aumentado de ocorrência de infecções localizadas e disseminadas, incluindo sepse generalizada. A leishmaniose visceral e outras infecções podem alterar a estrutura histológica do baço, o que leva a uma destruição dos microambientes da polpa branca. Trabalhos anteriores mostraram que a uptura da estrutura de polpa branca é mais frequente em cães com marcadores laboratoriais de suscetibilidade à leishmaniose visceral, como a cultura esplênica positiva e LST negativo, do que nos animais em que estes marcadores de susceptibilidade estavam ausentes. Neste estudo, o nosso objetivo é examinar a relação entre a desorganização histológica da polpa branca esplênica e a gravidade da leishmaniose visceral. As amostras e os dados utilizados neste estudo foram coletados de 206 cães de rua provenientes de uma área endêmica para leishmaniose visceral, a cidade de Jequié (Bahia, Brasil). Os animais foram examinados clinicamente e foram realizados os testes ELISA e LST. Aspirados de baço foram coletados para a cultura, e fragmentos de baço foram coletadas para estudos de biologia molecular e de estudos morfológicos. Os animais foram classificados de acordo com o grau de organização estrutural da polpa branca esplênica em grupos com baço (a), bem organizado, (b) ligeiramente desorganizado, (c) a moderadamente a extensivamente desorganizado. Em relação à positividade no ELISA juntamente com a desorganização do baço, conjuntivite ( P= 0,0116), hiperproteinemia (p= 0,021) foram mais frequentes no grupo de animais com ELISA positivo e baço desorganizado, quando comparado com os outros grupos. Os animais polissintomáticos são mais frequentes no grupo com ELISA positivo e baço do tipo 3 (p= 0,004). Os scores clínicos atribuídos à intensidade da conjuntivite (P <0,05), dermatite (P <0,05) e linfadenopatia (P <0,01), alopecia (P <0,01), onicogrifose (P <0,05) foram mais elevados nos animais com ELISA positivo e baço desorganizado do que outros grupos, bem como o número de sinais clínicos atribuíveis à leishmaniose visceral canina (p= 0,0014).Em relação à análise da positividade na cultura esplênica juntamente com a desorganização do baço, a frequência de cães polissintomáticos foi maior em animais com baço ligeiramente desorganizado (P <0,05) e baço desorganizado (P <0,005), do que em animais com baço organizado. Alopecia (P <0,01), conjuntivite (P <0,05), desidratação (P <0,001), dermatite (P <0,05), onicogrifose (p <0,01), anemia (P <0,05), úlcera (P <0,001) e alto escore clínico (P <0,001) foram mais frequentes em animais com cultura esplênica positiva e baço desorganizado, do que nos animais com cultura negativa e baço organizado. Em conclusão, os cães com desorganização do baço associada com leishmaniose visceral têm mais sinais clínicos e pior estado clínico do que os animais com leishmaniose visceral, mas sem desorganização do baço.

Current relevance of fungal and trypanosomatid glycolipids and sphingolipids: studies defining structures conspicuously absent in mammals

Recently, glycosphingolipids have been attracting attention due to their role on biological systems as second messengers or modulators of signal transduction, affecting several events, which range from apoptosis to regulation of the cell cycle. In pathogenic fungi, glycolipids are expressed in two classes: neutral monohexosylceramides (glucosyl-or galactosylceramide) and acidic glycosylinositol phosphorylceramides (the latter class carries longer glycan chains). It is worth to mention that monohexosylceramides exhibit significant structural differences in their lipid moieties compared to their mammalian counterparts, whereas the glycosylinositol phosphorylceramides exhibit remarkable structural differences in their carbohydrate moieties in comparison to mammal glycosphingolipids counterpart. We observed that glycosylinositol phosphorylceramides are capable of promoting immune response in infected humans. In addition, inhibiting fungal glycosphingolipid biosynthetic pathways leads to an inhibition of colony formation, spore germination, cell cycle, dimorphism and hyphal growth. Other pathogens, such as trypanosomatids, also present unique glycolipids, which may have an important role for the parasite development and/or disease establishment. Regarding host-pathogen interaction, cell membrane rafts, which are enriched in sphingolipids and sterols, participate in parasite/fungal infection. In this review, it is discussed the different biological roles of (glyco) (sphingo) lipids of pathogenic/opportunistic fungi and trypanosomatids.

Recentemente, glicoesfingolipídeos têm atraído atenção devido ao seu papel na biologia celular como segundo-mensageiro ou moduladores da transdução de sinal, afetando vários eventos, desde apoptose até a regulação do ciclo celular. Em fungos patogênicos, existem duas classes de glicolipídeos: monohexosil ceramidas neutras (glucosil-ou galactosilceramida) e glicosilinositol fosforilceramidas (os quais apresentam cadeias de carboidratos mais longas). É importante enfatizar que as monohexosil ceramidas exibem diferenças estruturais nas suas porções lipídicas quando comparadas às de mamíferos, enquanto que glicosilinositol fosforilceramidas exibem diferenças estruturais marcantes em suas porções carboidratos em comparação aos glicoesfingolipídeos de mamíferos. Observamos também que glicosilinositol fosforilceramidas são capazes de promover resposta imune em indíviduos infectados. Além do mais, inibição das vias biossintéticas de glicoesfingolipídeos de fungos acarreta a inibição da formação de colônias, germinação de esporos, ciclo celular, dimorfismo e crescimento de hifas. Outros patógenos, como os tripanosomatídeos, também apresentam glicolipídeos únicos, os quais apresentam um papel importante para o desenvolvimento do parasita e/ou para o estabelecimento da doença. Em relação à interação hospedeiro-patógeno, os "membrane rafts", estruturas da membrana plasmática enriquecidas em esfingolipídeos e esteróis, têm participação fundamental na infecção do parasita/fungo. Nesta revisão, discutimos os diferentes papéis biológicos dos (glico) (esfingo) lipídeos de fungos patogênicos/oportunistas e de tripanosomatídeos.

Preferência alimentar sanguínea de flebotomíneos da Amazônia do Maranhão, Brasil / Feeding preference of sand flies in the Amazon, Maranhão State, Brazil

O objetivo deste estudo foi determinar as fontes alimentares sanguíneas de flebotomíneos por meio da reação da precipitina, em Buriticupu, na Amazônia maranhense, Brasil, de julho de 2002 a junho de 2004. Foram detectadas reações simples (87,6 por cento), duplas (8 por cento) e não reagentes (4,4 por cento). A presença de flebotomíneos alimentados com sangue humano (6,7 por cento) e de possíveis reservatórios de Leishmania no peridomicílio ajuda a explicar a ocorrência de casos autóctones de leishmaniose tegumentar no Município de Buriticupu.

The objective of this study was to determine the blood feeding sources for sand flies based on the precipitin test in Buriticupu, Amazon Region, Maranhão State, Brazil, from July 2002 to June 2004. Single (87.6 percent) and double (8 percent) reactions and non-reactive samples (4.4 percent) were found. The presence of sand flies fed on human blood (6.7 percent) and blood of animals that are possible peridomiciliary Leishmania reservoirs helps explain the reporting of autochthonous tegumentary leishmaniasis cases in Buriticupu.

Distribuição geográfica e características epidemiológicas da leishmaniose tegumentar americana em áreas de colonização antiga do Estado do Paraná, Sul do Brasil / Geographic distribution and epidemiological features of American tegumentary leishmaniasis in old rural settlements in Paraná State, Southern Brazil

Analisa-se a epidemiologia da leishmaniose tegumentar americana em municípios das mesorregiões norte central, centro ocidental e noroeste do Estado do Paraná, Brasil. O diagnóstico dos casos de leishmaniose tegumentar americana foi realizado na Universidade Estadual de Maringá, de 1987 a 2004. Conforme o provável local de infecção, os casos foram divididos em autóctones (infectaram-se no domínio doméstico) ou alóctones (infectaram-se fora do domínio doméstico). Observou-se que em todos os anos do período houve atendimento de casos provenientes das mesorregiões supracitadas. Os municípios com maior número de casos notificados foram Maringá (458), Doutor Camargo (126), São Jorge do Ivaí (121), Terra Boa (114), Cianorte (98) e Colorado (95). De 1.938 casos, 66,9 por cento eram do sexo masculino. Entre 667 casos autóctones, o número de mulheres afetadas pela doença foi semelhante ao de homens, com casos em menores de cinco anos de idade, fatos que não ocorreram entre os 794 casos alóctones. As condições necessárias à produção da leishmaniose tegumentar americana foram criadas no processo de construção do espaço rural das mesorregiões em pauta, particularmente no modelo de colonização e na crise da monocultura cafeeira.

This study analyzes the epidemiology of American tegumentary leishmaniasis in the municipalities of the Central North, Central West, and Northwest mesoregions of Paraná State, Brazil. Diagnosis of American tegumentary leishmaniasis cases was performed at the State University in Maringá from 1987 to 2004. According to the probable site of infection, cases were classified as autochthonous (infection inside the household domain) or allochthonous (outside the household domain). Municipalities with the most cases were Maringá (458), Doutor Camargo (126), São Jorge do Ivaí (121), Terra Boa (114), Cianorte (98), and Colorado (95). Of the total of 1,938 cases, 66.9 percent were male. Among the 667 autochthonous cases, similar numbers of men and women were infected, with cases in minors as young as five years of age, with the latter not occurring in the 794 allochthonous cases. Conditions favoring American tegumentary leishmaniasis were created in the processes involved in occupying the rural areas of these mesoregions, particularly in the agricultural settlement model and the crisis in coffee monoculture.

Leishmania (Viannia) lainsoni: occurrence of intracellular promastigote forms in vivo and in vitro

Experimental chronic (45-day-old) skin lesion in hamster hind foot induced by Leishmania (Viannia) lainsoni infection showed the presence of promastigote forms in the tissue, inside parasitophorous vacuoles, as assessed by transmission electron microscopy. Experimental in vitro interaction (24 and 48 h) between Leishmania (V.)lainsoni and J774-G8 macrophage cells also demonstrated the same profile. This morphological aspect is unusual, since in this parasite genus only amastigote forms have been described as the resistant and obligate intracellular forms.

Leishmania (Viannia) lainsoni (Kinetoplastida: Trypanosomatidae), a divergent Leishmania of the Viannia subgenus: a mini review

Leishmania (Viannia) lainsoni is the Leishmania species that presents the most distinct biological (morphology, growth in axenic culture medium), biochemical (enzymatic electrophoresis profile), and molecular biology characteristics, when compared to other species of the Viannia subgenus. Development of promastigote forms of this parasite attached to the wall of the pyloric and hind gut regions of sand fly vectors is a solid characteristic that allows its positioning in the Viannia subgenus. However, taxonomic data from biochemical and molecular techniques on this Leishmania species are still not conclusive. It is evident the difficulty in taxonomically positioning this borderline Leishmania species. In this review we present the data accumulated since L. (Viannia) lainsoni has been described and we discuss its position in the Viannia subgenus.

Phenotypic, functional, and quantitative characterization of canine peripheral blood monocyte-derived macrophages

The yield as well as phenotypic and functional parameters of canine peripheral blood monocyte-derived macrophages were analyzed. The cells that remained adherent to Teflon after 10 days of culture had high phagocytic activity when inoculated with Leishmania chagasi. Flow cytometric analysis demonstrated that more than 80 percent of cultured cells were positive for the monocyte/macrophage marker CD14.

Apoptotic mimicry: an altruistic behavior in host/Leishmania interplay

Apoptosis is the most common phenotype observed when cells die through programmed cell death. The morphologic and biochemical changes that characterize apoptotic cells depend on the activation of a diverse set of genes. Apoptosis is essential for multicellular organisms since their development and homeostasis are dependent on extensive cell renewal. In fact, there is strong evidence for the correlation between the emergence of multicellular organisms and apoptosis during evolution. On the other hand, no obvious advantages can be envisaged for unicellular organisms to carry the complex machinery required for programmed cell death. However, accumulating evidence shows that free-living and parasitic protozoa as well as yeasts display apoptotic markers. This phenomenon has been related to altruistic behavior, when a subpopulation of protozoa or yeasts dies by apoptosis, with clear benefits for the entire population. Recently, phosphatidylserine (PS) exposure and its recognition by a specific receptor (PSR) were implicated in the infectivity of amastigote forms of Leishmania, an obligatory vertebrate intramacrophagic parasite, showing for the first time that unicellular organisms use apoptotic features for the establishment and/or maintenance of infection. Here we focus on PS exposure in the outer leaflet of the plasma membrane - an early hallmark of apoptosis - and how it modulates the inflammatory activity of phagocytic cells. We also discuss the possible mechanisms by which PS exposure can define Leishmania survival inside host cells and the evolutionary implications of apoptosis at the unicellular level.

Leishmaniose visceral canina: avaliação de modelo experimental utilizando saliva de Flebotomíneos e parámetros imunológicos associados à proteção / Canine leishmaniasis: evaluation of experimental model using Flebotomine saliva and immunological parameters associated with protection

A expansão geográfica das leishmanioses justifica a necessidade de pesquisas sobre vacinas, testes de drogas e imunoterapia da leishmaniose canina. O presente trabalho estuda o modelo experimental de infecção por Leishmania chagasi em cão, e alterações clínicas e imunes na infecção natural. A associcação de fatores na saliva à promastigotas de Leishmania não aumentou a infectividade em camundongos nem em cães Beagle, em nossas condições. Para identificar padrões de resposta lmune que possam ser utilizados como marcadores de progressão de doença, foram estudados parâmetros imunológicos e parasitológicos em câes infectados por L. chagasi, os quais exibiram padrões de aparente resistência ou doença progressiva. O teste de Montenegro, contendo timerosal, provocou enduração e deve ser evitado. Altos títulos de anticorpos anti-Leishmania associados à uma fraca resposta ao teste de Montenegro indicariam doença progressiva, enquanto o contrário indicaria resistência adquirida ou imunidade protetora. Há concomitância de uma baixa resposta linfoproliferativa à concanavalina A e ao lisado de Leishmania, o que é indicativo de imunodepressão. Os resultados confirmam e ampliam dados da literatura sobre a existência de diferentes características clínicas e imunológicas, que estão relacionadas a resistência ou susceptibilidade, demonstrando a possibilidade de distinguir grupos de cães com diferentes perfis. Os resultados da infecção por L.(L.) chagasi e o desenvolvimento de leishmaniose visceral em cães revelam vários aspectos peculiares, que não mostram similaridade com o que acontece no homem.

Ultrastructural observations on the etiologic agent of cutaneous leishmanasis in south western Saudi Arabia

The ultrastructure of three isolates of the promastigote stage of the etiologic agent of cutaneous leishmaniasis in South Western Saudi Arabia is described. The Utrastructural features of all isolates are similar and are compared with other described leishmaniasis. A hypothetical diagrammatic drawing of the promastigote stage was compiled from a number of electron micrographs. The periplast of the cell is formed of a thin smooth plasma membrane which lacks any substantial coating. A single layer of subpellicular microtubules is seen in a ribosome free area. Subpellicular microtubules show a striated appearance in longitudinal sections. The number of these microtubules in the three isolates seems to be significant to the plane of transverse sections; being the largest in the nuclear leveled sections. The number also differs in each of the three isolates and differs from those recorded in other species. The arrangement of these microtubules seems to be in a helical pattern Subpellicular microtubules are not seen the area of the flagellar pocket; instead there is a group of 3-4 flagellum associated microtubules parallel to the flagellar pocket. These microtubules are associated with desmosomes. The ultrastructure of the promastigote is affected to some extent according to the phase of the cell in the culture. Some peculiarities may occur in long sustained promastigote cultures of leishmaniasis

Isoenzyme characterization of leishmania isolates from patients in El-Nour specialized hospital Saudi Arabia

No doubt, the three forms of leishmaniasis [VL, ZCL and ACL] are well documented in Saudi Arabia. The basis of epidemiological studies must be adequate identification of the Leishmania patients. Seven leishmanial strains have been isolated from patients attending El Nour Specialized Hospital, Makka Al Mokarrama. The majority of the patients of this hospital are temporary visitors to Makka Al Mokarrama for "Haj and Omra". Isoenzyme characterization by cellulose acetate electrophores's used nine enzymes was done. The seven isolates were: two L. donovani zymodeme LON 41 [Indian patient] and LON 46 [Sudanese patient]; three L. tropica zymodeme LON 71 [2 Yemeni patients] and LON 22 [Egyptian patient] and two L. major zymodeme LON 4 [2 Saudi patients]

Perfil epidemiológico da leishmaniose tegumentar no Brasil / Epidermological profile of cutaneous and mucocutaneous leishmaniasis in Brazil

A discussäo sobre o perfil epidemiológico da leishmaniose tegumentar no Brasil levou em conta as notificaçöes de casos humanos, raio de dispersäo dos agentes etiológicos e sinantropia de populaçöes silvestres. Foi analisado o resultado de 105.988 casos nos últimos dez anos e a persistência de focos ativos em matas remanescentes. O crescimento anual da incidência na regiäo Norte a tornou mais problemática no Brasil. Destacou-se também o crescente intercâmbio de populaçöes que sobreviveram em matas residuais com as do ambiente domiciliar. Nesta situaçäo, L. intermedia e L. braziliensis mostraram variado grau de adaptaçäo ao último ambiente. O processo sinantrópico em desenvolvimento para ambas espécies e seus reflexos nas mudanças de padräo epidemiológico da doença sugerem clara evoluçäo da leishmaniose tegumentar. Portanto, permanecerá tendência para aumento ds infecçöes humanas em ambiente extraflorestal no Brasil. O risco de contraí-la é igual para todos os indivíduos independente da idade e sexo

Distinctions between promastigotes of Leishmania species developing in the digestive tract of laboratory reared Lutzomyia longipalpis

Female Lutzomya longipalpis were exposed to infection by three different species/strains of Leishmania. When the insects were dissected four days after exposure, stained preparations were made of the flagellates contained in the digestive tract. Using traditional morphometric methods, L. amazonensis, L. guyanensis and an unnamed species of the mexicana complex could be distinguished from one another