Bite Of Infected Sand Fly Research Articles

Investigating potential sand fly vectors after the first reported outbreak of cutaneous leishmaniasis in Ghana

BackgroundLeishmaniasis is a parasitic disease caused by species of the genus Leishmania, which are transmitted through the bite of infected female sand flies. Since the first reported outbreak of cutaneous leishmaniasis in Ghana, in 1999, there has been limited published information on its vectors and reservoir hosts there. Previous studies have shown strong dominance of the sand fly genus Sergentomyia over the genus Phlebotomus in Ghana. Thus the aim of this study was to determine the possible sand fly vector species in Ghana, as well as their human-feeding behavior, from the time of the first reported outbreak of CL in the country.MethodsSand flies were collected from randomly selected houses in three communities. They were identified and used for blood meal source identification and the detection of Leishmania infection using molecular methods. ResultsA total of 1051 female sand flies were morphologically identified, of which Sergentomyia africana africana (29%) was the predominant species. Among the 275 female sand flies that had blood-fed, the identified blood meal sources included chicken (33.8%) and goat (12.4%); the percentage of human blood meals was 32%. Single-source and mixed-source blood meals were identified in Sergentomyia africana africana (11.6%), Sergentomyia ingrami (14.9%) and Sergentomyia simillima (20%), with S. simillima having the highest proportion of blood meals that included human blood (14.6%). Using molecular methods, unfed sand flies and identified human-feeding species were examined for the presence of Leishmania DNA. Pool screening analysis revealed three pools of S. ingrami positive for Leishmania major DNA, with an infection rate of 1.27% (95% confidence interval 2.467–3.647).ConclusionsThe findings suggest that some Sergentomyia species may be involved in the transmission of cutaneous leishmaniasis in Ghana. However, the role of S. ingrami as a vector of leishmaniasis in Ghana needs to be conclusively validated by isolating the parasite from this species and through experimental transmission studies.Graphical abstract

Pediatric lymphatic leishmaniasis: a case report

BackgroundThere are three main forms of leishmaniases: visceral (the most serious form because it is almost always fatal without treatment), cutaneous (the most common, usually causing skin ulcers), and mucocutaneous (affecting mouth, nose, and throat). Leishmaniasis is caused by protozoan parasites, which are transmitted by the bite of infected female phlebotomine sandflies. The disease affects some of the world’s poorest people and is associated with malnutrition, population displacement, poor housing, a weak immune system, and lack of financial resources. An estimated 700,000 to 1 million new cases occur annually. Only a small fraction of those infected by parasites causing leishmaniasis will eventually develop the disease. We report a case of exclusive lymph node involvement in leishmaniasis, presenting as localized lymphadenopathies. The diagnosis of lymphatic leishmaniasis was confirmed by the presence of Leishmania donovani bodies in fine needle aspiration cytology, and positive anti-rK39 antibodies. The bone marrow aspiration was negative for Leishmania donovani bodies. Abdominal ultrasound was done and there was no organomegaly. Furthermore, localized lymphadenopathies may provide a diagnostic challenge by clinically mimicking a lymphoma or other causes of lymphadenopathy. Due to its rarity and its tendency to pose a clinical diagnostic challenge, we decided to report a case of lymphatic leishmaniasis.Case presentationA 12-year-old Amara male patient presented to the University of Gondar comprehensive specialized hospital, Northwestern Ethiopia, with six discrete right lateral cervical lymphadenopathies, the largest measuring 3 × 2 cm2, with no cutaneous lesion. Fine needle aspiration cytology confirmed the diagnosis of leishmaniasis in lymph node, and he was put on sodium stibogluconate (20 mg/kg body weight/day) and paromomycin (15 mg/kg body weight/day) injections, which are given intramuscularly for 17 days. Having completed his medication at the University of Gondar comprehensive specialized hospital, he had a smooth course and was discharged with appointment scheduled for follow-up after 3 months.ConclusionIn the clinical evaluation of a patient with isolated lymphadenopathies, leishmaniasis must be considered as a differential diagnosis in immunocompetent subjects in endemic areas for early diagnostic workup and management.

A short-term method to evaluate anti-leishmania drugs by inhibition of stage differentiation in Leishmania mexicana using flow cytometry

Leishmaniasis is a vector-borne neglected tropical disease caused by the Leishmania spp. The disease is transmitted to humans and animals by the bite of infected female sandflies during the ingestion of bloodmeal. Because current drug treatments induce toxicity and parasite resistance, there is an urgent need to evaluate new drugs. Most therapeutics target the differentiation of promastigotes to amastigotes, which is necessary to maintain Leishmania infection. However, in vitro assays are laborious, time-consuming, and depend on the experience of the technician. In this study, we aimed to establish a short-term method to assess the differentiation status of Leishmania mexicana (L. mexicana) using flow cytometry. Here, we showed that flow cytometry provides a rapid means to quantify parasite differentiation in cell culture as reliably as light microscopy. Interestingly, we found using flow cytometry that miltefosine reduced promastigote-to-amastigote differentiation of L. mexicana. We conclude that flow cytometry provides a means to rapidly assay the efficacy of small molecules or natural compounds as potential anti-leishmanials.

Knowledge, attitude, and practice of the rural community about cutaneous leishmaniasis in Wolaita zone, southern Ethiopia.

Cutaneous leishmaniasis (CL) is a neglected tropical disease that is caused by a Leishmania parasite and transmitted by the bite of infected female sandflies. Community awareness is an essential component of disease control and prevention. Therefore, this study aimed to assess the community's knowledge, attitude, and practice toward CL in Wolaita zone, southern Ethiopia. A community-based cross-sectional study design was employed to include 422 study subjects selected using a systematic sampling technique from two districts, Kindo Didaye and Sodo Zuria. A pretested structured questionnaire was used to collect data from the household heads. Bivariate and multivariate logistic regression analyses were performed to determine the relationship between the participants' knowledge about CL and socio-demographic characteristics. Out of the 422 study participants, only 19% had good knowledge of CL in general. Most (67.1%) of the respondents knew CL by its local name ("bolbo" or "moora") though this knowledge varied highly over the study districts. The majority (86.3%) of respondents did not know how CL is acquired, though they considered CL a health problem. Most (62.8%) respondents believed that CL was an untreatable disease. Most (77%) participants responded that CL patients preferred to go to traditional healers for treatment. Herbal treatment was the most (50.2%) used to treat CL. Knowledge about CL was significantly associated with sex, age, and study districts. The overall knowledge, attitude, and practice about CL and its prevention in the study area were low. This emphasizes the need to implement health education and awareness campaign to reduce the risk of CL infection. Policymakers and stakeholders should also give due attention to the prevention and treatment of CL in the study area.

Leishmania major-Infected Phlebotomus duboscqi Sand Fly Bites Enhance Mast Cell Degranulation.

Leishmania parasites infect mammalian hosts through the bites of sand fly vectors. The response by mast cells (MC) to the parasite and vector-derived factors, delivered by sand fly bites, has not been characterized. We analyzed MC numbers and their mediators in BALB/c mice naturally infected in the ear with Leishmania major through the bite of the sand fly vector Phlebotomus duboscqi and compared them to non-infected sand fly bites. MC were found at the bite sites of infective and non-infected sand flies throughout 48 h, showing the release of granules with intense TNF-α, histamine, and tryptase staining. At 30 min and 48 h, the MC numbers were significantly higher (p < 0.001) in infected as compared to non-infected bites or controls. Neutrophil recruitment was intense during the first 6 h in the skin of infected and non-infected sand fly bites and decreased thereafter. An influx of neutrophils also occurred in lymph nodes, where a strong TNF-α stain was observed in mononuclear cells. Our data show that MC orchestrate an early inflammatory response after infected and non-infected sand fly bites, leading to neutrophilic recruitment, which potentially provides a safe passage for the parasite within the mammalian host.

Evaluation of Susceptibility Status of Phlebotomus papatasi, the Main Vector of Zoonotic Cutaneous Leishmaniasis, to Different WHO Recommended Insecticides in an Endemic Focus, Central Iran.

Among neglected zoonotic diseases, leishmaniases caused by Leishmania parasite through infected female sand fly bite, are a group of diseases found in 98 countries and territories representing a critical burden of disease worldwide. Vector management plays a crucial role in reducing the burden of vector-borne diseases by WHO's global plan. The objective of the current study was to assess the susceptibility status of wild phlebotomine sand flies from Esfahan Province, central Iran, to the recommended insecticides by WHO. Sand flies were collected by mouth aspirator in Matin Abad desert Eco-resort and were tested using WHO adult mosquito test kit against Dichlorodiphenyltrichloroethane (DDT) 4%, Deltamethrin 0.05%, Malathion 5% and Propoxur 0.1%. The number of knockdown sand flies were recorded during exposure time in ten minutes interval for DDT and Deltamethrin and they were allowed to recover for 24 hours. Knockdown Time50 (KD50) and KD90 were generated for them using Probit software. They were mounted and identified by valid keys. Among the tested insecticides against female Phlebotomus papatasi, DDT, Deltamethrin, and Malathion recorded the highest mortality rate of 100%, followed by Propoxur with 92.2% mortality for a one-hour exposure. For DDT, KD50 and KD90 were calculated 21.87 and 42.93 and for Deltamethrin, they were 23.74 and 56.50 minutes respectively. Total sand flies exposed with DDT and Deltamethrin shed their leg(s). It is concluded that Ph. papatasi from central Iran is susceptible to DDT, Deltamethrin, Malathion, and Propoxur.

The Designing of a Gel Formulation with Chitosan Polymer Using Liposomes as Nanocarriers of Amphotericin B for a Non-invasive Treatment Model of Cutaneous Leishmaniasis.

Leishmaniasis is a disease caused by different Leishmania spp., which are transmitted to humans by a bite of infected female sand flies. Cutaneous leishmaniasis (CL, oriental sore), visceral leishmaniasis (VL), and mucocutaneous leishmaniasis (MCL) are three main clinical forms, however, only CL and VL are seen in Turkey. Cutaneous leishmaniasis is characterized by skin lesion(s) and is one of the most important vector-borne diseases in Turkey with over 2000 cases reported annually in 40 out of 81 provinces. The treatment is usually made invasively and painfully by intralesional injection of pentavalent antimony compounds. Non-invasive and innovative treatment methods are needed as aimed in this study. In the present study, one of the classical antileishmanial drugs, amphotericin B (AmB), encapsulated in liposomes was evaluated using non-invasive design based on chitosan, which is a nontoxic, biocompatible and biodegradable polymer. To avoid the invasive effect of conventional intralesional needle application, the drug was encapsulated in liposomes and incorporated into a chitosan gel for applying topically on the skin lesion. The efficacy of encapsulation of amphotericin B into liposomes and the drug release from liposomes were studied. The chitosan gel was evaluated for viscosity, flowability, appearance and pH. The efficacy of the drug embedded into chitosan gel, liposomal AmB alone and chitosan gel alone in four different concentrations was also tested using Leishmania spp. promastigotes in vitro. The findings have shown that AmB was encapsulated into the liposomes with high efficiency (86.6%) and long-term physical and chemical stability. Therefore, designed liposomal formulation was suitable for sustained release. The appearance of the drug-embedded chitosan gel was transparent and appropriate. Chitosan gels showed non- Newtonian behavior and plastic flow. The liposomal AmB also showed higher efficacy with no parasites in all concentrations while drug embedded into chitosan gel and chitosan gel alone were effective in two higher concentrations. The lower efficacy of the drug-embedded chitosan gel in 24h in in-vitro study was probably due to slow release of the drug. The gel design created in this study will provide ease of use for the lesions of CL patients that do not have a specific number, size, and shape. Follow-up studies by the ex-vivo macrophage infection model with Leishmania intracellular amastigote forms and Leishmania-infected animal models are needed to understand the present design's efficacy better.

Visceral Leishmaniasis and Disposal of Solid Waste in Minas Gerais, Brazil

Visceral leishmaniasis (VL) is a vector-borne disease that is caused by the protozoan Leishmania infantum and transmitted to humans and other mammals through the bites of infected female sandflies. VL has been prevalent in Minas Gerais, Brazil, since the 1940s. As the vector completes its reproductive cycle in the soil with organic matter, the association between the occurrence of VL and unimproved solid waste disposal sites has been investigated. Thus, in this study, we analyzed the relationship of waste disposal conditions, inadequacies in disposal, and waste collection with the rates of VL, using statistical regression models. A case-control study was conducted to elucidate the relationship between VL and waste management; sick individuals (cases) were compared to healthy individuals (control), to determine the cause, by constructing a multiple regression model to analyze data through a stepwise method. In Minas Gerais, according to the reports of the government in 2017, 60.1% of the urban population has access to an adequate final disposal system for urban solid waste, with an increase of 2.3% compared to the size of the disposal system in 2016. Thus, almost 40% of the population is forced to use poor or unimproved waste disposal sites. The results confirmed the direct relationship between VL and the unimproved disposal of solid waste in the municipalities (waste coverage collection: p = 0.004; waste found in the streets: p = 9.69 × 10–13). These rates also indicated that the proper management of wastes can help to combat VL by considerably reducing the breeding sites of sandflies, curbing adverse health effects, and improving the health of the population.

An assessment of serological techniques for the identification of asymptomatic visceral leishmaniasis in blood donors in Northeastern Brazil

Background: Visceral leishmaniasis (VL) is a neglected disease caused by species of the Leishmania donovani complex and transmitted mainly by the bite of infected sandflies. A less frequent form of transmission is the transfusion route, important in countries lacking screening procedures for VL in blood banks. Methods: To identify asymptomatic infection by Leishmania sp, our goal here was to evaluate and compare the performance of three different serological techniques: Flow Cytometry (FC); Direct Agglutination Test (DAT); and Immunoenzymatic Test (ELISA). Thirty-one asymptomatic carriers of L. infantum were selected, from a single blood bank located in Recife, northeastern Brazil. Results : Foi avaliada a frequência de amostras positivas assintomáticas nos testes, no ELISA baseado no antígeno solúvel de Leishmania (25,8%), FC (22,8%), DAT (9,7%) e ELISA baseado em uma única proteína recombinante (12,9%). A sensibilidade dos testes também foi avaliada, o FC (22,58%) e o ELISA com o antígeno solúvel (22,58%) apresentaram os maiores valores de sensibilidade que o DAT (6,45%) e o ELISA recombinante (12,9%). Apenas a CF apresentou baixa especificidade (22,22%), em contraste com as demais técnicas (100% de especificidade). Conclusion: Given the results presented, we highlight the low effectiveness of serological techniques for the identification of asymptomatic individuals, thus emphasizing the need to develop more accurate methods for this purpose.

Utilizing Quantitative Proteomics to Identify Species-Specific Protein Therapeutic Targets for the Treatment of Leishmaniasis.

Leishmaniasis is a tropical disease caused by Leishmania parasites, which are transmitted through the bites of infected sandflies. We focused on the emergence of leishmaniasis in Thailand caused by a species (Leishmania orientalis). Treatment by chemotherapy is not effective against L. orientalis. Hence, we intended to solve this issue using a proteomics approach to investigate protein profiles and in silico analysis for the identification of antigenic proteins from L. orientalis, Leishmania martiniquensis, and Leishmania donovani. Using principal component analysis (PCA), protein profile comparisons indicated that different species of Leishmania are different at the protein level. Proteomics analysis identified 6099 proteins. Among these proteins, 1065 proteins were used for further analysis. There were 16 proteins that were promising candidates for therapeutic aspects as they were abundantly expressed and common to all species. In silico analysis of protein’s antigenicity revealed that eight proteins had the potential for the development of antigenic molecules. Protein profile information and these antigenic proteins may play key roles in the pathogeny of leishmaniasis and can be used as novel therapeutic targets against leishmaniasis in the future.

Leishmania Exosomes/Extracellular Vesicles Containing GP63 Are Essential for Enhance Cutaneous Leishmaniasis Development Upon Co-Inoculation of Leishmania amazonensis and Its Exosomes.

Protozoan parasites of the genus Leishmania are transmitted by the bite of infected sand flies leading to a wide range of diseases called leishmaniasis. Recently, we demonstrated that Leishmania spp.-derived exosomes/extracellular vesicles (EVs/LeishEXO) were released in the lumen of the sand fly midgut and to be co-egested with the parasite during the blood meal and that LeishEXO were found to stimulate an inflammatory response conducting to an exacerbated cutaneous leishmaniasis, also it was shown that these vesicles cargo important virulence factors like GP63. Thus, this study aimed to confirm through morphological and proteomic analysis a novel model specificity utilizing another set of GP63-altered Leishmania amazonensis parasite strains. Consequently, we proposed to further study the impact of different GP63 vesicle expression levels on their ability to modulate innate inflammatory cell responses, and finally to determine the importance of GP63 vesicle content on the exacerbation of the cutaneous Leishmania spp. pathology after their host co-inoculation. Our results revealed that the protein composition of extracted extracellular vesicles were similar to each other and that GP63 was the sole virulence factor changed in the exosomes composition confirming the specificity of the chosen novel model. We further demonstrated that vesicles with different GP63 EVs cargo displayed distinctive macrophage immunomodulatory capabilities at both gene and protein expression in vitro. Finally, we showed their diverse impact on the Leishmania spp. cutaneous pathology in an in vivo setting and confirmed GP63 as a primordial component of the ability of these EVs in augmenting the inflammatory cutaneous response in Leishmania spp. infection. Our findings provide new insight on the immune response happening in cutaneous leishmaniasis, shade light on the mechanism behind the host-pathogen interaction occurring in the initial moments of infection, thus creating the opportunity of using them as the target of new pharmacological treatments and vaccinations.

The lectin pathway of complement and the initial recognition of Leishmania infantum promastigotes

Visceral leishmaniasis (VL) is a neglected and highly lethal disease. VL is endemic in South American countries, with Brazil being responsible for 96% of the cases. In this continent, VL is caused by the protozoan Leishmania (Leishmania) infantum (L. infantum), transmitted by the bite of infected female phlebotomine sandflies. Immediately after the inoculation of L.infantum promastigotes into the vertebrate host, the complement, as part of the first line of innate response, becomes activated. L. infantum promastigotes glycocalyx is rich in carbohydrates that can activate the lectin pathway of complement system. In this study, we evaluated whether the lectin pathway collectins [manose binding lectin (MBL) and collectin-11 (CL-11)] and ficolins (-1, -2 and -3) interact with L.infantum promastigotes, using confocal microscopy and flow cytometry. The binding of MBL, CL-11 and ficolins -1 and -3, but not ficolin-2, was observed on the surface of live metacyclic promastigotes after incubation with normal human serum (NHS) or recombinant proteins. C3 and C4 deposition as well as complement mediated lyses was also demonstrated after interaction with NHS. These results highlight a role for collectins and ficolins in the initial immune response to L.infantum.

Assessing public perception of a sand fly biting study on the pathway to a controlled human infection model for cutaneous leishmaniasis

BackgroundA controlled human infection model (CHIM) involves deliberate exposure of volunteers to pathogens to assess their response to new therapies at an early stage of development. We show here how we used public involvement to help shape the design of a CHIM to support future testing of candidate vaccines for the neglected tropical disease cutaneous leishmaniasis, a disease transmitted by the bite of infected sand flies in tropical regions.MethodsWe undertook a public involvement (PI) consultation exercise to inform development of a study to test the safety and effectiveness of a sand fly biting protocol using uninfected sand flies (FLYBITE: ClinicalTrials.gov ID NCT03999970) and a CHIM using Leishmania major-infected sand flies (LEISH_Challenge: ClinicalTrials.gov ID NCT04512742), both taking place in York, UK. We involved 10 members of the public including a patient research ambassador and a previous CHIM volunteer. The session took place at The University of York, UK and examined draft study volunteer-facing material and included the CHIM study design, potential adverse events and therapeutic interventions at study endpoints. A discussion of the scientific, ethical, humanitarian and economic basis for the project was presented to the participants to provoke discourse. An inductive, thematic analysis was used to identify the participants’ key concerns.ResultsThemes were identified relating to i) quality of volunteer-facing written information, ii) improving study design, and iii) factors to motivate involvement in the research. Group participants responded positively to the overall study aims. Initial concerns were expressed about potential risks of study involvement, but further explanation of the science and mitigations of risk secured participant support. Participants provided advice and identified improved terminology to inform the volunteer-facing material. Lastly, treatment options were discussed, and excision of any cutaneous lesion was favoured over alternatives as a treatment.ConclusionThe consultation exercise provided invaluable information which led to improved study design and enhanced clarity in the volunteer-facing material. The session also reinforced the need to maintain public trust in scientific rigour prior to initiation of any study. The investigators hope that this description strengthens understanding of PI in clinical research, and encourages its use within other studies.

Enhanced activation of blood neutrophils and monocytes in patients with Ethiopian localized cutaneous leishmaniasis in response to Leishmania aethiopica Neutrophil activation in Ethiopian cutaneous leishmaniasis

Recent studies suggest an essential role of the innate immune effector cells neutrophils and monocytes in protection or disease progression in the early course of Leishmania infection. In areas endemic for cutaneous leishmaniasis in Ethiopia most individuals are exposed to bites of infected sandflies. Still only a minor ratio of the inhabitants develops symptomatic disease. Neutrophils, followed by monocytes, are the first cells to be recruited to the site of Leishmania infection, the initial response of neutrophils to parasites appears to be crucial for the protective response and disease outcome. Our working hypothesis is that neutrophils and/or monocytes in localized cutaneous leishmaniasis (LCL) patients may have defects in function of innate immune cell that contribute to failure to parasite clearance that lead to establishment of infection.The response of cells in Ethiopian LCL patients and healthy controls to Leishmania aethiopica and to the Toll like receptor (TLR) agonists lipopolysaccharide (LPS) and macrophage activating lipopeptide-2 (MALP-2) was investigated by assessing the cell surface expression of CD62L (on neutrophil and monocyte) and CD66b (only on neutrophil), as well as reactive oxygen species (ROS) production by using whole blood-based assays in vitro. No impaired response of neutrophils and monocytes to the microbial constituents LPS and MALP-2 was observed. Neutrophils and monocytes from LCL patients responded stronger to Leishmania aethiopica in the applied whole blood assays than cells from healthy individuals. These experimental findings do not support the hypothesis regarding a possible dysfunction of neutrophils and monocytes in cutaneous leishmaniasis. On the contrary, these cells react stronger in LCL patients as compared to healthy controls. The differential response to L. aethiopica observed between LCL patients and healthy controls have the potential to serve as biomarker to develop FACS based diagnostic/ prognostic techniques for LCL.

A comprehensive overview on sandfly fever

Sandfly fever is a febrile emerging arboviral illness which is a huge threat posed to public health. Sandfly fever viruses (Sicilian, Naples, and Toscana) are endemic to the Mediterranean region. Evidence suggests an increase in the activity of sandfly-borne phleboviruses and their extension to other places. The infection is relatively benign but may cause severe clinical manifestations and complications. Sandfly fever viruses belongs to the genus Phlebovirus (family Bunyaviridae), and the four main serotypes include sandfly fever Sicilian virus, sandfly fever Naples virus, sandfly fever Cyprus virus, and Toscana virus. Sandfly fever has flu-like symptoms such as fever, headache, photophobia, malaise, myalgia, and retro-orbital pain. The incubation period of the disease is 4-8 days, and the patient usually recovers within a week. The first infection provides the host with immunity. Sandfly fever viruses are transmitted through the bites of infected female sandflies, thus, the epidemiology of sandfly fever is closely related to the presence and activity of sandfly species that act as the vectors for transmission. Cases and outbreaks of the disease have been reported worldwide for more than 100 years. All in all, this disease is important for non-endemic countries because it is a travel-related and/or imported illness.

Feline Leishmaniasis: A Review on Epidemiology, Diagnosis and Treatment

Leishmaniasis is an infectious disease caused by the protozoan of the genus Leishmania. It is a tropical disease, considered endemic worldwide and the natural infection occurs through the bite of infected sandflies of the genus Lutzomya. Dogs are considered the main zoonotic reservoirs of this parasite and cats are considered to be potential reservoirs of this disease. Thus, the objective of the study was to review the epidemiology, clinical and laboratory findings, diagnosis, differential diagnosis and treatment of feline leishmaniasis.

Prevalence and Risk Factors of Human Leishmaniasis in Ethiopia: A Systematic Review and Meta-Analysis.

IntroductionTropical diseases are public health problems affecting hundreds of millions of people globally. However, the development of adequate, affordable, and accessible treatments is mostly neglected, resulting in significant morbidity and mortality that could otherwise be averted. Leishmaniasis is one of the neglected tropical diseases caused by the obligate intracellular protozoan Leishmania parasite and transmitted by the bite of infected phlebotomine sandflies. No systematic review and meta-analysis has been done to identify the prevalence and risk factors of leishmaniasis to the authors’ knowledge. Therefore, the objective was to determine the prevalence and risk factors of human leishmaniasis in Ethiopia.MethodsEleven studies conducted in all regions of Ethiopia, which were fully accessible, written in any language, and original articles done on prevalence and risk factors of leishmaniasis, were included. STATA™ version 11.1 was used for statistical analysis. Chi-square, I2, and p values were assessed to check heterogeneity. A random effects model with heterogeneity taken from an inverse-variance model was employed to estimate the pooled effect. Subgroup meta-analysis was computed to reduce random variations among each article’s point prevalence, and Egger and funnel plots were used to check for publication bias.ResultsThe highest proportion of human leishmaniasis was reported from a study done in Amhara region (39.1%), and the lowest was reported from a survey done in Tigray (2.3%). The overall pooled prevalence of leishmaniasis was 9.13% (95% CI 5–13.27). Subgroup analysis by region revealed moderate heterogeneity (I2 = 51.8%) in studies conducted in the Southern Nations Nationalities and Peoples Region (SNNPR). The presence of hyraxes and being male were associated with an increased risk of human leishmaniasis.ConclusionThe prevalence of leishmaniasis in Ethiopia remains high (9.13%), with significant risk factors being male and the presence of hyraxes within a 300-m radius of the sleeping area.

The role of dermis resident macrophages and their interaction with neutrophils in the early establishment of Leishmania major infection transmitted by sand fly bite.

There is substantial experimental evidence to indicate that Leishmania infections that are transmitted naturally by the bites of infected sand flies differ in fundamental ways from those initiated by needle inocula. We have used flow cytometry and intravital microscopy (IVM) to reveal the heterogeneity of sand fly transmission sites with respect to the subsets of phagocytes in the skin that harbor L. major within the first hours and days after infection. By flow cytometry analysis, dermis resident macrophages (TRMs) were on average the predominant infected cell type at 1 hr and 24 hr. By confocal IVM, the co-localization of L. major and neutrophils varied depending on the proximity of deposited parasites to the presumed site of vascular damage, defined by the highly localized swarming of neutrophils. Some of the dermal TRMs could be visualized acquiring their infections via transfer from or efferocytosis of parasitized neutrophils, providing direct evidence for the “Trojan Horse” model. The role of neutrophil engulfment by dermal TRMs and the involvement of the Tyro3/Axl/Mertk family of receptor tyrosine kinases in these interactions and in sustaining the anti-inflammatory program of dermal TRMs was supported by the effects observed in neutrophil depleted and in Axl-/-Mertk-/- mice. The Axl-/-Mertk-/- mice also displayed reduced parasite burdens but more severe pathology following L. major infection transmitted by sand fly bite.

Prevalence of Leishmania major Yakimoff and Schokhor (Kinetoplastida: Trypanosomatidae) in Sandflies in Iran: A Systematic Review and Meta-Analysis.

Cutaneous leishmaniasis is an important parasitic and vector-borne disease in Iran and can be transmitted to humans and animals through bites of infected female sand flies. The present study aimed to determine the pooled prevalence of Leishmania major in sand flies in Iran. A systematic review and meta-analysis was performed in the present study, so that databases, namely PubMed, Web of Sciences, Science Direct, ProQuest, Embase, Cochrane Reviews, and Scopus as well as IranDoc, SID, Elmnet, and Magiran were searched for finding Persian articles. Inclusion criteria of study contained the study in Iran and investigation of L. major parasite in sand flies. The quality of studies was examined by Joanna Briggs Institute Critical Appraisal Checklist for studies that reported prevalence data; and the data were analyzed by Stata 14 software. In total, 42 studies were evaluated, all of which had investigated the infection of Phlebotomus papatasi Scopoli (Diptera: Psychodidae). The infection of Phlebotomus caucasicus group was investigated in 13 studies, Phlebotomus ansarii Lewis in four studies, Phlebotomus salehi Mesghali and Rashti in five studies, and the infection of other species of sandflies in seven studies. According to the meta-analysis, the pooled prevalence of Ph. papatasi, Ph. caucasicus group, Ph. salehi, and Ph. ansarii were equal to 2.4, 6.2, 1.6, and 9.2%, respectively, with 95% confidence interval. According to reports of different rates of sand fly infection in different regions, all studies should have certain and standard forms and formats to determine the pooled prevalence of sand fly infection.

Specification of blood meals ingested by female sand flies caught in Palestinian foci and identification of their concomitant leishmanial infections.

Since leishmaniases are zoonotic vector-borne diseases transmitted through the bites of infected female sand flies, identification of the sources of imbibed blood meals and the detection and identification of leishmanial DNA in them are important in discerning animal reservoirs, clarifying the epidemiology and facilitating control of local leishmaniases. CDC light traps, aspirators and sticky paper traps were used to collect sand flies in four Palestinian foci of both, CL and VL. Phlebotomine species identification was based on morphological keys. Female specimens were screened to detect and identify leishmanial infections, using kDNA-PCR and ITS1-PCR, and engorged female specimens were analyzed to identify the origin of their blood meals, using an RDB blood meal assay based on the amplification of the cytochrome b gene (cytb) of vertebrate mitochondrial DNA (mtDNA). Twenty sand fly species, 11 of the genus Phlebotomus and nine the genus Sergentomyia, were identified. The most abundant species was Ph. papatasi (33.7%), followed by Ph. sergenti (21%). Among the 691 female sand fly specimens, 18.5% (128/691) were positive for leishmanial DNA, using the kDNA-PCR and 6.4% (44/691) were positive using the ITS1-PCR. DNA from parasites of the genus Leishmania was identified in only 1.5% of the infected sand flies. That of Leishmania tropica parasites was detected in six female specimens of Ph. sergenti and that of L. major parasites in two female specimens of Ph. papatasi. Interestingly, two engorged females of the species Se. (Neophlebotomus) sp. were positive for L. tropica DNA. Ninety engorged female sand flies of Ph. papatasi and 104 of Ph. sergenti had fed on a large variety of vertebrate hosts such as humans, hyraxes, rats, cows, goats and birds. Regarding blood-meals showing a mixture from different species of animal host, hyrax and rat blood was revealed in 8/104 (7.7%) females of Ph. sergenti. Detection of hyrax blood in engorged female sand flies of the species Ph. sergenti supports the role of hyraxes being a potential reservoir of L. tropica in Palestinian regions. Rat blood meals might be significant since a few strains L. tropica and L. infantum were isolated from rats. Further studies must be undertaken before conclusions could be drawn.