Distribution Of Sand Fly Species Research Articles

Surveillance of sand flies (Psychodidae, Phlebotominae) from Mexico: Altitudinal and climatic patterns after historical and new geographic records in endemic areas of leishmaniasis

This study updates knowledge on historical geographic distribution of sand fly species through identifying altitudinal and bioclimatic patterns in leishmaniasis endemic areas in Mexico. We analyze and identify sand fly specimens obtained through national efforts by the Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, Mexico), collected between 1995 and 2001, 2008–2012, and 2017–2023, and add bibliographic information (427 additional records). After a principal components analysis of WorldClim variables and altitudinal ranges, variables that better explain the distribution of sand fly species were chosen (BIO6, BIO12, and BIO16, explaining 72 % of variation). A total of 1,187 specimens of 22 species were retrieved from eight states, providing 29 new municipalities and 48 new localities, being Lutzomyia cruciata, Micropygomyia chiapanensis, and Psathyromyia shannoni the most common species. We presented new historical records of distribution for sand fly species from Morelos (3), Oaxaca (7) and Tabasco (1). The 82.7 % of sand fly species analyzed were distributed in areas with altitudinal ranges below 420 m. The anthropophilic species Psathyromyia shannoni, and Lutzomyia cruciata showed the greatest variability regarding altitudinal range, and climatic preferences, while several wild species showed abiotic preferences. It is likely that the effect of urbanization and climate change generate new beneficial biotopes for the proliferation of the vector sand fly species. Complementary studies that consider seasonality, vegetation types, and change in land use could provide new information to better understand the spread of vector-borne diseases.

Diversity and temporal distribution of sand flies in an endemic area of cutaneous leishmaniasis in Centre-West Colombia.

The community structure of sand flies indicates the level of adaptation of vector species in a region, and in the context of vector management and control, this information allows for identifying the potential risks of pathogen transmission. This study aimed to analyze sand fly diversity and spatial-temporal distribution in an endemic area of cutaneous leishmaniasis. The study was carried out in the Carrizales hamlet (Caldas), between September 2019 and October 2021. The monthly distribution of sand fly species was evaluated through collections with CDC traps. Shannon and evenness indices were calculated and used to compare species frequencies at each house. The association between climatic variables and the frequency of sand flies was evaluated using Spearman's correlation. A total of 6,265 females and 1,958 males belonging to 23 species were found. Low diversity and evenness were observed, with the dominance of Nyssomyia yuilli yuilli (Young & Porter). Ecological and diversity indices did not reveal differences between the houses. The sand fly community was composed of 3 dominant species, Ny. yuilli yuilli, Psychodopygus ayrozai (Barretto & Coutinho), and Ps. panamensis (Shannon), representing 75.8% of the total catches. No statistical association was found between the absolute frequency of sand flies, rainfall, and temperature. The results show one dominant species, this fact has epidemiological relevance since density influences parasite-vector contact. The high densities of sand flies recorded in peri- and intradomiciliary areas highlight the necessity of periodic monitoring of vector populations and control activities to reduce the risk of Leishmania transmission in this endemic area.

Ecological site distribution of sand fly species of Mokolo, an endemic focus of cutaneous leishmaniasis in northern Cameroon

Leishmaniasis is a vector borne disease present in two major clinical forms (cutaneous and visceral) in the northern part of Cameroon. The disease is classified as a neglected tropical disease by the World Health Organization and thus, requires more attention. The aim of this study was to correlate the previously established composition and abundance of sand fly fauna with the putative vector status and the ecological behavior in the Mokolo cutaneous leishmaniasis focus to propose fighting strategies integrating vectors control.Over a 12-month period light traps were used for sand flies’ collection in urban, peri-urban and sylvatic environment found in Mokolo, an endemic focus of leishmanisis in northern Cameroon, microscope and taxonomic keys were used for their identification. Nineteen (19) species were identified belonging to the genera Sergentomyia, and Phlebotomus. The influence of human population density on sand fly's species density and composition was assessed trough the evaluation of ecological distribution of sand flies in Mokolo. It came out that, Se. coronula and Se. thomsoni mandarai are strictly wild species and Ph. duboscqi, a domestic species. The other species are generalists.The number of Se. antennata and Se. adami decreases with the increase of the density of human population while Se. distincta, Se. vorax and Ph. duboscqi increase with the density of human population in the study site. Based on its previous reports in the Leishmania transmission in West Africa, Ph. duboscqi should still be considered as the main suspected vector in Mokolo. Ph. duboscqi, Se. distincta, Se. affinis ssp. vorax and Se. schwetzi are highly represented around human dwellings.

Distribution of Phlebotomine Sand Flies (Diptera: Psychodidae) in the Lombardy Region, Northern Italy.

Simple SummaryPathogens transmitted to humans and animals by Phlebotomines are relatively neglected, as they cause infectious diseases which represent an underestimated burden in most European countries. Several sand fly species are competent vectors of Leishmaniasis, an endemic disease that has spread widely throughout the Mediterranean region in conjunction with sand flies’ movements. In the Lombardy region, information on sand flies is poor and/or outdated. Therefore, the present study was undertaken to preliminarily ascertain the species composition, distribution, and diversity in representative Lombardy localities. The sampling took advantage of regional surveillance plans namely, West Nile virus and leishmaniasis monitoring plans. A focused sampling was also performed in areas identified as favorable for vector presence. Sampling was conducted using CO2–CDC traps conducted every two and/or three weeks. From trapping for the West Nile monitoring plan, 21 out of 44 capture sites were positive for sand flies, while for the leishmaniasis monitoring plan, 11 out of the 40 trapping sites detected sand flies’ presence. Specimen identification was conducted by identifying morphological features. Phlebotomus perniciosus was the most abundant species (87.76% of specimens collected). Adequate and well-structured monitoring of sand fly populations is essential to provide information about distribution patterns of vector species present in defined geographical areas, as they could enhance pathogen circulation.This study investigated the species composition and density of sand flies in the Lombardy region (Northern Italy). Sand flies were collected using CDC traps baited with CO2 (CO2–CDC traps) between June and August 2021. A total of 670 sand flies were collected. The specimens were identified as seven species belonging to two genera, Phlebotomus and Sergentomyia, namely, S. minuta, Ph. perniciosus, Ph. perfiliewii, Ph. neglectus, Ph. mascitti, Ph. papatasi, and Ph. ariasi. Phlebotomus perniciosus was the most abundant species (87.76%), followed by Ph. perfiliewii (7.31%), Ph. neglectus (3.13%), S. minuta (0.75%), Ph. mascitti (0.6%), Ph. papatasi (0.3%), and Ph. ariasi, for which only one specimen was identified. Among these identified species, five are considered vectors of Leishmania, which causes cutaneous and visceral leishmaniasis. As vector presence increases the risk of vector-borne leishmaniasis, these results suggest that Northern Italy could be a potential area of pathogen circulation over the next few years. These preliminary results suggest that the risk of borne leishmaniasis is high in this region of Northern Italy. Monitoring the distribution of sand fly species in areas suitable for their persistence is important for control programs aimed at reducing the risk of leishmaniasis infection.

Phlebotomine sand flies (Diptera: Psychodidae) from an emergent focus of localized cutaneous leishmaniasis in Yucatan, Southeast Mexico.

Localized cutaneous leishmaniasis (LCL) is endemic in the Yucatan Peninsula, with historical and contemporary records mainly in the states of Campeche and Quintana Roo. Recently, we reported autochthonous LCL cases and 27.6% of asymptomatic infection in the municipality of Tinum, Yucatan, where no studies of Phlebotominae (Diptera: Psychodidae) sand flies have been carried out. In this work, from November, 2019 to February, 2020, we conducted a field study in three areas of Tinum to document, for the first time, the species of Phlebotominae in areas with records of human leishmaniasis transmission. In order of abundance, the species identified were Pifanomyia serrana, Psathyromyia shannoni, Psathyromyia cratifer, Lutzomyia cruciata, Bichromomyia olmeca olmeca, and Dampfomyia deleoni. Most of the sand flies were captured in a Shannon trap where 77.8% of collected specimens were females. The distribution of sand fly species showed some degree of heterogeneity among sites, and the highest species richness was registered in a site located in Xcalakoop. We also discuss the medical importance of Lu. cruciata, Ps. shannoni, and Pi. serrana as potential vectors of causal agents of LCL in this area.

Ecology and Distribution of Sand Fly Species of Mokolo, an Endemic Focus of Cutaneous Leishmaniasis in Cameroon

Ecology and Distribution of Sand Fly Species of Mokolo, an Endemic Focus of Cutaneous Leishmaniasis in Cameroon

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.

Ecology and spatial distribution of sand fly species in low endemic areas for American Tegumentary Leishmaniasis in the municipality of Seropédica, Rio de Janeiro, Brazil.

Due to the fundamental role that sand flies (Diptera: Psychodidae) have in Leishmania spp. (Kinetoplastida: Trypanosomatidae) transmission, the objective of this study was to evaluate the ecology and spatial distribution of species circulating in the municipality of Seropédica, Rio de Janeiro, Brazil. A total of 17 371 specimens were collected between August 2016 and July 2017, and five species were identified: Nyssomyia intermedia (Lutz & Neiva, 1912), Migonemyia migonei (França, 1920), Nyssomyia whitmani (Antunes & Coutinho, 1939), Pintomyia pessoai (Coutinho & Barretto, 1940), and Pintomyia fischeri (Pinto, 1926). In relation to the number of sand flies collected, we observed a significant difference between rural and periurban areas and between the neighbourhoods. We observed that N. intermedia has a relatively greater adaptation to the peridomiciliary environment. This is the first report of Pi. pessoai and Pi. fischeri (only females) in Seropédica as well as the first record of the frequency of phlebotomine species focusing on some ecological indices and the spatial distribution of sand flies. The results presented here aimed to provide an insight into the spatial population dynamics of phlebotomine species in low endemic areas of American Tegumentary Leishmaniasis (ATL) in Seropédica, highlighting important areas for entomological surveillance.

Spatial Distribution of Phlebotomine Sand Fly Species (Diptera: Psychodidae) in Qom Province, Central Iran.

Zoonotic cutaneous leishmaniasis (ZCL) is transmitted to humans by phlebotomine sand fly bites. ZCL is a major health problem in Iran, where basic knowledge gaps about sand fly species diversity persist in some ZCL-endemic areas. This paper describes the richness and spatial distribution of sand fly species, collected with sticky traps, in Qom province, a ZCL-endemic area in central Iran, where sand fly fauna has been poorly studied. Collected species were mapped on urban and rural digital maps based on a scale of 1/50,000. All analyses were undertaken with rural- and urban-level precision, i.e., rural and urban levels were our basic units of analysis. After identifying the sand flies, high-risk foci were determined. For spatial analysis of vector species population, the entomological sampling sites were geo-referenced using GPS. Arc GIS 9.3 software was used to determine the foci with leishmaniasis vector species. Following the analyses, two genera (Phlebotomus and Sergentomyia) and 14 species were identified. Based on the mapping and sand fly dispersion analysis, the rural districts were categorized into three groups-infection reported, without infection, and no report. Based on Geographical Information System analyses, Kahak and Markazi districts were identified as high-risk foci with leishmaniasis vector species. These findings can act as a help guide to direct active control measures to the identified high-risk foci and, eventually, lead to reduction in incidence of the disease.

Spatial distribution of sand fly species (Psychodidae: Phlebtominae), ecological niche, and climatic regionalization in zoonotic foci of cutaneous leishmaniasis, southwest of Iran.

Cutaneous leishmaniasis (CL) is a complex vector-borne disease caused by Leishmania parasites that are transmitted by the bite of several species of infected female phlebotomine sand flies. Monthly factor analysis of climatic variables indicated fundamental variables. Principal component-based regionalization was used for recognition of climatic zones using a clustering integrated method that identified five climatic zones based on factor analysis. To investigate spatial distribution of the sand fly species, the kriging method was used as an advanced geostatistical procedure in the ArcGIS modeling system that is beneficial to design measurement plans and to predict the transmission cycle in various regions of Khuzestan province, southwest of Iran. However, more than an 80% probability of P. papatasi was observed in rainy and temperate bio-climatic zones with a high potential of CL transmission. Finding P. sergenti revealed the probability of transmission and distribution patterns of a non-native vector of CL in related zones. These findings could be used as models indicating climatic zones and environmental variables connected to sand fly presence and vector distribution. Furthermore, this information is appropriate for future research efforts into the ecology of Phlebotomine sand flies and for the prevention of CL vector transmission as a public health priority.

Anthropic effects on sand fly (Diptera: Psychodidae) abundance and diversity in an Amazonian rural settlement, Brazil

Sand flies (Diptera: Psychodidae) are responsible for the transmission of protozoan parasites that cause leishmaniases. They are found predominantly in forests, but some species exploit environments that have been subject to deforestation and subsequent human colonization. Studies conducted in Brazil over the past 30 years show that some species are adapting to peri-urban and urban settings. We evaluated sand fly diversity and abundance in the rural settlement of Rio Pardo, Presidente Figueiredo Municipality, Amazonas State, Brazil. Settlement households were divided into four categories. These categories were determined by the human population density and the degree of deforestation in the immediate area. We used CDC light traps to sample the area surrounding 24 households (6 households in each category). Samples were taken on six occasions during September–November 2009 and June–August 2010. A total of 3074 sand fly specimens were collected, including 1163 females and 1911 males. These were classified into 13 genera and 52 species. The greatest abundance of sand flies and the greatest richness of species were observed in areas where human population density was highest. Our results show that changes in the human occupancy and vegetation management in rural settlements may affect the population dynamics and distribution of sand fly species, thereby affecting the local transmission of cutaneous leishmaniases.

Phlebotomine sand flies on the crossroads of Anatolia: transmitted diseases and vectors

The Western Palearctic (WP) is composed of Europe, Middle East and North Africa. In this territory, the Mediterranean Sea, and the land under the influence of the Mediterranean Sea is the most important geographical character for both migration and dispersion of organisms; especially for invertebrates including sand flies. Anatolia (Asia-Minor) takes place on the crossroads of this area and these events. The phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae) are vectors of several infectious pathogens causing leishmaniases and arbovirus infections due to phleboviruses. Several of these diseases have wide geographical distributions in the WP, and give rise to occasional epidemic outbreaks. In numerous countries, increasing risk factors are making sand fly-borne diseases a major public and veterinary health problem. Many studies on phylogenetic relationship among sand fly taxa, their distribution, population structure and diseases of phlebotomine species have been already published, but there are still many gaps waiting to be filled up in, especially, Anatolia. In this point, scientists have to discuss some deficiencies under cover of geography, history and phylogenetic studies to understand the mechanisms of distribution of both sand fly species and their pathogens in Anatolia. In this presentation, updates in distribution of sand fly species with state of art maps of EU-VBORNET project, possible new species, leishmaniasis and phleboviruses epidemiology will be discussed with an emphasis on several studies performed by our group between 2000 and present in Anatolia. Studies were supported by EU-FP7 Edenext project, HU-Scientific Research Foundation and Turkish Scientific and Technical Research Council.

Molecular Typing of Sand Fly Species (Diptera, Psychodidae, Phlebotominae) from Areas Endemic for Leishmaniasis in Ecuador by PCR-RFLP of 18S Ribosomal RNA Gene

Surveillance of the distribution of sand fly species is important for prediction of the risk and expansion of Leishmania infection in endemic and surrounding areas. In the present study, a simple and reliable method of typing New World Lutzomyia species circulating in endemic areas in Ecuador was established by using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique. PCR-RFLP of 18S ribosomal RNA (rRNA) genes with the restriction enzyme AfaI and subsequently HinfI successfully identified seven sand fly species in nine endemic areas in Ecuador. Although intraspecific genetic-diversity affecting the RFLP-patterns was detected in a species, the patterns were species specific. The method promises to be a powerful tool for the classification of New World Lutzomyia species.

Vertical stratification and development aspects of phlebotomine sand flies (Diptera: Psychodidae) in an area of Atlantic Forest tree species in a metropolitan region in northeastern Brazil

In the state of Rio Grande do Norte in northeast Brazil, cases of visceral leishmaniasis (VL) occur mainly in the periurban areas of the city of Natal. Lutzomyia longipalpis Lutz & Neiva 1912 (Diptera: Psychodidae), a vector of Leishmania chagasi (Protozoa: Trypanosomatidae) to humans, is found throughout the state. Flora and fauna influence the distribution of sand fly species, whose horizontal or vertical stratification can be used as a parameter for identifying potential vectors, considering the presence of vertebrate hosts in the area. The purpose of this study was to obtain information about the vertical stratification of phlebotomine sand flies in an endemic area of leishmaniasis in Rio Grande do Norte, and associate it with the presence of other animals in the peridomiciliary environment as well as to analyze, under laboratory conditions, aspects of L. longipalpis reproduction in wild females. The sand flies were captured with light traps hung at different heights in species of Atlantic Forest trees and in a peridomiciliary environment in animal shelters. The traps were placed between 17:30 and 6:00 of the following day, in a peridomiciliary and extradomiciliary area of a forest fragment in both dry and rainy months. In the extradomiciliary environment, the traps were installed at 1, 3 and 5 m above the ground. The biological cycle of L. longipalpis was followed from the eggs of 200 wild females. Specimens of L. lenti, L. walkeri, and L. migonei were captured. The comparison and statistical analysis showed that L. longipalpis is more abundant at a height of 3 m and L. evandroi at 1 m. In the animal shelters (chickens, horses, and armadillos), we captured mainly specimens of L. longipalpis and L. evandroi. The duration of the biological cycle of L. longipalpis was approximately 38 days at a temperature of 28 degrees C.