Aspectos da ecologia e do comportamento de flebotomíneos em área endêmica de leishmaniose visceral, Minas Gerais

Abundance of Leishmania (Kinetoplastida: Trypanosomatidae) vectors in Baldim, a municipality in the Espinhaço Range Biosphere Reserve in Brazil

Leishmaniasis is a zoonoses caused by protozoan parasites belonging to the Leishmania genus that is transmitted to humans through the bite of previously infected phlebotomine sandflies (Diptera:Psychodidae:Phlebotominae). In Brazil, 2 types of leishmaniasis are endemic, tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL). In Baldim, a municipality in the Espinhaço Range Biospere Reserve (ERBR), 5 autochthonous cases of TL, and one autochthonous case of VL were reported from 2017 to 2022. Owing to the lack of data on entomological fauna, we surveyed the occurrence and distribution of phlebotomine sandflies that could act as Leishmania vectors, as well as natural Leishmania infection. During 1 year, 918 sandfly specimens belonging to 12 species were collected. The predominant species was Lutzomyia longipalpis (Lutz & Neiva, 1912) (32.0%), a proven VL agent, followed by Evandromyia evandroi (Costa Lima & Antunes, 1936) (20.7%), Evandromyia cortelezzii (Brèthes, 1923) (17.0%), Nyssomyia whitmani (Antunes & Coutinho, 1939) (12.2%), and Nyssomyia intermedia (Lutz & Neiva, 1912) (10.5%), all putative or proven TL agents. Seasonal fluctuations and endo-exophilic behavior were delineated for the main phlebotomine sandflies. The population of Lu. longipalpis was higher during the coolest and driest months, although different profiles were noted for the other species. Natural Leishmania infection was not detected in any of the 197 phlebotomine sandfly females analyzed. The results were compared with those previously obtained in other municipalities belonging to the ERBR. The presence of Leishmania vectors and human cases of leishmaniasis indicate a risk of Leishmania transmission in the region.

Survey of phlebotomine sand fly fauna in a public Zoo in Brazil: Species diversity, seasonality, and host variety

Leishmaniasis is a dynamic disease in which transmission conditions change due to environmental and human behavioral factors. Epidemiological analyses have shown modifications in the spread profile and growing urbanization of the disease, justifying the expansion of endemic areas and increasing number of cases in dogs and humans. In the city of Belo Horizonte, located in the southeastern state of Minas Gerais (Brazil), visceral leishmaniasis (VL) is endemic, with a typical urban transmission pattern, but with different regional prevalence. This study was conducted at the Zoo of the Foundation of Municipal Parks and Zoobotany of Belo Horizonte (FPMZB-BH), located in the Pampulha region, which is among the areas most severely affected by VL. This study aimed to determine the taxonomic diversity of native phlebotomine sand flies (Diptera: Psychodidae), identify climatic variables that potentially affect the phenology of these insects, and determine the blood meal sources for female phlebotomine sand flies. To achieve this, 10 mammal enclosures in the zoo were selected using the presence of possible leishmaniasis reservoirs as a selection criterion, and sampled using light traps between August 2019 and August 2021. A total of 6034 phlebotomine sand flies were collected, indicating nine species, with Lutzomyia longipalpis being the very abundant species (65.35% of the total). Of the 108 engorged phlebotomine collected females, seven samples (6.5%) were positive for blood meals from humans, marsupials, canids, and birds. Relative humidity and rainfall increased the phenology of phlebotomine sand flies, with population increases in the hottest and wettest months. The data obtained will provide guidelines for competent health agencies to implement vector control measures to reduce the risk of leishmaniasis transmission in the FPMZB-BH.

The Program for the Control of Visceral Leishmaniasis in Brazil: The Effect of the Systematic Euthanasia of Seropositive Dogs as a Single Control Action in Porteirinha, a Brazilian City with an Intense Transmission of Visceral Leishmaniasis

BACKGROUND

Porteirinha is endemic for visceral leishmaniasis (VL), with intense disease transmission of the disease. We evaluated the impact of canine euthanasia as a single control measure on the incidence of VL in humans and canines.

METHODS

A prospective observational cohort study was carried out over four years (1998-2002) in 8 of the 12 neighborhoods of the city. The dynamics of canine visceral leishmaniasis (CVL) transmission were evaluated for 2 years, before beginning the screening-culling intervention. The comparative morbidity index (CMI) was used to stratify areas with the greatest risk of CVL, and the spatial distribution of human and canine VL cases was compared using univariate and bivariate K-functions.

RESULTS

Human cases conglomerated in three neighborhoods. Spatial clusters were detected for CVL in 1998, 2000, and 2001, but not in 1999, when greater spatial dispersion occurred. The screening and culling intervention reduced the number of human VL cases and decreased the incidence of CVL, mainly in neighborhoods with a high CMI.

CONCLUSIONS

The systematic euthanasia of seropositive dogs was shown to be an effective control action of the Program for Control of Visceral Leishmaniasis (PCLV) in Brazil. The fundamental role of domestic dogs in the epidemiological chain of VL was reaffirmed.

Ecology and natural infection of phlebotomine sand flies in different ecotopes and environments in the municipality of Pains, Minas Gerais, Brazil

Phlebotomines (Diptera: Psychodidae) are vectors of protozoa of the genus Leishmania and distributed throughout Brazil, formerly restricted to rural areas, have expanded including to periurban and urban regions, been recorded in different habitats. This study aimed to understand the dynamics of sand flies in different ecotopes in the municipality of Pains. Sand flies were captured during thirty samplings using HP light traps installed in seven different ecotopes for two consecutive nights, once a month, from August 2018 to July 2019. A total of 1,352 sand flies were captured, representing 24 species belong to ten genera. Evandromyia edwardsi was the most abundant species, followed by Evandromyia lenti and Micropygomyia quinquefer. Leishmania DNA was detected in seven female sand flies in four ecotopes, for an infection rate of 0.9%. Sand flies were collected in all seven ecotopes, although forest (23.04%), cave (20.88%) and pasture (17.75%) had higher abundance and richness. Similarity was found among ecotopes, indicating that they are all important for the maintenance of the sand fly community. Spatial analysis indicated high densities of sand flies in areas with natural characteristics. All ecotopes in the municipality were evidenced to have an adequate and harmonious epidemiological profile for the transmission and expansion of leishmaniasis throughout the territory. Because of the increasing environmental changes and deforestation in the municipality, the risk of generating ecological imbalance and increased cases of leishmaniasis is imminent, which highlights the importance of developing preventive and control strategies.

Sand fly bioecological aspects and risk mapping of leishmaniasis by geographical information systems approach in a mineral exploration area of Brazil

Epidemiological studies of leishmaniasis in areas of great human influence and environmental change serve as important tools for the implementation of effective control plans. Mining is currently a major economic activity in Brazil with the municipality of Pains, in the state of Minas Gerais, being one of the main lime producing municipalities in the country. This study aimed to map areas of potential transmission risks within the municipality of Pains using an epidemiological approach in association with the ecological study of sand flies. Twelve samplings carried out between May 2015 and April 2016 collected a total of 12,728 sandflies, comprising 2,854 females (22.42%) and 9,874 males (77.58%), of 20 species belonging to ten genera. The most abundant species was Lutzomyia longipalpis (80%). Leishmania DNA was detected in seven pools of female sand flies with an infection rate of 0.37%. Geoprocessing and the use of maps revealed that vector sand flies are distributed throughout the urban area, as are cases of canine and human leishmaniasis. However, the greatest abundances of sand flies were at sampling points at the border of the urban area. Higher densities of sand flies and the presence of Leishmania DNA may be correlated with extensive degradation by limestone mining. Integrated and multidisciplinary research approaches are necessary to better understand how the impacts of environmental change influence these insect vectors of leishmaniasis.

Impact of vector control actions in the abundance of Lutzomyia longipalpis in Montes Claros, Brazil

Visceral leishmaniasis (VL) is endemic to many states in Brazil. To prevent further expansion of the disease, the Brazilian Ministry of Health adopted integrated measures through the Program of Surveillance and Control of Visceral Leishmaniasis (PSCVL), whose actions include the diagnosis and euthanasia of seropositive dogs (the main domestic reservoirs), the use of residual insecticides, environmental management (EM) to control vector population (mainly Lutzomyia longipalpis phlebotomine), rigorous epidemiological surveillance, and health education. The present study was conducted in areas with recent moderate VL transmission to evaluate the efficacy of vector control activities. The systematic capture of phlebotomine was performed for three consecutive days per month, from August 2015 to July 2017. The number of specimens captured was taken as a representative of the monthly insect population. A total of 38,055 phlebotomine specimens were captured and identified at the species level. Lu. longipalpis was consistently found to be the predominant species (97.7%) each month. In the first year of the study, no intervention was performed. In the second year, two cycles of chemical spraying, EM, or a combination of both were performed before and after the rainy season. All interventions, either individually or in combination, reduced the abundance of Lu. longipalpis in the study area.

Risk and protective factors of Leishmaniasis in the rural area of the western border region of Rio Grande do Sul, Brazil

Background

The Leishmaniases are on the top of the global list of tropical neglected diseases. The number of infected dogs in South America is estimated in millions and correlated to disease cases in humans, especially in Brazil. Equines may get infected too and can play a role in the epidemiological chain. Thus, the aim of the present study was to evaluate risk and protective factors of leishmaniasis in rural areas of the western border region of Rio Grande do Sul state, Brazil by Leishmania spp. protozoa molecular detection and serological evaluation (ELISA) in equine and canine blood samples. This work included nine farms around the city of Uruguaiana. Epidemiologic information regarding farm characteristics and biologic material collection of canine (22) and equine (91), totalizing 113 samples was collected. The polymerase chain reaction (PCR) technique was used to detect Leishmania spp. in biological samples. Variables related to the farm were collected and evaluated through descriptive analysis followed by chi-square test and a logistic regression analysis.

Results

Nineteen positive samples (19/113 – 16,81%) were detected, being 18 equines and 1 canine, in six of the nine farms included in the study. No animal showed clinical signs of the disease. According to the variables analyzed, when compared each characteristic separately, the presence of abundant vegetation and poor hygiene demonstrated to be risk factors to Leishmania infection in rural areas. The logistic regression showed that excellent general hygiene, proximity to the weir and trimmed grass were protective factors (p=0.038, p=0.001 and p=0.014, respectively). Having excellent hygiene represents a 70% lower chance of getting infected, keeping the grass cut protects the animal by more than 90% and the proximity of the weir represents a protective factor of 96%.

Conclusions

The presence of Leishmania infection in the western border region of Rio Grande do Sul was 16,81% and it was influenced by farm characteristics. The role of the excellent general hygiene as a protective factor is extremely relevant in the leishmaniases prevention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03021-6.

Maintenance and Productivity of a Lutzomyia longipalpis (Diptera: Psychodidae) Colony from an Area Endemic for Visceral and Cutaneous Leishmaniasis in Northeastern Brazil

Studies on experimental sand fly infection require the availability of colonies and laboratory conditions. In Brazil, Lutzomyia longipalpis (Diptera: Psychodidae) (Lutz and Neiva 1912) is responsible for the highest infection rates by Leishmania spp. and this species is one of the most suitable species for laboratory colonization. In this study, we describe a method for growing Lu. longipalpis in laboratory conditions (10 generations) from natural populations sampled from a region of high endemicity for visceral leishmaniasis in the state of Maranhão, Northeastern Brazil. Using two methods (individualized or grouped females), the colony's highest productivity occurred in the first four generations, where all stages presented with high frequency. Nonviable eggs represented more than 50% of the total eggs produced by engorged females, while pupae were more resistant to fungal contamination, with a mortality rate of only 2%. In both methods, there was a predominance of female emergence; however, the ratio between males and females did not show significant differences, IF (P = 0.8023) and GF (P = 0.1831). Using the method of individualized females, the F4 generation took the longest to appear (234 d; 64 ± 57 d); by grouped females, F3 took the longest to appear (102 d; 47 ± 20 d). This method provides sufficient numbers of insects to perform vector competence tests for Leishmania spp. that cause the cutaneous form of leishmaniasis, usually found in Lu. longipalpis sampled from the study location.

A follow-up study (2007-2018) on American Tegumentary Leishmaniasis in the municipality of Caratinga, Minas Gerais State, Brazil: Spatial analyses and sand fly collection

Background

The municipality of Caratinga is an important endemic area for American Tegumentary Leishmaniasis (ATL) and no epidemiological studies were performed during the past two decades. Here, we analyzed the epidemiological situation and the geographical distribution of ATL cases in the municipality of Caratinga from 2007 to 2018 using geographic information systems (GIS). Also, we evaluated the impact of several demographic parameters in ATL distribution and the sand flies incriminated in its transmission.

Methods

All demographic information (gender, age, educational level, clinical form, diagnostic criteria and case evolution) used in this study was retrieved from the public health archives and confirmed in the State Health Services databases. All cases were analyzed using GIS software based on ATL distribution. Also, non-systematic sand fly collections and molecular detection of Leishmania were performed in the hotspots.

Results and conclusions

During the period, ATL cases continued and increased especially in the past years (2016–2018). Hotspots included urban Caratinga areas and the districts of Patrocínio de Caratinga and Sapucaia. The species Nyssomyia whitmani, Nyssomyia intermedia, Migonemyia migonei and Evandromyia cortelezzii complex were captured. However, ITS1-PCR did not detect Leishmania DNA in those insects. Based on our analyses, urbanization of ATL in Caratinga has occurred in the past years. Due to the increase in the number of cases and vectors presence, it is recommended that health authorities focus on control measures in the most affected areas (Patrocínio of Caratinga and Sapucaia districts and urban Caratinga).

Leishmaniasis is an important health problem in Latin American countries and worldwide. In some places, notification is limited and underreported hindering correct assessment of existing data. In Brazil, ATL is mainly caused by Leishmania (Viannia) braziliensis. It is transmitted by sand fly vectors Nyssomyia whitmani and Nyssomyia intermedia. ATL comprises different clinical manifestations including cutaneous leishmaniasis, muco-cutaneous leishmaniasis and atypical leishmaniasis. The objective is to present the spatial distribution of cases of ATL notified by the Public Health System of Caratinga between the period of 2007 and 2018. This city is one of the most important endemic areas in the State of Minas Gerais and compose the panel of knowledge on epidemiological aspects of cutaneous leishmaniasis caused by L. braziliensis. This information will be important for developing strategies for ATL control in the affected areas. There is strong evidence that supports ATL urbanization in the city of Caratinga and increase of cases in two rural districts (Sapucaia and Patrocínio de Caratinga).

Factors associated with human visceral leishmaniasis cases during urban epidemics in Brazil: a systematic review

Visceral leishmaniasis (VL) is endemic in 70 countries and has been reported in 12 countries of Latin America, with over 90% of the cases reported in Brazil, where epidemics have occurred since 1980. The objective of this review is to describe the factors associated with the occurrence of VL epidemics in humans in urban areas. A systematic review was conducted according to the PRISMA-P guidelines. The databases PubMed (by Medline), Cochrane Library, Embase, Amed, LILACS and grey literature [Google Scholar and handsearch of the database of the Information System for Notifiable Diseases (SINAN) of Brazil's Unified Health System] were used. The protocol was registered under PROSPERO (CRD42019128998). Climatic, environmental factors and indicators of urban social structure were described as influencing the outbreaks in the North and Northeast regions. Gender and age characteristics were related to a greater chance of developing VL in the Central-West, Northeast and Southeast regions. Vector indicators showed a positive correlation with the incidence of VL in studies in the Northeast region. In the Southeast and Northeast regions, studies revealed the presence of dogs with positive correlation with VL. Knowledge gaps remain regarding the contribution to the increase in the risk factors described in ecological approaches, as no analysis was performed at the individual level, and it is still necessary to discuss the influence of other associated elements in epidemic episodes in the spread of VL.

Detection of Leishmania infantum DNA in blood samples of horses (Equus caballus) and donkeys (Equus asinus) by PCR

Visceral leishmaniasis (VL) is a neglected tropical disease caused by the Leishmania infantum parasite. The protozoan is able to infect several domestic and wild mammals. Since the first report on Leishmania spp. infection in horses in South America, leishmaniasis in equids has been highlighted in Brazil. A molecular epidemiological survey was carried out to verify the occurrence of Leishmania spp. DNA in horses and donkeys, in leishmaniases endemic areas in Sao Paulo State, Brazil. To this end, blood samples were obtained from 107 horses and 36 donkeys and subjected to DNA extraction followed by PCR targeting the ITS-1 region. Among the horses and donkeys, 1.87% (2/107) and 8.33% (3/36) were positive by PCR, respectively. The DNA sequencing of the ITS-1 amplification products confirmed L. infantum DNA in these animals. Our results suggest that horses and donkeys from non-VL and VL endemic areas of São Paulo State may be infected by the parasite.

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.

Spatial-Temporal Analysis of Lutzomyia trapidoi and Lutzomyia reburra (Diptera: Phlebotominae), in Rural Tourist Locations, Biosphere Reserve and Leishmaniasis Endemic Area, Ecuador

This research represents the first attempt to assess the spatial and temporal distribution based on micro-meso scales on two species with different host preference habits (anthropophilic vs zoophilic), in the major Leishmaniasis endemic area in Ecuador, tourist locations, and Biosphere reserve. Phlebotomine species, Lutzomyia trapidoi (Fairchild) and Lutzomyia reburra (Fairchild and Hertig), were analyzed by trap/habitat/month/locality/altitude, through the Poisson generalized regression model. Our data reveal a bimodal pattern for both species related with low precipitations and preference for forest habitat. Altitude, proximity to the forest, and the river were the variables that determine the hypervolume of the spatial distribution of relative abundance, where the overlap of these two species increases the risk of translocation and circulation of the etiological agent of leishmaniasis in sylvatic environments to rural-tourist-biosphere reserve areas and vice versa. The ecological characteristics of these two phlebotomines could explain the permanence of the major active and endemic focus of cutaneous leishmaniasis in the North-Western Ecuador a key aspect in tourism health-security in alternative tourism.

DNA extraction from individual Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) specimens: Which is the method with better results?

Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) are a group of small insects of great concern for Public Health. These dipterous are intensely studied worldwide due to their involvement in the transmission of several pathogens, mainly Leishmania spp. parasites. Nowadays, the molecular tools have been included in Phlebotomine sand flies studies and has shown to be powerful tools in bioecology studies of these dipterous. Thereby, when molecular approaches are employed, there is a great concern regarding the amount and quality of the DNA obtained for analysis. Here, seven methods of DNA extraction, between commercial kits and in house extraction protocols were evaluated. We considered measure of DNA concentration and purity ratios using a spectrophotometer to check the performance of each protocol. In addition, the quality evaluation of the DNA extracted was performed by endogenous gene PCR on samples. The results of the seven evaluated DNA extraction protocols and their implications are discussed.

Ecology of phlebotomine sand flies in a Brazilian area with recent leishmaniasis transmission (Itaúna, in Minas Gerais state)

INTRODUCTION:

Leishmaniasis constitutes a serious but neglected tropical disease. Recently, socio-environmental, biological and physical changes have altered the range of leishmaniasis, causing it to spread into urban areas. In Minas Gerais, the disease is endemic, exhibiting regional differences and reaching urban centers. The purpose of this study was to evaluate entomological aspects related to the ecoepidemiology of leishmaniasis in Itaúna.

METHODS:

Monthly catches with HP traps were carried out from June 2017 to May 2018, in three ecological areas (urban, rural, and forest). The adaptability of the species to anthropic environments was assessed using the synanthropy index (SI).

RESULTS:

We collected 1306 specimens of phlebotomine sand flies. Of the species of medical importance, Lutzomyia longipalpis, the vector of Leishmania infantum, represented 90.4% of the specimens identified at species level (n=1260). Nyssomyia whitmani, the vector of Leishmania braziliensis, represented 1.6% of the total. Lu. longipalpis displayed an SI of +95.8, a value that denotes a marked preference for human environments. For Ny. whitmani, the SI was -25, expressing the tendency of this species to occupy uninhabited areas. The population of the three most numerous species captured increased with rain, high temperatures, and high relative humidity. Although captured at low numbers, Ny. whitmani showed a different profile concerning the climate variables analyzed.

CONCLUSIONS:

Understanding the epidemiology of the disease may assist the health services in formulating effective control measures for improving community health and contributing to the establishment of a dynamic relationship and a global awareness of the health/disease process.

Human visceral leishmaniasis: epidemiological, temporal and spacial aspects in Northeast Brazil, 2003-2017

Visceral leishmaniasis is a highly lethal zoonosis transmitted by a sandfly. It is caused by a Leishmania protozoan parasite and dogs are the main reservoir. Ceara State is endemic to visceral leishmaniasis and it is considered a high risk transmission area. Temporal and spatial epidemiological studies have been used as tools to analyze the distribution and frequency of human visceral leishmaniasis (HVL). This study aimed to characterize HVL in its epidemiological andtemporal aspects in Ceara State, from 2003 to 2017, as this is a neglected disease and a public health problem. This is an ecological study carried out with HVL confirmed cases in Ceara, using three blocks of years (2003 to 2007, 2008 to 2012 and 2013 to 2017). The disease presented an endemic behavior, affecting mainly male residents in the urban area, especially children under five and young adults between 30 and 49 years old. HVL is recorded in all the municipalities, for more than 10 years, with a growing trend and territorial expansion to the Central and Eastern regions of the State. The results of this study indicated the increase in the incidence and lethality, as well as the expansion of leishmaniasis in Ceara State.

Sandflies in an endemic area for Visceral Leishmaniasis in Northeastern Brazil

Abstract Phlebotomines of the genus Lutzomyia are important vector for species of Leishmania, the etiological agent of leishmaniasis. The aim of this study was to assess the diversity of sandflies in an endemic area for Visceral Leishmaniasis (VL). Sampling was performed in four localities on the coast of the municipality of Goiana, state of Pernambuco, Northeastern Brazil. Specimens were collected monthly on three consecutive nights, from November 2017 to October 2018. CDC light traps were installed at a height of 1.5 m above the ground, in two ecotypes (i.e. tree and animal facility), both in peridomestic areas. A total of 5,205 sandflies were collected, among which the species Lutzomyia longipalpis (99.85%; 5,197/5,205) was the most common, followed by Lutzomyia evandroi (0.13%; 07/5,205) and Lutzomyia whitmani (0.02%; 01/5,205). Specimens of L. longipalpis were collected throughout the study period and most of them were found near to the animal facilities. The findings from this research indicate that vectors for Leishmania infantum are present in the study area throughout the year, along with occurrences of vectors relating to Cutaneous Leishmaniasis (CL). Preventive vector control measures need to be implemented in Goiana to reduce the risk of infection for the human and animal populations.

Sandflies (Diptera: Psychodidae: Phlebotominae), present in an endemic area of cutaneous leishmaniasis in western Boyacá, Colombia

Introduction:

Sandflies are known for having vector species of the tropical disease Leishmaniasis, a disease which is of an endemic nature in Western Boyacá, where the town of Otanche is one of the main source of Cutaneous Leishmaniasis.

Objective:

To identify the species of sandfly present in an endemic area of cutaneous leishmaniasis in West Boyacá.

Methods:

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.

Results:

Were recollected 361 individuals (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.

Conclusion:

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.

Entomological Studies in Itaúna, Brazil, an Area With Visceral Leishmaniasis Transmission: Fauna Survey, Natural Leishmania Infection, and Molecular Characterization of the Species Circulating in Phlebotomine Sand Flies (Diptera: Psychodidae)

Among neglected tropical diseases, visceral leishmaniasis (VL) shows great relevance in global terms and is a serious public health concern due to the possibility of severe and lethal forms in humans. In this study, we evaluate entomological factors such as diversity and abundance of phlebotomine sand flies (Diptera:Psychodidae) and the Leishmania species circulating in these species in possible association with VL transmission in the Brazilian town Itaúna. The entomological collections were performed during three consecutive nights, always in the third week of each month, within a period of 12 mo. A total of 1,786 sand fly specimens were collected, from which 20% were collected inside houses. The influence of three local climatic variables (temperature, rainfall, relative humidity) on the population sizes of these insects was evaluated. Temperature was the most influential factor, with a significant positive correlation with the local population size of phlebotomine sand flies collected per month. Lutzomyia longipalpis (Lutz & Neiva, 1912) was the predominant species in the study area. Leishmania DNA was detected in nine out of 133 pools of sand fly females, using nested/PCR, which resulted in a minimal natural infection rate of 2.91%. DNA from Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatida), was detected in Evandromyia cortelezzii (Bréthes, 1923), Ev. evandroi (Costa, Lima & Antunes, 1936), Ev. lenti (Mangabeira, 1938), and Ev. termitophila (Martins, Falcão & Silva, 1964), besides Lu. longipalpis. Our study indicates favorable conditions for VL spreading in Itaúna due to the presence of Lu. longipalpis and Le. infantum-infected phlebotomine sand flies.

Natural infection by Leishmania infantum in the Lutzomyia longipalpis population of an endemic coastal area to visceral leishmaniasis in Brazil is not associated with bioclimatic factors

Visceral leishmaniasis (VL) is a zoonosis caused by the protozoan Leishmania infantum and in Brazil is transmitted mainly by the bite of Lutzomuyia longipalpis sand flies. Data about the presence, distribution, natural infection rate, seasonal and monthly dynamics of the vector population are important for optimizing the measures to control VL in endemic areas. This study aimed to identify sand fly fauna in an endemic area for VL to detect the prevalence of L. infantum infection in the Lu. longipalpis population and to elucidate the influence of bioclimatic factors on the monthly fluctuations of this vector. HP light traps were monthly set in the intradomicile and peridomicile of residences located in the central and beachfront areas of Camaçari, a VL endemic area. The sand fly collection was conducted in two periods: i) period 1-between December 2011 and November 2012 and ii) period 2-August 2014 and July 2015. Sand fly species were identified and detection of L. infantum infection by qPCR was performed in pools of female Lu. longipalpis. For the first time, the parasite load of positive pools was correlated with the number of Lu. longipalpis captured per month in both periods. Correlation analyses between the monthly fluctuation of the sand fly population and bioclimatic indices of the municipality in both collection periods were also performed. In both evaluated periods, more than 98% of the collected sand flies were Lu. longipalpis, confirming the predominance of this species in the region. It was captured mostly in the beachfront area in all months evaluated (99%). For the period 1, Leishmania DNA was detected in 81% of tested pools representing a minimal infection rate of 9.6%. In the period 2, 40% of the pools were positive with a minimal infection rate of 10.2%. Infected sand flies were only detected in the beachfront area in both periods. The parasite load was low and did not vary in the evaluated months despite the number of collected sand flies. No correlation was observed for climatic factors in both areas of Camaçari. These findings emphasize the high risk of Leishmania transmission in Camaçari regardless of the season and that other factors, aside from bioclimatic elements, are influencing the sand fly population monthly fluctuation.

Ocorrência de anticorpos anti-Leishmania spp. em felinos em área endêmica do estado de São Paulo

RESUMO A leishmaniose visceral (LV) é uma zoonose de grande impacto em saúde pública. A infecção nos gatos tem sido relatada nos países onde a doença é endêmica. Seu papel como reservatório não está satisfatoriamente elucidado, embora a transmissão do parasito de um felino infectado para vetor tenha sido reportada por xenodiagnóstico. O objetivo do trabalho foi avaliar a presença de anticorpos anti-Leishmania spp. em animais da espécie felina em área endêmica para LV (Bauru-SP), por meio dos testes sorológicos de reação de imunofluorescência indireta (RIFI) e ensaio imunoenzimático (ELISA), e associá-los às variáveis: gênero, idade, raça e forma de criação. Foram testados soros de 276 felinos, dos quais 82 foram reagentes pelo método ELISA (29,71%), 17 pelo RIFI (6,15%) e 10 em ambos os testes (3,6%). Houve associação estatística significativa para a variável forma de criação, em que 100% dos animais errantes foram soropositivos a pelo menos um dos testes (P<0,005). Tal associação não foi encontrada para as demais variáveis analisadas (P>0,05). Não houve concordância entre o resultado dos testes, pois o método ELISA é mais sensível que o método RIFI.

Ecology of phlebotomine sand flies in an area of leishmaniasis occurrence in the Xakriabá Indigenous Reserve, Minas Gerais, Brazil

INTRODUCTION

Leishmaniasis is a complex vector-borne infectious diseases caused by protozoan parasites in the genus Leishmania and spread by hematophagous phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae). The aim of this study was to investigate the phlebotomine fauna, endophily and exophily of the species found, and possible influence of climatic factors on their populations.

METHODS

The study was conducted in the Xakriabá Indigenous Reserve (XIR) in the municipality of São João das Missões in northern Minas Gerais state, Brazil. Insects were collected over three consecutive nights in the last week of each month for 12 months from July 2015 to May 2016 from four houses in four different villages. Two traps were set up in each house: one in the intra-domicile and another in the peri-domicile.

RESULTS

A total of 2,012 phlebotomine sand fly specimens representing 23 species and belonging to 10 different genera were captured and identified. Among the studied villages, Riacho do Brejo showed the highest density and diversity of phlebotomine sand flies. The species Lutzomyia longipalpis (80.3%) and Nyssomyia intermedia (7.3%), which are major vectors of visceral and cutaneous leishmaniasis, respectively, had the highest population densities, both in the intra- and peri-domicile. No correlation was observed between climatic factors and the density of phlebotomine sand flies.

CONCLUSIONS

The results of the present study may contribute to a better understanding and targeting of the measures for preventing and controlling leishmaniasis by the authorities responsible for indigenous health.

First isolation of Leishmania infantum by blood culture in bovines from endemic area for canine visceral leishmaniasis

Leishmaniasis is considered a parasitic disease that still causes serious consequences for mankind, because it presents a high mortality rate worldwide. Considered multi-hosts, the parasites of the genus Leishmania are able of infecting a wide variety of animal species. The dog was considered the main source of infection of visceral leishmaniasis (VL), in the urban area. However, the role of other animal species in the epidemiological cycle of the disease, such as cattle, remains unclear. Therefore, the aim of the present study was to evaluate the occurrence of Leishmania spp. in 100 bovines (Bos taurus) from an area endemic for canine VL, using blood culture and molecular analysis. By the sequencing analysis, one sample showed 100% similarity with Leishmania infantum. The results provide the first case of L. infantum isolation in one bovine from the periurban areas of Bauru, state of São Paulo, Brazil.

PREVALÊNCIA DA LEISHMANIOSE VISCERAL CANINA E COINFECÇÕES EM REGIÃO PERIURBANA NO DISTRITO FEDERAL – BRASIL

Resumo Objetivou-se verificar a prevalência da leishmaniose visceral canina (LVC) em área periurbana com foco de transmissão no Distrito Federal (DF) e também avaliar a prevalência de coinfecções como dirofilariose, anaplasmose, erliquiose e doença de Lyme em cães sororreagentes para LVC. Inicialmente, amostras de soros dos cães da área de estudo foram testadas à reação imunocromatográfica que contém dois antígenos recombinantes ̶ rK39 e rK26 − (DPP) para Leishmania sp. O soro dos animais reagentes ao teste de DPP foi confirmado para LVC com ELISA. As amostras reagentes a ambos os testes foram analisadas para possíveis coinfecções através do teste de SNAP (IDEXX 4Dx Plus). Foram avaliados 240 cães, dos quais 132 (55%) obtiveram resultados reagentes para DPP e para ELISA concomitantemente, sendo diagnosticados com LVC. Destes, 26 (20%) foram reagentes para Ehrlichia canis ou E. ewangii, 9 (7%) apresentaram positividade para Anaplasma phagocytophilum ou A. platys e, nessas amostras que se apresentaram reagentes, observou-se a ocorrência de coinfecção de anaplasmose, erliquiose e leishmaniose em 3 (2,3%) animais. Verificou-se alta prevalência da LVC na região periurbana do DF, destacando-se a necessidade de diagnóstico mais preciso quanto a coinfecções que possivelmente podem influenciar no prognóstico e manifestação do quadro clínico desses pacientes.

Ecoepidemiological aspects of visceral leishmaniasis in an endemic area in the Steel Valley in Brazil: An ecological approach with spatial analysis

Leishmaniases are a group of infectious diseases transmitted by phlebotomine sand flies, and their distribution depends on the presence of vectors, parasites, reservoirs and susceptible hosts in the same environment. In the last decades, visceral leishmaniasis (VL) has become urbanized and reached economically important cities in countries within the transmission zone. Our study was conducted in one of those cities-Ipatinga-in the state of Minas Gerais, Brazil, where the first autochthonous case of VL dates back to 2011. Since no data regarding the epidemiological triad of VL (etiological agent/vector/domestic reservoir) were available for this city, we characterized the local entomological fauna, identified the presence of specific Leishmania DNA in the captured phlebotomine sand flies, and assessed the incidence of canine and human VL. For the entomological survey, we set twenty light traps in ten districts of the city with reports of human and canine VL. The insect captures were performed monthly, during one year, starting in March 2015. A total of 1501 specimens of phlebotomine sand flies belonging to 16 distinct species were captured, with predominance (61.9%) of Lutzomyia longipalpis. Leishmania infantum DNA was detected in L. longipalpis and in Evandromyia cortelezzii test samples. A total of 9,136 dogs were examined, 1,355 of which (14.8%) were serologically positive for VL. The cases were georeferenced and the data were plotted in thematic maps, along with human cases of VL registered by the local Department of Health, during the study period. Our results confirm that the VL transmission cycle is active in Ipatinga, with the presence of vectors carrying Leishmania DNA, canine and human cases of the disease. Spatial analysis allowed for the observation of a positive relationship between canine and human cases of VL and the identification of areas with high priority for control actions in the city. The mapping of high-risk areas, together with an epidemiological study in urban areas, is fundamental to improve the efficacy of the Program for Surveillance and Control of VL (PSCVL) in Brazil.

Impact of 4% Deltamethrin-Impregnated Dog Collars on the Prevalence and Incidence of Canine Visceral Leishmaniasis

In Brazil, visceral leishmaniasis is caused by the protozoan Leishmania infantum, primarily transmitted by Lutzomyia longipalpis and with the dog as its main urban reservoir. This study aims to evaluate the effectiveness of 4% deltamethrin-impregnated dog collars (DMC) DIC, Scalibor^® 65 cm model and MSD manufacturer, on the prevalence and incidence of canine visceral leishmaniasis (CVL) and on the rate of infection of sandflies by L. infantum. The research was conducted in two areas of the municipality Mossoró, State of Rio Grande do Norte in Northeast of Brazil. Two semiannual serosurveys, followed by culling seropositive dogs, and searches for phlebotominae were performed in the control area (CA), whereas in the collar intervention area (IA), aside from those procedures, DMC were fitted to dogs every 6 months. CVL was diagnosed by the Dual Path Platform rapid test (TR-DPP^®) and the Immunoenzymatic assay (EIE). The sandflies were collected monthly, identified, and the females were submitted to Quantitative Real-Time Polymerase Chain Reaction for detection of L. infantum DNA. The use of collars was associated with a 53-59% reduction in the incidence of CVL. The most abundant phlebotomine species were L. longipalpis (81.8%). Positive pools of L. longipalpis were obtained in the IA only in the first survey, whereas the presence of the DNA of the parasite in the vector was observed in the CA in both surveys. We conclude that the continuous use of these collars may have the potential to reduce both the incidence of CVL and the rate of infected phlebotomine sandflies.

Spatial and temporal trends of visceral leishmaniasis by mesoregion in a southeastern state of Brazil, 2002-2013

BACKGROUND

Visceral leishmaniasis (VL) is expanding in Brazil and in other South American countries, a process that has been associated with the urbanization of the disease. This study analyzes the spatial and temporal distribution of VL in the Brazilian state of Minas Gerais and identifies the areas with higher risks of transmission.

METHODOLOGY

An ecological study with spatial and time series analyzes of new confirmed cases of VL notified to the Brazilian Notifiable Disease Information System between 2002 and 2013, considering the 12 mesoregions of Minas Gerais. Two complementary methodologies were used: thematic maps of incidence and Poisson (log-linear) generalized linear model. Thematic maps using crude and smoothed cumulative incidences were generated for four trienniums. Poisson Regression measured the variation of the average number of cases from one year to the following, for each mesoregion.

PRINCIPAL FINDINGS

The 5,778 cases analyzed revealed a heterogeneous spatial and temporal distribution of VL in Minas Gerais. Six mesoregions (Central Mineira, Jequitinhonha, Metropolitan area of Belo Horizonte, Northwest of Minas, North of Minas, and Vale do Rio Doce) were responsible for the expansion and maintenance of VL, with incidence rates as high as 26/100,000 inhabitants. The Vale do Rio Doce and Jequitinhonha mesoregions showed a considerable increase in the incidence rates in the last period studied. The other six mesoregions reported only sporadic cases and presented low and unsteady incidence rates, reaching a maximum of 1.2/100,000 inhabitants.

CONCLUSIONS/SIGNIFICANCE

The results contribute to further the current understanding about the expansion of VL in Minas Gerais and may help guide actions for disease control.

Perceptions of the population and health professionals regarding visceral leishmaniasis

Based on theoretical qualitative research reference methodology, this study sought to investigate the perception of visceral leishmaniasis (VL) by social actors directly involved in the prevention and control of the disease. Thirty-eight semi-structured interviews were conducted with residents, focus groups were staged with 18 health workers in an endemic VL area and depositions were collected, which after being processed by content analysis revealed shortcomings and challenges. The population associated VL with dogs, acknowledged their co-responsibility in tackling the disease and demanded information. Health workers identified environmental sanitation as an essential factor for VL prevention. Among the shortcomings, the lack of information about the disease and culpability of the individual because of non-adherence to prevention measures were observed, especially environmental management. Probably, approaches emphasizing the role of the environment as a health promotion agent and the timely definition of specific environmental measures against VL, constitute a prospect for overcoming these shortcomings. The consensus is that the main challenge for enhancing the prevention and control might be the participatory and dialogical construction of these approaches between health professionals and the population.

Leishmania infection and blood food sources of phlebotomines in an area of Brazil endemic for visceral and tegumentary leishmaniasis

The aims of the study were to determine the blood feeding preferences of sandflies and to identify species of Leishmania that infected phlebotomines in Caxias, Maranhão, Brazil, an area that is highly endemic for leishmaniasis. Sandflies were captured in light traps located in the peridomiciliary environments of randomly selected houses in urban and rural settings between 1800 and 0600 hours on new moon days between March 2013 and February 2015. DNA extracts from 982 engorged female sandflies were submitted to fragment length polymorphism analysis to identify infecting species of Leishmania, and blood sources were identified for 778 of these specimens. Infection by Leishmania infantum was detected in Lutzomyia longipalpis, Lu. whitmani and Lu. termitophila; L. infantum/L. braziliensis in Lu. longipalpis, Lu. whitmani and Lu. trinidadensis; L. shawi in Lu. longipalpis; L. mexicana in Lu. longipalpis; L. braziliensis in Lu. longipalpis and Lu. whitmani; L. guyanensis in Lu. longipalpis and Lu. termitophila; L. amazonensis in Lu. longipalpis and L. lainsoni or L. naiffi in Lu. longipalpis, while Lu. longipalpis and Lu. trinidadensis were infected with unidentified Leishmania sp. Blood sources were identified in 573 individual phlebotomines and the preferred hosts were, in decreasing order, chicken, dog, rodent and human with lower preferences for pig, horse, opossum and cattle. Lu. longipalpis and Lu. whitmani performed mixed feeding on man, dog and rodent, while Lu. longipalpis was the most opportunistic species, feeding on the blood of all hosts surveyed, but preferably on dog/chicken, dog/rodent and rodent/chicken. Our findings reveal the concomitant circulation of Leishmania species that cause visceral leishmaniasis and tegumentary leishmaniasis in the study area, and explain the occurrence of autochthonous human cases of both clinical forms of leishmaniasis in Caxias, Maranhão. The results support our hypothesis that, in the municipality of Caxias, transmission of Leishmania occurs in close proximity to humans.

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.

Phlebotomines in an area endemic for American cutaneous leishmaniasis in northeastern coast of Brazil

Abstract Phlebotomines have worldwide distribution with many species present in Brazil, including the northeastern region, where the fauna is very diverse. The aim of this study was to identify the sandfly fauna in an area endemic for American cutaneous leishmaniasis (ACL) in the state of Pernambuco. Sandflies were caught on three consecutive nights every month from October 2015 to September 2016, from 5 pm to 5 am, using seven light traps of Centers for Disease Control (CDC) type. Females were identified and used for molecular Leishmania detection. A total of 2,174 specimens belonging to ten species were collected: Lutzomyia choti (88.2%; 1,917/2,174) was the most abundant species, followed by Lutzomyia whitmani (8.1%; 176/2,174) and Lutzomyia sordellii (1.5%; 33/2,174). The majority of the specimens were collected in peridomestic areas (64.1%; 1,394/2,174) and during the rainy period. All the samples examined were negative for Leishmania spp. The presence of Lutzomyia whitmani indoors and in peridomestic areas indicates that the inhabitants of this area are exposed to the risk of infection by the parasites responsible for ACL.

Evaluating the Adaptation Process of Sandfly Fauna to Anthropized Environments in a Leishmaniasis Transmission Area in the Brazilian Amazon

Phlebotomines (Diptera: Psychodidae) are vectors of several etiological agents of human and animal diseases, including protozoans of the gender Leishmania. Precarious socioeconomic conditions and uncontrolled population growth directly influence the transmission risk of parasites and the urbanization of vector species, previously restricted to wild environments. The Marajó Archipelago is considered a high incidence area of leishmaniasis in the Brazilian Amazon. However, it is poorly studied. The aim of this study was to assess the adaptation processes of phlebotomine species to anthropized environments in this region. For this purpose, the phlebotomine fauna was compared between three municipalities of the Marajó Archipelago: Anajás, Portel, and São Sebastião da Boa Vista. To survey the phlebotomine fauna, CDC (Center for Disease Control) light traps were installed in the wild areas and in the intra and peridomiciliary areas of rural and urban environments. The environments studied presented a diversified phlebotomine fauna, with higher richness in the wild environment (15 species), followed by the rural (seven species), and finally, the urban environment (three species). A migration of wild fauna to the adjacent anthropized areas (rural environment) and to urban areas was observed, evidencing the adaptation process of this vector to anthropized environments in the studied region. Thus, our study evidenced that the disorganized human occupation and utilization of the landscape might cause the invasion of urban areas by wild populations of phlebotomines, in this way enabling the settlement of urban leishmaniasis transmission cycles.

Frequency and diversity of phlebotomine sand flies (Diptera: Psychodidae) in Sinop, State of Mato Grosso, Brazil

INTRODUCTION:

Understanding the diversity of sand flies is important for the epidemiology and control of leishmaniasis. This study aimed to understand the frequency, diversity, and seasonality of medically important sand flies in the municipality of Sinop, State of Mato Grosso, Brazil.

METHODS:

The study was conducted in an urban area, including four ecotypes with different levels of urbanization. The sand flies were collected using light traps for three nights per month, from May 2014 to April 2015.

RESULTS:

A total of 62,745 sand flies was collected, 52.34% of which were female. The frequency and diversity of sand flies was the highest in areas of permanent preservation (APPs) (96.85%), and was lower in more urbanized areas. Lutzomyia dasypodogeton was the most frequent species in the APPs. Lutzomyia antunesi was the most frequent in neighborhoods with forest fragments and neighborhoods around APPs, and L. aragaoi was the most frequent in completely urbanized neighborhoods. A higher frequency and diversity of sand flies was observed in the rainy season (87.92%) than in the dry season (12.08%). Eight medically important species were captured, and Lutzomyia antunesi, which is associated with American cutaneous leishmaniasis and visceral leishmaniasis, was observed in all ecotypes throughout the year.

CONCLUSIONS:

We observed a high frequency and diversity of sand flies in all urban areas, and some species collected were major vectors of leishmaniasis. These results support the need for further studies of the natural rates of infection of these insects and the circulation of the disease in hosts and vectors.

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.

Comparative analysis of carbohydrate residues in the midgut of phlebotomines (Diptera: Psychodidae) from colony and field populations from Amazon, Brazil

Leishmaniasis are worldwide diseases that occur in 98 countries including Brazil, transmitted by the bite of female phlebotomines during blood feeding. In Brazil it is known that some species of sand flies as Lutzomyia longipalpis sensun latum (vector of Leishmania infantum chagasi), Lutzomyia flaviscutellata (vector of Leishmania (Leishmania) amazonensis) and Lutzomyia antunesi [suspected vector of Leishmania (Viannia) lindenbergi] are incriminated of transmitting the parasite Leishmania for the vertebrate host. The phlebotomine-parasite is mediated by the attachment of the promastigote lipophosphoglycan (LPG) to the midgut epithelium. However, another mechanism that is LPG-independent and mediated by N-acetyl-galactosamine (GalNAc) seems to occur in some species of phlebotomines that are classified as permissive. The aim of this study was to characterize the carbohydrate residues that, probably, play a role in parasite attachment to the midgut of phlebotomine from colony and field populations from the Brazilian Amazonian region. We observed the presence of GalNAc, mannose, galactose and GlcNAc in all phlebotomine species. A binding assay between L. (L.) amazonensis and L. i.chagasi to the midguts of different species of phlebotomines was performed. The attachment of both Leishmania and vector species suggests the presence of GalNAc on the midgut surfaces. Thus, these results suggested that GalNAc is a possible binding sites of Leishmania in sand flies from the Brazilian Amazonian region.

IDENTIFICATION OF SANDFLIES (Diptera: Psychodidae: Phlebotominae) BLOOD MEALS IN AN ENDEMIC LEISHMANIASIS AREA IN BRAZIL

The aim of this study was to identify blood meals of female sandflies captured in the municipality of Governador Valadares, an endemic area of visceral and cutaneous leishmaniasis, in the State of Minas Gerais, Brazil. From May 2011 to January 2012, captures were performed using HP light traps in four districts. There were 2,614 specimens (2,090 males and 524 females) captured; 97 engorged females were identified belonging to the species Lutzomyia longipalpis (82.1%) and Lutzomyia cortelezzii (17.9%). Considering simple and mixed feeding, the enzyme-linked immunosorbent assay revealed a predominance of chicken blood (43.6%) in Lutzomyia longipalpis, showing the important role that chickens exert around the residential areas of Governador Valadares. This finding increases the chances of sandflies contact with other vertebrates and consequently the risk of leishmaniasis transmission.

Abundance of Lutzomyia longipalpis in urban households as risk factor of transmission of visceral leishmaniasis

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

Canine visceral leishmaniasis and Chagas disease among dogs in Araguaína, Tocantins

The present study analyzed serum samples from 111 male and female dogs of various ages from the municipality of Araguaína in the State of Tocantins, Brazil. Serological diagnosis of canine visceral leishmaniasis (CVL) was initially performed at the Central Laboratory (Laboratório Central - LACEN) of Araguaína, resulting in 61 positive samples by an indirect immunofluorescence assay (IIFA) (≥1:40) and 50 non-reactive samples. The same samples were analyzed at the São Paulo Institute of Tropical Medicine (Instituto de Medicina Tropical de São Paulo - IMTSP) by an enzyme-linked-immunosorbent assay (ELISA), resulting in 57 positive samples (51.35%) and 54 negative samples (48.64%). The Kappa coefficient of agreement between the tests was 0.74. The serum samples were also subjected to a diagnostic assay for Trypanosoma cruzi (Trypomastigote Excreted/Secreted Antigens -TESA-blot) that detected five suspect animals; three of those animals were positive for leishmaniasis by ELISA but negative by IIFA. These findings suggest that the canine population of Araguaína may be simultaneously infected with Leishmania chagasi and T. cruzi. The results obtained demonstrate the difficulty of using serology to detect CVL, thus emphasizing the necessity for a reference test to diagnose CVL, particularly in regions where the infection is endemic.

Different host complement systems and their interactions with saliva from Lutzomyia longipalpis (Diptera, Psychodidae) and Leishmania infantum promastigotes

Background

Lutzomyia longipalpis is the vector of Leishmania infantum in the New World, and its saliva inhibits classical and alternative human complement system pathways. This inhibition is important in protecting the insect´s midgut from damage by the complement. L. longipalpis is a promiscuous blood feeder and must be protected against its host’s complement. The objective of this study was to investigate the action of salivary complement inhibitors on the sera of different host species, such as dogs, guinea pigs, rats and chickens, at a pH of 7.4 (normal blood pH) and 8.15 (the midgut pH immediately after a blood meal). We also investigated the role of the chicken complement system in Leishmania clearance in the presence and absence of vector saliva.

Results

The saliva was capable of inhibiting classical pathways in dogs, guinea pigs and rats at both pHs. The alternative pathway was not inhibited except in dogs at a pH of 8.15. The chicken classical pathway was inhibited only by high concentrations of saliva and it was better inhibited by the midgut contents of sand flies. Neither the saliva nor the midgut contents had any effect on the avian alternative pathway. Fowl sera killed L. infantum promastigotes, even at a low concentration (2%), and the addition of L. longipalpis saliva did not protect the parasites. The high body temperature of chickens (40°C) had no effect on Leishmania viability during our assays.

Conclusion

Salivary inhibitors act in a species-specific manner. It is important to determine their effects in the natural hosts of Leishmania infantum because they act on canid and rodent complements but not on chickens (which do not harbour the parasite). Moreover, we concluded that the avian complement system is the probable mechanism through which chickens eliminate Leishmania and that their high body temperature does not influence this parasite.

Study of sand flies (Diptera: Psychodidae) in visceral and cutaneous leishmaniasis areas in the central-western state of Minas Gerais, Brazil

The transmission of Leishmania involves several species of sand flies that are closely associated with various parasites and reservoirs, with differing transmission cycles in Brazil. A study on the phlebotomine species composition has been conducted in the municipality of Divinópolis, Minas Gerais, Brazil, an endemic area for cutaneous leishmaniasis (CL), which has intense occurrence of visceral leishmaniasis (VL) cases. In order to study the sand flies populations and their seasonality, CDC light traps (HP model) were distributed in 15 houses which presented at least one case of CL or VL and in five urban parks (green areas). Collections were carried out three nights monthly from September 2010 to August 2011. A total of 1064 phlebotomine specimens were collected belonging to two genera and seventeen species: Brumptomyia brumpti, Lutzomyia bacula, Lutzomyia cortelezzii, Lutzomyia lenti, Lutzomyia sallesi, Lutzomyia longipalpis, Lutzomyia migonei, Lutzomyia intermedia, Lutzomyia neivai, Lutzomyia whitmani, Lutzomyia christenseni, Lutzomyia monticola, Lutzomyia pessoai, Lutzomyia aragaoi, Lutzomyia brasiliensis, Lutzomyia lutziana, and Lutzomyia sordellii. L. longipalpis, the main vector of Leishmania infantum in Brazil, was the most frequent species, accounting for 76.9% of the total, followed by L. lenti with 8.3%, this species is not a proven vector. Green and urban areas had different sand flies species composition, whereas the high abundance of L. longipalpis in urban areas and the presence of various vector species in both green and urban areas were also observed. Our data point out to the requirement of control measures against phlebotomine sand flies in the municipality of Divinópolis and adoption of strategies aiming entomological surveillance.

Public Knowledge about and Detection of Canine Visceral Leishmaniasis in Urban Divinópolis, Brazil

Background. Leishmaniases are diseases with a wide spectrum of clinical manifestations including cutaneous (CL) and visceral (VL) forms. Many factors may affect their occurrence and expansion including environmental, geographic, and social conditions. In the past two decades, Divinópolis, Minas Gerais State, Brazil, has exhibited the potential for a disease outbreak, with the appearance of CL, and VL cases (human and canine). Hence, this study was initiated to monitor public knowledge of the disease. Questionnaires were administered in four neighborhoods (Jardim Belvedere, Esplanada, Danilo Passos I and II) where most of the human and canine cases have been reported. The analyses demonstrated that public knowledge of the disease is sparse and fragmented. A strong perception of the dog as the main reservoir was observed. Five veterinary clinics were evaluated for the presence of canine VL using serological (RIFI and ELISA) and molecular (PCR-RFLP) techniques. This is the first study demonstrating the occurrence of Leishmania infantum in Divinópolis, suggesting a possible urbanization of VL.

Recusas de borrifação de imóveis e ocorrência de casos de leishmaniose visceral na Regional Noroeste de Belo Horizonte

Os objetivos desta pesquisa foram caracterizar as recusas por parte da população em permitir a borrifação de seus imóveis, em quatro regiões de Belo Horizonte, no período de 2006 a 2008, e relacionar estas recusas com o surgimento de casos de leishmaniose visceral, no mesmo local e período. Utilizaram-se as localizações onde se encontraram 27 casos humanos de leishmaniose visceral obtidos do SINAN, todos referentes a quatro áreas de abrangência da região noroeste de Belo Horizonte, no período de 2006 a 2008. De um total de 33.579 residências visitadas pelo controle químico vetorial, 9636 (28,70%) aceitaram a borrifação interna e a externa do domicílio, 20741 (61,77%) concordaram com a borrifação apenas do peridomicílio, 141 (0,42%) aceitaram apenas a borrifação do intradomicílio, 909 (2,70%) se encontraram fechadas no momento da borrifação e 2152 (6,41%) recusaram qualquer tipo de borrifação no imóvel. Na maioria das residências, o controle químico foi permitido apenas no peridomicílio. A diferença entre o perfil de recusas dos quarteirões contidos em uma área de 200 metros ao redor de um caso humano de leishmaniose visceral e o mesmo perfil dos quarteirões fora desta área foi significativa (P<0,05) em sete (25,92%) dos 27 casos da doença.

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).

Current knowledge of Leishmania vectors in Mexico: how geographic distributions of species relate to transmission areas

Leishmaniases are a group of vector-borne diseases with different clinical manifestations caused by parasites transmitted by sand fly vectors. In Mexico, the sand fly Lutzomyia olmeca olmeca is the only vector proven to transmit the parasite Leishmania mexicana to humans, which causes leishmaniasis. Other vector species with potential medical importance have been obtained, but their geographic distributions and relation to transmission areas have never been assessed. We modeled the ecological niches of nine sand fly species and projected niches to estimate potential distributions by using known occurrences, environmental coverages, and the algorithms GARP and Maxent. All vector species were distributed in areas with known recurrent transmission, except for Lu. diabolica, which appeared to be related only to areas of occasional transmission in northern Mexico. The distribution of Lu. o. olmeca does not overlap with all reported cutaneous leishmaniasis cases, suggesting that Lu. cruciata and Lu. shannoni are likely also involved as primary vectors in those areas. Our study provides useful information of potential risk areas of leishmaniasis transmission in Mexico.

Epidemiological aspects of human and canine visceral leishmaniasis in Montes Claros, State of Minas Gerais, Brazil, between 2007 and 2009

INTRODUCTION: Visceral leishmaniasis (VL) is an expanding zoonosis in Brazil and is becoming urbanized in several Brazilian regions. This study aims to describe the epidemiological features of human and canine VL in the municipality of Montes Claros, State of Minas Gerais, by focusing on their spatial distribution. METHODS: Data concerning human cases and reactive dogs for VL from 2007 to 2009 were obtained from the Information System for Disease Notification (SINAN) and from reports of the local Centro de Controle de Zoonoses (CCZ), respectively. The addresses of human and canine cases have been georeferenced and localized in thematic maps, allowing their spatial visualization as well as the identification of areas at risk of VL transmission. RESULTS: Ninety-five cases of human VL were reported in the period. The 0-9-year-old age group (48.4%) was the most affected, within which the majority consisted of male patients (64%). Of the samples collected for the canine serological survey, 2,919 (6.3%) were reactive to VL. The spatial localization of these cases shows that the disease was scattered in the urban area of the municipality. Areas showing a higher dissemination risk were concentrated in the central, northwestern, and southern regions of the city. CONCLUSIONS: Identifying the areas most at risk in urban Montes Claros may help guide actions toward local epidemiological vigilance and control.

Forty years of visceral leishmaniasis in the State of Piaui: a review

Visceral leishmaniasis (VL) has been known to occur in the state of Piauí since 1934. The typically rural disease began to appear in urban areas over time, being concentrated mainly in Teresina, the capital of Piauí. Teresina was also affected by the first urban epidemic of VL in Brazil. Over 1,000 cases of the disease were reported during urbanization (1981-1986). Human population growth and migration led to land occupation on the outskirts of Teresina. These factors have contributed to vector proliferation, increasing the incidence of VL. At present, the incidence of human and canine disease is quite high and uncontrolled in Piauí. It seems that some measures, such as the elimination of seropositive dogs, failed to significantly reduce the number of new VL cases in Teresina. Despite previously conducted studies, little is known about VL epidemiology in urban areas. The aim of this review is to reveal the situation of VL in Teresina during the last 40 years, focusing on the major factors that may contribute to the high incidence and persistence of VL infection.

Sandflies (Psychodidae: Phlebotominae) survey in an urban transmission area of visceral leishmaniasis, Northeastern Brazil

Visceral leishmaniasis (VL) is a major public health challenge in Brazil, especially in states where it is endemic. The aim of this study was to investigate the relationship of sand fly population density with environmental variables (temperature, rainfall and relative humidity) in urban areas of the city of Mossoró, Rio Grande do Norte, Northeastern Brazil. Sand flies were captured with Center Disease Control (CDC) traps installed monthly in the intra and peridomicile of three houses. Data analysis was based on the chi-square test and linear regression. A total of 7,347 sand flies were captured, being 93.85% Lutzomyia longipalpis and 6.15% Lutzomyia evandroi. Sand flies were more commonly found in the peridomicile and there was no difference between the number of males and females. The variables rainy season as well as relative humidity and rainfall, alone or together, did not have an effect on sand fly population density. However, high temperatures had a negative effect. The study of the behavior of sand flies in specific units of endemic areas can provide input to public health authorities for planning appropriate VL vector control measures.