Phlebotomine sand flies (Diptera: Psychodidae) in the Greek Aegean Islands: ecological approaches

Leishmania-sand fly interactions: exploring the role of the immune response and potential strategies for Leishmaniasis control

Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the genus Leishmania, affecting millions of people worldwide. The disease is transmitted by the bite of infected female sand flies, which act as vectors and hosts for the parasites. The interaction between Leishmania parasites and sand flies is complex and dynamic, involving various factors that influence parasite development, survival and transmission. This review examines how the immune response of sand flies affects vector competence and transmission of Leishmania parasites, and what the potential strategies are to prevent or reduce infection. The review also summarizes the main findings and conclusions of the existing literature and discusses implications and recommendations for future research and practice. The study reveals that the immune response of sand flies is a key determinant of vector competence and transmission of Leishmania parasites, and that several molecular and cellular mechanisms are involved in the interaction between parasite and vector. The study also suggests that there are potential strategies for controlling leishmaniasis, such as interfering with parasite development, modulating the vector's immune response or reducing the vector population. However, the study also identifies several gaps and limitations in current knowledge and calls for more comprehensive and systematic studies on vector-parasite interaction and its impact on leishmaniasis transmission and control.

Leishmaniasis in Greece: Prospects of transitioning to a One Health surveillance system

Leishmaniasis is a high burden neglected disease in the Mediterranean ecoregion, lacking surveillance attention. We aimed to provide an overview of the state of leishmaniasis surveillance in Greece, investigating the prospect of transitioning to a One Health surveillance system. We conducted a narrative review describing human and animal leishmaniasis data from Greece, including entomological findings. Through a separate review process, we describe the current leishmaniasis surveillance system pertaining to humans, animals, vectors and the environment. Additionally, we distributed likert-scale questionnaires to key informants, capturing expert-view on the necessity, existing levels and barriers of OH leishmaniasis surveillance in Greece. We identified key system strengths, weaknesses, opportunities and threats respective to a OH transition through SWOT analysis. Greece is endemic for zoonotic visceral leishmaniasis (VL) and canine leishmaniasis (CanL), displaying an increasing VL trend in recent years and high national Leishmania seroprevalence rates in dogs (range: 13.8-23.4 %). Mandatory leishmaniasis notification in humans and animals, human case-based investigations, and active case finding activities in stray dogs, comprise valuable system components of high OH operational relevance. Conversely, the existing CanL surveillance governance and the lack of systematic entomological surveillance constitute important drawbacks. Moreover, the current context of public health and animal health financial constraints in Greece may impede a strategic OH transition in leishmaniasis surveillance. On the contrary, Greece's OH experience in West Nile Virus surveillance in conjunction with leishmaniasis-expert consensus on the necessity of OH surveillance and key barriers to its realization, compose important transition opportunities. Despite shortfalls in human, animal and vector surveillance, existing system characteristics, structures and practices comprise a promising basis for developing OH cross-sectoral leishmaniasis surveillance activities in Greece.

Phlebotomine sand flies (Diptera: Psychodidae) of Bosnia and Herzegovina: distribution, ecology and environmental preferences

Sand flies (Diptera: Phlebotominae) are the principal vectors for the protozoan parasites Leishmania spp. and for phleboviruses. The sand fly fauna on the Balkan Peninsula, including Bosnia and Herzegovina (BIH), is diverse and the circulation of Leishmania infantum as well as phleboviruses has been proven. However, recent data on the sand fly fauna in BIH are scarce. In this study, we surveyed understudied regions in central and northeastern BIH to update the sand fly distribution and gain insights into the ecological and environmental factors shaping their appearance. CDC light trapping was conducted in 2022 and 2023 and a combination of morphological and molecular methods (cytochrome oxidase I barcoding) was performed for species identifications. We mapped the currently known distribution, modelled climatic suitability patterns and performed environmental analyses by applying machine learning methods. In addition, we analyzed blood meals by host gene sequencing and MALDI-TOF peptide mass mapping and screened for Leishmania spp. DNA and Phlebovirus RNA. Altogether, 591 sand flies of four species were trapped, predominantly Phlebotomus neglectus (97 %), but also Ph. balcanicus, Ph. mascittii, and Ph. papatasi. Records of seven sand fly species known to be endemic were plotted onto distribution maps based on 101 datapoints, identifying Ph. neglectus as the overall predominant species. The environmental analyses of sand fly species indicated variation in altitudinal, thermal, and precipitation conditions across the sand fly-positive sites. Phlebotomus simici, Phlebotomus tobbi, and Sergentomyia minuta are typically found exclusively in Mediterranean and subtropical climate zones, whereas other species typically inhabit continental regions. The Inverse Distance Weighted (IDW) interpolation of sand fly species numbers and Shannon entropy values suggested the southeastern coastal region of BIH as a primary focus for sand fly occurrence. This finding was corroborated by modeled average climatic suitability patterns for sand flies, depicting four distinct meso-regions for sand fly occurrence. The results of the ensemble method highlight the importance of annual precipitation to distinguish between positive and negative sand fly trapping sites in BIH. In total, 55 blood meals of two sand fly species, Ph. neglectus and Ph. balcanicus, were analyzed and five host species identified. Our comprehensive assessment of ecological and environmental preferences of sand flies in BIH may support further entomological surveys and help to better understand and evaluate potential hot spots of disease transmission in the country.

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.

Genetic diversity and phylogeography of Phlebotomus argentipes (Diptera: Psychodidae, Phlebotominae), using COI and ND4 mitochondrial gene sequences

BACKGROUND

Phlebotomus argentipes complex is the primary vector for cutaneous leishmaniasis, a burgeoning health concern in contemporary Sri Lanka, where effective vector control is important for proper disease management. Understanding the genetic diversity of the P. argentipes population in Sri Lanka is vital before implementing a successful vector control program. Various studies have indicated that genetic divergence, caused by genetic drift or selection, can significantly influence the vector capacity of arthropod species. To devise innovative control strategies for P. argentipes, exploring genetic diversity and phylogeography can offer valuable insights into vector competence, key genetic trait transfer, and impact on disease epidemiology. The primary objective is to analyze the genetic diversity and phylogeography of the P. argentipes complex in Sri Lanka, based on two mitochondrial genomic regions in modern representatives of P. argentipes populations.

METHODOLOGY

A total of 159 P. argentipes specimens were collected from five endemic areas of cutaneous leishmaniasis and identified morphologically. Two mitochondrial regions (Cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4) were amplified using the total DNA and subsequently sequenced. Partial sequences of those mitochondrial genes were utilized to analyze genetic diversity indices and to explore phylogenetic and phylogeographic relationships.

PRINCIPAL FINDINGS

Among five sampling locations, the highest genetic diversity for COI and ND4 was observed in Hambantota (Hd-0.749, π-0.00417) and Medirigiriya (Hd-0.977, π-0.01055), respectively. Phylogeographic analyses conducted using COI sequences and GenBank retrieved sequences demonstrated a significant divergence of P. argentipes haplotypes found in Sri Lanka. Results revealed that they have evolved from the Indian ancestral haplotype due to historical- geographical connections of the Indian subcontinent with Sri Lanka.

CONCLUSIONS

Utilizing high-mutation-rate mitochondrial genes, such as ND4, can enhance the accuracy of genetic variability analysis in P. argentipes populations in Sri Lanka. The phylogeographical analysis of COI gene markers in this study provides insights into the historical geographical relationship between India and P. argentipes in Sri Lanka. Both COI and ND4 genes exhibited consistent genetic homogeneity in P. argentipes in Sri Lanka, suggesting minimal impact on gene flow. This homogeneity also implies the potential for horizontal gene transfer across populations, facilitating the transmission of genes associated with traits like insecticide resistance. This dynamic undermines disease control efforts reliant on vector control strategies.

Entomological surveillance and spatiotemporal risk assessment of sand fly-borne diseases in Cyprus

Visceral and cutaneous leishmaniases are important public health concerns in Cyprus. Although the diseases, historically prevalent on the island, were nearly eradicated by 1996, an increase in frequency and geographical spread has recently been recorded. Upward trends in leishmaniasis prevalence have largely been attributed to environmental changes that amplify the abundance and activity of its vector, the phlebotomine sand flies. Here, we performed an extensive field study across the island to map the sand fly fauna and compared the presence and distribution of the species found with historical records. We mapped the habitat preferences of Phlebotomus papatasi and P. tobbi, two medically important species, and predicted the seasonal abundance of P. papatasi at unprecedented spatiotemporal resolution using a climate-sensitive population dynamics model driven by high-resolution meteorological forecasting. Our compendium holds a record of 18 species and the locations of a subset, including those of potential public and veterinary health concern. We confirmed that P. papatasi is widespread, especially in densely urbanized areas, and predicted that its abundance uniformly peaks across the island at the end of summer. We identified potential hotspots of P. papatasi activity even after this peak. Our results form a foundation to inform public health planning and contribute to the development of effective, efficient, and environmentally sensitive strategies to control sand fly populations and prevent sand fly-borne diseases.

Discovery of the vector of visceral leishmaniasis, Phlebotomus (Artemievus) alexandri Sinton, 1928, in Kenya suggests complex transmission dynamics

Visceral and cutaneous leishmaniasis are endemic to specific regions due to the ecological preferences of phlebotomine sand flies and Leishmania spp. transmission. Sand fly entomological data in northern Kenya are scarce due to limited studies and neglect of leishmaniasis. The aim of this study was to investigate: (i) sand fly diversity and distribution; (ii) occurrence of Leishmania DNA within sand flies; and (iii) blood-meal sources of sand flies in Laisamis, northern Kenya. We conducted an entomological survey during February and March of 2021 in five areas of Laisamis sub-county using standard CDC light traps. A total of 1009 sand flies (394 male and 615 female) were morphologically identified, and representative samples verified by PCR amplification and sequencing of the cytochrome c oxidase subunit 1 (cox1) gene. Similarly, we identified blood-meal sources and Leishmania DNA in female sand flies by PCR amplicon sequencing of the vertebrate cytochrome b (cyt b) gene and internal transcribed spacer 1 (ITS1) of the 28S rRNA gene, respectively. Sergentomyia clydei (59.8%) was the most abundant sand fly species. Though collected mainly from one locality (Tirgamo), 14.8% of samples belonged to Phlebotomus (Artemievus) alexandri Sinton, 1928. We detected DNA of Leishmania major in 5.19% of Ph. alexandri, whereas Leishmania adleri DNA was detected in S. clydei (7.51%), Sergentomyia squamipleuris (8.00%), and Sergentomyia africanus (8.33%). Nine of 13 blood-fed sand flies had obtained blood from humans, of which 33.3% had L. major DNA. Both Ph. alexandri and S. clydei primarily fed on humans and could potentially be involved in the transmission of cutaneous leishmaniasis. The findings of this study contribute to the understanding of sand fly vector populations and their potential to transmit leishmaniasis in the area.

Concurrent molecular characterization of sand flies and Leishmania parasites by amplicon-based next-generation sequencing

BACKGROUND

Phlebotomine sand flies are vectors of Leishmania parasites, which are the causative agents of leishmaniasis. Herein, we developed an amplicon-based next-generation sequencing (Amp-NGS) to characterize sand flies and Leishmania parasites simultaneously targeting partial fragments of 18S rDNA and ITS1 genes, respectively.

METHODS

Our assay was optimized using reference sand fly (n = 8) and Leishmania spp. (n = 9) samples and validated using wild-caught sand flies from Palestine. The assay was highly specific, and all DNA references were successfully identified to the species level.

RESULTS

Among the wild-caught sand flies (n = 187), Phlebotomus spp. represented 95% of the collected samples (177/187), including Ph. sergenti (147/187, 79%), Ph. papatasi (19/187, 10.2%), Ph. perfiliewi (3/187, 1.6%), Ph. tobbi (2/187, 1.2%) and Ph. syriacus (6/187, 3.2%). Sergentomyia spp. represented only 5% (10/187) of the collected samples and included S. dentata (n = 6), S. fallax (n = 2), S. schwetzi (n = 1) and S. ghesquiere (n = 1). The study observed strong positive correlation between sand fly identification results of the Amp-NGS and morphological identification method (r = 0.84, df = 185, P < 0.001). Some discrepancies between the two methods in the identification of closely related species (i.e. Ph. perfiliewi, Ph. tobbi and Ph. syriacus) were observed. Leishmania DNA was detected and identified as L. tropica in 14 samples (14/187, 7.5%).

CONCLUSIONS

Our assay was sensitive to detect (limit of detection was 0.0016 ng/reaction) and identify Leishmania DNA in sand flies, thus representing a new tool for studying sand flies and their associated Leishmania parasites in endemic areas.

Identification of Leishmania infantum and Leishmania braziliensis in captive primates from a zoo in Brazil

Wild nonhuman primates (NHP) are considered natural hosts of a protozoan parasite from the genus Leishmania, the etiological agent of leishmaniasis. It is important to study the population of this infectious agent in zoo animals to establish surveillance and control mechanisms in Sorocaba through the application of a One Health approach, this is where human-animal-environment health and disease interface and can aid in the protection of endangered species. This study aimed to identify Leishmania infantum and Leishmania braziliensis in NHP living in a city where leishmaniasis is endemic. DNA was extracted from 48 NHP and analyzed using polymerase chain reaction primers that are specific for the species L. infantum and L. braziliensis. The results of our research revealed the first report of L. infantum and L. braziliensis naturally infecting primates at Sorocaba zoo. One primate from the species Plecturocebus vieirai was positive for L. infantum and five primates (four Alouatta caraya and one Ateles chamek) were positive for L. braziliensis. This indicates a possible role of these animals on the maintenance of these parasites.

Spatio-temporal visualisation of cutaneous leishmaniasis in an endemic, urban area in Iran

INTRODUCTION

Cutaneous Leishmaniasis (CL) is a significant public health concern worldwide. Iran is among the most CL-affected countries, being one of the six most endemic countries in the world. This study aimed to provide a spatio-temporal visualisation of CL cases in an endemic urban area in north-eastern Iran identifying high-risk and low-risk areas during the period 2016-2019.

METHODS

This ecological study was conducted in the city of Mashhad, north-eastern Iran. All cases (n=2425) were diagnosed based on clinical findings and parasitological tests. The patient data were aggregated at the census tract level (the highest resolution available). CL incidence rates were subjected to Empirical Bayesian smoothing across the census tracts followed by spatial autocorrelation analysis to identify clusters and outliers. Spatial scan statistic was used to explore the purely temporal, purely spatial and spatio-temporal trend of the disease. In all instances, the null hypothesis of no clusters was rejected at p ≤0.05.

RESULTS

The overall crude incidence rate decreased from 34.6 per 100,000 individuals in 2016 to 19.9 per 100,000 in 2019. Cluster analysis identified high-risk areas in south-western Mashhad and low-risk areas in the north-eastern areas. Purely time scan statistics identified March to July as the time period with highest risk for CL occurrence. One most likely purely high-risk spatial cluster and six secondary purely high-risk spatial clusters were identified. Further, two spatio-temporal high-risk clusters, one in the north of the city from April to August and a second in the south-western part from March to September were observed.

CONCLUSIONS

Significant spatial, temporal and spatio-temporal patterns of CL distribution were observed in the study area, which should be considered when designing tailored interventions, such as effective resource allocation models, informed control plans and implementation of efficient surveillance systems. Furthermore, this study generated new hypotheses to test potential relationships between socio-economic and environmental risk factors and incidence of CL in high-risk areas.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

The potential impact of climate change on the seasonality of Phlebotomus neglectus, the vector of visceral leishmaniasis in the East Mediterranean region

Phlebotomus neglectus is one of the most important vectors of visceral leishmaniasis in Southeast Europe and Asia Minor. It was aimed to study the impact of climate change on the seasonality and the range of the species for 2014-2060. In the inland areas of Asia Minor, the Balkan Peninsula and the Carpathian Basin the elongation of the activity season will reach or exceed the two months in the middle of the 21st century compared to the end of the 20th century. The most affected regions are the middle elevations of the mountainous regions and the plains of the northern distribution areas. In some areas of the southern distribution border, the season is expected to shorten. In the Apennine Peninsula, mainly the mountainous areas could be impacted notably by climate change. The results indicate the potential spread of leishmaniasis in Southeast Europe due to the increasing environmental suitability of the region.

Canine Leishmaniosis in Greece: An Updated Countrywide Serological Study and Associated Risk Factors

Canine leishmaniosis (Leishmania infantum) is a zoonotic disease that affects dogs worldwide. Greece is enzootic for this disease, and updated data for its current distribution are of major importance. The aim of this cross-sectional serological study was primarily to update the current knowledge of Leishmania infantum seropositivity status within the asymptomatic Greek canine population and, furthermore, to assess the possible climatological and other risk factors. In total, sera of 1265 asymptomatic dogs were collected from all prefectures of the country. A questionnaire that included all individual dog information was completed for all animals. The Speed Leish K^® canine Leishmania antibody test kit (BVT Groupe Virbac, France) was employed. Potential risk factors were evaluated utilizing logistic regression models. Overall, 13.8% (n = 175) of the sampled dogs were seropositive to Leishmania infantum originating from all geographical departments of the country, whereas most prefectures had at least one seropositive animal. Outdoor living, high mean humidity, low mean wind speed and high total annual rainfall were found to increase the seropositivity status against the parasite. Conclusively, Leishmania infantum remains a common parasite challenge in the asymptomatic canine population of Greece, and therefore, its early diagnosis and effective prevention are significant in the country.

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.

Surveillance data for human leishmaniasis indicate the need for a sustainable action plan for its management and control, Greece, 2004 to 2018

Background

The World Health Organization (WHO) lists human leishmaniasis as a neglected tropical disease; it is not under surveillance at European level.

Aim

We present surveillance data for visceral (VL) and cutaneous (CL) leishmaniasis for the period 2004 to 2018 in Greece to assess their public health importance.

Methods

We extracted data from the mandatory notification system to analyse separately imported and domestic cases of VL and CL. A case was defined by clinical manifestations compatible with VL or CL and laboratory confirmation.

Results

Between 2004 and 2018, 881 VL (862 domestic, 19 imported) and 58 CL cases (24 domestic, 34 imported) were recorded. The mean annual notification rate of domestic VL was 0.5 per 100,000 (range: 0.12–1.43/100,000) with a statistically significant increasing trend (p = 0.013). Cases were reported by all regions. The highest notification rate occurred in the age group 0–4 years (1.3/100,000). Overall 24% (164/680) of the cases were immunocompromised and their proportion increased after 2010 (p < 0.001). The mean annual notification rate of domestic CL was 0.05 per 100,000 (range: 0.01–0.19/100,000) with the highest rate in the age group 5–14 years (0.03/100,000). Cases were recorded in six of the 13 regions. Among 34 imported CL cases, 29 were foreign nationals.

Conclusion

VL is endemic in Greece, with an increasing trend and a considerable burden of severe disease and young children being most affected. CL is rarely reported. A sustainable action plan is needed to reduce the burden of VL and prevent local transmission of CL.

Ecology, seasonality and host preferences of Austrian Phlebotomus (Transphlebotomus) mascittii Grassi, 1908, populations

Background

Sand flies are principal vectors of the protozoan parasites Leishmania spp. and are widely distributed in all warmer regions of the world, including the Mediterranean parts of Europe. In Central European countries, the sand fly fauna is still under investigation. Phlebotomus mascittii, a suspected but unproven vector of Leishmania infantum, is regarded as the most widely distributed species in Europe. However, many aspects of its biology and ecology remain poorly known. The aim of this study was to provide new data on the biology and ecology of Ph. mascittii in Austria to better understand its current distribution and potential dispersal.

Methods

Sand flies were collected by CDC light traps at four localities in Austria for 11 (2018) and 15 weeks (2019) during the active sand fly season. Climatic parameters (temperature, relative humidity, barometric pressure and wind speed) were retrospectively obtained for the trapping periods. Sand flies were identified by a combined approach (morphology, DNA barcoding, MALDI-TOF protein profiling), and blood meals of engorged females were analysed by DNA sequencing and MALDI-TOF mass spectrometry.

Results

In total, 450 individuals of Ph. mascittii were caught. Activity was observed to start at the beginning of June and end at the end of August with peaks in mid-July at three locations and early August at one location. Increased activity was associated with relatively high temperatures and humidity. Also, more individuals were caught on nights with low barometric pressure. Analysis of five identified blood meals revealed chicken (Gallus gallus) and equine (Equus spp.) hosts. Sand fly abundance was generally associated with availability of hosts.

Conclusion

This study reports unexpectedly high numbers of Ph. mascittii at selected Austrian localities and provides the first detailed analysis of its ecology to date. Temperature and humidity were shown to be good predictors for sand fly activity. Blood meal analyses support the assumption that Ph. mascittii feeds on mammals as well as birds. The study significantly contributes to understanding the ecology of this sand fly species in Central Europe and facilitates prospective entomological surveys.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04787-2.

Investigation of Phlebotominae (Diptera: Psychodidae) Fauna, Seasonal Dynamics, and Natural Leishmania spp. Infection in Muğla, Southwest of Turkey

Due to its geographical location, Muğla province is one of the most frequently used places by refugees. Although leishmaniasis have been previously reported in this region, there is a lack of information on the etiological agent and possible vectors. The main objectives of this study were; i) to investigate the sand fly fauna, ii) to reveal the natural Leishmania spp. infection in wild caught sand flies using molecular tools, and iii) to determine the annual seasonal dynamics of the sand flies in Muğla region. Totally, 2093 specimens belonging to 15 species [12 Phlebotomus, three Sergentomyia; 51 unidentified] were collected during the one-year (June 2016- June 2017) period. Of the collected sand flies, 1928 (92.12%) were caught by the Centers for Disease Control (CDC) light traps, while 165 (7.88%) of them were caught by sticky traps. Phlebotomus major sensu lato (s.l.), the potential vector of visceral leishmaniasis (VL) and canine leishmaniasis (CanL) in the Mediterranean and Aegean region, was detected in all sampling locations and found as the dominant taxon (n=1035; 49.45%) of the study area and followed by Phlebotomus tobbi (n=371; 17.72%). During the sampling period, sand fly activity was started in March and peaked in August. Sand fly population size reduced dramatically between mid-September and early October. The number of collected specimens was peaked in August, while there is only one sample collected both in November and March. The majority of the sand flies (78.66%) were collected at an altitude range of 200-400 m. Seventy-two monospecific pools were screened for the presence of Leishmania DNA by real time ITS1 PCR and 24 (nine P. major s.l., eight P. tobbi, two P. papatasi, two S. minuta, one P. alexandri, one P. similis, and one Phlebotomus (Transphlebotomus spp.) of them (33.8%) were found positive (L. infantum, L. tropica, and L. major). To the best of our knowledge, the presence of fifteen sand fly species and their distribution, seasonal dynamics, molecular detection of Leishmania parasites in Muğla province was reported for the first time. The presence of vector species in the study area, appropriate temperature and humidity conditions, long sand fly activity season, and presence of Leishmania parasite suggests that there is a serious risk in the transmission of leishmaniasis in Muğla.

Eco-epidemiological aspects of Zoonotic cutaneous leishmaniasis in Ouarzazate Province, Morocco

Some epidemiological and ecological aspects of Zoonotic cutaneous leishmaniasis (ZCL) in Ouarzazate province, southern Morocco, were explored with the objective of analyzing ZCL distribution and associated ecological factors. Information on cutaneous leishmaniasis patients attending the local health centers of Ouarzazate during the period 2002-2009 was gathered and compiled. Urban, peri-urban, rural origin, precipitation, wind speed, temperature, water irrigation, dam volume, and altitude were studied. The findings show that the disease affected 5405 person during this period; the major part was found in the municipalities near both oases (desert oasis) and water resources, with a high concentration of cases in the peri-urban area. The highest percentage of cases was recorded mainly in September. Considerable associations were found between relative humidity and wind speed with ZCL occurrence. A large number of cases were recorded in areas with altitude ranging from 800 to 2000 m.a.s.l. and spatial precipitation from 15 to 150 mm. The statistical analysis showed a strong association between water storage volume and water irrigation with the annual ZCL occurrence recorded in the downstream area (Zagora province). The results will lead us to understand ZCL risk areas for effective control. Further work is needed mainly for gathering these variables in one single and simplest model.

First molecular identification of Leishmania major in Phlebotomus papatasi in an outbreak cutaneous leishmaniasis area in Iraq

Cutaneous leishmaniasis (CL) is transmitted by Phlebotomine sand fly vectors, among which Phlebotomus papatasi is prevalent in Western Asia, Northern Africa and Southern Europe, and it is known as a vector for Leishmania major parasite in the world. However, in Iraq, morphological studies showed that P. papatasi is a predominant sand fly species and hypothesised to transmit CL causing Leishmania species including L. major and L. tropica. Few studies have found Leishmania species in sand flies in mixed pools of samples in this country. Accurate identification of sand flies as vectors of Leishmania species is required in Iraq. The current study aims to identify sand fly species, using both morphological and molecular phylogenetic analyses, in a region where CL tends to be endemic. Furthermore, molecular phylogenetic analysis has also used to confirm Leishmania species in the sand fly samples collected in 11 villages between Diyala and Sulaymaniyah Provinces. For the first time, we have found L. major in three individual sand flies, one engorged (with fresh blood meal) and two non-engorged (without visible fresh blood meal) P. papatasi females in an area of CL outbreaks since 2014-till now due to civil wars and internal conflicts happen in the region. Further study should be performed on sand fly population and Leishmania reservoirs in this region.

Phlebotomus (Adlerius) simici NITZULESCU, 1931: first record in Austria and phylogenetic relationship with other Adlerius species

Background

Phlebotomine sand flies are the principal vectors of Leishmania spp. (Kinetoplastida: Trypanosomatidae). Information on sand flies in Central Europe is scarce and, to date, in Austria, only Phlebotomus mascittii has been recorded. In 2018 and 2019, entomological surveys were conducted in Austria with the aim to further clarify sand fly distribution and species composition.

Results

In 2019, a Ph. simici specimen was trapped in Austria for the first time. Analyses of two commonly used marker genes, cytochrome c oxidase I (coxI) and cytochrome b (cytb), revealed high sequence identity with Ph. simici specimens from North Macedonia and Greece. Phylogenetic analyses showed high intraspecific distances within Ph. simici, thereby dividing this species into three lineages: one each from Europe, Turkey and Israel. Low interspecific distances between Ph. simici, Ph. brevis and an as yet unidentified Adlerius sp. from Turkey and Armenia highlight how challenging molecular identification within the Adlerius complex can be, even when standard marker genes are applied.

Conclusion

To our knowledge, this study reports the first finding of Ph. simici in Austria, representing the northernmost recording of this species to date. Moreover, it reveals valuable insights into the phylogenetic relationships among species within the subgenus Adlerius. Phlebotomus simici is a suspected vector of L. infantum and therefore of medical and veterinary importance. Potential sand fly expansion in Central Europe due to climatic change and the increasing import of Leishmania-infected dogs from endemic areas support the need for further studies on sand fly distribution in Austria and Central Europe in general.

Graphic abstract

Seasonal dynamics of phlebotomine sand flies and autochthonous transmission of Leishmania infantum in high-altitude ecosystems in southern Spain

Leishmaniasis is a vector-borne disease transmitted by sand flies. A dozen species have been involved in the transmission of Leishmania infantum in the Mediterranean region. Climate change may alter sand fly distribution at particular altitudes and latitudes. The objective of this study was to interrogate the existence of stable populations of sand flies in high-altitude ecosystems and evaluate if these populations are enough to support autochthonous transmission of leishmaniasis. These altitudinal conditions can be found in Sierra Nevada (southern Spain). Therefore, we have determined the sand fly population dynamics in different biotopes located at elevations above 1,300 m a.s.l. and searched for evidence of leishmaniasis transmission. Five collecting sites above 1,300 m a.s.l. containing large livestock concentrations were selected. Sand flies were caught using CDC light traps from May to November, annually from 2008 to 2013, and these were morphologically identified. Association between sand fly density or presence and temperature/humidity was estimated by linear and logistic regression, respectively. Leishmania infantum detection in female sand flies was performed by PCR. Diagnosis of canine leishmaniasis (CanL) was carried out by indirect immunofluorescence and PCR. A total of 2,973 specimens of 5 sand fly species were collected from June to October. Phlebotomus perniciosus was the most frequent (100%), abundant (80.1%) and densest species (9.8 sand flies/trap). The minimum temperature on the day of capture was the most important variable factor for sand fly presence and P. perniciosus density. An increase in altitude showed a negative effect over the sand fly diversity and activity period, driving changes in seasonal dynamics similar to those reported by latitudinal changes. CanL prevalence was 23%, a similar rate to previous surveys carried out on randomly selected dogs from towns in southern Spain. A successful host-vector-pathogen network was found at this altitude characterised by 9.9% L. infantum infection rate in non-blood fed P. perniciosus and Phlebotomus ariasi females and high CanL prevalence that entails an increase in the leishmaniasis risk area driven by sand fly colonization.

Leishmania infantum Seroprevalence in Cats From Touristic Areas of Italy and Greece

Leishmaniosis by Leishmania infantum is a major zoonotic Vector-Borne Disease (VBD) in terms of geographic distribution, pathogenicity and zoonotic potential. While dogs are the main reservoir of L. infantum, the infection in cats is poorly understood although increasingly reported from enzootic and non-enzootic areas. The Mediterranean basin is a key area for leishmaniosis and includes touristic spots that require continuous surveillance for VBDs in consideration of the growing tendency of tourists to travel with their pets. This study evaluated L. infantum seroprevalence in cats living in selected touristic localities of Italy and Greece. A total of 269 cat serum samples from three Sites i.e., 76, 40, and 153 from Adriatic Coast of Abruzzo, Italy (Site A), Giglio Island, Tuscany, Italy (Site B), and Mykonos Island, Greece (Site C), respectively, were included in the survey. Sera samples were subjected to an indirect immunofluorescence antibody assay for the detection of anti-L. infantum specific IgG. Associations between possible risk factors and seropositivity to L. infantum were statistically evaluated. Antibodies against L. infantum were detected in eight out of 269 (3.0%) cats tested i.e., 4/76 (5.3%), 1/40 (2.5%), and 3/153 (2.0%), from sites A, B, and C, respectively. A statistical association between anti-L. infantum antibodies and cohabitation with dogs was shown. This study indicates that feline populations living in the examined Italian and Greek touristic areas are exposed to L. infantum and that they may contribute to the circulation of L. infantum, enhancing the risk of infection for dogs and humans.

Mapping the canine vector-borne disease risk in a Mediterranean area

Background

The aim of this study was to determine exposure to vector-borne pathogens (VBPs) in populations of dogs living on Greek islands in the Ionian and Aegean seas.

Methods

In total, 1154 dogs with different lifestyles and of varying ages and breeds were randomly sampled and examined for the presence of clinical signs compatible with canine vector-borne diseases (CVBDs). Blood was collected from each individual animal. For the detection of antibodies against Leishmania spp., the WITNESS® Leishmania test was performed, and positive samples were further examined with indirect enzymatic immunoassay (ELISA). Antibodies to Borrelia burgdorferi, Ehrlichia canis or E. ewingii, as well as Anaplasma phagocytophilum or A. platys were investigated using the Snap® 4Dx® Plus test. Positive Ehrlichia spp. and Anaplasma spp. samples were further examined using an indirect ELISA for further identification of the species.

Results

In total, 25.6% of dogs were exposed to at least one of the pathogens investigated, with seroprevalences varying regionally. Of these seropositive dogs, 27.4% displayed clinical signs suggestive of CVBDs, such as cutaneous lesions, enlarged lymph nodes, pale mucous membranes, onychogryphosis and weight loss. The overall seroprevalence detected using the rapid tests was 15.3% for Leishmania spp., whereas 2.3% of the examined dogs were found to be positive for Anaplasma spp. and 7.5% for Ehrlichia spp. while B. burgdorferi was not detected. Twenty-four samples positive to A. phagocytophilum by ELISA were analysed by PCR for the presence of Anaplasma DNA. PCR and sequencing results showed the presence of A. platys DNA in 4 samples and E. canis DNA in 4 samples. The remaining samples (66.7%) were negative.

Conclusions

In the present study, exposure of dogs to VBPs was shown in the geographical areas investigated. Results confirm that on Greek islands VBPs represent a constant health risk for both native and visiting dogs, suggesting the presence of distinct “hot-spots” of VBP infections on different islands. In order to reduce the risk of transmission and the spread to non-endemic regions, the protection of dogs through use of repellents and vaccines, together with owner education, seem to be of paramount importance.

Host Species Determines the Composition of the Prokaryotic Microbiota in Phlebotomus Sandflies

Phlebotomine sandflies are vectors of the humans' and mammals' parasite Leishmania spp. Although the role of gut microbiome in the biological cycle of insects is acknowledged, we still know little about the factors modulating the composition of the gut microbiota of sandflies. We tested whether host species impose a strong structural effect on the gut microbiota of Phlebotomus spp. Sandflies were collected from the island of Leros, Greece, and classified to P. papatasi, P. neglectus, P. tobbi, and P. similis, all being negative to Leishmania spp. The prokaryotic gut microbiota was determined via 16S rRNA gene amplicon sequencing. Phlebotomus species supported distinct microbial communities (p < 0.001). P. papatasi microbiota was the most distinct over-dominated by three Spiroplasma, Wolbachia and Paenibacillus operational taxonomic units (OTUs), while another Wolbachia OTU prevailed in P. neglectus. Conversely, the microbiota of P. tobbi and P. similis was composed of several less dominant OTUs. Archaea showed low presence with the dominant OTUs belonging to methanogenic Euryarcheota, ammonia-oxidizing Thaumarcheota, and Nanoarchaeota. We provide first insights into the composition of the bacterial and archaeal community of Phlebotomus sandflies and showed that, in the absence of Leishmania, host genotype is the major modulator of Phlebotomus sandfly gut microbiota.

Impact of Environmental and Climate Factors on Spatial Distribution of Cutaneous Leishmaniasis in Northeastern Iran: Utilizing Remote Sensing

BACKGROUND

Cutaneous leishmaniasis (CL) is a dermal and parasitic disease.. The aim of this study was to determine the effect of environmental and climate factors on spatial distribution of CL in northeastern Iran by utilizing remote sensing from 20 March 2016 to 19 March 2017.

METHODS

In this ecological study, the data were divided into two parts: The descriptive data on human CL cases were gathered from Communicable Diseases center of Iran. The remote sensing techniques and satellite imagery data (TRMM, MODIS-Aqua, MODIS-Terra and AMSR-2 with spatial resolution 0.25°, 0.05°, 5600m and 10km) of environmental and climate factors were used to determine the spatial pattern changes of cutaneous leishmaniasis incidence.

RESULTS

The incidence of CL in North Khorasan, Razavi Khorasan, and South Khorasan was 35.80 per 100,000 people (309/863092), 34.14 per 100,000 people (2197/6,434,501) and 7.67 per 100,000 people (59/768,898), respectively. The incidence of CL had the highest correlation with soil moisture and evapotranspiration. Moreover, the incidence of disease was significantly correlated with Normalized Difference Vegetation Index (NDVI) and air humidity while it had the lowest correlation with rainfall. Furthermore, the CL incidence had an indirect correlation relation with the air temperature meaning that with an increase in the temperature, the incidence of disease decreased.

CONCLUSION

As such, the incidence of disease was also higher in the northern regions; most areas of North Khorasan and northern regions of Razavi Khorasan; where the rainfall, vegetation, specific humidity, evapotranspiration, and soil moisture was higher than the southern areas.

Phlebotomine sand flies and Leishmania species in a focus of cutaneous leishmaniasis in Algeria

Cutaneous leishmaniasis is a disease caused by various Leishmania spp., which are transmitted by phlebotomine sand flies. Algeria is one of the most affected countries, with thousands of cutaneous leishmaniasis cases registered every year. From March to November of 2016 and 2017, sand flies were collected in 12 municipalities in Setif province, North-Eastern Algeria. Sand flies were identified and females were tested by PCR for detecting Leishmania DNA. Additionally, cutaneous leishmaniasis cases notified during the study period were analysed. Out of 1804 sand flies collected, 1737 were identified as belonging to seven species, with Phlebotomus perniciosus (76.2%), Ph. papatasi (16.7%) and Ph. sergenti (5.0%) being the most common species, representing together 97.9% of the collected specimens. The remaining specimens were identified as Sergentomyia minuta, Se. fallax, Ph. longicuspis and Ph. perfiliewi. The number of sand flies collected monthly was positively correlated with temperature. Out of 804 females tested, nine Ph. perniciosus (1.1%) scored positive for Leishmania infantum (n = 5), L. major (n = 3) and L. tropica (n = 1), respectively. During the study period, 34 cutaneous leishmaniasis cases were notified in Setif, of which 58.8% were patients residing in two urban and peri-urban municipalities and 41.2% in rural areas. The finding of Ph. perniciosus as the most abundant species in Setif suggests that this sand fly may be adapted to different biotopes in the North-East region of Algeria. The detection of different Leishmania spp. in Ph. perniciosus suggests a complex epidemiological picture of cutaneous leishmaniasis in Setif, with the involvement of different etiological agents and possibly with different reservoir hosts and vectors.

Leishmaniasis is a group of neglected diseases, with more than 350 million people at risk and 2 million new cases every year. Leishmania parasites are transmitted by phlebotomine sand flies. Algeria is one of most affected countries, with thousands of cutaneous leishmaniasis cases registered every year. However, in spite of the scientific knowledge gained over the last decades, the understanding of the biology and the ecology of sand flies in some areas of Algeria is still fragmentary. The present study was conducted from 2016 to 2017 to assess the sand fly population in Setif and also the Leishmania spp. circulating in this province. Our data suggest a complex epidemiological picture of cutaneous leishmaniasis in Setif, with the involvement of different etiological agents and possibly with different reservoir hosts and vectors.

Updates on the distribution and diversity of sand flies (Diptera: Psychodidae) in Romania

BACKGROUND

Phlebotomine sand flies (Diptera: Psychodidae) are haematophagous insects that transmit the protozoan parasite Leishmania infantum (Kinetoplastida: Trypanosomatidae), the main causative agent of both zoonotic visceral leishmaniasis (VL) and canine leishmaniasis (CanL) in the Mediterranean basin. Eight species of sand flies have been previously recorded in Romania: Phlebotomus papatasi, Phlebotomus alexandri, Phlebotomus sergenti, Phlebotomus perfiliewi, Phlebotomus neglectus, Phlebotomus longiductus, Phlebotomus balcanicus and Sergentomyia minuta. Three of them (P. perfiliewi, P. neglectus and P. balcanicus) were incriminated as vectors of L. infantum. Recent reports of autochthonous CanL in Romania require updates on sand fly distribution and diversity in this country.

METHODS

Between 2013-2014 and 2016-2018, CDC light traps and mouth aspirators were used to collect sand flies in 132 locations from Romania, indoors and around various animal species shelters. Species identification of collected specimens was done using morphological keys, genetic tools and MALDI-TOF protein profiling.

RESULTS

Sand flies were present in seven localities (5.3%): Eibenthal, Baia Nouă, Gura Văii (south-western Romania, Mehedinţi County); Fundătura, Pâhneşti, Epureni (eastern Romania, Vaslui County); and Schitu (southern Romania, Giurgiu County). Of the total number of collected sand flies (n = 251), 209 (83.27%) were Phlebotomus neglectus, 39 (15.53%) P. perfiliewi, 1 (0.40%) P. papatasi, 1 (0.40%) P. balcanicus and 1 (0.40%) P. sergenti (sensu lato).

CONCLUSIONS

We confirmed the presence of five sand fly species previously recorded in Romania. However, their updated distribution differs from historical data. The diversity of sand fly species in Romania and their presence in areas with Mediterranean climatic influences constitutes a threat for the reemergence of vector-borne diseases. In the context of CanL and VL reemergence in Romania, but also due to imported cases of the diseases in both humans and dogs, updates on vector distribution are imperative.

Controlling phlebotomine sand flies to prevent canine Leishmania infantum infection: A case of knowing your enemy

Leishmaniosis caused by Leishmania infantum is a widespread zoonotic disease that can be transmitted to animals and humans by their vectors, blood-sucking phlebotomine sand flies. To prevent canine leishmaniosis across the whole Mediterranean region, vector control is essential. Because of phlebotomine breeding sites are diverse, environmental larval controls have limited practical value. Control methods of adults are being evaluated, such as selective baits based on sugar feeding of males and females or Attractive Toxic Sugar Baits (ATSB), and the indoor use of Long-Lasting-Insecticidal Nets (LLINs) treated with permethrin to prevent sand fly bites complementing the Indoor Residual Spraying (IRS) approach suggested by WHO. Although several strategies exist, the best control measure to prevent canine Leishmania infantum is to treat dogs using biocidal topical formulations based on legal insecticides (PTs18) or repellents (PTs19) (as collars, spot-ons and/or sprays) during the period when the vectors are active. This means we need to really know the biology and life cycle of the sand fly vector. According to available data, by mapping ambient temperatures we can already predict high risk areas where vector densities will be higher. In ongoing research, new candidates are emerging to fight against sand flies including natural plant extracts with low impacts on the environment and host animal. Other options in the future could be systemic insecticides to help reduce sand fly populations in high density areas. In parallel, health authorities and professionals involved in animal and public health (veterinarians, physicians, entomologists and epidemiologists) must work together in a One Health approach to minimize Leishmania infection. Veterinarians play a crucial role in liaising between key stake holders and dog owners to ensure the latter act responsibly in using repellents as a preventive measure against sand fly bites.