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1.
Mem. Inst. Oswaldo Cruz ; 116: e200571, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154878

ABSTRACT

Leishmania infantum chagasi is the causative agent and Lutzomyia longipalpis is the main vector of visceral leishmaniasis in the Americas. We investigated the expression of Leishmania genes within L. longipalpis after artificial infection. mRNAs from genes involved in sugar and amino acid metabolism were upregulated at times of high parasite proliferation inside the insect. mRNAs from genes involved in metacyclogenesis had higher expression in late stages of infection. Other modulated genes of interest were involved in immunomodulation, purine salvage pathway and protein recycling. These data reveal aspects of the adaptation of the parasite to the microenvironment of the vector gut and reflect the preparation for infection in the vertebrate.


Subject(s)
Animals , Psychodidae/parasitology , Leishmania infantum/genetics , Insect Vectors/parasitology , Leishmania/isolation & purification , Leishmaniasis, Visceral/transmission , Psychodidae/genetics , Brazil , Gene Expression , Reverse Transcriptase Polymerase Chain Reaction/methods , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/epidemiology , Life Cycle Stages
2.
Hist. ciênc. saúde-Manguinhos ; 27(3): 741-761, set. 2020. tab, graf
Article in Portuguese | LILACS | ID: biblio-1134073

ABSTRACT

Resumo O artigo faz análise histórica da emergência da leishmaniose tegumentar americana como objeto do conhecimento e desafio médico-sanitário no Amazonas desde a década de 1970. Fornece visão geral dessa época, as medidas sanitárias e os estudos científicos realizados no contexto de implantação dos principais projetos de desenvolvimento regionais executados em nome da política de integração nacional do governo federal. Utiliza como metodologia a análise documental de leis, produção científica, relatórios de pesquisa, boletins epidemiológicos e jornais. Os resultados da pesquisa mostram que a doença surgiu no Amazonas associando o grande problema de saúde com mudanças político-econômicas e alterações socioambientais.


Abstract The history of the emergence of American cutaneous leishmaniasis in the Brazilian state of Amazonas since the 1970s is analyzed as an object of knowledge and a medical and public health challenge. An overview of the period is provided, including the public health measures and scientific studies undertaken in the context of the execution of large-scale regional developments pursued in the name of national integration by the federal government. The methodology uses documental analysis of laws, the scientific literature, research reports, epidemiological bulletins, and newspapers. The results show that American cutaneous leishmaniasis emerged as a major health problem in Amazonas in close association with the political, economic, and socioenvironmental changes seen in the period.


Subject(s)
Humans , Animals , Public Health/history , Leishmaniasis, Cutaneous/history , Conservation of Natural Resources , Leishmania/isolation & purification , Psychodidae/parasitology , Urbanization/history , Leishmania braziliensis/isolation & purification , Brazil/epidemiology , Insect Control/history , Leishmaniasis, Cutaneous/transmission , Leishmaniasis, Cutaneous/epidemiology , Leishmania guyanensis/isolation & purification , Industrial Development/history , Insect Vectors
3.
Mem. Inst. Oswaldo Cruz ; 115: e190284, 2020. tab
Article in English | LILACS | ID: biblio-1056772

ABSTRACT

Despite some phlebotomines being well recognised as vectors of leishmaniasis agents, vector importance of those belonging to the genus Trichophoromyia has not been extensively studied. The present study provides evidence regarding the putative vector role played by some species of Trichophoromyia on leishmanine enzootics, based on literature reports and findings obtained from field experiments conducted in the ecotopes of Pará State, Brazil. The species Th. ubiquitalis, Th. velascoi, Th. auraensis, Th. ininii and Th. brachipyga possess minimal criteria to be included in the list of suspected leishmanine vectors. However, knowledge on man-biting behavior, substantiation of vector competence and determination of epidemiological implications are limited for all of the above mentioned species. Published studies together with present data draw attention to prioritize these phlebotomine species in entomological surveillance programs and studies on experimental susceptibility to Leishmania spp. infection.


Subject(s)
Animals , Psychodidae/parasitology , Insect Vectors/parasitology , Leishmania/classification , Leishmaniasis/transmission , Polymerase Chain Reaction , DNA, Protozoan/genetics , Leishmania/genetics
4.
Rev. Soc. Bras. Med. Trop ; 53: e20190320, 2020. tab, graf
Article in English | LILACS | ID: biblio-1057289

ABSTRACT

Abstract INTRODUCTION: This study aimed to investigate human exposure to Leishmania spp. infection and sandflies in an area endemic for the disease. METHODS: The presence of antibodies specific for Leishmania spp. and saliva of Lutzomyia spp. and that of L. infantum DNA in blood were evaluated. RESULTS: Antibodies against Leishmania spp. and sandfly saliva were observed in 20.8% and 37.7% of individuals, respectively. DNA of Leishmania spp. was amplified from the blood of one patient. CONCLUSIONS: The results suggest that Leishmania spp. infection may be underdiagnosed in this area.


Subject(s)
Humans , Animals , Male , Female , Adolescent , Adult , Aged , Young Adult , Psychodidae/parasitology , Insect Vectors/parasitology , Leishmania/isolation & purification , Leishmaniasis, Visceral/transmission , Brazil , Enzyme-Linked Immunosorbent Assay , Polymerase Chain Reaction , Leishmania/genetics , Leishmania/immunology , Leishmaniasis, Visceral/epidemiology , Middle Aged
5.
Mem. Inst. Oswaldo Cruz ; 115: e200113, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135235

ABSTRACT

BACKGROUND Lutzomyia longipalpis-derived cell line (Lulo) has been suggested as a model for studies of interaction between sandflies and Leishmania. OBJECTIVES Here, we present data of proteomic and gene expression analyses of Lulo cell related to interactions with Leishmania (Viannia) braziliensis. METHODS Lulo cell protein extracts were analysed through a combination of two-dimensional gel electrophoresis and mass spectrometry and resulting spots were further investigated in silico to identify proteins using Mascot search and, afterwards, resulting sequences were applied for analysis with VectorBase. RESULTS Sixty-four spots were identified showing similarities to other proteins registered in the databases and could be classified according to their biological function, such as ion-binding proteins (23%), proteases (14%), cytoskeletal proteins (11%) and interactive membrane proteins (9.5%). Effects of interaction with L. (V.) braziliensis with the expression of three genes (enolase, tubulin and vacuolar transport protein) were observed after an eight-hour timeframe and compared to culture without parasites, and demonstrated the impact of parasite interaction with the expression of the following genes: LLOJ000219 (1.69-fold), LLOJ000326 (1.43-fold) and LLOJ006663 (2.41-fold). CONCLUSIONS This set of results adds relevant information regarding the usefulness of the Lulo cell line for studies with Leishmania parasites that indicate variations of protein expression.


Subject(s)
Animals , Psychodidae/parasitology , Leishmania braziliensis/genetics , Proteomics , Leishmania/genetics , Cell Line , Transcriptome
6.
Mem. Inst. Oswaldo Cruz ; 115: e200157, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135268

ABSTRACT

BACKGROUND In Acre state, Brazil, the dissemination of cutaneous leishmaniasis has increased in recent years, with limited knowledge of the potential Leishmania spp. vectors involved. OBJECTIVES Here, data concerning the sandfly fauna of Brasiléia municipality, Leishmania DNA-detection rates and the identification of blood meal sources of insects captured in 2013-2015 are presented. METHODS Parasite detection in female sandflies was performed individually by multiplex polymerase chain reaction (PCR) (Leishmania kDNA/sandfly cacophony-gene), with the identification of Leishmania spp. by hsp70-PCR and sequencing. The identification of blood gut-content from fed females was performed by cyt b-PCR and sequencing. FINDINGS A total of 4,473 sandflies were captured. A subgroup of 864 non-blood-fed females evaluated for the presence of Leishmania DNA showed 2.9% positivity for Leishmania (Viannia) braziliensis and L. (V.) guyanensis. The identification of blood meal sources was performed in 96 blood-fed females, allowing the identification of 13 vertebrate species. In nine/96 fed females, DNA from L. (V.) shawi, L. (V.) guyanensis, L. (V.) braziliensis and Endotrypanum sp. was detected. MAIN CONCLUSIONS In Brumptomyia sp. and Evandromyia termitophila, the first report of Leishmania DNA-detection is provided in Acre; Nyssomyia shawi is implicated as potential vector of L. (V.) braziliensis and L. (V.) guyanensis for the first time in Brazil.


Subject(s)
Animals , Female , Psychodidae/parasitology , DNA/analysis , Insect Vectors/genetics , Leishmania/genetics , Psychodidae/classification , Brazil , Polymerase Chain Reaction , DNA, Protozoan/analysis , Leishmaniasis, Cutaneous/transmission , Insect Vectors/classification , Insect Vectors/parasitology , Leishmania/isolation & purification
7.
Rev. bras. parasitol. vet ; 29(4): e017820, 2020. graf
Article in English | LILACS | ID: biblio-1144228

ABSTRACT

Abstract Leishmania infantum infection in cats has been reported in several countries, including Brazil. However, the transmission of visceral leishmaniasis (VL) from cats to another host has not been proven yet. Therefore, the aim of this study was to verify the possibility of L. infantum transmission from cats to dogs. In order to verify the possibility of VL transmission from the cat to the dog, xenodiagnosis was carried out in a VL-positive cat, using 55 female Lutzomyia longipalpis. Five days later, 40 insects were dissected to verify Leishmania infection. The remaining 15 females were fed in a healthy dog. The potential infection of the dog was verified through clinical, serological, parasitological examinations, and PCR, at three, six, and twelve months post-infection. All 55 L. longipalpis females became visibly engorged. Leishmania promastigotes were detected in 27.5% of the dissected insects. Leishmania infection in the dog was confirmed upon first evaluation. DNA sequencing of the parasite isolated from the cat confirmed L. infantum infection and showed 99% similarity with the L. infantum DNA sequences from the dogs. Through this study, it was possible to confirm the L. infantum experimental transmission from a domestic cat to a domestic dog through its biological vector L. longipalpis.


Resumo A infecção por Leishmania infantum em gatos tem sido relatada em vários países, incluindo o Brasil. No entanto, a transmissão da leishmaniose visceral (LV) de gatos para outro hospedeiro ainda não foi comprovada. Portanto, o objetivo deste estudo foi verificar a possibilidade de transmissão de L. infantum de gatos para cães. Para verificar a possibilidade de transmissão da LV do gato para o cão, foi realizado xenodiagnóstico em um gato com LV, utilizando-se 55 fêmeas de Lutzomyia longipalpis. Cinco dias depois, 40 insetos foram dissecados para verificar a infecção por Leishmania. As 15 fêmeas restantes foram alimentadas em um cão saudável. A possível infecção no cão foi verificada por meio de exames clínicos, sorológicos, parasitológicos e PCR, três, seis e doze meses após a infecção. Todas as 55 fêmeas de L. longipalpis ficaram visivelmente ingurgitadas. Promastigotas de Leishmania foram detectadas em 27,5% dos insetos dissecados. A infecção por Leishmania no cão foi confirmada na primeira avaliação. O sequenciamento do DNA do parasito isolado do gato confirmou a infecção por L. infantum e apresentou 99% de similaridade com sequências de DNA de L. infantum de cães. Através deste estudo, foi possível confirmar a transmissão experimental de L. infantum de um gato doméstico para um cão doméstico através do seu vetor biológico L. longipalpis.


Subject(s)
Animals , Female , Cats , Dogs , Cat Diseases/parasitology , Cat Diseases/transmission , Leishmania infantum/genetics , Dog Diseases/parasitology , Dog Diseases/transmission , Leishmaniasis, Visceral/transmission , Psychodidae/parasitology , Brazil , DNA, Protozoan/chemistry , Insect Vectors/parasitology , Leishmaniasis, Visceral/veterinary
8.
Mem. Inst. Oswaldo Cruz ; 114: e180482, 2019. graf
Article in English | LILACS | ID: biblio-1040621

ABSTRACT

The leishmaniases are caused by Leishmania parasites and transmitted through the bites of phlebotomine sand flies. During parasite development inside the vector's midgut, promastigotes move towards the stomodeal valve, a mechanism that is crucial for transmission. It has been reported that the sugar meal acquired by sand flies during feeding between bloodmeals is essential for the development and migration of parasites. We demonstrated that the distribution of Leishmania mexicana parasites was affected by the sugar meals obtained by the sand flies. Promastigote migration towards the cardia region seems to be only partially based on the stimuli provided by sugar molecules. In the absence of sugars, significant amounts of parasites developed in the hindgut. In addition, sugar meals were important for the survival of sand flies, especially during blood digestion, presumably supporting their energy requirements.


Subject(s)
Animals , Female , Psychodidae/parasitology , Leishmania mexicana/physiology , Gastrointestinal Tract/parasitology , Sugars/metabolism , Feeding Behavior/physiology , Insect Vectors/parasitology , Psychodidae/physiology , Leishmania mexicana/growth & development , Insect Vectors/physiology , Longevity
9.
Braz. j. med. biol. res ; 52(9): e8224, 2019. tab, graf
Article in English | LILACS | ID: biblio-1019569

ABSTRACT

Leishmaniasis is a neglected disease that affects a large part of the world population. Knowing the sand fly fauna of a region is of fundamental importance for guiding health surveillance actions related to the prevention and control of leishmaniasis. A total of 86 specimens of sand flies (60 females and 26 males) were collected. Using the classification proposed by Galati (2003), the following species were identified: Lutzomyia longipalpis (Lutz & Neiva, 1912), Migonemyia migonei (França, 1920), Evandromyia cortelezzi (Brethes, 1923), Ev. sallesi (Galvão & Coutinho, 1939), Nyssomyia whitmani (Atunes & Coutinho, 1939), Psathyromyia lutziana (Costa Lima, 1932), Ev. lenti (Mangabeira, 1938), Brumptomyia sp. (França and Parrot, 1921), and Pressatia sp. (Mangabeira, 1942). Using PCR with internal transcribed spacer target to identify infected sand flies, five Lu. longipalpis females were infected with Leishmania spp. Despite the small number of specimens collected, considerable species diversity was found in the study area.


Subject(s)
Animals , Male , Female , Psychodidae/classification , Psychodidae/parasitology , RNA, Protozoan/genetics , Insect Vectors/classification , Insect Vectors/parasitology , Leishmania/isolation & purification , Brazil , Leishmaniasis/transmission , Polymerase Chain Reaction , DNA, Ribosomal Spacer/genetics , Leishmania/genetics
10.
Mem. Inst. Oswaldo Cruz ; 113(3): 202-205, Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-1040591

ABSTRACT

BACKGROUND Lutzomyia umbratilis, the vector for Leishmania guyanensis in northern South America, has been found naturally infected with L. guyanensis only in areas north of the Negro and Amazon rivers. While populations of this sand fly species are also found in areas south of these rivers, these populations have never been reported to be infected and/or transmitting L. guyanensis. However, no studies on the corresponding host-parasite interactions are available. OBJECTIVES This study evaluated the interaction between Lu. guyanensis promastigotes and field-collected Lu. umbratilis sand flies from Rio Preto da Eva and Manacapuru, which are located to the north and south, respectively, of the Negro River. METHODS Procyclic and metacyclic attachment was quantified using an in vitro system. FINDINGS Low attachment of parasites to the midguts of insects collected from Manacapuru was detected. Conversely, greater binding of metacyclic parasites was observed in the midguts of insects collected from Rio Preto da Eva, and this attachment was more pronounced than that observed for procyclics (p < 0.03). MAIN CONCLUSIONS The Lu. umbratilis population from an area south of the Negro River has lower in vitro interaction with L. guyanensis. The higher attachment of L. guyanensis to midguts of insects from Rio Preto da Eva may suggest better vector competence. These findings are in accordance with previously reported epidemiological information of American cutaneous leishmaniasis (ACL) transmission in the Amazon.


Subject(s)
Animals , Female , Psychodidae/parasitology , Leishmania guyanensis/physiology , Digestive System/parasitology , Host-Parasite Interactions/physiology , Psychodidae/classification , Brazil , Rivers , Geography
11.
Rev. Assoc. Med. Bras. (1992) ; 64(3): 281-289, Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-896453

ABSTRACT

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.


Subject(s)
Humans , Animals , Leishmaniasis/epidemiology , Psychodidae/parasitology , Brazil/epidemiology , Leishmaniasis/physiopathology , Leishmaniasis/drug therapy , Host-Parasite Interactions/physiology , Leishmania/physiology , Antiprotozoal Agents/therapeutic use
12.
Mem. Inst. Oswaldo Cruz ; 112(10): 681-691, Oct. 2017. tab, graf
Article in English | LILACS | ID: biblio-894835

ABSTRACT

BACKGROUND Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. OBJECTIVE To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. METHODS Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. FINDINGS A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. MAIN CONCLUSIONS These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil.


Subject(s)
Animals , Female , Psychodidae/classification , Psychodidae/parasitology , Leishmania/isolation & purification , Forests , Grassland , Insect Vectors
13.
Rev. Soc. Bras. Med. Trop ; 50(4): 483-488, July-Aug. 2017. tab
Article in English | LILACS | ID: biblio-896987

ABSTRACT

Abstract INTRODUCTION The control of reservoirs for Leishmania infantum -induced zoonotic visceral leishmaniasis requires the identification of dogs posing a population risk. Here, we assessed the performance of several assays to identify Lutzomyia longipalpis infectious dogs. METHODS We evaluated 99 dogs that were positive for visceral leishmaniasis based on parasite identification. Serological analyses were performed using an enzyme-linked immunosorbent assay, immunofluorescence antibody tests in 1:40 and 1:80 dilutions, rapid dual path platform tests, immunochromatographic assay with a recombinant rK39 antigen, fast agglutination screening tests, and direct agglutination tests. We also performed PCR to analyze peripheral blood and xenodiagnosis. RESULTS Forty-six dogs infected at least one L. longipalpis specimen. Although the serological test sensitivities were above 85% for detecting L. longipalpis infectious dogs, none showed a satisfactory performance, as both specificity (0.06 to 13%) and the area under the receiver operating characteristic curve (45 to 53%) were low. The PCR results were also weak, with a sensitivity of 30%, specificity of 72%, and an area under the receiver operating characteristic curve of 51%. The infected L. longipalpis proportion was higher among asymptomatic dogs than symptomatic dogs. Among the symptomatic dogs, those with ulceration-free skin diseases were more infectious, with an odds ratio of 9.3 (confidence interval of 1.10 - 428.5). The larger the number of insects fed, the greater the detected infectiousness. CONCLUSIONS Our study supports the imperative to develop novel technologies for identifying the infectious dogs that transmit L. infantum for the benefit of public health.


Subject(s)
Humans , Animals , Male , Dogs , Psychodidae/parasitology , Serologic Tests/veterinary , Antibodies, Protozoan/blood , Leishmania infantum , Dog Diseases/diagnosis , Mosquito Vectors/parasitology , Leishmaniasis, Visceral/veterinary , Serologic Tests/methods , Sensitivity and Specificity , Dog Diseases/parasitology , Dog Diseases/transmission , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/transmission
14.
Mem. Inst. Oswaldo Cruz ; 112(7): 517-519, July 2017.
Article in English | LILACS | ID: biblio-841810

ABSTRACT

The sandfly Trichophoromyia auraensis has recently evolved as a proven vector of Leishmania (Viannia) endemic to state of Acre in the north of Brazil. This note is intended to propose a correction in the report of the first occurrence of natural infection of Leishmania (Viannia) in this species. We and the other scientific groups reinforced that Tr. auraensis is a possible vector involved in the transmission of American cutaneous leishmaniasis in Acre, Brazil.


Subject(s)
Animals , Leishmaniasis, Cutaneous/parasitology , Insect Vectors/classification , Insect Vectors/parasitology , Leishmania/isolation & purification , Psychodidae , Psychodidae/parasitology , Brazil
15.
Mem. Inst. Oswaldo Cruz ; 112(4): 309-318, Apr. 2017. tab, graf
Article in English | LILACS | ID: biblio-841787

ABSTRACT

BACKGROUND Leishmaniases are a serious health problem in southeast Brazil, including the city of Belo Horizonte (BH), Minas Gerais state (MG), where there are high rates of incidence and mortality due to visceral leishmaniases. BH is divided into nine sanitary districts (SD) of which one, the Venda Nova SD, was selected for this study because it has high rates of positivity for canine leishmaniasis and high incidence of human leishmaniasis. OBJECTIVES This study aimed to survey the sand fly fauna in Venda Nova SD from August 2011 to July 2013 and perform a descriptive analysis of the vector population. METHODS The sampling was carried out using automatic HP light traps at all covered areas of the Venda Nova SD, in a total of eighteen light traps. Sampled specimens were identified following Galati (2003), and females were submitted to molecular techniques for the detection and identification of Leishmania DNA. A simple environmental description was done for it area and Kernel estimation was used to infer vector density for each study site. FINDINGS A total of 2,427 sand fly specimens belonging to eight species and five genera were collected of which 95.3% were Lutzomyia longipalpis. The seasonal variation curve was delineated by this species. Lu. longipalpis was the most abundant at all collection points and in all months of the study, and exhibited a natural infection rate of 1.01% for Leishmania infantum and 1.77% for Leishmania braziliensis. MAIN CONCLUSIONS The results show the presence and adaptation of Lu. longipalpis to the anthropic environment of BH and reinforces its role as the main vector of L. infantum in the region.


Subject(s)
Humans , Animals , Male , Female , Dogs , Psychodidae/classification , Psychodidae/parasitology , Leishmaniasis/transmission , DNA, Protozoan/analysis , Insect Vectors/classification , Insect Vectors/parasitology , Leishmania/isolation & purification , Leishmania/classification , Leishmania/genetics , Seasons , Brazil , Population Density
16.
Mem. Inst. Oswaldo Cruz ; 112(1): 75-78, Jan. 2017. graf
Article in English | LILACS | ID: biblio-841757

ABSTRACT

Studies on the sandfly fauna to evaluate natural infection indexes are still limited in the Brazilian Amazon, a region with an increasing incidence of cutaneous leishmaniasis. Here, by using a multiplex polymerase chain reaction directed to Leishmania kDNA and hybridisation, we were able to identify L. (Viannia) subgenus in 12 out of 173 sandflies captured in the municipality of Rio Branco, Acre state, revealing a positivity of 6.94%. By sequencing the Leishmania 234 bp-hsp70 amplified products from positive samples, infection by L. (V.) braziliensis was confirmed in five sandflies: one Evandromyia saulensis, three Trichophoromyia auraensis and one Pressatia sp. The finding of L. (Viannia) DNA in two Ev. saulensis corresponds to the first record of possible infection associated with this sandfly. Moreover, our study reveals for the first time in Brazil, Th. auraensis and Pressatia sp. infected by L. (Viannia) parasites.


Subject(s)
Animals , Psychodidae/classification , Psychodidae/parasitology , Leishmaniasis, Cutaneous/transmission , Insect Vectors/classification , Insect Vectors/parasitology , Leishmania/isolation & purification , Leishmania/classification , Brazil , Multiplex Polymerase Chain Reaction
17.
Rev. Soc. Bras. Med. Trop ; 49(6): 772-773, Dec. 2016.
Article in English | LILACS | ID: biblio-1041388

ABSTRACT

Abstract: INTRODUCTION: The present note discusses some evidence on the increasing potential risk for American visceral leishmaniasis (AVL) transmission in the Northern Brazilian State of Amapá, the Guianan-Amazon biome. METHODS Early and present data about AVL were collected, including our recent entomological findings. RESULTS: The spread of the sand fly vector Lutzomyia longipalpis, and a sylvatic reservoir host, the crab-eating fox Cerdocyon thous in that region represents important findings related to the epidemiology of AVL in the Guianan-Amazon biome. CONCLUSIONS: These observations suggest that Brazilian authorities need to develop surveillance strategies in these risk areas.


Subject(s)
Humans , Animals , Male , Psychodidae/parasitology , Leishmania donovani/isolation & purification , Disease Reservoirs , Foxes/parasitology , Insect Vectors/parasitology , Leishmaniasis, Visceral/transmission , Brazil/epidemiology , Leishmaniasis, Visceral/epidemiology
18.
Mem. Inst. Oswaldo Cruz ; 111(8): 517-522, Aug. 2016. tab, graf
Article in English | LILACS | ID: lil-788994

ABSTRACT

Currently, the only method for identifying infective hosts with Leishmania infantum to the vector Lutzomyia longipalpis is xenodiagnosis. More recently, quantitative polymerase chain reaction (qPCR) has been used to model human reservoir competence by assuming that detection of parasite DNA indicates the presence of viable parasites for infecting vectors. Since this assumption has not been proven, this study aimed to verify this hypothesis. The concentration of amastigotes in the peripheral blood of 30 patients with kala-azar was microscopically verified by leukoconcentration and was compared to qPCR estimates. Parasites were identified in 4.8 mL of peripheral blood from 67% of the patients, at a very low concentration (average 0.3 parasites/mL). However, qPCR showed 93% sensitivity and the estimated parasitaemia was over a thousand times greater, both in blood and plasma, with higher levels in plasma than in blood. Furthermore, the microscopic count of circulating parasites and the qPCR parasitaemia estimates were not mathematically compatible with the published proportions of infected sandflies in xenodiagnostic studies. These findings suggest that qPCR does not measure the concentration of circulating parasites, but rather measures DNA from other sites, and that blood might not be the main source of infection for vectors.


Subject(s)
Humans , Animals , Male , Female , Child , Adolescent , Young Adult , Insect Vectors/parasitology , Leishmania infantum/physiology , Leishmaniasis, Visceral/parasitology , Parasitemia/parasitology , Polymerase Chain Reaction/methods , Psychodidae/parasitology , Child, Preschool , DNA, Protozoan/blood , Leishmaniasis, Visceral/transmission , Microscopy/methods , Sensitivity and Specificity
19.
Mem. Inst. Oswaldo Cruz ; 111(7): 423-432, tab, graf
Article in English | LILACS | ID: lil-787560

ABSTRACT

In this study, we identified the phlebotomine sandfly vectors involved in the transmission of American Cutaneous Leishmaniasis (ACL) in Assis Brasil, Acre, Brazil, which is located on the Brazil-Peru-Bolivia frontier. The genotyping of Leishmania in phlebotomines was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. A total of 6,850 sandflies comprising 67 species were captured by using CDC light traps in rural areas of the municipality. Three sandfly species were found in the state of Acre for the first time: Lutzomyia georgii, Lu. complexa and Lu. evangelistai. The predominant species was Lu. auraensis/Lu. ruifreitasi and Lu. davisi (total 59.27%). 32 of 368 pools were positive for the presence of Leishmania DNA (16 pools corresponding to Lu. davisi, and 16 corresponding to Lu. auraensis/Lu. ruifreitasi), with a minimal infection prevalence of 1.85% in Lu. davisi and 2.05% in Lu. auraensis/Lu. ruifreitasi. The Leishmania species found showed maximum identity with L. (Viannia) guyanensis and L. (V.) braziliensis in both phlebotomine species. Based on these results and similar scenarios previously described along the Brazil/Peru/Bolivia tri-border, the studied area must take into consideration the possibility of Lu. davisi and Lu. auraensis/Lu. ruifreitasi as probable vectors of ACL in this municipality.


Subject(s)
Humans , Animals , Female , DNA/analysis , Insect Vectors/genetics , Leishmania/genetics , Psychodidae/genetics , Biodiversity , Bolivia , Brazil , DNA, Kinetoplast , Genotype , Insect Vectors/classification , Insect Vectors/parasitology , Leishmaniasis, Cutaneous/transmission , Peru , Polymerase Chain Reaction , Population Density , Psychodidae/classification , Psychodidae/parasitology
20.
Mem. Inst. Oswaldo Cruz ; 111(5): 302-310, May 2016. tab, graf
Article in English | LILACS | ID: lil-782045

ABSTRACT

Urban occurrence of human and canine visceral leishmaniasis (VL) is linked to households with characteristics conducive to the presence of sand flies. This study proposes an ad hoc classification of households according to the environmental characteristics of receptivity to phlebotominae and an entomological study to validate the proposal. Here we describe the phlebotominae population found in intra- and peridomiciliary environments and analyse the spatiotemporal distribution of the VL vector Lutzomyia longipalpis of households receptive to VL. In the region, 153 households were classified into levels of receptivity to VL followed by entomological surveys in 40 of those properties. Kruskal-Wallis verified the relationship between the households’ classification and sand fly abundance and Kernel analysis evaluated L. longipalpis spatial distribution: of the 740 sand flies were captured, 91% were L. longipalpis; 82% were found peridomiciliary whilst the remaining 18% were found intradomiciliary. No statistically significant association was found between sandflies and households levels. L. longipalpis counts were concentrated in areas of high vulnerability and some specific households were responsible for the persistence of the infestation. L. longipalpis prevails over other sand fly species for urban VL transmission. The entomological study may help target the surveillance and vector control strategies to domiciles initiating and/or maintaining VL outbreaks.


Subject(s)
Humans , Animals , Dogs , Insect Vectors/classification , Leishmaniasis, Visceral/transmission , Psychodidae/classification , Brazil , Insect Vectors/parasitology , Population Density , Psychodidae/parasitology , Risk Factors , Seasons , Spatio-Temporal Analysis , Urban Population
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