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The genus Lutzomyia has a variety of species, where some are vectors of the disease called leishmaniasis which has implications for public health developing different clinical manifestations that highly affect humans such as cutaneous, visceral and mucocutaneous leishmaniasis. The aim of the study was to update the registry of the Lutzomyia species that are present in six areas of the Atlántico department. Three traditional capture techniques were implemented, with CDC traps implemented from 18:00 to 6:00 o'clock, Shannon traps from 19:00 to 10:00 and active search with mouth aspirators on trunks, tree bases and other rest sites from 09:00 to 11:00 and 16:00 to 17:30, in six municipalities of the Atlántico department, Colombia. Ten phlebotomine species were captured during the present work, from which the finding of Lutzomyia longipalpis and Lutzomyia atroclavata are reported for the first time at the Atlántico department. From the ten species captured, Lutzomyia longipalpis has antecedents as a vector of Leishmania infantum in Colombia and other regions of Latin America. The most abundant species with the greatest spatial distribution was Lu. evansi, which is the main vector of visceral leishmaniasis in the Caribbean region. In conclusion, the richness of phlebotomineal fauna of the department of Atlántico is updated to twelve species, with the first record of Lu. longipalpis and Lu. atroclavata. Phlebotomy fauna is also reported for the first time in localities of the department of Atlántico such as Campeche, Puerto Colombia, Luruaco, Ponedera and Campo de la Cruz. [ABSTRACT FROM AUTHOR]

Purpose: Sand flies are vectors of medical and veterinary concern, responsible for the transmission of Leishmania parasites. These invertebrates are widely distributed throughout the world and their abundance and diversity is dependent on several biotic and physical factors. Based on the epidemiological importance of these insects, the aim of this study was to assess the sand fly fauna of a new area of occurrence of leishmaniasis. Methods: From October 2018 to September 2019, samplings were performed using CDC light traps at six different collection points located in a high altitude area in the municipality of Garanhuns, Northeastern Brazil. Geographic coordinates were recorded using the satellite remote sensing Global Positioning System (GPS) Garmin Etrex20. The spatial distribution of sand flies was evaluated using kernel density estimation (KDE). Engorged females (n = 12) were molecularly processed to search for Leishmania DNA. Results: A total of 138 sand fly specimens were collected during the study period, with 100% (138/138) identified as Lutzomyia evandroi. Climatic conditions did not influence the number of sand flies (males and females) collected monthly, but a statistically significant difference was observed between the number of specimens and different collections points. The kernel map showed a heterogeneous spatial distribution of sand flies in the municipality of Garanhuns with a hotspot in the south of the region. Conclusion: Data presented herein are pivotal in filling the gap on the epidemiology of leishmaniasis in this high altitude area, serving as an alert to local health authorities. It also indicated that the putative role of L. evandroi in the transmission of Leishmania parasites should be clarified. [ABSTRACT FROM AUTHOR]

During Leishmania transmission sand flies inoculate parasites and saliva into the skin of vertebrates. Saliva has anti-haemostatic and anti-inflammatory activities that evolved to facilitate bloodfeeding, but also modulate the host's immune responses. Sand fly salivary proteins have been extensively studied, but the nature and biological roles of protein-linked glycans remain overlooked. Here, we characterised the profile of N-glycans from the salivary glycoproteins of Lutzomyia longipalpis, vector of visceral leishmaniasis in the Americas. In silico predictions suggest half of Lu. longipalpis salivary proteins may be N-glycosylated. SDS-PAGE coupled to LC–MS analysis of sand fly saliva, before and after enzymatic deglycosylation, revealed several candidate glycoproteins. To determine the diversity of N-glycan structures in sand fly saliva, enzymatically released sugars were fluorescently tagged and analysed by HPLC, combined with highly sensitive LC–MS/MS, MALDI-TOF–MS, and exoglycosidase treatments. We found that the N-glycan composition of Lu. longipalpis saliva mostly consists of oligomannose sugars, with Man5GlcNAc2 being the most abundant, and a few hybrid-type species. Interestingly, some glycans appear modified with a group of 144 Da, whose identity has yet to be confirmed. Our work presents the first detailed structural analysis of sand fly salivary glycans. [ABSTRACT FROM AUTHOR]

This study aimed to describe the sand fly fauna and detect trypanosomatids in these insects from Casa Branca, state of Minas Gerais, Brazil, an endemic area of both visceral (VL) and tegumentary leishmaniasis (TL). Sand flies were collected bimonthly from May 2013 to July 2014, using automatic light traps exposed for three consecutive nights in peridomiciliary areas of nine houses with previous reports of VL and TL. ITS1-PCR and DNA sequencing were performed for trypanosomatids identification. A total of 16,771 sand flies were collected belonging to 23 species. The most abundant species was Nyssomyia whitmani (Antunes & Coutinho, 1939) (70.9%), followed by Lutzomyia longipalpis (Lutz & Neiva, 1912) (15.2%) and Migonemyia migonei (França, 1920) (9.1%). Leishmania amazonensis DNA was detected in Ny. whitmani (four pools) and Le. braziliensis DNA was detected in Psychodopygus lloydi (one pool). In seven pools of Ny. whitmani and in one pool of Lu. longipalpis positive for Leishmania DNA, the parasite species was not determined due to the low quality of the sequences. Moreover, DNA of Herpetomonas spp. was detected in Ny. whitmani (two pools) and Cortelezzii complex (one pool). DNA of Crithidia spp. was detected in Ny. whitmani and Ps. lloydi (both one pool). Our results suggest that Ny. whitmani may be involved in the transmission of Le. amazonensis in the study area. The molecular detection of Le. amazonensis suggests the presence of this species in a sylvatic cycle between vertebrate and invertebrate hosts in the region of Casa Branca. Our data also reveal the occurrence of other non-Leishmania trypanosomatids in sand flies in Casa Branca District. [ABSTRACT FROM AUTHOR]

Local anomalies in rainfall and temperature induced by El Niño and La Niña episodes could change the structure of the vector community. We aimed to estimate the effect of the El Niño–La Niña cycle in the potential distribution of cutaneous leishmaniasis (CL) vector species in Colombia and to compare the richness of the vectors with the occurrence of CL in the state of Norte de Santander. The potential distributions of four species were modeled using a MaxEnt algorithm for the following episodes: La Niña 2010–2011, Neutral 2012–2015 and El Niño 2015–2016. The relationship between the potential richness of the vectors and the occurrence of CL in Norte de Santander was evaluated with a log-binomial regression model. During the El Niño 2015–2016 episode, Lutzomyia ovallesi and Lutzomyia panamensis increased their distribution into environmentally suitable areas, and three vector species (Lutzomyia gomezi, Lutzomyia ovallesi and Lutzomyia panamensis) showed increases in the range of their altitudinal distribution. During the La Niña 2010–2011 episode, a reduction was observed in the area suitable for occupation by Lutzomyia gomezi and Lutzomyia spinicrassa. During the El Niño 2015–2016 episode, the occurrence of at least one CL case was related to a higher percentage of rural localities showing a richness of vectors = 4. The anomalies in rainfall and temperature induced by the episodes produced changes in the potential distribution of CL vectors in Colombia. In Norte de Santander, during Neutral 2012–2015 and El Niño 2015–2016 episodes, a higher probability of at least one CL case was related to a higher percentage of areas with a greater richness of vectors. The results help clarify the effect of the El Niño–La Niña cycle in the dynamics of CL in Colombia and emphasize the need to monitor climate variability to improve the prediction of new cases. Author summary: The cutaneous leishmaniasis is a disease transmitted by insects. The incidence of cutaneous leishmaniasis has increased in Colombia and the state of Norte de Santander is one of the Colombian states where cutaneous leishmaniasis transmission is high. Local changes in rainfall and temperature induced by El Niño and La Niña episodes could change the distribution of the vector. A database of published records and field collections of four vectors of cutaneous leishmaniasis in Colombia was compiled. Also, a database with cases of cutaneous leishmaniasis from Norte de Santander was obtained. Maps of potential distribution in Colombia of the four vectors during the La Niña 2010–2011, Neutral 2012–2015 and El Niño 2015–2016 episodes were elaborated. During the El Niño 2015–2016 episode, two vector species increased their distribution into environmentally suitable areas, and three vector species showed increases in the range of their altitudinal distribution. During the La Niña 2010–2011 episode, a reduction was observed in the area suitable for occupation by two vectors. During the El Niño 2015–2016 episode, the occurrence of at least one cutaneous leishmaniasis case was related to a higher percentage of area with a predicted distribution of four vectors. [ABSTRACT FROM AUTHOR]

Background: Leishmaniasis is a human and animal disease caused by parasites of the genus Leishmania, which is now divided into four subgenera, Leishmania, Viannia, Sauroleishmania and Mundinia. Subgenus Mundinia, established in 2016, is geographically widely dispersed, its distribution covers all continents, except Antarctica. It consists of 5 species; L. enriettii and L. macropodum are parasites of wild mammals while L. martiniquensis, L. orientalis and an unnamed Leishmania sp. from Ghana are infectious to humans. There is very little information on natural reservoir hosts and vectors for any Mundinia species. Methods: Experimental infections of guinea pigs with all five Mundinia species were performed. Animals were injected intradermally with 107 culture-derived promastigotes into both ear pinnae. The courses of infections were monitored weekly; xenodiagnoses were performed at weeks 4 and 8 post-infection using Lutzomyia migonei. The distribution of parasites in different tissues was determined post-mortem by conventional PCR. Results: No significant differences in weight were observed between infected animals and the control group. Animals infected with L. enriettii developed temporary lesions at the site of inoculation and were infectious to Lu. migonei in xenodiagnoses. Animals infected with L. martiniquensis and L. orientalis developed temporary erythema and dry lesions at the site of inoculation, respectively, but were not infectious to sand flies. Guinea pigs infected by L. macropodum and Leishmania sp. from Ghana showed no signs of infection during experiments, were not infectious to sand flies and leishmanial DNA was not detected in their tissue samples at the end of experiments at week 12 post-inoculation. Conclusions: According to our results, guinea pigs are not an appropriate model organism for studying Mundinia species other than L. enriettii. We suggest that for better understanding of L. (Mundinia) biology it is necessary to focus on other model organisms. [ABSTRACT FROM AUTHOR]

Background: Since the introduction of miltefosine (MIL) as first-line therapy in the kala-azar elimination programme in the Indian subcontinent, treatment failure rates have been increasing. Since parasite infectivity and virulence may become altered upon treatment relapse, this laboratory study assessed the phenotypic effects of repeated in vitro and in vivo MIL exposure. Methods: Syngeneic Leishmania donovani lines either or not exposed to MIL were compared for drug susceptibility, rate of promastigote multiplication and metacyclogenesis, macrophage infectivity and behaviour in the sand fly vector, Lutzomyia longipalpis. Results: Promastigotes of both in vitro and in vivo MIL-selected strains displayed a slightly reduced drug susceptibility that was associated with a reduced MIL-accumulation linked to a lower copy number (disomic state) of chromosome 13 harboring the miltefosine transporter (LdMT) gene. In vitro selected promastigotes showed a lower rate of metacyclogenesis whereas the in vivo derived promastigotes displayed a moderately increased growth rate. Repeated MIL exposure did neither influence the parasite load nor metacyclogenesis in the sand fly vector. Conclusions: Recurrent in vitro and in vivo MIL exposure evokes a number of very subtle phenotypic and genotypic changes which could make promastigotes less susceptible to MIL without attaining full resistance. These changes did not significantly impact on infection in the sand fly vector. [ABSTRACT FROM AUTHOR]

Visceral leishmaniasis (VL) is a neglected tropical disease, caused by Leishmania (Kinetoplastida, Trypanosomatidae) species. In Brazil, the transmission of this parasite essentially occurs through the bite of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) previously infected with Leishmania infantum. Aiming at preventing VL expansion over the country, integrated control actions have been implemented through a Visceral Leishmaniasis Surveillance and Control Program (VLSCP). Among the actions currently adopted by the program, the screening-culling of seropositive dogs for canine VL (CVL) is particularly polemic. Dogs with negative or divergent serology for CVL remain in their owner's domicile and are monitored by public health agents. In the present study, we determined the prevalence of CVL and analyzed the implementation of the VLSCP screening-culling action, in an area in Brazil where there has been a recent expansion of VL. Canine census surveys were conducted semiannually for two years (Aug/2015 to Feb/2017). Serological diagnosis of CVL was performed in accordance with current VLSCP protocol: immunochromatography (TR-DPP) followed by enzyme-linked immunosorbent assay (ELISA EIE). 6,667 dogs were serologically screened for CVL, of which 567 (8.5%) were positive in both tests and 641 (9.6%) had divergent results. A variable percentage (6.3% to 65.4%) of the dogs in the latter group became positive within nine months from the first result. Xenodiagnosis was conducted in canine samples belonging to any of the three possible serological statuses for CVL–positive, divergent or negative. Leishmania spp. DNA was detected in Lu. longipalpis that fed on 50.0% (5/10) of dogs with positive serology and on 29.4% (5/17) of dogs with divergent serological status for CVL. Therefore, dogs with divergent serology for CVL may be as Leishmania-infective to Lu. longipalpis as seropositive ones. Even with the adoption of euthanasia for seropositive dogs, part of the canine population will continue to serve as a source of Leishmania infection for phlebotomine sand flies. Author summary: Visceral leishmaniasis (VL) is a neglected tropical disease caused by a protozoan of the genus Leishmania. In Brazil, the parasites are mainly transmitted through the bite of female Lutzomyia longipalpis sand flies that have been previously infected with Leishmania infantum. Dogs are the main domestic reservoirs of Leishmania. The Brazilian Ministry of Health has implemented euthanasia of VL-seropositive dogs as a measure to prevent VL expansion in the country, using the Dual-Path Platform Immunochromatographic Rapid Test (TR-DPP) as the screening method and the enzyme-linked immunoassay (ELISA EIE) as the confirmatory test for diagnosis. Dogs with positive results in both tests are considered seropositive and recommended for euthanasia. Dogs with divergent serology between these tests remain at their owners' home and part of them become seropositive within months. Therefore, even adopting euthanasia of seropositive dogs, part of the canine population will continue to serve as a source of Leishmania infection for sand flies, causing new canine and / or human cases of the disease. Difficulties and limitations to implement the screening-culling policy are also discussed. [ABSTRACT FROM AUTHOR]

Visceral leishmaniasis (VL) is a disease transmitted by phlebotomine sandflies, in a complex interaction with the nosogeography entity. This work is a geographical approach of VL in the state of São Paulo, supported by Ecological Niche Modeling. The goal is to verify the correlation between the spatial distribution of the sandfly Lutzomyia longipalpis and environmental variables, and verify the overlay distribution of reported human cases and final model of Maximum Entropy (MaxEnt). Data reports of the occurrence of Lu. longipalpis by municipalities from 1997-2016 were collected. Also environmental data from bioclimatic variables (BIOCLIM) in a 1km spatial resolution were collected. In the state, some variables were correlated with the sandfly distribution, such as: day-to-night ascilations in temperature (4%), maximum monthly temperature occurrence over a given year (16.1%), total precipitation during the driest month (22.7%), variation in monthly precipitation totals over the course of the year (16.7%), total precipitation that prevails during the wettest quarter (21.8%), total precipitation that prevails during the driest quarter (10.3%) and total precipitation that prevails during the coldest quarter (8.3%). The data clearly indicate a likelihood of expansion from the center of the state into Campinas and Piracicaba (east). Regarding the first expansion axis in the state, from center to the west, it is suggested working with the settlements, which can be a source of a specific case of VL expansion, the "new rural", enclosing the rural-urban-new rural hypothesis. [ABSTRACT FROM AUTHOR]

Introduction: this study aims to investigate the eco-epidemiological factors associated with Leishmania spp. infection in dogs from the Metropolitan Area of Bucaramanga (MAB)‚ Santander‚ eastern Colombia‚ which is a region at risk of VL. Methods: we conducted molecular and serological surveillance of Leishmania spp. in 207 dogs from MAB to determine the epidemiological factors associated with infection. Subsequently‚ we carried out a molecular and serological analysis of phlebotomine and humans in the area to describe the main features associated with the transmission cycle. Results: out of the 207 dogs tested‚ 37 (17.8 %‚ 95 % CI=12.6 - 23.1 %) were positive for Leishmania spp. by the IFAT test‚ and only 9 (4.3 %‚ 95 % CI=1.55 - 7.15 %) were positive for L. infantum in the molecular analysis. Multivariate analyses indicated that canine shelters had a higher prevalence of infection (p < 0.05). In the entomological survey‚ 69 blood-fed female phlebotomine of the genus Lutzomyia were captured in canine shelters‚ among them‚ 55 % were identified as Lutzomyia camposi‚ 29 % as Lu. ovallesi‚ 7 % as Lu. dubitans‚ 6 % as Lu. torvida‚ and 3 % as Lu. cayennensis. The identified meal sources of the phlebotomine included human‚ pig‚ avian‚ cattle‚ and porcupine (Coendou quichua) blood. However‚ no phlebotomine positive for Leishmania spp. were detected by molecular analyses. Finally‚ 14 humans who had frequent contact with L. infantum-positive dogs were analyzed through rK39 test‚ but none was positive for IgG/IgM antibodies. Conclusion: the molecular and serological analyses indicate a low prevalence of L. infantum in dogs from MAB‚ with canine shelters having the highest prevalence of infection. The entomological survey of canine shelters showed a significant diversity of phlebotomine without potential vectors of L. infantum‚ suggesting that the infection in dogs from these areas could take place in other locations or through other transmission routes. The circulation of L. infantum in multiple dogs from MAB suggests a latent risk of zoonotic transmission of VL in these cities. [ABSTRACT FROM AUTHOR]

ABSTRACT Few cases of human cutaneous leishmaniasis (CL) caused by Leishmania naiffi were described in the medical literature. The aim of this study was to report and analyze new cases of L. naiffi in the period between the years 1992 to 2011. The strains were characterized by isoenzyme analysis. All patients assisted had small lesions; ranging from 1.0x1.0 mm and 13.5x11.5 mm. The lesions observed were widely distributed: 55.5% on the lower limb, 5.5% in the abdominal area, 16.6% on upper limb and 22.2% in upper limb and back. Seventy-two percent of patients had ulcerated lesions. Clinical course of the disease varied from 1 to 10 months. According to gender, most infected individuals were men (83.3%). The patients came from Amazonas (10), Pará (01) and Rondônia (01), north States of Brazil. Five patients were infected in experimental stations of the National Institute of Amazonian Research (INPA). Although the results of this study were similar to other reports in the literature, some of the patients had more of one skin lesion. It is also reported the first case of CL caused by L. naiffi in the State of Rondônia and identified an area of disease transmission in the experimental station of INPA.

Phlebotomine sand flies are remarkable vectors of several etiologic agents (virus, bacterial, trypanosomatid Leishmania), posing a heavy health burden for human populations mainly located at developing countries. Their intestinal microbiota is involved in a wide range of biological and physiological processes, and could exclude or facilitate such transmission of pathogens. In this study, we investigated the Eubacterial microbiome from digestive tracts of Lu. evansi adults structure using 16S rRNA gene sequence amplicon high throughput sequencing (Illumina MiSeq) obtained from digestive tracts of Lu. evansi adults. The samples were collected at two locations with high incidence of the disease in humans: peri-urban and forest ecosystems from the department of Sucre, Colombia. 289,068 quality-filtered reads of V4 region of 16S rRNA gene were obtained and clustered into 1,762 operational taxonomic units (OTUs) with 97% similarity. Regarding eubacterial diversity, 14 bacterial phyla and 2 new candidate phyla were found to be consistently associated with the gut microbiome content. Proteobacteria, Firmicutes, and Bacteroidetes were the most abundant phyla in all the samples and the core microbiome was particularly dominated by Methylobacterium genus. Methylobacterium species, are known to have mutualistic relationships with some plants and are involved in shaping the microbial community in the phyllosphere. As a remarkable feature, OTUs classified as Wolbachia spp. were found abundant on peri-urban ecosystem samples, in adult male (OTUs n = 776) and unfed female (OTUs n = 324). Furthermore, our results provide evidence of OTUs classified as Cardinium endosymbiont in relative abundance, notably higher with respect to Wolbachia. The variation in insect gut microbiota may be determined by the environment as also for the type of feeding. Our findings increase the richness of the microbiota associated with Lu. evansi. In this study, OTUs of Methylobacterium found in Lu. evansi was higher in engorged females, suggesting that there are interactions between microbes from plant sources, blood nutrients and the parasites they transmit during the blood intake. [ABSTRACT FROM AUTHOR]

Lutzomyia longipalpis is the main vector of Leishmania infantum, the causative agent of visceral leishmaniasis in the Neotropical realm. Its taxonomic status has been widely discussed once it encompasses a complex of species. The knowledge about the genetic structure of insect vector populations helps the elucidation of components and interactions of the disease ecoepidemiology. Thus, the objective of this study was to genotypically analyze populations of the Lu. longipalpis complex from a macrogeographic perspective using Next Generation Sequencing. Polymorphism analysis of three molecular markers was used to access the levels of population genetic structure among nine different populations of sand flies. Illumina Amplicon Sequencing Protocol® was used to identify possible polymorphic sites. The library was sequenced on paired-end Illumina MiSeq platform. Significant macrogeographical population differentiation was observed among Lu. longipalpis populations via PCA and DAPC analyses. Our results revealed that populations of Lu. longipalpis from the nine municipalities were grouped into three clusters. In addition, it was observed that the levels of Lu. longipalpis population structure could be associated with distance isolation. This new sequencing method allowed us to study different molecular markers after a single sequencing run, and to evaluate population and inter-species differences on a macrogeographic scale. [ABSTRACT FROM AUTHOR]

The sex-aggregation pheromone sobralene produced by the sandfly Lutzomyia longipalpis is isomerised to verticillenes in the presence of mild acid, thereby providing credence to the proposal that sobralene is a likely shunt metabolite of the taxadiene synthase cascade. [ABSTRACT FROM AUTHOR]

Introducción: Sandfly are known for having vector species for the tropical disease known as leishmaniasis, endemic to West Boyacá; the municipality of Otanche displays one of the main focus for cutaneous leishmaniasis. Objetivo: To identify the species of sandfly present in an endemic area of cutaneous leishmaniasis in West Boyacá. Métodos: The search and collection of sandflies was carried out using CDC gravid traps, over a period of twelve hours (18:00- 06:00). Identification was carried out by revising the genitalia on both male and female samples under a microscope. The distribution took as reference households with a history of people infected with this disease, locating them intra, peri and extra domicile. Resultados: 361 individuals were recollected (252 females and 109 male), belonging to 9 genres and 16 species. 60% of all recollected phlebotominae consists of Nyssomyia yuilli and Nyssomyia trapidoi. Other species recollected and relevant, due to vector precedent, are Lutzomyia hartmanni, Psychodopygus panamensis, Lutzomyia gomezi and Psychodopygus carrerai. Conclusión: It was established that, due to its abundance and vector precedent for the country and the area under study, Nyssomyia yuilli and Nyssomyia trapidoi constitute the species of phlebotominae which may be involved in the transmission of cutaneous Leishmaniasis in the region. [ABSTRACT FROM AUTHOR]

Lutzomyia longipalpis, a sand fly, is a vector-spreading pathogenic protozoan in the New World. MicroRNA (miRNA) is evolutionarily-conserved non-coding RNA, which plays critical roles in various biological processes. To date, the functions of most proteins in L. longipalpis are unknown, and few studies have addressed the roles of miRNAs in this species. In the present study, we re-annotated the protein-coding genes and identified several miRNAs using a set of comparative genomics tools. A large number of L. longipalpis proteins were found to be homologous with those in the mosquito genome, indicating that they may have experienced similar selective pressures. Among these proteins, a set of 19 putative salivary proteins were identified, which could be used for studying the transmission of Leishmania. Twenty-one novel miRNAs were characterized, including two miRNAs, miR-4113-5p and miR-5101, which are unique to L. longipalpis. Many of the targets of these two genes were found to be involved in ATP hydrolysis-coupled proton transport, suggesting that they may have important roles in the physiology of energy production. Topology analysis of the miRNA-gene network indicated that miR-9388-5p and miR-3871-5p regulate several critical genes in response to disease development. In conclusion, our work provides a basis for improving the genome annotation of L. longipalpis, and opens a new door to understanding the molecular regulatory mechanisms in this species. [ABSTRACT FROM AUTHOR]

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Lutzomyia cruciata (Diptera: Phlebotominae) is an important Leishmania vector with wide distribution in America. However, geographical patterns of morphological variation of populations along its longitudinal and latitudinal distribution are still unknown. In this work, we quantified morphological variation and disparity in 243 specimens (females) from nine sample groups of Lu. cruciata from two biogeographical provinces in Mexico: Veracruzan Province (five groups) and Yucatan Peninsula Province (four groups). We registered two linear morphometric data of a reproductive structure (spermatheca) and one landmark configuration for wing shape. Our questions were if intraspecific morphological variation and disparity are related to contrasting environmental factors in these two provinces. First, our results from canonical variates analyses of the spermatheca and wing shape revealed more differences among groups of specimens within a biogeographic province than between. Second, our regression analyses revealed that morphometric variation is weakly related to 20 environmental variables considered for the two biogeographic provinces. Levels of morphological disparity in the spermatheca and wing shape within the two provinces are the same regardless of environmental homogeneity in the Yucatan Province or heterogeneity in the Veracruzan Province. These patterns of morphological variation and disparity weakly correlated with environmental variables suggest that intraspecific variation in Lu. cruciata is not clinal within a province. Subsequent investigations will be required to elucidate suspected correlations of local discontinuous phenotypes with genetic divergence within a biogeographical province. [ABSTRACT FROM AUTHOR]

Multiple species of Phlebotominae are vectors of Leishmania (Protozoa: Trypanosomatidae), which causes visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). To describe the Phlebotominae (Diptera: Psychodidae) related to the environments of black and gold howler monkeys Alouatta caraya (Humbodlt, 1812) (Primates: Atelidae), potential vectors were sampled in different landscapes and vertical strata of sleeping trees. Phlebotomine captured between December 2011 and March 2012 (2365 individuals) belonged to eight species, of which Nyssomyia neivai (Pinto, 1926) (61.4%) and Migonemyia migonei (França, 1920) (18.73%) were the most abundant, and Ny. withmani was recorded for the first time in the Chaco province. In the 'peri‐domestic' landscape, the phlebotomine were mainly captured in henhouses (78.7%), whereas the tree canopy in 'rural' and 'wild' landscapes yielded 31.2% and 29.1% of the phlebotomine, respectively. A significant association between the type of landscape and the species of phlebotomine was observed by multivariate analysis. Lutzomyia longipalpis (Lutz & Neiva, 1912) and Mg. migonei were associated with 'peri‐domestic' landscape, and Ny. neivai was associated with the 'wild' landscape. The results of this prospective study suggest that the interaction between phlebotomine and A. caraya could be a key factor with respect to understanding the epidemiology of leishmaniasis. [ABSTRACT FROM AUTHOR]

The genus Bartonella encompasses several zoonotic species that cause emerging infectious diseases in humans. These species are transmitted to humans by hematophagous arthropods. In South America, sand flies are the most important vectors of Bartonella bacilliformis, the etiological agent of Verruga peruana. Due to the importance of bartonellosis in public health, the aim of this study was to detect Bartonella in wild populations of phlebotomine sand flies in southern Mexico. In total, 29 sand flies belonging to 6 species were collected. Only 2 specimens were positive, representing a prevalence of 8.69% (2/23). This appears to be the first report of Bartonella sp. in phlebotomine sand flies outside the endemic area of Verruga peruana in South America. Further studies are needed to clarify the relation between this bacterium and sand flies in Mexico. [ABSTRACT FROM AUTHOR]

The protozoan parasite Leishmania possesses a single flagellum, which is remodelled during the parasite’s life cycle from a long motile flagellum in promastigote forms in the sand fly to a short immotile flagellum in amastigotes residing in mammalian phagocytes. This study examined the protein composition and in vivo function of the promastigote flagellum. Protein mass spectrometry and label free protein enrichment testing of isolated flagella and deflagellated cell bodies defined a flagellar proteome for L. mexicana promastigote forms (available via ProteomeXchange with identifier PXD011057). This information was used to generate a CRISPR-Cas9 knockout library of 100 mutants to screen for flagellar defects. This first large-scale knockout screen in a Leishmania sp. identified 56 mutants with altered swimming speed (52 reduced and 4 increased) and defined distinct mutant categories (faster swimmers, slower swimmers, slow uncoordinated swimmers and paralysed cells, including aflagellate promastigotes and cells with curled flagella and disruptions of the paraflagellar rod). Each mutant was tagged with a unique 17-nt barcode, providing a simple barcode sequencing (bar-seq) method for measuring the relative fitness of L. mexicana mutants in vivo. In mixed infections of the permissive sand fly vector Lutzomyia longipalpis, paralysed promastigotes and uncoordinated swimmers were severely diminished in the fly after defecation of the bloodmeal. Subsequent examination of flies infected with a single paralysed mutant lacking the central pair protein PF16 or an uncoordinated swimmer lacking the axonemal protein MBO2 showed that these promastigotes did not reach anterior regions of the fly alimentary tract. These data show that L. mexicana need directional motility for successful colonisation of sand flies. [ABSTRACT FROM AUTHOR]

Lutzomyia longipalpis (Diptera: Psychodidae) is the primary vector of Leishmania infantum (Kinetoplastida: Trypanosomatidae) in the Americas. Studies have been carried out to identify new alternatives for monitoring and controlling this sandfly species, particularly with the use of chemical baits. The attractiveness of odours emitted by foxes and alcohols found in some plants has already been demonstrated in laboratory tests with Lu. longipalpis. However, no studies have evaluated the responses of these insects to volatile organic compounds (VOCs) emitted by dogs. The present study was carried out to investigate the effects on Lu. longipalpis of individual and blends of VOCs identified in hair from dogs infected with L. infantum. Effects in male and female Lu. longipalpis were assessed using wind tunnel methodology. Individual compounds including octanal, nonanal, decanal and heptadecane showed capacity for activating and/or attracting male Lu. longipalpis. Only decanal and nonanal showed effects on females. The combination of octanal, decanal and heptadecane increased activation and attraction behaviour in male sandflies, as did the blend of octanal and decanal. These findings indicate that VOCs emitted by dogs may be an interesting source of new attractants of sandflies. [ABSTRACT FROM AUTHOR]

Introduction: The study of the interaction between the parasite, the vector and the mammalian hosts, including man, allows to understand the behavior of the leishmaniases. Objetive: To determine the presence of Lutzomyia species and to detect the Leishmania infection in D. marsupialis in an endemic area for visceral leishmaniasis. Materials and methods: Phlebotomine fauna and individuals of D. marsupialis were collected with CDC and Tomahawk® traps, respectively. The species of Lutzomyia were identified using the Young & Duncan (1994) key. Ear and tail biopsies and blood samples from D. marsupialis were taken to identify the Leishmania species by amplifying a fragment of the gene associated with the 70 kD heat shock protein. Results: Seven Lutzomyia species were identified: Lu. evansi, Lu. gomezi, Lu. panamensis, Lu. dubitans, Lu. cayennensis cayennensis, Lu. rangeliana and Lu. trinidadensis. The first three species have epidemiological importance in Colombia because of their implications in the transmission of the Leishmania parasite. Sixty-five tissue samples from 19 D. marsupialis individuals were negative for Leishmania spp. Conclusions: The presence of the Lutzomyia species that have been identified as vectors for Leishmania inside and around houses in the village of El Bledo, in El Carmen de Bolivar represents a risk of infection. Furthermore, the presence of Lu. panamensis is reported for first time in El Carmen de Bolivar in Colombia. Although the lack of detection of Leishmania spp in D. marsupialis samples may suggest that D. marsupialis does not play an important role in the transmission cycle of Leishmania in this region, it is necessary to carry out further longitudinal studies to confirm this hypothesis. [ABSTRACT FROM AUTHOR]

Leishmaniasis is a zoonotic disease of worldwide relevance. Visceral leishmaniasis is endemic in Brazil, where it is caused by Leishmania infantum with Lutzomyia longipalpis being the most important invertebrate vector. Non-human primates are susceptible to L. infantum infection. However, little is known about the role of these species as reservoirs. The aim of this study was to evaluate the transmissibility potential of visceral leishmaniasis by non-human primates through xenodiagnosis using the phlebotomine Lu. longipalpis as well as to identify phlebotomine species prevalent in the area where the primates were kept in captivity, and assess infection by Leishmania in captured phlebotomine specimens. Fifty two non-human primates kept in captivity in an endemic area for leishmaniasis were subjected to xenodiagnosis. All primates were serologically tested for detection of anti-Leishmania antibodies. Additionally, an anti-Lu. longipalpis saliva ELISA was performed. Sand flies fed on all animals were tested by qPCR to identify and quantify L. infantum promastigotes. Eight of the 52 non-human primates were positive by xenodiagnosis, including three Pan troglodytes, three Leontopithecus rosalia, one Sapajus apella, and one Miopithecus talapoin, with estimated numbers of promastigotes ranging from 5.67 to 1,181.93 per μg of DNA. Positive animals had higher levels of IgG anti-Lu. longipalpis saliva when compared to negative animals, prior to xenodiagnosis. Captive non-human primates are capable of infecting Lu. longipalpis with L. infantum. Our findings also demonstrate the relevance of non-human primates as sentinels to zoonotic diseases. Several phlebotomine species, including Lu. longipalpis, have been identified in the area where the primates were maintained, but only one pool of Lutzomyia lenti was infected with L. infantum. This study has implications for public health strategies and conservation medicine. [ABSTRACT FROM AUTHOR]

Lutzomyia longipalpis is the main vector of Leishmania infantum and exploits different food sources during development. Adults have a diet rich in sugars, and females also feed on blood. The sugar diet is essential for maintaining longevity, infection, and Leishmaniasis transmission. Carbohydrases, including α-glucosidases, are the main enzymes involved in the digestion of sugars. In this context, we studied the modulation of α-glucosidase activities in different feeding conditions and compartments of Lutzomyia longipalpis females, in order to characterize in detail their roles in the physiology of this insect. All tissues showed activity against MUαGlu and sucrose, with highest activities in the midgut and crop. Activity was 1,000 times higher on sucrose than on MUαGlu. Basal activities were observed in non-fed insects; blood feeding induced activity in the midgut contents, and sugar feeding modulated activity in midgut tissues. α-glucosidase activity changed after female exposure to different sugar concentrations or moieties. α-glucosidases from different tissues showed different biochemical properties, with an optimum pH around 7.0–8.0 and K M between 0.37 and 4.7 mM, when MUαGlu was used as substrate. Using sucrose as substrate, the optimum pH was around 6.0, and K M ranges between 11 and 800 mM. Enzymes from the crop and midgut tissues showed inhibition in high substrate concentrations (sucrose), with K I ranging from 39 to 400 mM, which explains the high K M values found. Chromatographic profiles confirmed that different α-glucosidases are been produced in L. longipalpis in different physiological contexts, with the distinction of at least four α-glucosidases. The results suggest that some of these enzymes are involved in different metabolic processes, like digestion of plant sugars, digestion of blood glycoproteins or glycolipids, and mobilization of energetic storages during starvation. [ABSTRACT FROM AUTHOR]

Despite the increasing number of studies concerning insect immunity, Lutzomyia longipalpis immune responses in the presence of Leishmania infantum chagasi infection has not been widely investigated. The few available studies analyzed the role of the Toll and IMD pathways involved in response against Leishmania and microbial infections. Nevertheless, effector molecules responsible for controlling sand fly infections have not been identified. In the present study we investigated the role a signal transduction pathway, the Transforming Growth Factor-beta (TGF-β) pathway, on the interrelation between L. longipalpis and L. i. chagasi. We identified an L. longipalpis homolog belonging to the multifunctional cytokine TGF-β gene family (LlTGF -β), which is closely related to the activin/inhibin subfamily and potentially involved in responses to infections. We investigated this gene expression through the insect development and in adult flies infected with L. i. chagasi. Our results showed that LlTGF -β was expressed in all L. longipalpis developmental stages and was upregulated at the third day post L. i. chagasi infection, when protein levels were also higher as compared to uninfected insects. At this point blood digestion is finished and parasites are in close contact with the insect gut. In addition, we investigated the role of LlTGF-β on L. longipalpis infection by L. i. chagasi using either gene silencing by RNAi or pathway inactivation by addition of the TGF-β receptor inhibitor SB431542. The blockage of the LlTGF-β pathway increased significantly antimicrobial peptides expression and nitric oxide levels in the insect gut, as expected. Both methods led to a decreased L. i. chagasi infection. Our results show that inactivation of the L. longipalpis TGF-β signal transduction pathway reduce L. i. chagasi survival, therefore suggesting that under natural conditions the parasite benefits from the insect LlTGF-β pathway, as already seen in Plamodium infection of mosquitoes. [ABSTRACT FROM AUTHOR]

The spatiotemporal population dynamics of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) were evaluated in a city in Argentina in which visceral leishmaniasis is endemic. Over 14 sampling sessions, 5244 specimens of five species of Phlebotominae (Diptera: Psychodidae) were captured, of which 2458 (46.87%) specimens were L. longipalpis. Generalized linear models were constructed to evaluate the associations between L. longipalpis abundance and explanatory variables derived from satellite images. The spatial variable 'stratum' and the temporal variable 'season' were also included in the models. Three variables were found to have significant associations: the normalized difference vegetation index; land surface temperature, and low urban coverage. The last two of these were associated with L. longipalpis abundance only during summer and winter, respectively. This variation between seasons supports the development of models that include temporal variables because models of distributions of the abundance of a species may show different critical variables according to the climatic period of the year. Abundance decreased gradually towards the downtown area, which suggests that L. longipalpis responds to a meta‐population structure, in which rural–periurban source populations that persist over time may colonize adjacent areas. This information allows for a spatiotemporal stratification of risk, which provides public health authorities with a valuable tool to help optimize prevention measures against visceral leishmaniasis. The spatiotemporal population dynamics of Lutzomyia longipalpis were evaluated over 14 sampling sessions in a city in Argentina in which visceral leishmaniasis is endemic.Generalized linear models were constructed to evaluate the associations between L. longipalpis abundance and explanatory variables derived from satellite images.Three variables showed significant associations with L. longipalpis abundance: the normalized difference vegetation index; land surface temperature (in summer only), and low urban coverage (in winter only). [ABSTRACT FROM AUTHOR]

Leishmaniasis encompasses a group of diverse clinical diseases caused by protozoan parasites of the Leishmania genus. This disease is a major public health problem in the New World affecting people exposed in endemic regions. The city of Governador Valadares (Minas Gerais/Brazil) is a re-emerging area for visceral leishmaniasis, with 191 human cases reported from 2008 to 2017 and a lethality rate of 14.7%. The transmission of the parasite occurs intensely in this region with up to 22% of domestic dogs with positive serology for the visceral form. Lu. longipalpis is one of the most abundant sand fly species in this area. Despite this scenario, so far there is no information regarding the circulating Leishmania species in the insect vector Lutzomyia longipalpis in this focus. We collected 616 female Lutzomyia longipalpis sand flies between January and September 2015 in the Vila Parque Ibituruna neighborhood (Governador Valadares/MG), which is located on a transitional area between the sylvatic and urban environments with residences built near a preserved area. After DNA extraction of individual sand flies, the natural Leishmania infections in Lu. longipalpis were detected by conventional PCR, using primers derived from kDNA sequences, specific for L. (Leishmania) or L. (Viannia) subgenus. The sensitivity of these PCR reactions was 0.1 pg of DNA for each Leishmania subgenus and the total infection rate of 16.2% (100 positive specimens). Species-specific PCR detected the presence of multiple Leishmania species in infected Lu. longipalpis specimens in Governador Valadares, including L. amazonensis (n = 3), L. infantum (n = 28), L. (Viannia) spp. (n = 20), coinfections with L. infantum and L. (Viannia) spp. (n = 5), and L. (Leishmania) spp (n = 44). Our results demonstrate that multiple Leishmania species circulate in Lu. longipalpis in Governador Valadares and reveal a potential increasing risk of transmission of the different circulating parasite species. This information reinforces the need for epidemiological and entomological surveillance in this endemic focus, and the development of effective control strategies against leishmaniasis. [ABSTRACT FROM AUTHOR]

American visceral leishmaniasis (VL) is a vector-borne disease transmitted by some species of phlebotomine sandflies from the genus Lutzomyia. This neglected tropical zoonosis shows increasing urbanization process, since the end of the 1980s. After the emergence of foci of the disease in urban areas, VL has assumed an important role in public health. Although VL is widely prevalent in several parts of the world, diagnosing the illness is still difficult. We present a case of a 12-year-old girl with a history of recurrent fever, anorexia, cachexia, chronic fatigue, weight loss, left palpebral unilateral edema, persistent cough and pancytopenia. A diagnosis of VL was performed using a reference immunochromatographic rapid test. Identification of the infecting protozoan was directly obtained by PCR of bone marrow. The patient responded favorably to treatment using liposomal amphotericin B. This is the first report of human visceral leishmaniasis in the city of Lavras in the South of Minas Gerais State. This first report of VL highlighted the need of maintenance of permanent surveillance and control programs in the city of Lavras, including the active search of sandflies, human and canine cases. The current situation of Lavras should also be taken as an alert to other near cities where favorable eco-epidemiological conditions may exist. [ABSTRACT FROM AUTHOR]

In South America, the Protist parasite that causes visceral leishmaniasis, a potentially fatal human disease, is transmitted by blood-feeding female Lutzomyia longipalpis sand flies. A synthetic copy of the male produced sex-aggregation pheromone offers new opportunities for vector control applications. We have previously shown that the pheromone placed in plastic sachets (lures) can attract both females and males to insecticide treated sites for up to 3 months. To use the pheromone lure in a control program we need to understand how the application of lures in the field can be optimised. In this study we investigated the effect of increasing the number of lures and their proximity to each other on their ability to attract Lu. longipalpis. Also for the first time we applied a Bayesian log-linear model rather than a classic simple (deterministic) log-linear model to fully exploit the field-collected data. We found that sand fly response to pheromone is significantly related to the quantity of pheromone and is not influenced by the proximity of other pheromone sources. Thus sand flies are attracted to the pheromone source at a non-linear rate determined by the amount of pheromone being released. This rate is independent of the proximity of other pheromone releasing traps and indicates the role of the pheromone in aggregation formation. These results have important implications for optimisation of the pheromone as a vector control tool and indicate that multiple lures placed in relatively close proximity to each other (5 m apart) are unlikely to interfere with one another. [ABSTRACT FROM AUTHOR]

The article discusses tropical distribution of phlebotomine sand flies. It mentions that species of flies including Lutzomyia oppidana, Lutzomyia apache, and Lutzomyia aquilonia live in arid rocky areas in Colorado. It also mentions that sand flies are stored in ethanol, cleared and slide mounted in Hoyer's solution for identification.

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Leishmaniasis is a debilitating and often fatal neglected tropical disease. Males from sub-populations of the Leishmania -harbouring sandfly, Lutzomyia longipalpis , produce the diterpene sex and aggregation pheromone, sobralene, for which geranylgeranyl diphosphate (GGPP) is the likely isoprenoid precursor. We have identified a GGPP synthase (lz GGPPS) from L. longipalpis , which was recombinantly expressed in bacteria and purified for functional and kinetic analysis. In vitro enzymatic assays using LC-MS showed that lz GGPPS is an active enzyme, capable of converting substrates dimethylallyl diphosphate (DMAPP), (E)-geranyl diphosphate (GPP), (E,E)-farnesyl diphosphate (FPP) with co-substrate isopentenyl diphosphate (IPP) into (E,E,E)-GGPP, while (Z,E)-FPP was also accepted with low efficacy. Comparison of metal cofactors for lz GGPPS highlighted Mg2+ as most efficient, giving increased GGPP output when compared against other divalent metal ions tested. In line with previously characterised GGPPS enzymes, GGPP acted as an inhibitor of lz GGPPS activity. The molecular weight in solution of lz GGPPS was determined to be ∼221 kDa by analytical SEC, suggesting a hexameric assembly, as seen in the human enzyme, and representing the first assessment of GGPPS quaternary structure in insects. [Display omitted] • Geranylgeranyl diphosphate synthase (lz GGPPS) from Lutzomyia longipalpis expressed and functionally tested. • Mg2+ identified as the most efficient cofactor of lz GGPPS. • lz GGPPS displayed product inhibition by GGPP. • Assessment of native molecular weight in solution suggests the enzyme is hexameric. [ABSTRACT FROM AUTHOR]

• Detection of Leishmania braziliensis DNA in Lutzomyia cruzi. • Identification of three food sources in engorged females of sand flies. • Potential role of Lutzomia cruzi in transmitting Leishmania braziliensis. In this study, we investigated the presence of Leishmania in sand flies collected from a peridomestic area in Corumbá, Mato Grosso do Sul, after an autochthonous case of cutaneous leishmaniasis was confirmed. A total of 1,542 sand flies belonging to seven species were collected, with Lu. cruzi being the most prevalent (94.3%). We detected the presence of DNA from Le. infantum (7 pools) and Le. braziliensis (3 pools) by sequencing the ITS1 amplicon in ten pools, all of which were composed of engorged (3) and non-engorged (7) females of Lu. cruzi. We collected 24 engorged females, with Homo sapiens being the most common blood meal source (91.6%), followed by Dasyprocta azarae and Canis lupus familiaris (4.2% each). To our knowledge, this is the first molecular evidence of Le. braziliensis in wild-caught Lu. cruzi in Brazil, suggesting its potential role as a vector for this parasite. [ABSTRACT FROM AUTHOR]

Lutzomyia evansi es importante en salud pública por su participación en la trasmisión de la leishmaniasis visceral y cutánea en la costa caribe de Colombia. Diversos estudios se han desarrollado sobre la poblaciones naturales de Lutzomyia evansi, sin embargo pocos estudios han explorado en profundidad la detección de microorganismos simbióticos (ej. Wolbachia) y de manera simultánea la presencia de Leishmania sp.. El endosimbionte Wolbachia ha sido propuesto en la actualidad como control biológico de insectos vectores de diversas enfermedades tropicales. En el presente estudio el ADN de tres especies del género Lutzomyia colectadas en el municipio de Ovejas (Departamento de Sucre) fue evaluado para detectar la infección natural por la bacteria Wolbachia y la presencia de parásitos del género Leishmania. El ADN total de 176 individuos adultos y 34 inmaduros (larvas y pupas) de Lu. evansi, fue utilizado para evaluar la detección de Wolbachia mediante amplificación por PCR del gen WSP (Proteína Mayor de la Superficie de Wolbachia) y la infección por Leishmania mediante amplificación por PCR de segmentos de los genes HPSN70 (Proteína de Choque Térmico). Se encontró un grupo de machos infectado de forma natural por Wolbachia y nueve grupos de hembras con infección natural por Leishmania, todos pertenecientes a Lutzomyia evansi. El análisis filogenético de la secuencia del gen WSP de Wolbachia indica la ubicación de la cepa detectada dentro del supergrupo B (haplogrupo wLeva) y su relación con haplotipos previamente reportados de Lutzomyia evansi y Lutzomya dubitans. Una región de 418 pb del gen HSP-70N fue secuenciada y mostró similaridad con secuencias de Leishmania luego de realizar el análisis en BlastN. Se confirma la presencia de Wolbachia en poblaciones silvestres de machos de L. evansi y la infección natural por Leishmania spp. en hembras de la misma especie cuya infección por Wolbachia resulto negativa.

BACKGROUND Behavioural effects of insecticides on endophagic phlebotomine sand fly vectors of Leishmania are poorly understood mainly because of the lack of an experimental hut (EH) in which to study them. OBJECTIVE To build an EH to evaluate the effects of long-lasting insecticide-treated nets (LLINs) on Lutzomyia longiflocosa. METHODS The study had two phases: (1) Laboratory experiments using tunnel tests to select the traps for the EH; and (2) EH construction and evaluation of the effects of deltamethrin and lambda-cyhalothrin LLINs on L. longiflocosa females inside the EH. FINDINGS Phase 1: The horizontal-slit trap was the best trap. This trap collected the highest percentage of sand flies, and prevented them from escaping. Therefore, this trap was used in the EH. Phase 2: The main effects of LLINs on L. longiflocosa in the EH were: landing inhibition, inhibition from entering the bednet, induced exophily, and high mortality (total and inside exit traps). CONCLUSIONS The EH was effective for evaluating the effects of LLINs on endophagic sand flies. Although both types of LLINs showed high efficacy, the lambda-cyhalothrin-treated LLIN performed better. This is the first report of induced exophily in sand flies.

Abstract Background The Lençóis Maranhenses National Park, located in Maranhão, Brazil, is a region of exceptional beauty and a popular tourist destination. The adjoining area has suffered from the impact of human activity and, consequently, has experienced outbreaks of leishmaniasis. This study aimed to evaluate the composition, abundance, species richness and seasonal distribution of sand flies in the region and to determine the constancy of the insect population. Methods The survey was conducted at three sites located in the municipalities of Barreirinhas and Santo Amaro between September 2012 and August 2013. Sampling was performed monthly using automatic light traps installed 1.5 m above the soil adjacent to 13 randomly selected rural dwellings. At each site, one trap was placed in the peridomicile near to animal enclosures and another (extradomicile) at 500 m from the peridomicile. Results A total of 4,474 individual sand flies were collected over the year with the highest abundance recorded during the rainy season (December to June). Nine species were collected: L. whitmani, L. longipalpis, L. lenti, L. sordellii, L. evandroi, L. flaviscutellata, L. wellcomei, L. termitophila and L. intermedia. Although peridomiciliary and extradomiciliary environments presented similar species richness, the Shannon diversity index was significantly lower in the former (H’ = 2.4) compared with the latter (H’ = 4.98). Lutzomyia whitmani and L. longipalpis were the most abundant species and were classified as constant (constancy index, CI = 100 %) along with L. lenti (CI = 58.3), L. evandroi (CI = 58.3) and L. sordellii (CI = 66.7). The remaining four species presented CI values between 25 and 50 % and were considered accessory. Conclusions The present results confirm the present of L. whitmani and L. longipalpis in the peridomicile of houses in Lençóis National Park. The abundance of these species could explain, respectively, the endemicity of cutaneous leishmaniasis and sporadic cases of visceral leishmaniasis in the study area. However, in the case of cutaneous leishmaniasis, the presence of other sand fly vectors (in addition to L. whitmani) cannot be neglected. Finally, this study emphasizes the need for a more effective and permanent supervision to control the expansion of these vectors and leishmaniasis outbreaks.

La leishmaniasis constituye un grave problema de salud pública en diferentes partes del mundo. Es conocido que los efectos del calentamiento global han aumentado en los últimos años, con la consecuente modificación, a corto y largo plazo, de los hábitats de los flebotominos, lo que potencialmente puede impactar en la transmisión de la leishmaniasis. En el presente trabajo se evaluó el efecto del cambio climático en la distribución geográfica de los flebotominos transmisores de la leishmaniasis cutánea, en Mérida, Venezuela. Para el análisis se tuvieron en cuenta cuatro especies vectoras Lutzomyia youngi, L. gomezi, L. ovallesi y L. walkeri y se usó un modelo atmósfera-océano Hadcm3, bajo la premisa de cambio climático en un escenario pesimista A2, con proyecciones para los años 2020, 2050 y 2080. Los resultados del modelo mostraron para L. youngi un incremento en su distribución, para L. gomezi cambios y desplazamiento en su distribución potencial futura, para L. ovallesi se mostró como la especie que puede ser más afectada por el aumento de la temperatura, con predicciones de cambios en su distribución futura, y para la distribución de L. walkeri no se mostró afectación por el cambio climático. Por otro lado, el modelo recreó escenarios de cambio climático, con predicciones de solapamiento de las principales especies transmisora, en los municipios de mayor densidad poblacional, lo que sugiere un mayor riesgo de transmisión de la leishmaniasis en el estado Mérida en los próximos años. Los mapas generados proporcionan información relevante para alertar sobre cambios en los patrones de transmisión de la leishmaniasis, además serán una herramienta útil para los entes de control y prevención.

Background/aim: Leishmaniasis is a disease group carried by Phlebotomus and Lutzomyia sand flies infected with Leishmania and is mostly observed in rural areas. In this study, using high-resolution melting analysis (HRMA), we aim to identify the active types of leishmaniasis, which are inadequately identified by classical methods. Materials and methods: Samples of 85 patients were examined in the study. Six of the patients were suspected of having visceral leishmaniasis (VL) and 79 cutaneous leishmaniasis (CL). The slides prepared from the samples were stained with Giemsa stain and examined under a light microscope. The results were compared with those determined in real-time PCR. When the real-time PCR result was positive for Leishmania, we determined the type by HRMA. Results: Among 85 Leishmania amastigote samples, 28 (32.9%) of them were detected and accepted as positive by microscopic examination. On the other hand, 25 (29.4%) of the 85 samples were found as positive using real-time PCR. In addition, when 25 Leishmania-positive samples were examined by HRMA, the results showed that 21 (84%) were L. tropica, 3 (12%) were L. major, and 1 (4%) was L. infantum. Conclusion: Based on our findings, we conclude that using real-time PCR and HRMA is useful in determining the cause of the disease in leishmaniasis. [ABSTRACT FROM AUTHOR]

Lutzomyia migonei is incriminated as a vector of Leishmania braziliensis , the main causative agent of cutaneous leishmaniasis in Brazil. Recently, this phlebotomine sand fly species has been suggested as a vector for Leishmania infantum , which causes zoonotic visceral leishmaniasis. Considering the widespread distribution of Lu. migonei in South America, the existence of isolated populations has been hypothesized. Three Lu. migonei populations, two from north-eastern Brazil (Machados, Pernambuco State, and Baturité, Ceará State) and other from the south-eastern region (Niterói, Rio de Janeiro State) were analysed both morphologically and genetically. Though no significant morphological differences were found amongst the sand fly specimens analysed, discriminant analysis based on specific morphometric characters (i.e., length of wing, antennal segment 3 and coxite for males, and length of wing and antennal segment 3 for females), showed that specimens from Machados were closer to Baturité than to Niterói. The molecular analysis of cytochrome c oxidase subunit I gene sequences also supported this observation by the distinct separation of two monophyletic clades, grouping specimens from Machados and Baturité separately from those of Niterói. Our results suggest the existence of different populations within the distribution range of Lu. migonei . Whether these populations are reproductively isolated and/or present differences in terms of vector competence/capacity for L. braziliensis and L. infantum needs to be further investigated. [ABSTRACT FROM AUTHOR]

In some transmission foci of Leishmania infantum in Brazil, Lutzomyia cruzi could be considered the main vector of this pathogen. In addition, L. cruzi is a permissive vector of L. amazonensis. Its geographical distribution seems to be restricted and limited to Cerrado and Pantanal biomes, which includes some areas in Brazil and Bolivia. Considering that predicting the distribution of the species involved in transmission cycles is an effective approach for assessing human disease risk, this study aims to predict the spatial distribution of L. cruzi using a multiscale ecological niche model based in both climate and habitat variables. Ecological niche modelling was used to identify areas in South America that are environmentally suitable for this particular vector species, but its presence is not recorded. Vector occurrence records were compiled from the literature, museum collections and Brazilian Health Departments. Bioclimatic variables, altitude, and land use and cover were used as predictors in five ecological niche model algorithms: BIOCLIM, generalised linear model (logistic regression), maximum entropy, random forests, and support vector machines. The vector occurs in areas where annual mean temperature values range from 21.76°C to 26.58°C, and annual total precipitation varies from 1005 mm and 2048 mm. Urban areas were most present around capture locations. The potential distribution area of L. cruzi according to the final ecological niche model spans Brazil and Bolivia in patches of suitable habitats inside a larger climatically favourable area. The bigger portion of this suitable area is located at Brazilian States of Mato Grosso do Sul and Mato Grosso. Our findings identified environmentally suitable areas for L. cruzi in regions without its known occurrence, so further field sampling of sand flies is recommended, especially in southern Goiás State, Mato Grosso do Sul (borders with Mato Grosso, São Paulo and Minas Gerais); and in Bolivian departments Santa Cruz and El Beni. [ABSTRACT FROM AUTHOR]

Background: The Lutzomyia longipalpis complex has a wide but discontinuous distribution in Latin America, extending throughout the Neotropical realm between Mexico and northern Argentina and Uruguay. In the Americas, this sandfly is the main vector of Leishmania infantum, the parasite responsible for Visceral Leishmaniasis (VL). The Lu. longipalpis complex consist of at least four sibling species, however, there is no current consensus on the number of haplogroups, or on their divergence. Particularly in Argentina, there have been few genetic analyses of Lu. longipalpis, despite its southern expansion and recent colonization of urban environments. The aim of this study was to analyze the genetic diversity and structure of Lu. longipalpis from Argentina, and to integrate these data to re-evaluate the phylogeography of the Lu. longipalpis complex using mitochondrial markers at a Latin America scale. Methodology/Principal findings: Genetic diversity was estimated from six sites in Argentina, using a fragment of the ND4 and the 3´ extreme of the cyt b genes. Greatest genetic diversity was found in Tartagal, Santo Tomé and San Ignacio. There was high genetic differentiation of Lu. longipalpis in Argentina using both markers: ND4 (FST = 0.452, p < 0.0001), cyt b (FST = 0.201, p < 0.0001). Genetic and spatial Geneland analyses reveal the existence of two primary genetic clusters in Argentina, cluster 1: Tartagal, Santo Tomé, and San Ignacio; cluster 2: Puerto Iguazú, Clorinda, and Corrientes city. Phylogeographic analyses using ND4 and cyt b gene sequences available in GenBank from diverse geographic sites suggest greater divergence than previously reported. At least eight haplogroups (three of these haplogroups identified in Argentina), each separated by multiple mutational steps using the ND4, are differentiated across the Neotropical realm. The divergence of the Lu. longipalpis complex from its most recent common ancestor (MRCA) was estimated to have occurred 0.70 MYA (95% HPD interval = 0.48–0.99 MYA). Conclusions/Significance: This study provides new evidence supporting two Lu. longipalpis genetic clusters and three of the total eight haplogroups circulating in Argentina. There was a high level of phylogeographic divergence among the eight haplogroups of the Lu. longipalpis complex across the Neotropical realm. These findings suggest the need to analyze vector competence, among other parameters intrinsic to a zoonosis, according to vector haplogroup, and to consider these in the design and surveillance of vector and transmission control strategies. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work was to study the distribution of Phlebotominae (Diptera: Psycodidade) abundance in time and space in an area in northeastern Argentina with vector transmission of visceral and tegumentary leishmaniasis. For this, 51 households were selected using a ‘worst scenario’ criterion where one light trap was set during two consecutive nights in peridomiciles in the transitions between the four seasons, and the environment was surveyed simultaneously. The relationships of phlebotomine assemblage structure and the most abundant species with seasonality and environmental variables were evaluated using a canonical correspondence analysis and generalized linear mixed models, respectively. A total of 5110 individuals were captured. Lutzomyia longipalpis (Lutz & Neiva, 1912) and Nyssomyia whitmani (Antunes & Coutinho, 1939) were the most abundant species captured in all samplings (98.3% of the total capture). The period of highest abundance of Lu. longipalpis was early autumn, and it was distributed in the most urbanized areas. Nyssomyia whitmani occupied mainly the less urbanized areas, showing peaks of abundance in early spring and summer. Other species were captured in low numbers and showed seasonal−spatial variations similar to those of Ny. whitmani. We confirmed Leishmania spp. vector persistence throughout the year in spatial patches of high abundance even during the less favorable season. [ABSTRACT FROM AUTHOR]

The skin is the first organ to be infected by the parasite in canine visceral leishmaniasis. The enzyme matrix metalloproteinase (MMP) acts towards degradation of the extracellular matrix (ECM) and modulation of the inflammatory response against many kinds of injuries. The aims of this study were to evaluate the expression of MMP-2 and MMP-9 through immunohistochemistry and zymography on the skin (muzzle, ears, and abdomen) of dogs that were naturally infected by Leishmania spp. and to compare these results with immunodetection of the parasite and with alterations to the dermal ECM. Picrosirius red staining was used to differentiate collagen types I and III in three regions of the skin. The parasite load, intensity of inflammation, and production of MMP-2 (latent) and MMP-9 (active and latent) were higher in the ear and muzzle regions. MMP-9 (active) predominated in the infected group of dogs and its production was significantly different to that of the control group. Macrophages, lymphocytes, and plasma cells predominated in the dermal inflammation and formed granulomas in association with degradation of mature collagen (type I) and with discrete deposition of young collagen (type III). This dermal change was more pronounced in dogs with high parasite load in the skin. Therefore, it was concluded that the greater parasite load and intensity of inflammation in the skin led consequently to increased degradation of mature collagen, caused by increased production of MMPs, particularly active MMP-9, in dogs with visceral leishmaniasis. This host response profile possibly favors systemic dissemination of the parasite. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]