Cutaneous leishmaniasis in sub-Saharan Africa: a systematic review of Leishmania species, vectors and reservoirs.

BACKGROUND: Cutaneous leishmaniasis (CL) is understudied in sub-Saharan Africa. The epidemiology of CL is determined by the species involved in its transmission. Our objectives were to systematically review available data on the species of Leishmania, along with vectors and reservoirs involved in the occurrence of human cases of CL in sub-Saharan Africa, and to discuss implications for case management and future research. METHODS: We systematically searched PubMed, Scopus, Cochrane and African Index Medicus. There was no restriction on language or date of publication. The review was conducted according to PRISMA guidelines and was registered on PROSPERO (CRD42022384157). RESULTS: In total, 188 published studies and 37 reports from the grey literature were included. An upward trend was observed, with 45.7% of studies published after 2010. East Africa (55.1%) represented a much greater number of publications than West Africa (33.3%). In East Africa, the identification of reservoirs for Leishmania tropica remains unclear. This species also represents a therapeutic challenge, as it is often resistant to meglumine antimoniate. In Sudan, the presence of hybrids between Leishmania donovani and strictly cutaneous species could lead to important epidemiological changes. In Ghana, the emergence of CL in the recent past could involve rare species belonging to the Leishmania subgenus Mundinia. The area of transmission of Leishmania major could expand beyond the Sahelian zone, with scattered reports in forested areas. While the L. major-Phlebotomus duboscqi-rodent complex may not be the only cycle in the dry areas of West Africa, the role of dogs as a potential reservoir for Leishmania species with cutaneous tropism in this subregion should be clarified. Meglumine antimoniate was the most frequently reported treatment, but physical methods and systemic agents such as ketoconazole and metronidazole were also used empirically to treat L. major infections. CONCLUSIONS: Though the number of studies on the topic has increased recently, there is an important need for intersectional research to further decipher the Leishmania species involved in human cases of CL as well as the corresponding vectors and reservoirs, and environmental factors that impact transmission dynamics. The development of molecular biology in sub-Saharan Africa could help in leveraging diagnostic and research capacities and improving the management of human cases through personalized treatment strategies.

Seasonal life cycle of Pintomyia longiflocosa (Diptera: Psychodidae) under semi-controlled conditions in the Huila state, Colombia.

BACKGROUND: Pintomyia longiflocosa is considered a vector of etiological agents of cutaneous leishmaniasis. The objective of this research was to establish the parameters of the life cycle of Pi. longiflocosa in semi-controlled conditions in a rural area of the Campoalegre municipality, Huila, Colombia. METHODOLOGY/PRINCIPAL FINDINGS: The life cycle of individuals of Pi. longiflocosa, obtained from two cohorts of collected, fed, and individualized females, was monitored during two different times of the year (between February and August 2020 and between July 2020 and January 2021, respectively). Determining parameters associated with the fertility and fecundity, time and attributes of development and survival, and its association with abiotic variables. The average duration of Cycle 1 (C1) and Cycle 2 (C2) was 134.9 and 148.78 days, respectively. The gonotrophic cycle of parental females presented significant differences (p-value <0.05) between C1 and C2 (8.47 and 11.42 days) as well as between fecundity and fertility parameters. The number of days it takes the development of the immature stages between the two cycles studied, also showed significant differences in the larvae II (15.21 and 22.23), larvae III (11.93 and 17.56), and pupae (24.48 and 22.9) stages. During C1, the survival rate was higher and consistent with the productivity of adult individuals (F1), compared to C2. Fecundity and fertility values were significantly higher in C2. Finally, a significant correlation between the number of individuals and temperature was evidenced in C1 while, for C2, there was a negative correlation with precipitation. CONCLUSIONS/SIGNIFICANCE: Significant differences were found in several biological and reproductive parameters between the two cycles monitored. The parameters of the life cycle of Pi. longiflocosa in its natural habitat would be influenced by environmental factors related to the annual seasonality in the sub-Andean rural area, conditioning the temporal distribution of this species and, consequently, the possible transmission of causative agents of cutaneous leishmaniasis.

Indicators sandflies and environment associated to spatial landscaping change in Chocó Biosphere Reserve UNESCO.

BACKGROUND OBJECTIVES: Sandflies are vector insects associated with terrestrial forest ecosystems; in the Ecuadorian Andes, they participate in the transmission of human cutaneous leishmaniasis. This geographical area represents an opportunity to evaluate the role of sandflies as bioindicators of the degree of intervention of tropical humid forest ecosystems (THF) associated with changes in the ecology of the local landscape. METHODS: CDC-light traps were used for collecting adult sandflies in February 2020 in a humid tropical forest within the Chocó Biosphere Reserve. All species were identified using morphological keys. Analysis data about abundance, richness, species accumulation, diversity index, species composition communities, species sex proportion, spatial sandflies environmental, Renyi's Diversity Profile were performed to compare six spatial habitats in Mashpi locality, Ecuador. RESULTS: Sandflies were collected (n-1435); the main species are represented by Trichophoromyia reburra, Nyssomyia trapidoi, Psathyromyia aclydifera, Psychodopygus panamensis and Lutzomyia hartmanni. Only Th. reburra is associated with not intervened forest, while the other three species are associated with intervened forest within Mashpi in the Choco Biosphere Reserve. The secondary forest has major sandflies' richness, while the primary forest exhibits major abundance. INTERPRETATION CONCLUSION: Th. reburra is a sandfly restricted to the Andean Forest and is a bioindicator of the high environmental health quality of the forest, while Ny. trapidoi and Pa. aclydifera are bioindicators of environmental disturbances in the forest. Additionally, Ps. panamensis, Lu. hartmanni and Ny. trapidoi are bioindicators of human impact and the risk of leishmaniasis.

Distribution changes of cutaneous leishmaniasis: A postulated risk of disease transmission in Hambantota, Sri Lanka.

BACKGROUND OBJECTIVES: Leishmaniasis is caused by various species of parasite Leishmania. Approximately twenty of them are pathogenic to mammals. In Sri Lanka, cutaneous leishmaniasis (CL) is an established vector-borne disease. CL originates and spreads mainly through sandfly bite in many endemic countries. The aim of the present study was to compare the geographical distribution and demographic features of CL cases in Hambantota district, Sri Lanka in 2014 and 2016. METHODS: The patients who were presented to the Tangalle Base Hospital from June to December in 2014 and 2016 were examined and a descriptive study was carried out using a structured-questionnaire. Slit-skin smears were collected from each patient, Giemsa-stained and examined under the light microscope to identify Leishmania amastigotes. RESULTS: Out of 256 and 314 suspected CL patients, 156 and 155 were identified positive for the year 2014 and 2016, respectively. Out of 12 District Secretary Divisions (DSD) in Hambantota district, the highest number of CL cases, 85 and 86 was reported from Tangalle DSD in 2014 and 2016 respectively. Number of identified CL patients in Beliatta DSD had increased from 50 to 67 during the study period. In both years, majority of CL patients were ≥50 years old with males more infected than females. Although CL association with occupations were insignificant, housewives were the highly (23%) infected occupants in this area. INTERPRETATION CONCLUSION: Based on the present findings, geographical distribution within DSDs in Hambantota district had changed. This emphasizes the importance of CL as a health problem in Hambantota district.

Molecular investigation of Leishmania in sandflies (Diptera: Psychodidae) and rodents (Mammalia: Rodentia) in Nahavand, west of Iran.

Cutaneous leishmaniasis caused by different species of Leishmania is transmitted by Phlebotominae sandflies. This disease remains a public health concern in Iran. Therefore, the present study aimed to examine Leishmania infection in sandflies and reservoir rodents in six rural regions of Nahavand, located in western Iran. From May to October 2022, sandflies and rodents were collected and identified at the species level. Additionally, rodents' skin lesions and earlobe specimens were collected separately for microscopic and molecular examination. All specimens were tested for Leishmania DNA by PCRs targeting the parasite's ITS-2 and 18S rRNA gene and positive were Sanger sequenced. A total of 3396 sandflies belonging to seven subgenera and 11 species, i.e., Phlebotomus papatasi (42.7%), P. major (20.6%), P. mascitti (0.3%), P. neglectus (0.2%), P. alexandri (0.2%), P. turanicus (0.3%), Sergentomyia murgabiensis (18.1%), S. dentata (10.5%), S. theodori (5.8%), S. antennata (1.1%), and S. pawlowski (0.1%) were identified. Based on the species population, 29 pools of sandflies were examined for the presence of Leishmania DNA using conventional PCR (cPCR), and individual DNAs were tested when positive. Leishmania major DNA was detected in two P. papatasi and Leishmania sp. in one P. major individual sandfly. This is the first report of Leishmania infection in sandflies from Hamadan province. The captured rodents (n = 61) belonged to four families and seven species, i.e., Arvicola amphibius (37.7%), Mus musculus (29.5%), Microtus socialis (13.1%), Apodemus sylvaticus (11.5%), Talpa davidiana (4.9%), Apodemus witherbyi (1.6%), and Rattus norvegicus (1.6%). Microscopic and molecular examinations of the rodent lesions and earlobes scored negative results. The presence of Leishmania in the Phlebotominae sandflies in Nahavand indicates a potential threat to humans and animals in the region. Regular monitoring and examination of the sandflies' population and timely diagnosis and treatment of new patients are strongly recommended.

Spatio-Temporal distribution of a vector of cutaneous leishmaniasis: Pintomyia longiflocosa, in a population from the Colombian Andean Mountains.

BACKGROUND: Leishmaniasis, a neglected disease and public health concern, is associated with various factors such as biological, social, economical conditions and climate, increasing the risk of human infection. Understanding the population dynamics of the vectors, like Pintomyia longiflocosa, and its relationship with ecological variables is crucial for developing effective strategies to control sand fly populations and combat cutaneous leishmaniasis in a tropical country like Colombia. METHODOLOGY: Adult sand flies were collected in three different sample locations: outdoor, indoor, and peri-domestic areas in three houses located in the rural settlement of Campoalegre (Huila) between February 2020 and February 2021, using the CDC light traps. The sand fly density was quantified and associated with the sample locations and the sampling months using Analysis of Variance and Pearson correlations. PRINCIPAL FINDINGS: In the period of the sample, 98.86% of sand fly collected was identified as Pi. longiflocosa. The density of this species was significantly different between males and females, the latter contributing more to density in all sample locations (P<0.0001). The outdoor was the sample location with the highest and most significative density in this study (70%, P = 0.04). The density of these sand flies is related to the seasonality of Campoalegre, revealing a density peak from February and June to October (P < 0.05). Finally, precipitation is the environmental variable prominently linked to the density pattern, showing a negative correlation with it. Months with the highest precipitations show the lowest values of Pi. longiflocosa abundance. CONCLUSIONS/SIGNICANCE: Our investigation reveals a inverse correlation between precipitation levels and the abundance of Pi. longiflocosa in Campoalegre (Huila), particularly in outdoor areas. This suggests that vector control strategies to periods of reduced precipitation in outdoor settings could offer an effective approach to minimizing cases of cutaneous leishmaniasis in the region.

Effect of Phlebotomus papatasi on the fitness, infectivity and antimony-resistance phenotype of antimony-resistant Leishmania major Mon-25.

Leishmania major is responsible for zoonotic cutaneous leishmaniasis. Therapy is mainly based on the use of antimony-based drugs; however, treatment failures and illness relapses were reported. Although studies were developed to understand mechanisms of drug resistance, the interactions of resistant parasites with their reservoir hosts and vectors remain poorly understood. Here we compared the development of two L. major MON-25 trivalent antimony-resistant lines, selected by a stepwise in vitro Sb(III)-drug pressure, to their wild-type parent line in the natural vector Phlebotomus papatasi. The intensity of infection, parasite location and morphological forms were compared by microscopy. Parasite growth curves and IC50 values have been determined before and after the passage in Ph. papatasi. qPCR was used to assess the amplification rates of some antimony-resistance gene markers. In the digestive tract of sand flies, Sb(III)-resistant lines developed similar infection rates as the wild-type lines during the early-stage infections, but significant differences were observed during the late-stage of the infections. Thus, on day 7 p. i., resistant lines showed lower representation of heavy infections with colonization of the stomodeal valve and lower percentage of metacyclic promastigote forms in comparison to wild-type strains. Observed differences between both resistant lines suggest that the level of Sb(III)-resistance negatively correlates with the quality of the development in the vector. Nevertheless, both resistant lines developed mature infections with the presence of infective metacyclic forms in almost half of infected sandflies. The passage of parasites through the sand fly guts does not significantly influence their capacity to multiply in vitro. The IC50 values and molecular analysis of antimony-resistance genes showed that the resistant phenotype of Sb(III)-resistant parasites is maintained after passage through the sand fly. Sb(III)-resistant lines of L. major MON-25 were able to produce mature infections in Ph. papatasi suggesting a possible circulation in the field using this vector.

Characterization of bacteria expectorated during forced salivation of the Phlebotomus papatasi: A neglected component of sand fly infectious inoculums.

The infectious inoculum of a sand fly, apart from its metacyclic promastigotes, is composed of factors derived from both the parasite and the vector. Vector-derived factors, including salivary proteins and the gut microbiota, are essential for the establishment and enhancement of infection. However, the type and the number of bacteria egested during salivation is unclear. In the present study, sand flies of Phlebotomus papatasi were gathered from three locations in hyperendemic focus of zoonotic cutaneous leishmaniasis (ZCL) in Isfahan Province, Iran. By using the forced salivation assay and targeting the 16S rRNA barcode gene, egested bacteria were characterized in 99 (44%) out of 224 sand flies. Culture-dependent and culture-independent methods identified the members of Enterobacter cloacae and Spiroplasma species as dominant taxa, respectively. Ten top genera of Spiroplasma, Ralstonia, Acinetobacter, Reyranella, Undibacterium, Bryobacter, Corynebacterium, Cutibacterium, Psychrobacter, and Wolbachia constituted >80% of the saliva microbiome. Phylogenetic analysis displayed the presence of only one bacterial species for the Spiroplasma, Ralstonia, Reyranella, Bryobacter and Wolbachia, two distinct species for Cutibacterium, three for Undibacterium and Psychrobacter, 16 for Acinetobacter, and 27 for Corynebacterium, in the saliva. The abundance of microbes in P. papatasi saliva was determined by incorporating the data on the read counts and the copy number of 16S rRNA gene, about 9,000 bacterial cells, per sand fly. Both microbiological and metagenomic data indicate that bacteria are constant companions of Leishmania, from the intestine of the vector to the vertebrate host. This is the first forced salivation experiment in a sand fly, addressing key questions on infectious bite and competent vectors.

Evaluation of the biodiversity and distribution of sand flies and tracking of Leishmania major in them in central Iran.

Many areas of Iran are endemic regarding Cutaneous leishmaniasis (CL) as a parasitic disease transmitted by a female sand fly vector's bite. The present study investigated the distribution of sand flies in Harand and Egieh in Isfahan province, Central Iran. Overall, 408 out of 1260 collected sand flies were identified morphologically, among which 353 and 55 were isolated from Harand and Egieh, respectively. Also, 66.4% and 33.6% of the sand flies were female and male, respectively. The most prevalent sand fly species were Phlebotomus papatasi (52%), followed by Ph. caucasicus (40.4%), Sergentomyia sintoni (4.9%), and Ph. kazeruni (0.7%). Among 180 molecularly-analyzed sand flies, 14 (7.77%) were found infected with L. major, with 9 out of 103 (8.73%) Ph. papatasi and 5 out of 75 (6.66%) Ph. caucasicus.

Geographical and Molecular Analysis of Haplotype Variations in Leishmania major Among Infected Iranian Phlebotomus papatasi.

PURPOSE: Leishmania major is main causative agent and Phlebotomus papatasi is only proven vector of Zoonotic Cutaneous Leishmaniasis (ZCL) in Iran. Human leishmaniasis is mostly susceptible to climatic conditions and molecular variations of Leishmania parasites within sandflies. METHODS: L. major was analyzed based on geographical, environmental, climatic changes and haplotype variations within P. papatasi. Molecular tools and different geographical aspects were employed using Arc-GIS software for mapping the geographic distribution of samples and other statistics tests. Fragments of ITS-rDNA, k-DNA, and microsatellite genes of Leishmania were used for PCR, RFLP, sequencing, and phylogenetic analyses. RESULTS: Totally 81 out of 1083 female P. papatasi were detected with Leishmania parasites: 70 and five were L. major and L. turanica, respectively. Golestan and Fars provinces had the highest (13.64%) and lowest (4.55%) infection rates, respectively. The infection rate among female P. papatasi collected from gerbil burrows was significantly higher (15.15%) than animal shelters, yards, and inside houses (4.48%) (P < 0.0%). Microsatellite was more sensitive (22.72%) than k-DNA (18.8%) and ITS-rDNA (7.48%). More molecular variations of L. major were found in Isfahan province. CONCLUSIONS: Arc-GIS software and other statistics tests were employed to find Leishmania positive and haplotype variations among sand flies. Geographical situations, altitude, climate, precipitation, humidity, temperature, urbanization, migrations, regional divergences, deforestation, global warming, genome instability, ecology, and biology of the sand flies intrinsically, and the reservoir hosts and neighboring infected locations could be reasons for increasing or decreasing the rate of Leishmania infection and haplotype variations.

Baseline susceptibility of a wild strain of main vectors of leishmaniasis to WHO-recommended insecticides in southeastern Iran.

BACKGROUND: In Iran, both cutaneous leishmaniases (CL) and visceral leishmaniases (VL) are endemic, recording one of the 10 highest CL prevalence in the world. Parasites are transmitted by the bite of infected Phlebotomus sand fly females. Several sand fly species have been identified as vectors in the studied region of Kerman province. Residual spraying to control adult sand flies, is the only way to decrease the spreading of the diseases but, following control treatment against malaria vectors in endemic areas in Iran, resistance or tolerance to insecticides emerged in some sand fly species. The objective of this study was to survey insecticides susceptibility levels of 3 vector species in wild sand fly populations in different foci of the diseases in Kerman province. Ph. sergenti, and Ph. papatasi respectively vectors of anthroponotic and zoonotic cutaneous leishmaniases and for the first time Ph. alexandri one of the anthroponotic visceral leishmaniases vector were tested against: deltamethrin 0.05%, malathion 5%, dichloro-diphenyl-trichloroethane (DDT) 4%. MATERIALS AND METHODS: In leishmaniases endemic areas species specific sand fly sites were selected in Kerman province, and specimens were collected by manual aspirators at different time intervals during the spring and summer 2019. All the susceptibility tests were performed according to the WHO tube test recommended procedure. RESULTS: Twenty five blood-fed female sand flies from the region's prevalent species were used in each pooled test replicates. All wild specimens died within 60 min of exposure to DDT 4%, malathion 5%, and deltamethrin 0.05%, but the mortality rate for Ph. papatasi exposed to malathion and DDT was 91.6% and 66.6%, respectively. CONCLUSION: According to current study results, Ph. sergenti and Ph. alexandri are highly susceptible to all the evaluated insecticides in the study areas. However, Ph. papatasi was susceptible to deltamethrin (100% mortality), possibly resistant or tolerant to malathion (91.6% mortality), and confirmed to be resistant to DDT (66.6% mortality).

Phlebotominae Fauna (Diptera: Psychodidae) and Molecular Detection of Leishmania (Kinetoplastida: Trypanosomatidae) in Urban Caves of Belo Horizonte, Minas Gerais, Brazil.

Sand flies are often collected in urban areas, which has several implications for the risk of transmission of Leishmania Ross, 1903, to humans and other mammals. Given this scenario, we describe the sand fly fauna of caves and their surroundings in Mangabeiras Municipal Park (MMP) and Paredão Serra do Curral Park (PSCP), both located in the urban area of Belo Horizonte, Minas Gerais, Brazil, an endemic focus of visceral and cutaneous leishmaniasis. Collections were conducted monthly from November 2011 to October 2012, using CDC light traps exposed for two consecutive nights in four caves and their surroundings. Nonsystematized collections using Shannon traps and active searches were also performed around the caves. The presence of Leishmania DNA in collected female sand flies was evaluated by ITS1-PCR. A total of 857 sand flies representing fourteen species were collected in MMP, of which Evandromyia edwardsi (Mangabeira, 1941) was the most abundant. Leishmania amazonensis was detected in Brumptomyia nitzulescui (Costa Lima, 1932) and Ev. edwardsi, with the latter also having Leishmania braziliensis, Leishmania infantum, and Leishmania sp. A total of 228 sand flies representing four species were collected in PSCP, of which Sciopemyia microps (Mangabeira, 1942) was the most abundant. No females from PSCP were positive for Leishmania-DNA. Studies aimed at describing sand fly faunas of cave environments and detecting Leishmania are essential to understanding the relationship between these insects and this ecotope and assessing and monitoring areas that may pose risks to the health of visitors and employees.

Cutaneous leishmaniasis–Awareness, knowledge and practices among general population in rural and urban areas in Malakand region, Pakistan / Leishmaniose cutânea - conscientização, conhecimentos e práticas entre a população em geral nas áreas rurais e urbanas da região de Malakand, Paquistão

Malakand region is an endemic area for cutaneous leishmaniasis (CL). However, there are limited number of studies of this disease in Pakistan. Therefore, a study was conducted to understand the level of awareness attitude and practice among the residents of Makaland towards CL and the disease vectors. This study adopted a cross-sectional approach with a total of 400 respondents (n=93 rural and n= 307 urban). Overall, the population in Malakand region (61.2%) were well-informed in the role of sand fly in transmitting diseases, but most lack knowledge on the vector's behavior and almost a quarter (24.5%) were unable to provide knowledge on proper control measures. Alarmingly, the practice and attitudes of the general population was not satisfactory as close to half (49.8%) of the population did adopt any control method. This study calls for increase in awareness through health education campaign to reduce the risk of cutaneous leishmaniasis outbreaks in the future.

A região de Malakand é uma área endêmica para leishmaniose cutânea (CL). No entanto, há um número limitado de estudos sobre esta doença no Paquistão. Portanto, foi realizado um estudo para entender o nível de atitude e prática de conscientização entre os residentes de Makaland em relação aos CL e os vetores da doença. Este estudo adotou uma abordagem transversal com um total de 400 entrevistados (n = 93 rural e n = 307 urbano). No geral, a população da região de Malakand (61,2%) estava bem informada sobre o papel da mosca na transmissão de doenças, mas a maioria não possui conhecimento sobre o comportamento do vetor e quase um quarto (24,5%) foi incapaz de fornecer conhecimento sobre medidas de controle adequadas . De maneira alarmante, a prática e as atitudes da população em geral não foram satisfatórias, pois cerca da metade (49,8%) da população adotou algum método de controle. Este estudo apela ao aumento da conscientização por meio de campanhas de educação em saúde para reduzir o risco de surtos de leishmaniose cutânea no futuro.

The effect of geo-climatic determinants on the distribution of cutaneous leishmaniasis in a recently emerging focus in eastern Iran.

BACKGROUND: Cutaneous leishmaniasis (CL) has been reported in recent years in South Khorasan Province, a desert region of eastern Iran, where the main species is Leishmania tropica. Little is known of the influence of geography and climate on its distribution, and so this study was conducted to determine geo-climatic factors by using geographic information system. METHODS: The home addresses of patients with CL patients who were diagnosed and notified from 2009 to 2017 were retrieved from the provincial health center and registered on the village/town/city point layer. The effects of mean annual rainfall (MAR) and mean annual humidity (MAH), mean annual temperature (MAT), maximum annual temperature (MaxMAT), minimum annual temperature (MinMAT), mean annual number of high-velocity wind days (MAWD), mean annual frosty days (MAFD) and snowy days (MASD), elevation, soil type and land cover on CL distribution were examined. The geographical analysis was done using ArcMap software, and univariate and multivariate binary logistic regression were applied to determine the factors associated with CL. RESULTS: A total of 332 CL patients were identified: 197 (59.3%) male and 135 (40.7%) female. Their mean age was 29.3 ± 2.1 years, with age ranging from 10 months to 98 years. CL patients came from a total of 86 villages/towns/cities. By multivariate analysis, the independent factors associated with increased CL were urban setting (OR = 52.102), agricultural land cover (OR = 3.048), and MAWD (OR = 1.004). Elevation was a protective factor only in the univariate analysis (OR = 0.999). Soil type, MAH, MAT, MinMAT, MaxMAT, and MAFD did not influence CL distribution in eastern Iran. CONCLUSIONS: The major risk zones for CL in eastern Iran were urban and agricultural areas with a higher number of windy days at lower altitudes. Control strategies to reduce human vector contact should be focused in these settings.

Behaviors and Perceptions Related to Cutaneous Leishmaniasis in Endemic Areas of the World: A Review.

The investigation of perceptions and behaviors associated with cutaneous leishmaniasis (CL) in different societies has indicated that mere attention to biological and medical aspects is not enough to prevent and control diseases and it is necessary to know the disease-associated behaviors and beliefs. The present study aimed to answer a question: what are the behaviors and perceptions associated with cutaneous leishmaniasis in endemic regions of the world?. This study is a review of the articles published on CL from January 2010 to January 2021, on the International databases Science Direct, Scopus and PubMed. We utilized the terms cutaneous leishmaniasis, in combination with some keywords, including belief, perceptions, knowledge, attitude, practices, prevention, and behavior. Non-original studies, including editorials, reviews, prefaces, brief communications, and letters to the editor, CL epidemiological articles, pre-published articles that has not been peer reviewed, and articles that not provide complete findings on CL-related perceptions and behaviors were excluded from the present paper. After screening, 25 articles from 17 regions of the world were included in the study. The results depicted a novel classification of behaviors and perceptions related to CL prevention and control. Two positive and negative categories of perceptions and behaviors were discovered. Positive perceptions and behaviors were classified into five categories, including: 1- good awareness, 2- perceived susceptibility, 3- perceived severity, 4- perceived response efficiency, and 5- appropriate behaviors. Furthermore, negative perceptions and behaviors were classified into four categories: 1- poor awareness 2- misconceptions (A. About the disease vector B.about the cause of the disease, C. about the consequences of the disease and the treatment process), 3- perceived barriers (A. in prevention, B. in medical treatment), and 4- misbehaviors (A. negligence, B. local and traditional behavioral patterns). In most endemic parts of the world, misconceptions are probably the leading cause of several misbehaviors in dealing with CL. It seems that providing educational programs to strengthen positive beliefs and correct negative beliefs are rooted in the studies in different countries and could be useful for improving the relevant behaviors and ultimately, taking a step towards the prevention and control of CL.

Parasitological and molecular search for Leishmania natural infection in phlebotomine sand flies in peri-urban and rural sites of an Argentinean area endemic for tegumentary leishmaniasis.

Leishmaniases are neglected tropical diseases caused by Leishmania spp. parasites transmitted by the bite of phlebotomine sand flies. In Argentina, the most endemic area of American tegumentary leishmaniasis (ATL) has been Orán department, Province of Salta, where Leishmania (Viannia) braziliensis prevails and Nyssomyia neivai is considered as its vector, although there is no accurate and sufficient information in this regard. The aim of this work was to search for natural infection by Leishmania spp. in sand flies from peri-urban and rural sites with ATL background in Orán department. For this, sand flies were caught at five sites; female sand flies captured with Shannon trap were dissected to microscopically examine their gut contents, while females captured with CDC traps were molecularly analyzed by duplex PCR with two primer pairs to simultaneously amplify kinetoplast DNA (kDNA) and mammalian actin. A total of 1921 females were captured, with Ny. neivai being the most abundant species (89%), followed by Migonemyia migonei (6%) and cortelezzii complex (3%). No natural infection was found in any of them neither by dissection nor by PCR, although the detection limit of kDNA PCR was up to 25 promastigotes. The absence of infected females in peri-urban sites suggest that the transmission did not take place in those environments during the study period. Future searches for natural infection should focus on rural settings to deepen knowledge and elucidate the role of the circulating sand fly species as all have been linked to ATL transmission at other sites.

Species diversity and spatial distribution of CL/VL vectors: assessing bioclimatic effect on expression plasticity of genes possessing vaccine properties isolated from wild-collected sand flies in endemic areas of Iran.

BACKGROUND: Leishmaniasis is one of the ten most important neglected tropical diseases worldwide. Understanding the distribution of vectors of visceral and cutaneous leishmaniasis (VL/CL) is one of the significant strategic frameworks to control leishmaniasis. In this study, the extent of the bioclimatic variability was investigated to recognize a rigorous cartographic of the spatial distribution of VL/CL vectors as risk-maps using ArcGIS modeling system. Moreover, the effect of bioclimatic diversity on the fold change expression of genes possessing vaccine traits (SP15 and LeIF) was evaluated in each bioclimatic region using real-time PCR analysis. METHODS: The Inverse Distance Weighting interpolation method was used to obtain accurate geography map in closely-related distances. Bioclimatic indices were computed and vectors spatial distribution was analyzed in ArcGIS10.3.1 system. Species biodiversity was calculated based on Shannon diversity index using Rv.3.5.3. Expression fold change of SP15 and LeIF genes was evaluated using cDNA synthesis and RT-qPCR analysis. RESULTS: Frequency of Phlebotomus papatasi was predominant in plains areas of Mountainous bioclimate covering the CL hot spots. Mediterranean region was recognized as an important bioclimate harboring prevalent patterns of VL vectors. Semi-arid bioclimate was identified as a major contributing factor to up-regulate salivary-SP15 gene expression (P = 0.0050, P < 0.05). Also, Mediterranean bioclimate had considerable effect on up-regulation of Leishmania-LeIF gene in gravid and semi-gravid P. papatasi population (P = 0.0109, P < 0.05). CONCLUSIONS: The diversity and spatial distribution of CL/VL vectors associated with bioclimatic regionalization obtained in our research provide epidemiological risk maps and establish more effectively control measures against leishmaniasis. Oscillations in gene expression indicate that each gene has its own features, which are profoundly affected by bioclimatic characteristics and physiological status of sand flies. Given the efficacy of species-specific antigens for vaccine production, it is essential to consider bioclimatic factors that have a fundamental role in affecting the regulatory regions of environmentally responsive loci for genes used in vaccine design.

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

BACKGROUND: The municipality of Caratinga is an important endemic area for American Tegumentary Leishmaniasis (ATL) and no epidemiological studies were performed during the past two decades. Here, we analyzed the epidemiological situation and the geographical distribution of ATL cases in the municipality of Caratinga from 2007 to 2018 using geographic information systems (GIS). Also, we evaluated the impact of several demographic parameters in ATL distribution and the sand flies incriminated in its transmission. METHODS: All demographic information (gender, age, educational level, clinical form, diagnostic criteria and case evolution) used in this study was retrieved from the public health archives and confirmed in the State Health Services databases. All cases were analyzed using GIS software based on ATL distribution. Also, non-systematic sand fly collections and molecular detection of Leishmania were performed in the hotspots. RESULTS AND CONCLUSIONS: During the period, ATL cases continued and increased especially in the past years (2016-2018). Hotspots included urban Caratinga areas and the districts of Patrocínio de Caratinga and Sapucaia. The species Nyssomyia whitmani, Nyssomyia intermedia, Migonemyia migonei and Evandromyia cortelezzii complex were captured. However, ITS1-PCR did not detect Leishmania DNA in those insects. Based on our analyses, urbanization of ATL in Caratinga has occurred in the past years. Due to the increase in the number of cases and vectors presence, it is recommended that health authorities focus on control measures in the most affected areas (Patrocínio of Caratinga and Sapucaia districts and urban Caratinga).

A sand fly salivary protein acts as a neutrophil chemoattractant.

Apart from bacterial formyl peptides or viral chemokine mimicry, a non-vertebrate or insect protein that directly attracts mammalian innate cells such as neutrophils has not been molecularly characterized. Here, we show that members of sand fly yellow salivary proteins induce in vitro chemotaxis of mouse, canine and human neutrophils in transwell migration or EZ-TAXIScan assays. We demonstrate murine neutrophil recruitment in vivo using flow cytometry and two-photon intravital microscopy in Lysozyme-M-eGFP transgenic mice. We establish that the structure of this ~ 45 kDa neutrophil chemotactic protein does not resemble that of known chemokines. This chemoattractant acts through a G-protein-coupled receptor and is dependent on calcium influx. Of significance, this chemoattractant protein enhances lesion pathology (P < 0.0001) and increases parasite burden (P < 0.001) in mice upon co-injection with Leishmania parasites, underlining the impact of the sand fly salivary yellow proteins on disease outcome. These findings show that some arthropod vector-derived factors, such as this chemotactic salivary protein, activate rather than inhibit the host innate immune response, and that pathogens take advantage of these inflammatory responses to establish in the host.

Genetic diversity of Leishmania tropica: Unexpectedly complex distribution pattern.

In this study, we characterized a collection of clinical samples obtained from Syrian and Turkish patients with cutaneous leishmaniasis using internal transcribed spacer 1 (ITS1) sequences. All obtained sequences belonged to Leishmania tropica. Combining them with those available from GenBank allowed us performing a broad-scale analysis of genetic diversity for this species. We demonstrated that L. tropica has a complex phylogeographic pattern with some haplotypes being widespread across endemic countries and others restricted to particular regions. We hypothesize that at least some of them may be associated with alternative vectors or animal reservoirs.