[Phlebotomines (Diptera: Psychodidae) focusing visceral leishmaniasis in the State of Mato Grosso do Sul, Brazil]

Spatiotemporal changes in exposition risk to leishmaniases vector in residences within a fishing tourism area of Pantanal wetland

Miranda Municipality of Mato Grosso do Sul, borders the Pantanal wetland, a famous fishing destination visited by tourists from all over the world, and is a location where visceral leishmaniasis has been reported. To assess the risk of Leishmania infantum transmission, we studied the sandfly community, focusing on known vector and parasite presence. We conducted light trap collections twice per month at nine sites within the city (including two forested areas) for one year. We collected a total of 12,727 sand flies, 10,891 males and 1,836 females belonging to 11 species: Brumptomyia avellari, Evandromyia aldafalcaoae, Ev. evandroi, Ev. lenti, Ev. sallesi, Ev. walkeri, Lu. longipalpis, Nyssomyia whitmani, Psathyromyia bigeniculata, Pa. hermanlenti and Pa. punctigeniculata. Lutzomyia longipalpis, the proven vector of Leishmania infantum, was captured each month, and was the most abundant species observed, accounting for more than 99% of sand flies captured in most sites, especially where chicken coops were present. Evidence of Leishmania infantum infection was detected in 0.40% of Lu. longipalpis tested. We developed a generalized mixed multilevel model for Lu. longipalpis, that includes within-year seasonality, location of capture (indoors vs. outdoors), vector abundance, and sex ratio. The VL vector was abundant both inside and outside houses. Large numbers of Lu. longipalpis were observed in outdoor sites where domestic animals were present but were absent from forest sites. Our findings suggest high vector populations and Le. infantum presence in a city where tourists could be exposed to visceral leishmaniasis, with significant implications for more surveillance and control activities.

Molecular detection of Leishmania and blood meal analysis in sand flies from Corumbá, Mato Grosso do Sul, Brazil

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.

Sciopemyia sordellii in the Neotropical region: distribution, biology, and ecology

The species Sciopemyia sordellii (Diptera, Phlebotominae) is widely distributed throughout the American continent. This raises doubts about their identity as a single biological entity and points to the occurrence of species complex. Here, we review the geographic distribution of S. sordellii in the Neotropical region, as well as data on its biology and ecology. Records were obtained from literature and from specimens deposited in biological collections. In total, 149 records were analysed, from 12 countries in America. However, after taxonomic revision, some specimens were wrongly identified as S. sordellii, especially those from Peru, putting in doubt the occurrence of the species in that country. In Brazil, it has been recorded in all five geographic regions and collected in different biomes, besides to other ecotypes such as caves. Furthermore, its presence in an anthropized environment has also been reported. Some studies have also diagnosed Leishmania DNA in S. sordellii, indicating that parasite circulation is being maintained between the reservoir hosts. The data evaluated in our study allowed us to provide updated information on the distribution of S. sordellii in America, which may be useful in the taxonomy of this species.

Exposure to and infection by Leishmania infantum among domestic dogs in an area of the Cerrado biome, Maranhão, Brazil

Visceral Leishmaniasis is a serious public health problem and dogs are considered to be the main source of infection in urban areas. In Brazil, this disease is present in all regions, but with high concentration of cases in the Northeast, and the state of Maranhão is considered to be an endemic region. The aim of this study was to conduct an epidemiological, spatial, molecular and serological survey on Leishmania infantum among domestic dogs in the municipality of Belágua, Maranhão. Blood samples were collected from dogs and questionnaires were applied to their owners to obtain epidemiological data and risk factors relating to this zoonosis in the region. The coordinates of the dogs' homes were obtained to produce a disease risk map. Serological diagnoses were made using the indirect immunofluorescence reaction (IFAT) and the dual-path platform chromatographic immunoassay test (DPP®) (Bio-Manguinhos/FIOCRUZ, Brazil). A molecular investigation was undertaken using the polymerase chain reaction (PCR). Georeferencing was performed using the global positioning system (GPS) and cases of canine visceral leishmaniasis in the municipality were spatially represented and analyzed using QGIS version 3.16.6 (QGIS Development Team, 2021). A total of 205 blood samples were collected, of which 122 (59.51%) were seroreactive for L. infantum through IFAT, while the DPP test showed 84 reactive samples (40.97%). IFAT and DPP detected 16 positive animals simultaneously. One sample that was seroreactive through IFAT was also positive through PCR. In the clinical evaluation, it was observed that among the seropositive dogs, 112 (91.80%) were symptomatic and 10 (8.20%) were asymptomatic. In the spatial analysis, the Kernel density estimator enabled determination of the place at greatest risk of occurrence of the disease. The areas with the highest concentrations of cases were in districts with large quantities of precarious housing and lack of basic sanitation. This was the first report on the occurrence of L. infantum among dogs in the municipality of Belágua. The results show that canine visceral leishmaniasis is well dispersed in this municipality, thus putting at risk the human population.

Ecological Aspects of the Phlebotominae Fauna (Diptera: Psychodidae) among Forest Fragments and Built Areas in an Endemic Area of American Visceral Leishmaniasis in João Pessoa, Paraíba, Brazil

Sand flies are dipterans of medical importance, as some species are vectors of American visceral leishmaniasis (AVL). The municipality of João Pessoa (Paraíba, northeastern Brazil), is an endemic region for AVL, having high rates of human and canine cases. The main objective was to evaluate the sand fly fauna among forest fragments and built areas, and its relationship with environmental conditions. HP light traps were placed in the studied areas from March 2019 to July 2021. A total of 2141 specimens of phlebotomines were captured, comprising nine genera and ten species. Temperature and humidity were significant and positive only in built areas. The diversity composition among forest fragments and built areas was different and the AVL vector, Lutzomyia longipalpis, was the most prevalent species in built areas. The study showed that the built areas present differences in their richness and diversity of sand flies in relation to forest fragments, concluding that the conservation of forest areas, even if urban fragments, favors the diversity of phlebotomine species.

Revisiting the cave-dwelling sand flies (Diptera, Psychodidae, Phlebotominae) from Brazil: Diversity and potential role in the transmission of Leishmania Ross, 1903 (Kinetoplastida: Trypanosomatidae)

Brazilian caves, one of the many tourist attractions of the country, may act as a shelter for insects, such as sand flies (Diptera: Psychodidae), natural hosts of various microorganisms including parasites of the genus Leishmania Ross, 1903. In the last decades, with the increasing global need for sustainable development, ecotourism has emerged as one of the major activities in Brazil. However, the constant monitoring in environmentally protected areas is not often carried out, endangering visitors and professionals, especially due to the occurrence of zoonoses. Several sand fly species have already been recorded in Brazilian caves, drawing attention to the possibility of Leishmania transmission at this ecotope. Indeed, this current systematic review summarizes the fauna of cave-dwelling sand flies in Brazil, focusing on their biological behaviour and the occurrence of potential vectors of Leishmania parasites.

Diversity of cave Phlebotomines (Diptera: Psychodidae) from a Colombian cave

Sandflies are vector species of Leishmania, among many other pathogens, with a global distribution and a variety of ecological niches. Previous samplings have found that karstic formations (i.e., caves, grottos, and folds formed by the erosion of limestone) serve as a natural habitat to sandfly species. The majority of samplings of cave sandfly diversity have occurred in Brazil and to date none have studied the species composition in a cave in the Northern Andes. We collected sandflies in the Cave "Los Guácharos", in the state of Antioquia, Colombia. The sampling was carried out during two consecutive nights in September 2019. CDC-type light traps were installed inside the cavern and in other surrounding karst systems (caves, rock-breaks, and folds). In total, we identified 17 species of sandfly from the cave and surrounding karst systems, including a new record for Colombia (Bichromomyia olmeca), and provide the first karstic reports for four other species (Lutzomyia gomezi, Lutzomyia hartmanni, Pintomyia ovallesi, and Psychodopygus panamensis). We then used the results of our survey and published literature to test two hypotheses. First, that sandfly diversity in Neotropical caves is richest nearer to the equator, and second that there is a phylogenetic signal of karstic habitat use in sandflies. Counter to our predictions, we found no evidence that diversity follows a latitudinal gradient. Further, we find no evidence of a phylogenetic signal of karstic habitat use, instead finding that the use of caves likely evolved multiple times across several genera. Our results highlight the importance of a wide sampling to understand the natural habitat of sandflies and other disease vectors.

First molecular evidence of frogs as a food source for sand flies (Diptera: Phlebotominae) in Brazilian caves

Genus and species of phlebotomine sand flies have been recorded and described in caves in Brazil, but no study has provided the food source used by sand flies in these environments. Herein, we identified the blood source used by sand fly species in caves located at "Quadrilátero Ferrífero" (QF), Minas Gerais state. Specimens were manually collected near or on anurans inside ferruginous caves in Serra do Gandarela National Park and Serra do Rola Moça State Park. Males and females were placed in vials with 70% alcohol and stored at -10°C. Females engorged, after specific identification, had DNA extracted and followed for PCR amplification using specific primers. Sequencing was analyzed in the GenBank and Barcode of Life. A total of 198 specimens were collected (107 females and 91 males), all of them belonging to species Sciopemyia aff. microps (88.89%), Sciopemyia sordellii (10.61%), or Martinsmyia oliveirai (0.50%). When it comes to the females, 89 were S. aff. microps and 18 S. sordellii. Nineteen engorged females of S. aff. microps were analyzed and most of them (n=18) presented blood from Bokermannohyla martinsi and one contained blood from Scinax fuscovarius. The blood present in engorged females of S. sordellii (n=4) was from B. martinsi. Sciopemyia genus specimens are commonly found in collections carried out inside natural caves, but this was the first study to prove that females of this genus feed on cold-blooded animals in nature. HIGHLIGHTS: • Here we proved that sand flies feed in cold-blooded animals in in Brazilian caves. • Females of the Sciopemyia genus were for the first time found feeding in natural habitats. • Anurans of the family Hylidae were identified as source by molecular analyzes. • Insect bloodmeal identification can help assessing the fauna in several biomes. • This is the first record of S. aff. microps in caves of Brazil.

Detection of Pintomyia fischeri (Diptera: Psychodidae) With Leishmania infantum (Trypanosomatida: Trypanosomatidae) Promastigotes in a Focus of Visceral Leishmaniasis in Brazil

Visceral leishmaniasis is spreading in Brazil where the main vector of its agent, Leishmania infantum Nicolle, 1908, is the Lutzomyia longipalpis (Lutz & Neiva, 1912) species complex (Diptera: Psychodidae: Phlebotominae), on which many of the activities of the visceral leishmaniasis surveillance program are based. However, there are areas where canine, and/or human cases have been occurring without the presence of this species complex as in the western part of the Greater São Paulo Metropolitan region, where Embu das Artes municipality is situated. In this area, Pintomyia fischeri (Pinto, 1926) has been implicated as potential vector of Le. infantum but so far its natural infection with this parasite has not yet been ascertained. Therefore, the present study sought to investigate the natural infection in sand flies of a CVL focus in Embu das Artes. The sand fly collections were undertaken with Shannon and CDC traps, monthly, between 1800 and 2100 hours from November 2018 to October 2019, inclusive. A total of 951 sand flies (457 males and 494 females), belonging to 10 species, were captured. Pintomyia fischeri was the predominant species (89.5%); of which 426 females were dissected and one of them (0.23%) was found to be harboring flagellates in its midgut. A sample of these flagellates was isolated in culture and characterized by a 234 base pair fragment of Leishmania heat-shock protein 70 gene (hsp70) and restriction fragment length polymorphism with Hae III restriction enzyme as Le. infantum. This finding reinforces previous evidence of Pi. fischeri as a vector of Le. infantum in foci of visceral leishmaniasis and highlights the importance of vector surveillance in areas where this species occurs.

Demographic and spatial study of visceral leishmaniasis in the state of Alagoas, Brazil, during 2007-2018

INTRODUCTION

Visceral leishmaniasis has a broad worldwide distribution and constitutes a public health problem in the Northeast of Brazil. Located in this region is the state of Alagoas, where the disease is endemic in humans and where there has been a significant increase in the number of positive dogs. The objective of this study was to describe the temporal and spatial distribution of the cases of human VL in the state of Alagoas with the aim of identifying transmission risk areas in the period from 2007 to 2018.

METHODS

The data available in the National Disease Notification System (SINAN-NET) were used. The Bayesian incidence rate and the Moran's global index were calculated using the Terra View 4.2.2 program, and the maps were created using QGIS2.18.0.

RESULTS

From the 102 municipalities, 68.6% (n= 70) had at least one notified case of VL in the years of study. A total of 489 cases were registered, with an average of 40.7 cases per year and an incidence rate of 1.25/100,000 inhabitants. The highest number of confirmed cases (105) occurred in 2018. Male individuals and children between 1-4 years old were the most affected, and 64% of the cases were in rural areas. Spatial dependence was detected in all the intervals except for the first triennium, and clusters were formed in the west of the state.

CONCLUSIONS

Alagoas presented an accentuated geographical expansion of VL, and it is necessary to prioritize areas and increase surveillance actions and epidemiological control.

Phlebotomine sand flies (Diptera, Psychodidae) from iron ore caves in the State of Pará, Brazil

The present study aimed to evaluate the distribution of sand fly species in iron ore caves in the State of Pará, Brazil and to associate the richness and abundance of these insects with the capacity of leishmaniasis transmission. Entomological captures were carried out in the years 2010, 2013, 2014 and 2015, throughout active samples with brushes, along the entire caves’ extension, in dry and rainy periods. A total of 9,807 sand flies were counted during the 532 samplings events, being 4,340 in the dry period and 5,467 in the rainy period. A random sample of 802 morphologically identified specimens consisted of 8 genera and 17 species, being 369 males (46%) and 433 females (54%). The predominant species was Sciopemyia sordellii with 60.6% of the total of sand flies collected. Differences in composition and richness were observed between caves located inside of forest and anthropized areas. The mean richness and abundance were different between the wet and rainy periods, with a greater abundance of these insects in the rainy period. The phlebotomine fauna proved to be rich and abundant in the sampled caves, however, environmental degradation seems to be the main factor determining changes in the composition and richness, reinforces the importance of these places as a shelter for sand flies in degraded areas.

Phlebotominae (Diptera: Psychodidae) and Biomes in the State of Mato Grosso do Sul, Brazil

The state of Mato Grosso do Sul, Brazil is an important region of South America regarding leishmaniasis, with the great diversity of sandflies reported since 1938 and wide biodiversity represented by its biomes (Atlantic Forest, Cerrado, and Pantanal). A checklist of sandflies is presented here for the state and respective biomes. The data base was compiled from primary and secondary data. The primary data collection involved automatic light traps at Miranda-Abobral Pantanal subregion and in subregion Baixa Nhecolância of Pantanal. The secondary data were obtained from entomology scientific collections and a literature review of articles from 1938 to 2019, including entomological museum collections. A total of 71 species were reported, belonging to 14 genera and 13 subgenera, in 61 municipalities of the state, including the type locality of 9 species, and the first report of Lutzomyia cruzi (Mangabeira 1938), vector of Leishmania infantum (Nicolle 1937), in the Pantanal region of Miranda-Abobral. Other vector species, Bichromomyia flaviscutellata (Mangabeira 1942), Lutzomyia longipalpis (Lutz & Neiva 1912), Nyssomyia antunesi (Coutinho 1939), Nyssomyia intermedia (Lutz & Neiva 1912), Nyssomyia neivai (Pinto 1926), and Nyssomyia whitmani (Antunes & Coutinho 1939), are reported in the entire area of the state. Maps containing the distribution of sandflies on Mato Grosso do Sul biomes were produced. The eclecticism of the species in relation to their ecotypes was observed, with several species using the three biome types as habitats and breeding sites.

Synanthropy and diversity of Phlebotominae in an area of intense transmission of visceral leishmaniasis in the South Pantanal floodplain, Midwest Brazil

Phlebotomines have been recorded from a wide variety of habitats, and some of these vector species have shown preference for human environments, with high levels of adaptation. This study evaluated the degree of preference of these vectors for urban, rural, and forested environments (synanthropic behavior), as well as the diversity of these species, in three areas (forested, rural, and urban, exhibiting different degrees of anthropogenic changes) in a region of intense transmission of visceral leishmaniasis in Corumbá county, Mato Grosso do Sul, Brazil. Using light traps, sand fly specimens were collected from the three environments simultaneously, from May 2015 to April 2017, totaling 7 213 sand flies of 14 species in eight genera. Nuorteva's synanthropy index was determined for the species Lutzomyia cruzi, Brumptomyia brumpti, Micropygomyia peresi, Lu. forattinii, Martinsmyia oliveirai and Evandromyia corumbaensis. Lutzomyia cruzi, the vector of Leishmania infantum in Corumbá, was the most abundant vector species, recorded from all three areas and sampling plots, on all 24 months investigated. This species exhibited the highest synanthropic index (+75.09), indicating a strong preference for urban environments. Brumptomyia brumpti, Micropygomyia peresi, Lu. forattinii, and Martinsmyia oliveirai showed preference, albeit not strong, for urban environments. Overall, males were more abundant than females (W = 490; p < 0.0001). High density, high synanthropic index, and sustained indoor presence were found for Mi. peresi in the rural area. Monitoring changes in the ecological behavior of sand flies is of vital importance, as these changes may indicate an increased likelihood of leishmaniasis emergence or reemergence.

Ecological niche modelling and predicted geographic distribution of Lutzomyia cruzi, vector of Leishmania infantum in South America

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.

The role of wing geometric morphometrics in the identification of sandflies within the subgenus Lutzomyia

The Lutzomyia subgenus (Diptera: Psychodidae) includes sibling species with morphologically indistinguishable females. The aims of this study were to analyse variations in the size and shape of wings of species within the Lutzomyia subgenus and to assess whether these analyses might be useful in their identification. Wings (n = 733) of 18 species deposited in Brazilian collections were analysed by geometric morphometrics, using other genera and subgenera as outgroups. Shape variation was summarized in multivariate analyses and differences in wing size among species were tested by analysis of variance. The results showed significant variation in the sizes and shapes of wings of different Lutzomyia species. Two clusters within the Lutzomyia subgenus were distinguished in analyses of both males and females. In Cluster 1 (Lutzomyia ischnacantha, Lutzomyia cavernicola, Lutzomyia almerioi, Lutzomyia forattinii, Lutzomyia renei and Lutzomyia battistinii), scores for correct reclassification were high (females, kappa = 0.91; males, kappa = 0.90), whereas in Cluster 2 (Lutzomyia alencari, Lutzomyia ischyracantha, Lutzomyia cruzi, Lutzomyia longipalpis, Lutzomyia gaminarai and Lutzomyia lichyi), scores for correct reclassification were low (females, kappa = 0.42; males, kappa = 0.48). Wing geometry was useful in the identification of some species of the Lutzomyia subgenus, but did not allow the identification of sibling species such as L. longipalpis and L. cruzi.

Sandfly fauna (Diptera: Psychodidae) in an urban area, Central-West of Brazil

Biological and ecological relations among vectors and their pathogens are important to understand the epidemiology of vector-borne diseases. Camapuã is an endemic area for visceral and tegumentary leishmaniasis. The aim of this study was to characterize the sandfly fauna present in Camapuã , MS, Brazil. Sand flies were collected every fortnight from May 2014 to April 2015 using automatic light traps in the domicile and peridomicile of twelve neighborhoods and forest. The collected specimens were identified based on morphology according to the valid identification keys. In total, 2005 sandflies of five genera and nine species were collected. Nyssomyia whitmani and Lutzomyia cruzi were the most abundant species. Males were more abundant, with a male-to-female ratio of 2.14. The highest diversity was observed in peripheral neighborhood, with abundant plant cover. The peridomicile presented greater abundance of sandflies, with the predominance of Ny. whitmani . No significant correlation between the absolute frequencies of the most abundant species and the precipitation variable was observed; however, there was a predominance of Lu. cruzi in the rainy season. We observed a high frequency of sandflies in urban area, especially vector species. The presence of Nyssomyia whitmani and Lutzomyia cruzi indicate the necessity for health surveillance in the municipality. Additional method of collection such as sticky trap is also recommended for appropriate faunestic study.

T lymphocytes and macrophages in the intestinal tissues of dogs infected with Leishmania infantum

This study was about a semi-quantitative analysis of T lymphocytes (CD4+ and CD8+, FoxP3+ regulatory T cells), and macrophages in the gut wall of dogs naturally infected with Leishmania infantum. Thirteen dogs were divided into three groups: group 1 (G1, n=5), dogs with canine visceral leishmaniasis (CVL) and infected with L. infantum amastigotes in the intestine; group 2 (G2, n=5), dogs with CVL but without intestinal amastigotes; and group 3 (G3, n=3), uninfected dogs (control group). There was no significant difference (p ≥ 0.05) on CD4+ and Treg cell numbers among the groups, whereas the levels of CD8+ T cells and macrophages were significantly higher in dogs from G1 group than in G2 and G3 (p ≤ 0.05), especially in intestinal segments with high parasite burden. Parasite burden correlated positively with levels of CD8+ T cells and macrophages (p ≤ 0.05), but was inversely correlated to levels of CD4+ T lymphocytes and FoxP3+ Treg cells. In conclusion, in the intestine of dogs with CVL, the increase of CD8+ T cells and macrophages population associated with high parasite burdens, but no changes of CD4+ T cells and FoxP3+ Treg cells suggest a possible immunoregulation by the parasite not dependent on Treg cells.

Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae): Aspects of the ecology of parasite-vector interactions

Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis–infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis–infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial capacity for L. infantum transmission. Moreover, it was also permissive to L. amazonensis.

Leishmaniasis is a vector-borne disease caused by the Leishmania parasite. It is transmitted by phlebotomine sand flies when infected females take a bloodmeal from a mammalian host. The transmission of Leishmania species involves complex ecological interactions between parasite–vector and vector–host. Until recently, the sand fly Lutzomyia longipalpis, which belongs to a species complex, had been solely incriminated in Latin American transmission of Leishmania infantum. However, there are still uncertainties concerning the L. infantum transmission, especially in an urban area endemic for visceral leishmaniasis in Brazil. Along the years, Lutzomyia cruzi has been suspected of transmitting L. infantum in Corumbá and vicinity, and this study aimed to provide more accurate evidence of this phenomenon. Laboratory-reared Lu. cruzi were infected experimentally by allowing them to feed on dogs naturally infected with L. infantum and on hamsters infected with L. amazonensis. Our results identified important life cycle parameters of Lu. cruzi infected by Leishmania in laboratory conditions. We identified the components related to vectorial capacity, and also the vector incrimination criteria of Lu. cruzi for L. infantum. Additionally, we demonstrated the experimental transmission of L. amazonensis by Lu. cruzi to a naïve host, and revealed strong evidence that supports Lu. cruzi as a vector of L. infantum and as a permissive vector for L. amazonensis.

SAND FLIES (DIPTERA: PSYCHODIDAE) IN AN ENDEMIC AREA OF LEISHMANIASIS IN AQUIDAUANA MUNICIPALITY, PANTANAL OF MATO GROSSO DO SUL , BRAZIL

The Aquidauana municipality is considered an endemic area of leishmaniasis and an important tourist site in Mato Grosso do Sul State. The aim of this study was to investigate the sand fly fauna in the city of Aquidauana. Captures were carried out twice a month, from April 2012 to March 2014 with automatic light traps and active aspiration, in the peridomicile and domicile of six residences. A total of 9,338 specimens were collected, 3,179 and 6,159 using light traps and active aspiration, respectively. The fauna consisted of: Brumptomyia brumpti, Evandromyia aldafalcaoae, Ev. evandroi, Ev. lenti, Ev. orcyi, Ev. sallesi, Ev. termitophila, Ev. walkeri, Lutzomyia longipalpis and Psathyromyia bigeniculata. The most abundant species captured was Lutzomyia longipalpis, present in all the ecotopes, predominantly in peridomicile areas, and mainly males. Leishmania DNA was not detected in the insects. It was observed the abundance of the sand fly fauna in the region, as well as the high frequency of Lu. longipalpis, the main vector of L. infantum. The results of this study show the need to increase the monitoring and more effective control measures. It is noteworthy that the studied region presents several activities related to tourism and recreation, increasing the risk of transmission of leishmaniasis to this particular human population.

Vector Competence of Lutzomyia cruzi Naturally Demonstrated for Leishmania infantum and Suspected for Leishmania amazonensis

Corumbá city is one of the oldest visceral leishmaniasis-endemic foci in the state of Mato Grosso do Sul, Brazil, where the transmission of Leishmania infantum has been attributed to Lutzomyia cruzi Aiming at investigating the parameters of the vectorial capacity of Lu. cruzi for L. infantum, a project was undertaken in this city. Among these parameters, vector competence was investigated and the results obtained are reported herein. Of the 12 hamsters exposed to feed wild-caught female sandflies, two developed infection with L. infantum and surprisingly, one with Leishmania amazonensis In addition, hamsters with L. infantum infection were bitten only by females of Lu. cruzi, whereas the hamster infected with L. amazonensis was bitten by 124 Lu. cruzi females and one of Evandromyia corumbaensis Although there is a strong suspicion regarding the competence of Lu. cruzi in transmitting L. amazonensis naturally, it was not demonstrated.

Anthropophily of Lutzomyia wellcomei (Diptera: Psychodidae) in an Atlantic Forest Conservation Unit in Northeast Brazil

Lutzomyia wellcomei (Fraiha, Shaw & Lainson) (Diptera: Psychodidae) can act as an important vector of Leishmania (Viannia) braziliensis This study presents the results of collections carried out in a fragment of Atlantic Forest in a Conservation Unit of Rio Grande do Norte state. Collections occurred over 12 consecutive months using Shannon and CDC traps. A total of 777 sand flies from eight species were collected: Lutzomyia walkeri (Newstead), Lutzomyia evandroi (Costa Lima & Antunes), Lutzomyia wellcomei (Fraiha, Shaw & Lainson), Lutzomyia sordellii (Shannon & Del Ponte), Lutzomyia brasiliensis (Costa Lima), Lutzomyia lenti (Mangabeira), Lutzomyia longipalpis (Lutz & Neiva), and Lutzomyia abonnenci (Floch & Chassignet). Lutzomyia wellcomei was the most abundant species using the Shannon trap (97%) and L. walkeri in the CDC trap (81%). It is important to note the abundance of L. wellcomei in Shannon trap collections, which favors the capture of anthropophilic species. Lutzomyia wellcomei was only present in months where rainfall was above 100 mm, confirming it as a species adapted to wetter months.

Monthly Distribution of Phlebotomine Sand Flies, and Biotic and Abiotic Factors Related to Their Abundance, in an Urban Area to Which Visceral Leishmaniasis Is Endemic in Corumbá, Brazil

The monthly distribution and abundance of sand flies are influenced by both biotic and abiotic factors. The present study aimed to evaluate the seasonal distribution of sand flies and the relation between their abundance and environmental parameters, including vegetation and climate. This study was conducted over a 2-year period (April 2012 to March 2014). Monthly distribution was evaluated through the weekly deployment of CDC light traps in the peridomicile area of 5 residences in an urban area of the municipality of Corumbá in the State of Mato Grosso do Sul, Brazil. Meteorological data were obtained from the Mato Grosso do Sul Center for Weather, Climate, and Water Resources. The spectral indices were calculated based on spatial resolution images (GeoEye) and the percentage of vegetal coverage. Differences in the abundance of sand flies among the collection sites were assessed using the Kruskal-Wallis test, and the strength of correlations between environmental variables was determined by calculating Spearman’s correlation coefficients. Lutzomyia cruzi, Lu. forattinii, and Evandromyia corumbaensis were the most frequently found species. Although no significant association was found among these sand fly species and the tested environmental variables (vegetation and climate), high population peaks were found during the rainy season, whereas low peaks were observed in the dry season. The monthly distribution of sand flies was primarily determined by Lu. cruzi, which accounted for 93.94% of the specimens collected each month throughout the experimental period. The fact that sand flies were detected year-round indicates a continuous risk of infection to humans, demonstrating the need for targeted management and education programs.

Ecology of Lutzomyia longipalpis and Lutzomyia migonei in an endemic area for visceral leishmaniasis

The main vector for visceral leishmaniasis (VL) in Brazil is Lutzomyia longipalpis. However, the absence of L. longipalpis in a region of autochthonous VL demonstrates the participation of other species in the transmission of the parasite. Studies conducted in La Banda, Argentina, and São Vicente Férrer, Pernambuco State, Brazil, have correlated the absence of L. longipalpis and the presence of L. migonei with autochthonous cases of VL. In São Vicente Férrer, Pernambuco, there was evidence for the natural infection of L. migonei with Leishmania infantum chagasi. Thus, the objective of this work was to assess the ecology of the sand flies L. longipalpis and L. migonei in Fortaleza, an endemic area for VL. Insect capture was conducted at 22 sampling points distributed across four regions of Fortaleza. In total, 32,403 sand flies were captured; of these, 18,166 (56%) were identified as L. longipalpis and 14,237 (44%) as L. migonei. There were significant density differences found between the vectors at each sampling site (indoors and outdoors) (p <0.0001). These findings confirm that L. migonei and L. longipalpis are distributed throughout Fortaleza, where they have adapted to an indoor environment, and suggest that L. migonei may share the role as a vector with L. longipalpis in the transmission of VL in Fortaleza.

PERFORMANCE OF CONVENTIONAL PCRs BASED ON PRIMERS DIRECTED TO NUCLEAR AND MITOCHONDRIAL GENES FOR THE DETECTION AND IDENTIFICATION OF Leishmania spp

In visceral leishmaniasis, the detection of the agent is of paramount importance to identify reservoirs of infection. Here, we evaluated the diagnostic attributes of PCRs based on primers directed to cytochrome-B (cytB), cytochrome-oxidase-subunit II (coxII), cytochrome-C (cytC), and the minicircle-kDNA. Although PCRs directed to cytB, coxII, cytC were able to detect different species of Leishmania, and the nucleotide sequence of their amplicons allowed the unequivocal differentiation of species, the analytical and diagnostic sensitivity of these PCRs were much lower than the analytical and diagnostic sensitivity of the kDNA-PCR. Among the 73 seropositive animals, the asymptomatic dogs had spleen and bone marrow samples collected and tested; only two animals were positive by PCRs based on cytB, coxII, and cytC, whereas 18 were positive by the kDNA-PCR. Considering the kDNA-PCR results, six dogs had positive spleen and bone marrow samples, eight dogs had positive bone marrow results but negative results in spleen samples and, in four dogs, the reverse situation occurred. We concluded that PCRs based on cytB, coxII, and cytC can be useful tools to identify Leishmania species when used in combination with automated sequencing. The discordance between the results of the kDNA-PCR in bone marrow and spleen samples may indicate that conventional PCR lacks sensitivity for the detection of infected dogs. Thus, primers based on the kDNA should be preferred for the screening of infected dogs.

A Historical Overview of the Classification, Evolution, and Dispersion of Leishmania Parasites and Sandflies

BACKGROUND

The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale.

METHODOLOGY AND PRINCIPAL FINDINGS

Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate?

CONCLUSIONS AND SIGNIFICANCE

We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites.

Performance of light-emitting diode traps for collecting sand flies in entomological surveys in Argentina

The performance of two light-emitting diode traps with white and black light for capturing phlebotomine sand flies, developed by the Argentinean Leishmaniasis Research Network (REDILA-WL and REDILA-BL traps), were compared with the traditional CDC incandescent light trap. Entomological data were obtained from six sand fly surveys conducted in Argentina in different environments. Data analyses were conducted for the presence and the abundance of Lutzomyia longipalpis, Migonemyia migonei, and Nyssomyia whitmani (106 sites). No differences were found in presence/absence among the three types of traps for all sand fly species (p>0.05). The collection mean of Lu. longipalpis from the REDILA-BL didn´t differ from the CDC trap means, nor were differences seen between the REDILA-WL and the CDC trap collection means (p>0.05), but collections were larger from the REDILA-BL trap compared to the REDILA-WL trap (p<0.05). For Mg. migonei and Ny. whitmani, no differences were found among the three types of traps in the number of individuals captured (p>0.05). These results suggest that both REDILA traps could be used as an alternative capture tool to the original CDC trap for surveillance of these species, and that the REDILA-BL will also allow a comparable estimation of the abundance of these flies to the CDC light trap captures. In addition, the REDILA-BL has better performance than the REDILA-WL, at least for Lu. longipalpis.

Leishmania amazonensis DNA in wild females of Lutzomyia cruzi (Diptera: Psychodidae) in the state of Mato Grosso do Sul, Brazil

Studies on natural infection by Leishmania spp of sandflies collected in endemic and nonendemic areas can provide important information on the distribution and intensity of the transmission of these parasites. This study sought to investigate the natural infection by Leishmaniain wild female sandflies. The specimens were caught in the city of Corumbá, state of Mato Grosso do Sul (Brazil) between October 2012-March 2014, and dissected to investigate flagellates and/or submitted to molecular analysis to detect Leishmania DNA. A total of 1,164 females (77.56% of which were Lutzomyia cruzi) representing 11 species were investigated using molecular analysis; 126 specimens of Lu. cruziwere dissected and also submitted to molecular analysis. The infection rate based on the presence of Leishmania DNA considering all the sandfly species analysed was 0.69%; only Leishmania (Leishmania) amazonensis was identified in Lu. cruzi by the molecular analysis. The dissections were negative for flagellates. This is the first record of the presence of L. (L.) amazonensis DNA in Lu. cruzi, and the first record of this parasite in this area. These findings point to the need for further investigation into the possible role of this sandfly as vector of this parasite.

Lutzomyia longipalpis urbanisation and control

Since the description of Lutzomyia longipalpis by Lutz and Neiva more than 100 years ago, much has been written in the scientific literature about this phlebotomine species. Soares and Turco (2003) and Lainson and Rangel (2005) have written extensive reviews focused on vector-host-parasite interactions and American visceral leishmaniasis ecology. However, during the last two decades, the success of Lu. longipalpis in colonising urban environments and its simultaneous geographical spreading have led to new theoretical and operational questions. Therefore, this review updates the general information about this species and notes the more challenging topics regarding the new scenario of urbanisation-spreading and its control in America. Here, we summarise the literature on these issues and the remaining unsolved questions, which pose recommendations for operational research.

Alternative Method for the Mass Rearing of Lutzomyia (Lutzomyia) cruzi (Diptera: Psychodidae) in a Laboratory Setting

The understanding of the transmission dynamics of Leishmania spp. Ross as well as the epidemiology and spread of leishmaniasis is related to parasite-vector-host interactions. These interactions can be studied using specimens of a sand fly population reared in the laboratory, exposing individuals to experimental infection for the investigation of vector competence and parameters of the vectorial capacity of the species. The present study sought to describe an alternative method for the implantation of a Lutzomyia (Lutzomyia) cruzi colony with wild specimens captured in the municipality of Corumbá, Brazil. With Method 1, engorged females were individualized for oviposition. The eggs were transferred to an acrylic petri dish with a layer of plaster on the bottom, on which food was placed after hatching of the first larvae. With Method 2, females were kept in groups for oviposition in containers, in which soil and food were placed on their bottom for the larvae. In addition, the exposure time of the larvae to light was reduced in comparison with Method 1. With Method 2, a significantly greater number of specimens of Lu. cruzi was obtained. The ratio between the number of emerged adults and the females followed for oviposition was 0.42 with Method 1 and 2.75 with Method 2. The optimization of the rearing conditions for Lu. cruzi will enable the establishment of a colony providing a sufficient number of specimens to develop experimental infection by Leishmania as well as vectorial competence and some parameters of the vectorial capacity of this sand fly.

Geographic distribution of phlebotomine sandfly species (Diptera: Psychodidae) in Central-West Brazil

This study updates the geographic distributions of phlebotomine species in Central-West Brazil and analyses the climatic factors associated with their occurrence. The data were obtained from the entomology services of the state departments of health in Central-West Brazil, scientific collections and a literature review of articles from 1962-2014. Ecological niche models were produced for sandfly species with more than 20 occurrences using the Maxent algorithm and eight climate variables. In all, 2,803 phlebotomine records for 127 species were analysed. Nyssomyia whitmani, Evandromyia lenti and Lutzomyia longipalpis were the species with the greatest number of records and were present in all the biomes in Central-West Brazil. The models, which were produced for 34 species, indicated that the Cerrado areas in the central and western regions of Central-West Brazil were climatically more suitable to sandflies. The variables with the greatest influence on the models were the temperature in the coldest months and the temperature seasonality. The results show that phlebotomine species in Central-West Brazil have different geographical distribution patterns and that climate conditions in essentially the entire region favour the occurrence of at least one Leishmania vector species, highlighting the need to maintain or intensify vector control and surveillance strategies.

Spatiotemporal analysis of sandfly fauna (Diptera: Psychodidae) in an endemic area of visceral leishmaniasis at Pantanal, central South America

BACKGROUND

Environmental changes caused by urbanization can cause alterations in the ecology and behavior of sandflies and in the epidemiology of leishmaniasis. Geotechnological tools allow the analysis and recognition of spatiotemporal patterns by monitoring and mapping risk areas of this vector-borne disease. This study aims to describe the sandfly fauna in the municipality of Corumbá and to compare it with the data described in a three-year period from 1984 to 1986 by Galati. A further aim was to analyze the influence of environmental changes on the composition of the fauna.

METHODS

Captures were conducted weekly from April 2012 to March 2013, in intra and peridomicile areas with automatic light traps, from 6:00 pm to 6:00 am. The following indices were calculated for both periods analyzed: Standardized Index of Species Abundance (SISA), Shannon's diversity index (H) and Pielou's index (J). The Normalized Difference Vegetation Index (NDVI) was extracted from a remote sensing LANDSAT-5 image.

RESULTS

In total, 7,370 specimens (6,169 males and 1,201 females) were collected, distributed among 12 species. Lutzomyia cruzi was the most frequent species (93,79%) and the first in the ranking of standardized species abundance index in both studies. The dominance of the species Lu. cruzi in the neighborhoods of Maria Leite and Centro was demonstrated by the low equitability index. The neighborhood of Cristo Redentor had the greatest diversity of sandflies in the present study and the second greatest in the study performed by Galati et al. (Rev Saúde Pública 31:378-390, 1997). Analyzing the satellite images and the NDVI from 1984 and 2010, the largest amount of dense vegetation was found in the neighborhood of Cristo Redentor.

CONCLUSIONS

It was, therefore, possible to show how changes caused due to urbanization have affected the density and distribution of Lu. cruzi and other species over time. Moreover, the data suggest that different populations of sandflies adapt in different ways according to environmental conditions and the adaptation does not necessarily depends on the presence of high vegetation cover.

Ecological aspects of the Phlebotominae fauna (Diptera: Psychodidae) in the Xakriabá Indigenous Reserve, Brazil

Background

Sand fly collections were performed to study ecological aspects of the Phlebotominae fauna of the Xakriabá Indigenous Reserve, an area with endemic cutaneous leishmaniasis, located in the state of Minas Gerais, Brazil.

Methods

The collections were performed in peridomicile areas and along trails previously selected for the study of wild and synanthropic Leishmania hosts. Differences in the distribution patterns of the sand fly species as well as in species richness and abundance between the different ecotopes were investigated during both rainy and dry seasons over the course of the study period.

Results

A total of 8,046 sand flies belonging to 11 genera and 28 species were collected. Lutzomyia longipalpis and Nyssomyia intermedia were the most abundant species in peridomicile areas, whereas Martinsmyia minasensis and Lutzomyia cavernicola were the most abundant species among the different trail ecotopes.

Conclusion

The different composition of the sand fly fauna observed in the peridomicile areas and in the trails during the study, reinforces the importance of sampled different areas in a phlebotomine fauna survey. The presence of Lutzomyia longipalpis and Ny. Intermedia most abundant in peridomicile can be important to Leishmania infantum and Leishmania braziliensis transmission in the Imbaúbas native village.

Epidemiological survey of Lutzomyia longipalpis infected by Leishmania infantum in an endemic area of Brazil

The objective of this study was to perform an epidemiological survey to determine the areas at risk of visceral leishmaniasis through the detection and quantification of natural infection by Leishmania infantum in Lutzomyia longipalpis. The sandflies were captured between February 2009 and January 2010, at 21 sites in four regions of the Fortaleza municipality. Samples were screened for the presence of Leishmania DNA by Real Time PCR (qPCR), amplification of kDNA minicircle sequence. Out of the 123 pools of analyzed sandflies, 45 were positive for L.infantum, and the minimum infection rate was 3.7%. In the north, south, east and west regions, the pool screen assay predicted sand-fly infection prevalence of 3.4%, 4.7%, 4.9% and 8.4%, respectively. The parasite load ranged from 2.45 ± 0.96 to 2,820,246 ± 106,072. No statistical differences were found with respect to the frequency of sand-fly infection between the regions (P=0.3014), seasons (P = 0.3906) or trap locations (P = 0.8486). Statistical differences were found with respect to the frequency of sand-fly infection between the two seasons only in the west region (P=0.0152). The qPCR was able to detect and quantify L. infantum in L. longipalpis, therefore succeeding in identifying the areas of greatest risk of VL transmission.

Epidemiological aspects of visceral leishmaniasis in Jaciara, Mato Grosso, Brazil, 2003 to 2012

Visceral leishmaniasis (VL) is caused by Leishmania (L.) infantum chagasi in the Americas. In Brazil, it is transmitted by sandflies of the species Lutzomyia longipalpis and L. cruzi, and dogs are the main domestic reservoirs. The aim of this study was to analyze data relating to VL transmission in Jaciara, state of Mato Grosso, and discuss vector distribution, domestic reservoirs, and human cases that occurred between 2003 and 2012. The data for analysis were obtained from the Notifiable Diseases Information System (human), the State Health Department's Environmental Monitoring Agency (canine data) and the State Health Department's Entomology Laboratory (sandfly data). Over this period, Jaciara had 19 autochthonous human cases (12 males and seven females), with one death 2,273. Out of the 7,545 dogs tested by enzyme immunoassay and indirect immunofluorescence were positive. The sandflies collected comprised 5,015 individuals belonging to 24 species, with a predominance of L. whitmani followed by L. cruzi. The results showed that the parasite has frequent circulation and that the vector L. cruzi is widely distributed over all months, thus suggesting that transmission may occur at any time of the year.

Climatic factors and population density of Lutzomyia longipalpis (Lutz & Neiva, 1912) in an urban endemic area of visceral leishmaniasis in midwest Brazil

The life cycle of vectors and the reservoirs that participate in the chain of infectious diseases have a strong relationship with the environmental dynamics of the ecosystems in which they live. Oscillations in population abundance and seasonality of insects can be explained by factors inherent in each region and time period. Therefore, knowledge of the relationship and influence of environmental factors on the population of Lutzomyia longipalpis is necessary because of the high incidence of visceral leishmaniasis (VL) in Brazil. This study evaluates the influence of abiotic variables on the population density and seasonal behavior of L. longipalpis in an urban endemic area of VL in Brazil. The sand fly captures were performed every two months between November, 2009 and November, 2010 in the peridomicile of 13 randomly selected residences. We captured 1,367 specimens of L. longipalpis, and the ratio of male/female flies was 2.86:1. The comparison of the total male specimens in the two seasons showed a statistical difference in the wet season, but there was no significant difference when considering the total females. With respect to climatic variables, a significant negative association was observed only with wind speed. During periods of high wind speeds, the population density of this vector decreased. The presence of L. longipalpis was found in all months of the study with bimodal behavior and population peaks during the wet season.

Ecological aspects of phlebotomine sandflies (Diptera: Psychodidae) from a cave of the speleological province of Bambuí, Brazil

Phlebotomines are invertebrate hosts of Leishmania genus species which are etiological agents of leishmaniases in humans and other mammals. Sandflies are often collected in entomological studies of caves both in the inner area and the adjacent environments. Caves are ecotypes clearly different from the external environment. Several caves have been opened to public visitation before any studies were performed and the places do not have scientific monitoring of the fauna, flora, geological and geographical characteristics. These events can lead to the loss of geological and biological information. Considering these aspects, this study aimed to describe the sand fly fauna, including the ecological features, in a limestone cave at the Speleological Province of Bambuí (Minas Gerais State, Brazil). A total of 8,354 specimens of sandflies belonging to 29 species were analyzed: Lutzomyia cavernicola (20%), Nyssomyia intermedia (15%), Martinsmyia oliveirai (13%), Evandromyia spelunca (12%), Evandromyia sallesi (11%), Migonemyia migonei (9%), Nyssomyia whitmani (9%), Sciopemyia sordellii (4%) and Lutzomyia longipalpis (2%). The others species represent 5% of the total. This manuscript presents data found on richness, diversity, evenness and seasonality, comparing the sand fly fauna trapped in the cave and its surroundings.

The distribution pattern of Lutzomyia longipalpis (Diptera: Psychodidae) in the peridomiciles of a sector with canine and human visceral leishmaniasis transmission in the municipality of Dracena, São Paulo, Brazil

The specimen distribution pattern of a species can be used to characterise a population of interest and also provides area-specific guidance for pest management and control. In the municipality of Dracena, in the state of São Paulo, we analysed 5,889 Lutzomyia longipalpis specimens collected from the peridomiciles of 14 houses in a sector where American visceral leishmaniasis (AVL) is transmitted to humans and dogs. The goal was to analyse the dispersion and a theoretical fitting of the species occurrence probability. From January-December 2005, samples were collected once per week using CDC light traps that operated for 12-h periods. Each collection was considered a sub-sample and was evaluated monthly. The standardised Morisita index was used as a measure of dispersion. Adherence tests were performed for the log-series distribution. The number of traps was used to adjust the octave plots. The quantity of Lu. longipalpis in the sector was highly aggregated for each month of the year, adhering to a log-series distribution for 11 of the 12 months analysed. A sex-stratified analysis demonstrated a pattern of aggregated dispersion adjusted for each month of the year. The classes and frequencies of the traps in octaves can be employed as indicators for entomological surveillance and AVL control.

Phlebotomine sandflies fauna (Diptera: Psychodidae) at rural settlements in the municipality of Cáceres, State of Mato Grosso, Brazil

INTRODUCTION: Leishmaniasis is expanding across Brazil, including the State of Mato Grosso (MT). The aim of this study was to characterize the phlebotomine sandfly fauna at threerural settlements located in the municipality of Cáceres, MT, from August 2010 to July 2011. METHODS: Sandfly captures were conducted at the forest border and in intra and peridomicile areas with automatic light traps, biweekly, from 5pm to 6am. RESULTS: Of the 630 sandflies collected, 348 were female, and 282 were male. Captured specimens were distributed across 11 genera - Brumptomyia, Evandromyia, Expapillata, Lutzomyia, Martinsmyia, Micropygomyia, Nyssomyia, Pintomyia, Psathyromyia, Psychodopygus, and Sciopemyia - and 28 species. Among these, six species had not been marked yet in MT (Brumptomyia avellari, Br. mangabeirai, Evandromyia aldafalcaoae, Micropygomyia echinatopharynx, Micropygomyia peresi, and Pa. campograndensis). Nyssomyia whitmani was the most abundant species across ecotopes at all settlements. Interestingly, Lutzomyia longipalpis and Lutzomyia cruzi were found in sympatry. CONCLUSIONS: The disorganized occupation of the environment that is happening at the rural settlements of Mata Comprida, Laranjeira I and II could provide opportunities for the domiciliation of wild populations of phlebotomine, including vectors of leishmaniasis. Therefore, more studies are needed to understand the epidemiology of the disease in these areas and its impact on the human population.

Phlebotomine sandflies (Diptera: Psychodidae) in São Vicente Férrer, a sympatric area to cutaneous and visceral leishmaniasis in the state of Pernambuco, Brazil

INTRODUCTION: In the last decades, a considerable geographic expansion of the leishmaniases in all regions of Brazil has been observed. The present study was carried out to identify the composition of the phlebotomine sandfly fauna and verify the seasonal variation of the main species after environmental changes occurred in São Vicente Férrer Municipality, State of Pernambuco, Brazil. METHODS: Captures were carried out during four consecutive nights of each month using Centers for Disease Control and Prevention light traps from September 2009 to September 2010. The correlation between the number of phlebotomine sandflies captured and climatic factors (temperature and rainfall) was evaluated. RESULTS: A total of 13,872 specimens belonging to 20 species were captured, of which, 6,247 (45%) were females, and 7,625 (55%) were males. Lutzomyia migonei was the most abundant species with 9,964 (71.8%) specimens, being predominant in the intradomicile and peridomicile areas with 108 (86.4%) and 9,746 (97%), respectively. In the forest remnants, Lutzomyia complexa 2,395 (65%) and Lutzomyia sordellii 770 (20.8%) predominated. The correlation analysis between the total number of sandflies captured and climatic factors did not show a significant influence on population density. CONCLUSIONS: The high abundance of Lutzomyia migonei and Lutzomyia complexa indicates the possibility of new cases of cutaneous leishmaniasis (CL).

Ecological aspects of phlebotomines (Diptera: Psychodidae) in endemic area of visceral leishmaniasis, Campo Grande, State of Mato Grosso do Sul, Brazil

Aspects of phlebotomine behavior were investigated in the city of Campo Grande, Mato Grosso do Sul state. The insects were captured weekly during December 2003 to November 2005, with Centers for Disease Control light traps at seven different sites including forests and residential areas. In total, 11,024 specimens (7,805 males and 3,219 females) were collected, from which 9,963 (90.38%) were identified as Lutzomyia longipalpis, the proven vector of American visceral leishmaniasis agent. The remaining 9.62% comprised 21 species. L. longipalpis was the most frequent species in all sampled sites, and the first in the ranking of standardized species abundance index. In residential areas this species clearly predominated in the peridomicile (90.96%), in contrast to the intradomicile (9.04%); in animal shelters, it was more numerous in hen houses and prevailed at ground level, inside, and at forest edge around the residences; this aspect is worrying because this insect may remain sheltered in forested environments during the use of insecticides in homes. In the forest environment, other probable or proven vector of cutaneous leishmaniasis agents were also captured such as Lutzomyia whitmani (=Nyssomyia whitmani, sensu Galati), Lutzomyia antunesi (=Nyssomyia antunesi, sensu Galati), and Lutzomyia flaviscutellata (=Bichromomyia flaviscutellata, sensu Galati).

Phlebotomine sand flies and canine infection in areas of human visceral leishmaniasis, Cuiabá, Mato Grosso

Visceral leishmaniasis is a systemic infectious disease that can cause to a severe, potentially life-threatening chronic condition in humans. Risk factors for infection in urban areas have been associated with poor living conditions, the presence of sand fly vectors and infected pets. This study aimed to describe sand fly and canine infection in the neighborhoods of human visceral leishmaniasis occurrence in the city of Cuiabá, Mato Grosso State, central-western Brazil, reported between January 2005 and December 2006. A total of 1,909 sand flies were collected. They were predominantly males and the most frequent species were Lutzomyia cruzi (81.25%), Lutzomyia whitmani (13.88%) and Lutzomyia longipalpis (2.62%). The sand fly density was not significantly correlated with the variation of environmental factors. The prevalence of canine visceral leishmaniasis in the neighborhoods studied was 26.82% and it was found that areas with high density of vectors coincided with areas of high prevalence of dogs and those with the highest rates of human cases. The study of vectors and other potential hosts are essential for a good understanding of visceral leishmaniasis and the related public health concerns, aiming at the prevention and control of leishmaniasis in the city of Cuiabá, Mato Grosso State.

Presença de formas amastigotas de Leishmania chagasi e perfil leucocitário no aparelho reprodutivo de cães

A leishmaniose visceral (LV) é uma zoonose causada pelo protozoário Leishmania (Leishmania) chagasi. A leishmaniose visceral canina (LVC) é a doença de maior relevância zoonótica. Usualmente, a infecção ocorre entre um hospedeiro invertebrado para um hospedeiro vertebrado, entretanto, a transmissão na ausência do vetor já é conhecida. O objetivo principal deste estudo foi identificar a presença de formas amastigotas, quantificar as células leucocitárias, estimar o risco relativo da presença de formas amastigotas no aparelho reprodutivo de cães sorologicamente positivos com e sem sinais clínicos. Para isso, foram utilizados cães sem raça definida, sexualmente maduros e testados sorologicamente para LVC (com sinais clínicos, n=25; sem sinais clínicos, n=25), que após eutanásia, tiveram fragmentos de testículo, epidídimo (cabeça, corpo e cauda) e glândula prostática (selecionados ao acaso) impressos em lâminas. Um grupo de 20 cãs sorologicamente negativos e sem sinais clínicos foi usado como controle. Amostras do baço foram incluídas como controle parasitológico positivo. O percentual de linfócitos foi superior (P<0,05) no corpo e cauda do epidídimo, assim como no testículo. Macrófagos foram superiores (P<0,05) apenas nas regiões do corpo e cauda epididimais. A presença de amastigotas correlacionou-se entre as distintas regiões do aparelho reprodutivo. Nos sintomáticos variaram entre 0,50 a 0,80 e entre 0,79 a 0,95 nos assintomáticos. A presença de amastigotas no testículo dos cães sintomáticos foi 6,5 vezes superior aos cães assintomáticos. Os resultados obtidos demonstram o potencial epidemiológico da transmissão venérea da doença, principalmente em áreas onde os programas de controle da LVC não consideram esta forma de transmissão, que pode ser importante em populações caninas não esterilizadas.

Sand fly captures with Disney traps in area of occurrence of Leishmania (Leishmania) amazonensis in the state of Mato Grosso do Sul, mid-western Brazil

INTRODUCTION: The work was conducted to study phlebotomine fauna (Diptera: Psychodidae) and aspects of American cutaneous leishmaniasis transmission in a forested area where Leishmania (Leishmania) amazonensis occurs, situated in the municipality of Bela Vista, State of Mato Grosso do Sul, Brazil. METHODS: The captures were conducted with modified Disney traps, using hamster (Mesocricetus auratus) as bait, from May 2004 to January 2006. RESULTS: Ten species of phlebotomine sandflies were captured: Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia bourrouli, Evandromyia lenti, Lutzomyia longipalpis, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The two predominant species were Ev bourrouli (57.3%) and Bi flaviscutellata (41.4%), present at all sampling sites. Two of the 36 hamsters used as bait presented natural infection with Leishmania. The parasite was identified as Leishmania (Leishmania) amazonensis. CONCLUSIONS: Analysis of the results revealed the efficiency of Disney traps for capturing Bichromomyia flaviscutellata and the simultaneous presence of both vector and the Leishmania species transmitted by the same can be considered a predictive factor of the occurrence of leishmaniasis outbreaks for the human population that occupies the location.

Species-specific identification of Leishmania in naturally infected sand flies captured in Mato Grosso do Sul State, Brazil

An increase in cutaneous and visceral leishmaniasis cases has been reported in recent years in the state of Mato Grosso do Sul, Brazil, and little is known to date about their etiological agents. An investigation into natural Leishmania infection of sand flies captured in this state between December 2003 and August 2004 was carried out. Mini-exon sequences were used as targets to identify Leishmania, and an RFLP technique was employed for those identified as belonging to the Viannia subgenus. Calculation of the minimal infection rate (MR) revealed that 1.6% of sand flies captured in the forest, peridomicile and intradomicile were positive. Six species were found to be infected by Leishmania (V.) braziliensis. Interestingly, two of the six species, Lutzomyia longipalpis and Nyssomyia whitmani, were captured in anthropic environments. The findings of this study constitute a useful tool for planning control measures against this disease in the State of Mato Grosso do Sul.

Lutzomyia longipalpis (Diptera, Psychodidae, Phlebotominae) and urbanization of visceral leishmaniasis in Brazil

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

Detection of natural infection in Lutzomyia cruzi and Lutzomyia forattinii (Diptera: Psychodidae: Phlebotominae) by Leishmania infantum chagasi in an endemic area of visceral leishmaniasis in Brazil using a PCR multiplex assay

In order to identify Lutzomyia spp. naturally infected by Leishmania parasites a PCR multiplex assay coupled to non-isotopic hybridization was used for the analysis of insect samples collected by CDC light traps in an endemic area of visceral leishmaniasis (VL) in the municipality of Corumbá, Mato Grosso do Sul State, Brazil in May/June 2006. Wild sand flies were identified and grouped into pools of 10 female specimens and 27 groups in total were collected. Positive results were obtained from Lutzomyia cruzi (2 out of 13 pools) and Lutzomyia forattinii (1 out of 14 pools). The positive pools were confirmed as being infected by Leishmania infantum chagasi after hybridizing the PCR products with a species-specific biotinylated probe derived from the kinetoplast minicircle conserved sequence. Given that we detected infection in 3 out of 27 groups and that there was at least 1 infected insect in each, it was possible to infer an infection rate of 1.5% for Lu. cruzi and 0.7% for Lu. forattinii in the analyzed samples. These results confirm the vectorial role of Lu. cruzi in transmitting L. infantum chagasi and suggest Lu. forattinii as a potential VL vector in the municipality of Corumbá, where notifications of the disease in humans and dogs have increased over the last two decades.

Phlebotomine sand flies (Diptera: Psychodidae) in the municipality of Várzea Grande: an area of transmission of visceral leishmaniasis in the state of Mato Grosso, Brazil

Visceral leishmaniasis (VL) has been naturally transmitted in periurban areas due to the emergence and reemergence of its vectors in such areas. Aimed to further knowledge on ecological aspects affecting the occurrence of phlebotomine sand flies in VL transmission areas in the municipality of Várzea Grande, state of Mato Grosso (MT), Brazil, sand fly captures were carried out. Monthly collections of sand flies were undertaken with CDC light-traps, which were left in both intradomiciliary and peridomiciliary areas of ten residences during four consecutive days between January 2004 and June 2006. Twenty-two species of genus Lutzomyia and one of Brumptomyia were captured. The most abundant species was Lutzomyia longipalpis (65.23%), followed by L. evandroi (16.26%), L. lenti (7.69%), L. whitmani (4.92%), L. sallesi (2.34%) and L. termitophila (1.32%). The highest density of the main VL vector, L. longipalpis, was found in peridomiciliary areas, mostly males. No significant correlation was found between environment (temperature, air relative humidity and rain fall) and phlebotomine density; although a slight increase in sand fly density has been observed in the period following rainfalls, particularly L. longipalpis. No correlation was observed between distribution and density of L. longipalpis, prevalence of human VL cases and the presence of serologically positive dogs. The presence of infected dogs, increased vector density, susceptibility rate and interruption of epidemiological surveillance may raise the risk of VL transmission to man in Várzea Grande.