Female Sand Flies Research Articles

First clinical cases of leishmaniosis in meerkats (Suricata suricatta) housed in wildlife parks in Madrid, Spain

BackgroundIn recent years, cases of leishmaniosis have been described in animals housed in captivity in zoos in Spain [Bennett’s wallaby (Macropus rufogriseus rufogriseus), orangutan (Pongo pygmaeus pygameus), and European otter (Lutra lutra)]. Some of these zoological parks are in endemic areas for both human and animal leishmaniosis, thus it should be very important to include this zoonosis in the differential diagnosis.MethodsThe study was carried out in two zoological parks in Madrid, Madrid Zoo and Faunia, and analyzed seven meerkats. Serological tests [rK-39 and enzyme-linked immunosorbent assay (ELISA)] and molecular tests [nested polymerase chain reaction (PCR) and real-time PCR] were performed to detect Leishmania DNA. Additionally, an entomological study was carried out in both zoological parks, with molecular tests performed on female Phlebotomus perniciosus sand flies to determine their blood meal source and detect Leishmania DNA.ResultsTwo meerkats were positive for L. infantum. A 9-year-old male from the Madrid Zoo died suddenly, showing pale mucous membranes and bilateral noninflammatory alopecia and hyperpigmentation in the lateral area of the eyes. Positive results were obtained in serology, nested PCR, and real-time PCR (blood, conjunctival and oral swabs, hair, spleen, lymph node, liver, kidney, and skin), as well as numerous amastigotes in the liver and kidney tissue samples. The other meerkat, a 12-year-old male from Faunia that is still alive, presented an alopecic lesion at the base of the tail. Positive results were obtained by nested and real-time PCR from different tissues such as blood, hair, oral, and conjunctival swabs. It was treated with oral allopurinol (25 mg/kg) and miltefosine (2 mg/kg), but the molecular diagnosis remained positive after 8 months, regarding it as a mild stage of the disease. The rest of the tested meerkats were negative. The presence of P. perniciosus phlebotomine sand flies was also detected in both zoos. Although no L. infantum DNA was detected in any of sand flies analyzed, it was determined that their food sources were rabbits and humans.ConclusionsTo our knowledge, this study describes, for the first time, the detection and infection by L. infantum in meerkats (Suricata suricatta).Graphical

Phlebotomus perniciosus response to volatile organic compounds of dogs and humans.

The olfactory response of insect vectors such as phlebotomine sand flies is a key facet for investigating their interactions with vertebrate hosts and associated vector-borne pathogens. Such studies are mainly performed by assessing the electrophysiological response and the olfactory behaviour of these arthropods towards volatile organic compounds (VOCs) produced by hosts. Nonetheless, few studies are available for species of the subgenera Lutzomyia and Nyssomyia in South America, leaving a void for Old World sand fly species of the genus Phlebotomus. In this study, we evaluated the olfactory responses of Phlebotomus perniciosus, one of the most important vectors of Leishmania infantum in the Old World. To test the P. perniciosus behavioural response to VOCs, 28 compounds isolated from humans and dogs were assessed using electrophysiological (i.e., electroantennogram, EAG) and behavioural assays (i.e., Y-tube olfactometer). In the EAG trials, 14 compounds (i.e., acetic acid, nonanoic acid, 2-propanol, 2-butanol, pentanal, hexanal, nonanal, trans-2-nonenal, decanal, myrcene, p-cymene, verbenone, 2-ethyl-1-hexanol, and acetonitrile) elicited high antennal responses (i.e., ≥ 0.30 mV) in female sand flies, being those VOCs selected for the behavioural assays. From the 14 compounds tested in the Y-tube olfactometer, nonanal was significantly attractive for P. perniciosus females, whereas myrcene and p-cymene were significantly repellents (p < 0.05). The attraction indexes varied from 0.53 for nonanal (i.e., most attractive) to -0.47 to p-cymene (i.e., most repellent). Overall, our results shed light on the role of olfactory cues routing host seeking behaviour in P. perniciosus, with implications to develop sustainable sand fly monitoring as well as control in leishmaniasis endemic areas.

Efficient Convolutional Neural Network Model for the Taxonomy and Sex Identification of Three Phlebotomine Sandfly Species (Diptera, Psychodidae, and Phlebotominae).

Sandflies, small insects primarily from the Psychodidae family, are commonly found in sandy, tropical, and subtropical regions. Most active during dawn and dusk, female sandflies feed on blood to facilitate egg production. In doing so, they can transmit infectious diseases that may cause symptoms such as fever, headaches, muscle pain, anemia, skin rashes, and ulcers. Importantly, sandflies are species-specific in their disease transmission. Determining the gender and species of sandflies typically involves examining their morphology and internal anatomy using established identification keys. However, this process requires expert knowledge and is labor-intensive, time-consuming, and prone to misidentification. In this paper, we develop a highly accurate and efficient convolutional network model that utilizes pharyngeal and genital images of sandfly samples to classify the sex and species of three sandfly species (i.e., Phlebotomus sergenti, Ph. alexandri, and Ph. papatasi). A detailed evaluation of the model's structure and classification performance was conducted using multiple metrics. The results demonstrate an excellent sex-species classification accuracy exceeding 95%. Hence, it is possible to develop automated artificial intelligence-based systems that serve the entomology community at large and specialized professionals.

Sand Fly Fauna in Urban Parks in the Brazilian Western Amazon: Potential Areas for American Cutaneous Leishmaniasis Transmission.

Sand flies are a group of insects (Diptera, Psychodidae, Phlebotominae) in which some species may transmit agents of leishmaniasis. This study aimed to analyze the sand fly fauna in urban parks in Rio Branco, capital of Acre state, addressing its diversity, infection by Leishmania, and food sources in sand fly females. The sand flies were collected with CDC-type automatic light traps installed in three urban parks in Rio Branco: Captain Ciríaco, Horto Florestal and Chico Mendes. For comparison analysis of species richness and diversity between the parks, we analyzed rarefaction and prediction curves. For detection of Leishmania spp., molecular tests were performed by polymerase chain reaction (PCR) using ITS1 as a marker, followed by genetic sequencing. Identification of the blood meal source in engorged females was performed by PCR using a fragment of the cytochrome b gene (cyt b), followed by sequencing and phylogenetic analysis. A total of 2,672 specimens were collected, distributed in 14 genera and 35 species. Of these, Nyssomyia antunesi and Evandromyia walkeri predominated, and important proven and suspected vectors were also found. Horto Florestal was the park with the greatest diversity, richness, and evenness of species, while the Captain Ciríaco presented the lowest diversity and richness. A female of Ny. antunesi was PCR-positive for Leishmania guyanensis. Human blood was the most frequent food source detected, mainly in Ev. walkeri and Ny. antunesi. This research showed that the studied parks of Rio Branco can act as foci for the maintenance of Leishmania, and people who frequent these urban areas may be in risk for contracting leishmaniasis.

Molecular Identification of Host Blood Meal from Phlebotomine Sandflies (Diptera: Psychodidae) from Kerala, India.

Female phlebotomine sandflies serve as vectors for the transmission of Leishmania parasites, perpetuating an enzootic cycle by disseminating between sylvatic and domestic animals. Humans form a part of this cycle because the sandflies search for a blood source required for egg development. The present study aimed to identify the feeding preferences of different sandfly fauna from six districts of Kerala, India, using molecular tools. An entomological survey was conducted during 2021-2023 in Kollam, Kottayam, Thiruvananthapuram, Thrissur, Malappuram, and Palakkad. Both indoor and outdoor habitats were targeted from sandfly collection using different standard tools and methods. Sandflies were identified using standard taxonomic keys, and DNA was extracted from blood meal collected from sandflies. A total of 7366 sandfly specimens were collected during the study period, which belonged to three different genera and 19 species. Blood source was successfully identified from 119 sandflies revealing that the Sergentomyia genus preferably fed on small reptiles and amphibians, whereas Phlebotomus genus was found to mainly feed on mammalian and avian blood. Sergentomyia zeylanica was an exception, as it primarily fed on mammalian blood sources. Interestingly, humans were the second feeding source for Phlebotomus species, which are the proven vectors. Comprehending the feeding patterns of sandflies is crucial, not just for public health but also for obtaining insights into the ecological dynamics between vectors and hosts, ultimately enabling more efficient strategies for disease control and prevention.

Molecular detection of Leishmania DNA in wild-caught sand flies, Phlebotomus and Sergentomyia spp. in northern Iran

Leishmaniasis is currently considered a major health problem in Iran, posing an increasing threat to society's development in various dimensions. This study aimed to detect Leishmania infection in wild-caught sand flies in Sari City, northern Iran. Sand flies were collected using sticky traps, and Leishmania DNA was identified using polymerase chain reaction (PCR) targeting the ITS2-rDNA region, followed by restriction fragment length polymorphism (RFLP) analysis. A total of 138 female sand flies were tested, among which, only 1 specimen of Ph. papatasi (11.11 %) and Ph. major (14.28 %), 4 specimens of Ph. kandelakii (7.27 %) and Se. dentata (8.33 %), and 2 specimens of Se. sintoni (50 %) were naturally infected with L. (L.) major. This was observed in the ITS2 nested-PCR amplification assays where a ∼ 245 bp PCR band was produced. Also, RFLP analysis by Mnl1 revealed the fragments of 55 and 70 and 120 bp for infected sand flies which are characteristic of L. (L.) major. Most of the sand flies were unfed, collected during warm season, found indoor. This study reperesents the first molecular detection of L. (L.) major in wild-caught sand flies, specifically in Ph. papatasi in this region, as well as Ph. kandelakii and Ph. major in Iran and even the world.

Leishmaniasis in Humans and Animals: A One Health Approach for Surveillance, Prevention and Control in a Changing World.

Leishmaniasis is classified as a neglected tropical disease (NTD), caused by protozoan parasites of the genus Leishmania, which are transmitted to humans and other animals through the bite of infected female phlebotomine sandflies. There are three forms of the disease: cutaneous leishmaniasis (CL) manifested by ulcers and scars; systemic or visceral leishmaniasis (VL), which can lead to life-threatening complications if left untreated; and mucocutaneous leishmaniasis (MCL), which can destroy the mucous membranes of the nose, mouth and throat. Human leishmaniasis is endemic in many countries across Africa, Asia, Southern Europe, the Middle East, and Central and South America. The interconnection of environmental, animal and human health underlies the spread of the Leishmania parasite. Environmental disruptions, such as climate change, deforestation or urbanisation, but also globalisation and migration, significantly affect the distribution and abundance of sand fly vectors and reservoir hosts. Climate change alters the breeding patterns of sandflies and expands their geographic range; deforestation and misuse of large areas disrupt ecosystems, leading to increased human-vector contact; and urbanisation increases the potential for contact between parties, particularly in densely populated areas. Migration of humans and animals, either through natural migration or, for example, the pet trade and breeding, can facilitate the spread of Leishmania parasites. In addition, socio-economic factors, including poverty and lack of access to healthcare, increase the burden of leishmaniasis in vulnerable populations. Due to this multitude of reasons, the geographic distribution of sandflies has expanded to higher latitudes and altitudes in recent years, with a consequent increase in disease burden. Indeed, despite ongoing challenges in the surveillance systems, data from the last available year have shown an increase in many cases in both humans and dogs. This perspective explores the interconnected factors influencing the spread of leishmaniasis worldwide and the epidemiology of the disease. In addition, it illustrates the importance of integrated strategies in a One Health approach: surveillance, prevention and control of vectors, animals and humans.

Prevalence of Leishmania infantum in felines from Heraklion region, Crete

Greece is recognized as an endemic region for various species of Leishmania, a genus of parasitic protozoa transmitted through the bites of infected female sandflies. This indicates that the country serves as a natural reservoir for this parasite, infecting both humans and animals. This study focuses on Heraklion, Crete, one of Greece's largest cities, where there is currently no available data on the prevalence of leishmaniosis in the feline population. While cases of canine leishmaniosis have been documented in various parts of the island, there have been no reported cases of feline leishmaniosis in Heraklion. This study primarily investigates the prevalence of leishmaniosis in cats as a means of detection in this species in Heraklion. To accomplish this, between 2018 – 2023, EDTA-blood samples and conjunctival swab samples were collected from a total of 253 feral cats. The cats were divided into two groups, depending on the location they lived (i.e., areas out of the city center or close to/in the city center): the initial group consisted of 112 cats, while the latter group comprised 141 cats. Both groups encompassed cats of various ages, habitats, and both genders. The samples were stored at -18 °C and analyzed with TaqMan real-time quantitative PCR for the presence of Leishmania infantum DNA.Out of the cat population included in the study, 15 were tested positive for FeL (5.93%). Despite the lower prevalence of leishmaniosis compared to dogs, it should be taken into account, especially for differential diagnosis. In conclusion, to the best of our knowledge, this is the first study that confirms the presence of FeL in felines in Heraklion.

Measuring the Concentration of Interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNF-α) in People infected with Cutaneous leishmaniasis in Tikrit

The study conducted in Salahaddeen Governorate aimed to measure the concentrations of cytokines (interleukin-6 and tumor necrosis factor-alpha) in patients infected with Baghdad boil and to compare these concentrations with those of the control group. The endemic disease of leishmaniasis manifests in three types in Iraq; cutaneous, mucocutaneous and visceral. The most common type is cutaneous leishmaniasis (CL) which causes skin sores. CL attributed to L. tropica is disseminated via the bite of an infected female sand fly. The study was conducted at Salahaddeen Teaching Hospital in Salahaddeen Governorate, Iraq, from March 1, 2021, to September 1, 2022. Detailed data were collected about age, gender, residence, location, number and type of lesions (wet or dry). Sixty clinical cases of cutaneous leishmaniasis were included in the study. The cytokine concentration of interleukin-6 (IL-6) exhibited an increase, reaching 94.7a±7.74 picograms/ml in patients infected with multiple leishmaniasis lesions (7-10 lesions). Conversely, the lowest concentration was observed at 56.3b±7.43 picograms/ml in patients with 1-3 lesions. Furthermore, the concentration of interleukin-6 reached its peak in patients with dry lesions (96.0a±10.9) compared to those with wet lesions (63.3b±12.4). An elevation in tumor necrosis factor (TNF-α) levels was observed across different age groups, with patients infected with cutaneous leishmaniasis typically falling within the age range of 11 to 40. Consistently, the highest TNF-α levels were documented annually in patients with cutaneous leishmaniasis, specifically within the age brackets of 11-20, 21-30 and 31-40, reaching 343.0a±28.3 picograms/ml, 316.7abd±41.2 picograms/ml and 295.9b±51.9 picograms/ml respectively, in comparison to the control group. Conversely, the lowest TNF-α level was noted in patients aged 41 (238.0c±42.6 picograms/ml). Moreover, TNF-α concentration was higher in patients with leishmaniasis in rural areas compared to urban areas. In rural regions, the TNF-α concentration was 436.7a±54.4 picograms/ml.

Determination of key hub genes in Leishmaniasis as potential factors in diagnosis and treatment based on a bioinformatics study.

Leishmaniasis is an infectious disease caused by protozoan parasites from different species of leishmania. The disease is transmitted by female sandflies that carry these parasites. In this study, datasets on leishmaniasis published in the GEO database were analyzed and summarized. The analysis in all three datasets (GSE43880, GSE55664, and GSE63931) used in this study has been performed on the skin wounds of patients infected with a clinical form of leishmania (Leishmania braziliensis), and biopsies have been taken from them. To identify differentially expressed genes (DEGs) between leishmaniasis patients and controls, the robust rank aggregation (RRA) procedure was applied. We performed gene functional annotation and protein-protein interaction (PPI) network analysis to demonstrate the putative functionalities of the DEGs. The study utilized Molecular Complex Detection (MCODE), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) to detect molecular complexes within the protein-protein interaction (PPI) network and conduct analyses on the identified functional modules. The CytoHubba plugin's results were paired with RRA analysis to determine the hub genes. Finally, the interaction between miRNAs and hub genes was predicted. Based on the RRA integrated analysis, 407 DEGs were identified (263 up-regulated genes and 144 down-regulated genes). The top three modules were listed after creating the PPI network via the MCODE plug. Seven hub genes were found using the CytoHubba app and RRA: CXCL10, GBP1, GNLY, GZMA, GZMB, NKG7, and UBD. According to our enrichment analysis, these functional modules were primarily associated with immune pathways, cytokine activity/signaling pathways, and inflammation pathways. However, a UBD hub gene is interestingly involved in the ubiquitination pathways of pathogenesis. The mirNet database predicted the hub gene's interaction with miRNAs, and results revealed that several miRNAs, including mir-146a-5p, crucial in fighting pathogenesis. The key hub genes discovered in this work may be considered as potential biomarkers in diagnosis, development of agonists/antagonist, novel vaccine design, and will greatly contribute to clinical studies in the future.

Development of Amphotericin B Decorated Gold Nanoparticles as a Promising Antileishmanial Nanoconjugate.

Leishmaniasis, attributed to the protozoan parasite Leishmania, manifests in diverse clinical forms, including cutaneous, mucocutaneous, and visceral leishmaniasis; VL constitutes a significant global health menace. Prevalent in tropical and subtropical regions, this affliction disproportionately impacts individuals below the poverty threshold, transmitted through the bite of female sandflies. Existing treatments, such as pentavalent antimony, miltefosine, and Amphotericin B, exhibit limitations. Despite the emergence of liposomal Amphotericin B (AmBisome) as a promising antileishmanial agent, its utility is impeded by adverse effects, elevated production expenses, and cytotoxicity. To address these challenges, our investigation introduces a potential remedy─a citrate-coated gold Amphotericin B nanoparticle formulation. Characterized using dynamic light scattering and transmission electron microscopy, this pioneering formulation exhibited efficacy against L. donovani Ag83 promastigotes as demonstrated by MTT cell viability testing. Evaluating internal reactive oxygen species (ROS) levels and dual staining with acridine orange and ethidium bromide unveiled its consequential impact on cell death. Significantly, our study discloses this novel nanoformulation's unprecedented inhibition of the trypanothione reductase enzyme. The findings posit the citrate-coated gold Amphotericin B nanoformulation as a promising and targeted antileishmanial agent, representing potential advancements in leishmaniasis therapeutics.

Abundance and Leishmania infection patterns of the sand fly Psathyromyia cratifer in Southern Mexico.

Localized cutaneous leishmaniasis (LCL) is a serious public health problem in Southern Mexico. Six species of Phlebotominae (Diptera: Psychodidae) have been found to be infected with Leishmania (Leishmania) mexicana, the causative agent of LCL in the region. However, little is known about the biology and potential participation of Psathyromyia cratifer in the Leishmania transmission cycle in Mexico, and the Americas. The present study provides evidence of temporal infection caused by Leishmania in Psathyromyia cratifer as well as data on its population dynamics in a LCL endemic area during the well-known transmission cycle of Leishmania in Southern Mexico. Individual specimens of Psathyromyia cratifer were collected in four sites over the course of five months (from November 2020 through March 2021) using animal-baited, human-baited, and light traps. The temporal activity pattern (month + hour) of Psathyromyia cratifer was assessed along with its relationship with environmental variables. Moreover, Leishmania DNA and blood meals were analyzed and detected in female sand flies. This evidenced an infection rate ranging from 8% to 83%, and the record of Homo sapiens and Ototylomys phyllotis as blood hosts of this sand fly species. High abundances of these sand flies in human-baited traps were recorded which revealed the marked anthropophilic behavior of Psathyromyia cratifer. As regards the transmission dynamics of the parasite within the region, it was observed that the potential highest epidemiological risk for Leishmania transmission by Psathyromyia cratifer occurred during the months of January and March. This is the first contribution ever made to both the population dynamic and the temporal Leishmania prevalence patterns in Psathyromyia cratifer. The resulting findings suggest that this sand fly specimen is the sixth potential vector of L. (L.) mexicana in Southern Mexico. Nonetheless, various biology, behavior, and ecology strands are yet to be addressed. The latter, to determine the role it plays in the transmission dynamics of the parasite within the region, and other areas of the country.

Phlebotomine sand fly (Diptera: Psychodidae) fauna, blood meal source, and detection of Leishmania (Kinetoplastida: Trypanosomatidae) DNA in the Gurupi Biological Reserve, Eastern Amazon, Brazil.

This study was conducted in the Gurupi Biological Reserve (REBIO-Gurupi), the largest area of Amazon rainforest in Maranhão State, Brazil. The objectives were to survey the sand fly (Diptera: Psychodidae) fauna of REBIO-Gurupi, identify blood meal sources, and investigate the presence of Leishmania (Ross, 1903) (Kinetoplastida: Trypanosomatidae) DNA. Individuals were collected using Centers for Disease Control (CDC) light traps and black and white Shannon traps in May and Jun 2022 and Jan 2023. DNA was extracted from female sand flies and subjected to amplification and sequencing of cytochrome b molecular marker (CYTB) for identification of blood meal sources and the first internal transcribed spacer (ITS-1) of ribosomal DNA for Leishmania detection. A total of 514 sand flies individuals were sampled, of which 93 were identified at the genus or series level (9 taxa) and 421 were identified at the species level (24 taxa). Psychodopygus davisi (Root, 1934) (41.1%), Nyssomyia antunesi (Coutinho, 1939) (10.3%), and Psychodopygus (Mangabeira, 1941) Chagasi Series Barretto, 1962 (9.7%) were the most frequently collected. Human (Homo sapiens, Primates, Hominidae) and tapir (Tapirus terrestris, Perissodactyla, Tapiridae) DNA was detected in 10 female sand flies. Leishmania (Leishmania) infantum Cunha and Chagas, 1937 DNA was detected in 2 specimens of Ps. davisi. Given the presence of vectors of Leishmania in REBIO-Gurupi, it is imperative to conduct more comprehensive studies on the interactions among sand flies, Leishmania, and pathogen reservoirs in the area.

Sand fly blood meal volumes and their relation to female body weight under experimental conditions

BackgroundSand fly females require a blood meal to develop eggs. The size of the blood meal is crucial for fecundity and affects the dose of pathogens acquired by females when feeding on infected hosts or during experimental membrane-feeding.MethodsUnder standard laboratory conditions, we compared blood meal volumes taken by females of ten sand fly species from four genera: Phlebotomus, Lutzomyia, Migonomyia, and Sergentomyia. The amount of ingested blood was determined using a haemoglobin assay. Additionally, we weighed unfed sand flies to calculate the ratio between body weight and blood meal weight.ResultsThe mean blood meal volume ingested by sand fly females ranged from 0.47 to 1.01 µl. Five species, Phlebotomus papatasi, P. duboscqi, Lutzomyia longipalpis, Sergentomyia minuta, and S. schwetzi, consumed about double the blood meal size compared to Migonomyia migonei. The mean body weight of females ranged from 0.183 mg in S. minuta to 0.369 mg in P. duboscqi. In males, the mean body weight ranged from 0.106 mg in M. migonei to 0.242 mg in P. duboscqi. Males were always lighter than females, with the male-to-female weight ratio ranging from 75% (in Phlebotomus argentipes) to 52% (in Phlebotomus tobbi).ConclusionsFemales of most species took a blood meal 2.25–3.05 times their body weight. Notably, the relatively tiny females of P. argentipes consumed blood meals 3.34 times their body weight. The highest (Mbl/Mf) ratios were found in both Sergentomyia species studied; females of S. minuta and S. schwetzi took blood meals 4.5–5 times their body weight. This parameter is substantially higher than that reported for mosquitoes and biting midges.Graphical

Isolation and Growth Kinetics of Bogoria Virus from Phlebotomine Sandflies Sampled in Baringo, Kenya.

Phleboviruses are an emerging threat to public health. Recent surveillance efforts in Kenya have unveiled novel phleboviruses. Despite these efforts, there remain knowledge gaps. This study tested female sandflies from diverse ecological settings in Kenya for arboviruses. Sandfly pools were cultured in Vero-CCL cells. Pools showing reproducible cytopathic effects were subjected to next-generation sequencing, followed by phylogenetic analysis. In vitro, cell kinetics analysis was performed using both Vero-E6 cells and C6/36 mosquito cells. One pool from Baringo, Kenya, tested positive for Bogoria virus (BOGV). The BOGV genome clustered in a single clade with previously obtained BOGV genomes. No significant differences were observed between Vero and C6/36 cell growth kinetics. This study has confirmed the presence of BOGV among sandflies in Baringo Kenya and demonstrated growth in mosquito cells.

Visceral Leishmaniasis with Renal Involvement: A Case Report

Visceral leishmaniasis (VL) is widespread in tropical and temperate region. It is caused by the protozoan parasite leishmania species and is transmitted through the bite of infected female sandflies. It manifests as pancytopenia, hepatosplenomegaly and fever. Here, we present a case of 20-year-old male presented with difficulty in swallowing for 2 months, abdominal distention for 30 days and shortness of breath for 20 days along with progressive renal impairment. Clinical examination revealed hepatosplenomegaly and laboratory investigations confirmed pancytopenia, nephrotic range proteinuria, hematuria and hypocomplementemia. Bone marrow aspiration and biopsy was performed which showed leishmania donovani (LD) bodies. It’suncommon presentation makes it challenging for physicians as well as pathologist to make a timely diagnosis.

Trypanosoma infection and bloodmeal analysis in post-feeding sand flies across Thailand

Phlebotomine sand flies are recognized as a primary vector of Leishmania and are also suspected vectors of Trypanosoma. The transmission cycle of these parasites relies on the distribution of sand fly vectors, parasites, and reservoir animals. This study aimed to detect Leishmania and Trypanosoma DNA and identify the sources of bloodmeals in post-feeding sand flies captured across Thailand. A total of 42,911 field female sand flies were collected from 11 provinces across Thailand using CDC light traps. Among these, 253 post-feeding sand flies were selected for analysis. The predominant species in this study was Sergentomyia khawi (33.60 %). The DNA was extracted from individual female sand flies. Polymerase chain reaction (PCR), specific to the internal transcribed spacer 1 (ITS1) and the small subunit ribosomal RNA (SSU rRNA) gene regions were used to detect the presence of Leishmania and Trypanosoma DNA, respectively. Additionally, cytochrome c oxidase subunit I (COI) gene region was utilized to identify the sources of host bloodmeals. Leishmania DNA was not detected in any specimens. The analysis of SSU rRNA sequences revealed the presence of Trypanosoma DNA (11.46 %, 29/253) in sand fly samples. Among these samples, T. noyesi (1.58 %, 4/253) was identified in Idiophlebotomus longiforceps and Phlebotomus asperulus, Trypanosoma Anura01+02/Frog2 (1.18 %, 3/253) in Se. khawi, and Trypanosoma Anura04/Frog1 (8.70 %, 22/253) in Se. khawi, Se. hivernus and Grossomyia indica. Bloodmeal analysis utilizing the COI gene revealed a diverse range of vertebrate hosts’ blood, including bird, bat, frog and sun skink. Our findings confirm the presence of Trypanosoma DNA and identify the sources of bloodmeals from vertebrate hosts in various sand fly species, suggesting their potential as possible vectors for Trypanosoma in Thailand. Furthermore, our study is the first to provide molecular evidence using the COI gene to identify frogs as a host blood source for sand flies in Thailand. Further studies focusing on the isolation of live parasites in sand flies to confirm vector potential and examining the role of animal reservoirs will enhance our understanding of the host-parasite relationship and enable more efficient control for disease transmission.

Distribution and seasonal fluctuation of visceral leishmaniasis vectors sandflie in Lüliang City of Shanxi Province in 2023

To investigate the distribution and seasonal fluctuations of visceral leishmaniasis vectors sandflies in Lüliang City, Shanxi Province, so as to provide insights into assessment of the visceral leishmaniasis transmission risk and formulation of visceral leishmaniasis control measures. A total of 12 natural villages were sampled from Shilou County, Lishi District, Lanxian County, Linxian County and Wenshui County in Lüliang City, Shanxi Province from June to September, 2023, and sandflies were captured using light traps from 7 breeding habitats, including farmers' houses, sheep pens, cattle pens, chicken coops, pig pens, mule and horse pens, and loess-cave dwellings. Following morphological identification of the sandfly species, the distribution of sandflies and the seasonal fluctuations of the sandfly density were analyzed. In addition, the Leishmania was detected in sandflies using a real-time fluorescence quantitative PCR assay. A total of 2 831 sandflies were captured with 156 light traps in Lüliang City from June to September, 2023, including 2 638 female sandflies (93.18%) and 193 male sandflies (6.82%), and the average density was 16.91 sandflies/(light-night). The seasonal fluctuations of the sandfly density all appeared a unimodal distribution in all survey sites, and the sandfly density peaked in July and then declined rapidly. Among all types of breeding habitats, the greatest sandfly density was found in sheep pens [39.04 sandflies/(light-night)]. In addition, 4.08% (2/49) of the sandfly samples were tested positive for Leishmania nucleic acid as revealed by the real-time fluorescence quantitative PCR assay. Sandflies were widely distributed in Lüliang City, Shanxi Province in 2023, and the peak of the sandfly density was observed in July, which had a visceral leishmaniasis transmission risk. Intensified surveillance of visceral leishmaniasis and sandfly vectors is required and targeted vector control is recommended.

Distribution and seasonal fluctuation of visceral leishmaniasis vectors sandflies in Henan Province in 2023

To investigate the geographical distribution and seasonal fluctuations of visceral leishmaniasis vectors sandflies in Henan Province in 2023, so as to provide insights into the prevention and control of visceral leishmaniasis vectors. A total of 23 counties (districts) were sampled from 18 cities of Henan Province from May to September, 2023 as sandfly surveillance sites, and sandflies were captured using human capture and light trapping methods. Following morphological identification, the changes in the sandfly density were calculated at different months and in different breeding habitats. A total of 406 light traps were set at sandfly surveillance sites in Henan Province from May to September, 2023, and a total of 3 137 female sandlies were captured, with an average density of 7.73 sandlies/(light·night). A total of 1 494 Phlebotomus chinensis sandflies were captured, including 1 222 female sandflies, with an average density of 3.01 sandflies/(light·night), and the highest density of P. chinensis was found in Gongyi City [17.00 sandflies/(light·night)]. A total of 5 544 sandflies were captured using the human capture method, including 230 P. chinensis, and the density of P. chinensis appeared a unimodal distribution, with a peak in early July [5.81 sandflies/(light·night)]. Among different breeding habitats, the highest P. chinensis density was detected in pigpens [4.50 sandflies/(light·night)]. P. chinensis was predominantly distributed in hilly areas of northern and central-western Henan Province in 2023, and the sandfly density appeared a unimodal distribution. Intensified monitoring of visceral leishmaniasis vectors is recommended.

Ecology and molecular analysis of sand flies in Bambuí, Minas Gerais, Brazil: Implications for leishmaniasis surveillance.

Leishmaniasis stands out as a public health problem in the state of Minas Gerais, Brazil, especially in the Midwest region. However, the entomological aspects in several municipalities remain unknown. Therefore, this study aimed to investigate the sand fly fauna in Bambuí, encompassing ecological dynamics and molecular detection of Leishmania. Monthly collections were conducted using CDC light traps from September 2018 to August 2020 across 16 selected points with urban and rural characteristics, chosen based on the coverage area of the Municipal Health Department and the occurrence of canine and human visceral leishmaniasis (VL) cases. Ecological indices of the sand fly population (Chao1, Shannon, Simpson and Pielou) were assessed, and sand fly abundance was correlated to climatic variables (humidity, temperature and rainfall). A total of 8838 specimens representing 17 species within nine genera were collected (estimated species richness by Chao 1 estimator = 17; SE ± 1.8). Predominantly, Lutzomyia longipalpis, Nyssomyia whitmani and Evandromyia cortelezzii constituted approximately 98% of all captured sand flies. While species richness and diversity displayed variations throughout the study, a positive correlation emerged between temperature (p < 0.0001; r = 0.7767), monthly rainfall (p < 0.0001; r = 0.7810) and sand fly abundance. Molecular analysis revealed Leishmania DNA in 2.05% of female sand flies, with the presence of Leishmania infantum in Lu. longipalpis and both Le. infantum and Leishmania braziliensis in Ev. cortelezzii. The entomological data, coupled with the occurrence of autochthonous cases of canine visceral leishmaniasis, offer valuable insights for evidence-based strategies to prevent leishmaniasis in Bambuí.