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1.
Acta Trop ; 237: 106719, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36288767

RESUMO

Cutaneous leishmaniasis is prevalent in Sri Lanka since 1992. It remains as a health issue with increasing numbers and spreading from endemic to non-endemic areas in the county. Kegalle district is a new disease focus, which notified the first case in 2016. However, there is no documented evidence of the vector distribution, abundance and potential risk factors in this district. Two Medical Officer of Health (MOH) areas (Rambukkana and Warakapola) that had reported the highest numbers of cases in the Kagalle district was selected and recorded cases (2016-2020) were obtained. The patients were visited and socio-economic, demographic, environmental and awareness-related information was collected using an interviewer-administered questionnaire. Entomological surveys were conducted from July 2019- July 2020 using three standard entomological techniques. Bioclimatic suitability for the disease transmission was evaluated using ecological niche modelling. A total of 107 patients were reported from both MOH areas and 88 were recruited for the study. The study showed that leishmaniasis in the Kegalle district progressed to an outbreak level within 3 years after reporting the first case. School students (n = 22, 25%, P < 0.05) and individuals between 11 and 20 years of age (n = 33, 37.5%, P<0.05) were identified as the main risk groups, while the presence of composting sites (n = 65, 73.9%, P < 0.05), abandoned lands (n = 63, 71.6%, P < 0.05) in the surrounding and suboptimal (dark or normal) lighting conditions (n = 87, 98.8%, P < 0.05) in the house were identified as main risk factors. Areas closer to the adjacent district (Kurunegala), which is a known endemic district for leishmaniasis indicated a high probability (0.3-0.5) for disease transmission. Sergentomyia zeylanica (n = 164, 56.94%), was identified as the predominant sand fly species followed by Phlebotomus argentipes (n = 121, 42.01%), Sergentomyia babu insularis (n = 2, 0.69%) and Sergentomyia punjabensis (n = 1, 0.35%). Phlebotomus argentipes was captured mostly for outdoor resting sites and S. zeylanica was recoded from both indoor and outdoor. The presence of vectors that can transmit leishmaniasis in these areas along with the potential risk factors could increase the transmission risk and disease establishment in new areas that are ecologically favourable for disease transmission. Therefore, vector control entities should undertake immediate measures to stop spreading the disease into new areas.


Assuntos
Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Sri Lanka/epidemiologia , Insetos Vetores , Ecossistema
2.
Parasit Vectors ; 15(1): 412, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36335408

RESUMO

Leishmania infections span a range of clinical syndromes and impact humans from many geographic foci, but primarily the world's poorest regions. Transmitted by the bite of a female sand fly, Leishmania infections are increasing with human movement (due to international travel and war) as well as with shifts in vector habitat (due to climate change). Accurate diagnosis of the 20 or so species of Leishmania that infect humans can lead to the successful treatment of infections and, importantly, their prevention through modelling and intervention programs. A multitude of laboratory techniques for the detection of Leishmania have been developed over the past few decades, and although many have drawbacks, several of them show promise, particularly molecular methods like polymerase chain reaction. This review provides an overview of the methods available to diagnostic laboratories, from traditional techniques to the now-preferred molecular techniques, with an emphasis on polymerase chain reaction-based detection and typing methods.


Assuntos
Leishmania , Leishmaniose , Phlebotomus , Psychodidae , Animais , Humanos , Feminino , Leishmaniose/diagnóstico , Leishmania/genética , Reação em Cadeia da Polimerase/métodos
3.
ScientificWorldJournal ; 2022: 5098005, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36408197

RESUMO

Leishmaniasis is a parasitosis caused by parasites of the genus Leishmania and is transmitted by Phlebotominae sand flies. An entomological survey was carried out in different localities of Zagora Province. Our work allowed us to establish an inventory of sand flies to study potential vectors of leishmaniasis and to compare the composition and the specific abundance of different endemic stations. The sand flies were collected using CDC miniature light traps during the month of July 2019 in the ten studied villages. The results indicate the presence of thirteen species, belonging to the genera Phlebotomus and Sergentomyia. Phlebotomus papatasi was the predominant species (46.65%) followed by Ph. alexandri (17%), Ph. longicuspis (11.55%), Ph. bergeroti (1.53%) and Ph. sergenti (1.27%). Phlebotomus kazeruni (0.03%) was rare, and only one female was captured in Ifred. Sergentomyia schwetzi (8.69%) was the most prevalent species in the Sergentomyia genus followed closely by Se. fallax (6.84%). Sergentomyia africana was present with a proportion of (3.86%) followed by Se. clydei (1.96%). Sergentomyia dreifussi (0.46%), Se. antennata (0.08%), and Se. minuta (0.08%) were very limited. Phlebotomus papatasi, Ph. alexandri, Ph. bergeroti, Ph. longicuspis, Ph. sergenti, Se. schwetzi, Se. clydei, and Se. fallax are constant species, being present at least in 50% of the stations (occurrence> 50%). Common species (25%-49%) were Se. minuta and Se. africana and rare species were Ph. kazeruni and Se. antennata with a very limited distribution (occurrence <12%). The greatest species richness was found in Ksar Mougni and Ifred with the occurrence of 11 species, but overall, it was high (>9 species) in most of the villages. The Shannon-Wiener index was high (H' > 1) in eight localities (Ksar Mougni, Tassaouante, Bleida, ZaouiteLeftah, Ifred, Timarighine, Ait Oulahyane, and Ait Ali Ouhassou). The high value of this index is in favor of the ZaouiteLeftah locality (Shannon-Wiener index = 1.679) which is explained by the presence of a stand dominated by Ph. papatasi. In order to avoid exposure to infections, a good epidemiological surveillance and vector with rodent control measures must be well maintained. Awareness campaigns are also required and must be conducted for better knowledge of the disease.


Assuntos
Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Feminino , Marrocos/epidemiologia , Insetos Vetores/parasitologia , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Phlebotomus/parasitologia
4.
Parasit Vectors ; 15(1): 355, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36199150

RESUMO

Phlebotomine sand flies are proven or suspected vectors of several pathogens of importance, including leishmaniasis, bartonellosis and sand fly fevers. Although sand flies have a worldwide distribution, there has been limited research published on sand flies and sand fly-borne pathogens throughout the Greater Mekong Sub-region (GMS). This review followed the PRISMA guidelines to determine the biodiversity and presence of phlebotomine sand flies and their associated pathogens in the GMS, specifically Cambodia, Thailand, the Lao People's Democratic Republic (Laos), Malaysia and Vietnam. A total of 1472 records were identified by searching electronic databases, scanning reference lists of articles and consulting experts in the field. After screening of title and abstracts, 178 records remained and were further screened for original data (n = 34), not having regional data (n = 14), duplication of data (n = 4), records not available (n = 4) and no language translation available (n = 2). A total of 120 studies were then included for full review, with 41 studies on sand fly-related disease in humans, 33 studies on sand fly-related disease in animals and 54 entomological studies focused on sand flies (5 papers contained data on > 1 category), with a majority of the overall data from Thailand. There were relatively few studies on each country, with the exception of Thailand, and the studies applied different methods to investigate sand flies and sand fly-borne diseases, impacting the ability to conduct meaningful meta-analysis. The findings suggest that leishmaniasis in humans and the presence of sand fly vectors have been reported across several GMS countries over the past 100 years, with local transmission in humans confirmed in Thailand and Vietnam. Additionally, local Mundinia species are likely transmitted by biting midges. Findings from this study provide a framework for future investigations to determine the geographic distribution and risk profiles of leishmaniasis and other associated sand fly-borne disease throughout the GMS. It is recommended that researchers expand surveillance efforts across the GMS, with an emphasis placed on entomological surveys, syndromic and asymptomatic monitoring in both humans and animals and molecular characterization of sand flies and sand fly-borne pathogens, particularly in the understudied countries of Cambodia, Vietnam and Laos.


Assuntos
Leishmania , Leishmaniose , Phlebotomus , Psychodidae , Animais , Humanos , Insetos Vetores , Leishmaniose/epidemiologia
5.
Viruses ; 14(10)2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36298764

RESUMO

Cases of sand fly-borne diseases in the Emilia-Romagna region, such as meningitis caused by Toscana virus and human leishmaniasis, are reported annually through dedicated surveillance systems. Sand flies are abundant in the hilly part of the region, while the lowland is unsuitable habitat for sand flies, which are found in lower numbers in this environment with respect to the hilly areas. In this study, we retrieved sand flies collected during entomological surveillance of the West Nile virus (from 2018 to 2021) to assess their abundance and screen them for the presence of pathogens. Over the four-year period, we collected 3022 sand flies, more than half in 2021. The most abundant sand fly species was Phlebotomus (Ph.) perfiliewi, followed by Ph. perniciosus; while more rarely sampled species were Ph. papatasi, Ph. mascittii and Sergentomyia minuta. Sand flies were collected from the end of May to the end of September. The pattern of distribution of the species is characterized by an abundant number of Ph. perfiliewi in the eastern part of the region, which then falls to almost none in the western part of the region, while Ph. perniciosus seems more uniformly distributed throughout. We tested more than 1500 female sand flies in 54 pools to detect phleboviruses and Leishmania species using different PCR protocols. Toscana virus and Leishmania infantum, both human pathogens, were detected in 5 pools and 7 pools, respectively. We also detected Fermo virus, a phlebovirus uncharacterized in terms of relevance to public health, in 4 pools. We recorded different sand fly abundance in different seasons in Emilia-Romagna. During the season more favorable for sand flies, we also detected pathogens transmitted by these insects. This finding implies a health risk linked to sand fly-borne pathogens in the surveyed area in lowland, despite being considered a less suitable habitat for sand flies with respect to the hilly areas.


Assuntos
Leishmania infantum , Phlebotomus , Phlebovirus , Psychodidae , Vírus da Febre do Flebótomo Napolitano , Animais , Feminino , Humanos , Phlebovirus/genética , Itália
6.
Biomed Res Int ; 2022: 4231978, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36312854

RESUMO

Phleboviruses transmitted by sandflies are among emerging public health threats. A novel Phlebovirus named Ntepes virus (NTPV) was recently described and found to infect humans from a wide geographic area in Kenya. However, the entomologic risk factors of this virus such as the potential vectors and the transmission cycles remain poorly defined. This study assessed the ability of the colonized sandfly Phlebotomus duboscqi to transmit NTPV and determined the bloodmeal host sources of field-collected sandflies from the area where NTPV was found in Baringo County, Kenya. Five-day old laboratory-reared P. duboscqi were orally challenged with an infectious dose of NTPV (≈106.0 pfu/ml) and incubated for up to 15 days postinfection. Individual sandflies were dissected into abdomens, legs, and salivary glands and screened for the virus infection by cell culture. Of the 205 virus-exposed sandflies, 19.5% developed non-disseminated infections in the midgut, with no evidence of virus dissemination or transmission in legs and salivary glands, respectively. The midgut infection rates decreased with increasing extrinsic incubation period (Spearman's correlation, ρ = -0.71). Blood-fed specimens analyzed by polymerase chain reaction (PCR) and sequencing of a region of the mitochondrial 12S rRNA, revealed almost exclusive feeding on humans (98%) represented by the sandflies Sergentomyia schwetzi, S. clydei, S. antennata, S. squamipleuris, S. africana, and Phlebotomus martini. One specimen of S. clydei had fed on cattle (2%). These findings suggest P. duboscqi is an incompetent laboratory vector of NTPV. The high human-feeding rate by diverse sandfly species increases the likelihood of human exposure to pathogens associated with these sandflies. Assessment of the susceptibility of Sergentomyia species to NTPV is recommended given their high human-feeding tendency.


Assuntos
Phlebotomus , Phlebovirus , Psychodidae , Humanos , Bovinos , Animais , Phlebovirus/genética , Quênia , Hábitos
7.
PLoS Negl Trop Dis ; 16(10): e0010347, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36264975

RESUMO

Leishmaniasis on the Indian subcontinent is thought to have an anthroponotic transmission cycle. There is no direct evidence that a mammalian host other than humans can be infected with Leishmania donovani and transmit infection to the sand fly vector. The aim of the present study was to evaluate the impact of sand fly feeding on other domestic species and provide clinical evidence regarding possible non-human reservoirs through experimental sand fly feeding on cows, water buffalo goats and rodents. We performed xenodiagnosis using colonized Phlebotomus argentipes sand flies to feed on animals residing in villages with active Leishmania transmission based on current human cases. Xenodiagnoses on mammals within the endemic area were performed and blood-fed flies were analyzed for the presence of Leishmania via qPCR 48hrs after feeding. Blood samples were also collected from these mammals for qPCR and serology. Although we found evidence of Leishmania infection within some domestic mammals, they were not infectious to vector sand flies. Monitoring infection in sand flies and non-human blood meal sources in endemic villages leads to scientific proof of exposure and parasitemia in resident mammals. Lack of infectiousness of these domestic mammals to vector sand flies indicates that they likely play no role, or a very limited role in Leishmania donovani transmission to people in Bihar. Therefore, a surveillance system in the peri-/post-elimination phase of visceral leishmaniasis (VL) must monitor absence of transmission. Continued surveillance of domestic mammals in outbreak villages is necessary to ensure that a non-human reservoir is not established, including domestic mammals not present in this study, specifically dogs.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Leishmaniose , Phlebotomus , Psychodidae , Feminino , Bovinos , Humanos , Cães , Animais , Leishmaniose Visceral/epidemiologia , Gado , Roedores
8.
Parasit Vectors ; 15(1): 377, 2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36261836

RESUMO

BACKGROUND: Leishmania parasites are deposited in the host through sand fly bites along with sand fly saliva. Therefore, salivary proteins are promising vaccine candidates for controlling leishmaniasis. Herein, two immunogenic salivary proteins, PpSP15 from Phlebotomus papatasi and PsSP9 from Phlebotomus sergenti, were selected as vaccine candidates to be delivered by live Leishmania tarentolae as vector. The stepwise in silico protocol advantaged in this study for multi-protein design in L. tarentolae is then described in detail. METHODS: All possible combinations of two salivary proteins, PpSP15 and PsSP9, with or without T2A peptide were designed at the mRNA and protein levels. Then, the best combination for the vaccine candidate was selected based on mRNA and protein stability along with peptide analysis. RESULTS: At the mRNA level, the most favored secondary structure was PpSP15-T2A-PsSP9. At the protein level, the refined three-dimensional models of all combinations were structurally valid; however, local quality estimation showed that the PpSp15-T2A-PsSP9 fusion had higher stability for each amino acid position, with low root-mean-square deviation (RMSD), compared with the original proteins. In silico evaluation confirmed the PpSP15-T2A-PsSP9 combination as a good Th1-polarizing candidate in terms of high IFN-γ production and low IL-10/TGF-ß ratio in response to three consecutive immunizations. Potential protein expression was then confirmed by Western blotting. CONCLUSIONS: The approach presented herein is among the first studies to have privileged protein homology modeling along with mRNA analysis for logical live vaccine design-coding multi-proteins.


Assuntos
Leishmania , Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Phlebotomus/parasitologia , Psychodidae/genética , Interleucina-10 , Leishmaniose Cutânea/parasitologia , Proteínas e Peptídeos Salivares/genética , Leishmania/genética , Vacinas Atenuadas , RNA Mensageiro/genética , Fator de Crescimento Transformador beta , Aminoácidos
9.
Acta Trop ; 236: 106680, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36087769

RESUMO

BACKGROUND: The search for attractive baits that may facilitate the capture of haematophagous insects has been epidemiologically relevant. Sand flies use chemical cues in different phases of their life cycles to find carbohydrate meals, mates, blood meals and oviposition sites. Few studies have related the behaviours of sand flies with volatile compounds that can influence their life cycles. Previous studies in our laboratory have shown that 1-hexanol released on filter paper is a good attractant for the sand fly Nyssomyia neivai, which is suspected in the transmission of the aetiologic agent of American cutaneous leishmaniasis. METHODS: In this study, we developed two release systems to modulated 1-hexanol release: system 1 contained gellan gum and pectin (4:1 ratio), 3% aluminium chloride and 1% glutaraldehyde; system 2 contained: gellan gum and pectin (4:1 ratio) and 3% aluminium chloride. After addition of 1-hexanol to each release system, trials were performed in a wind tunnel with Ny. neivai males and females (unfed, blood-fed and gravid) to evaluate activation and attraction responses. RESULTS: Males and unfed females showed the same response pattern to the systems. For both systems, the males and unfed females of the sand flies showed an activation response up to 24 h. The number of responsive gravid females was lower than unfed females for both systems. The blood-fed females showed no responses in any of the release systems. CONCLUSIONS: Our findings indicate that the state of the females (unfed, fed and gravid) can interfere with the sand fly responses to volatile compounds. Additionally, both systems evaluated with the compound showed effectiveness for sand fly attraction.


Assuntos
Phlebotomus , Psychodidae , Cloreto de Alumínio , Animais , Feminino , Glutaral , Hexanóis , Masculino , Pectinas , Psychodidae/fisiologia
10.
J Infect Dis ; 226(10): 1842-1851, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36052609

RESUMO

Incidence of visceral leishmaniasis (VL) in the Indian subcontinent (ISC) has declined by more than 95% since initiation of the elimination program in 2005. As the ISC transitions to the postelimination surveillance phase, an accurate measurement of human-vector contact is needed to assure long-term success. To develop this tool, we identified PagSP02 and PagSP06 from saliva of Phlebotomus argentipes, the vector of Leishmania donovani in the ISC, as immunodominant proteins in humans. We also established the absence of cross-reactivity with Phlebotomus papatasi saliva, the only other human-biting sand fly in the ISC. Importantly, by combining recombinant rPagSP02 and rPagSP06 we achieved greater antibody recognition and specificity than single salivary proteins. The receiver operating characteristics curve for rPagSP02 + rPagSP06 predicts exposure to Ph. argentipes bites with 90% specificity and 87% sensitivity compared to negative control sera (P >.0001). Overall, rPagSP02 + rPagSP06 provides an effective surveillance tool for monitoring vector control efforts after VL elimination.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Phlebotomus , Animais , Humanos , Leishmaniose Visceral/epidemiologia , Leishmania donovani/genética , Proteínas e Peptídeos Salivares , Biomarcadores , Índia/epidemiologia
11.
J Med Entomol ; 59(6): 2120-2129, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36130172

RESUMO

Northern Morocco is endemic for cutaneous and visceral leishmaniasis. Our entomological investigations aim to evaluate the risk of Leishmania transmission by determining the species composition, the density, and seasonal fluctuation of sand fly populations in endemic and nonendemic areas of leishmaniasis in Tetouan province (North-Western Morocco). Using Sticky-paper traps, 8,370 specimens were collected between May and November 2015 in two localities: peri-urban area of Tetouan city, where leishmaniasis is endemic and that of the Oued Laou village where no cases of leishmaniasis have been recorded. Six sand fly species were identified. The genus Phebotomus was represented by five species: Phlebotomus ariasi, Phlebotomus. longicuspis, Phlebotomus perniciosus, Phlebotomus kazeruni, and Phlebotomus sergenti, while the genus Sergentomyia was represented by only one species Sergentomyia minuta. Phlebotomus perniciosus was dominant in the nonendemic area (47%) while Phlebotomus sergenti was dominant in the endemic area (51%). The spatio-temporal distribution of sand fly populations is discussed according to biotic and abiotic variables. Seasonal fluctuation in sand fly density showed a bimodal pattern for the subgenus Larroussius and a unimodal pattern for the subgenus Paraphlebotomus in Tetouan city. But, in Oued Laou village, a unimodal density distribution for species of the Larroussius subgenus and a bimodal seasonal distribution for species of the subgenus Paraphlebotomus were identified. We affirm the coexistence, in the study area, of vectors of both cutaneous and visceral leishmaniasis, namely P. ariasi, P. longicuspis and P. perniciosus vectors of Leishmania infantum and P. sergenti vector of L. tropica. However, the geographic distribution, the specific abundance, and the activity reveal significant differences between endemic and nonendemic areas in the region.


Assuntos
Distribuição Animal , Leishmaniose Visceral , Phlebotomus , Animais , Leishmaniose Visceral/epidemiologia , Marrocos/epidemiologia , Estações do Ano
12.
Parasit Vectors ; 15(1): 327, 2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36123736

RESUMO

BACKGROUND: Most sand fly species are located in the Americas; some act as vectors of leishmaniasis and other human diseases. In Bolivia, about 25% of Neotropical species have been identified, and only a few have been implicated as vectors of cutaneous and visceral leishmaniasis. A new species of anthropophilic sand fly from the sub-Andean region of Alto Beni is described herein. METHODS: A large systematic entomological survey was carried out in a subtropical humid forest located in the Marimonos mountain range, at around 900 m altitude, in the municipality of Palos Blancos, Sud Yungas Province, Department of La Paz, Bolivia. Sand flies were captured over a period of 26 months between January 1982 and February 1984, at the ground and canopy level, using both CDC light traps and protected human bait. A total of 24,730 sand flies were collected on the ground, distributed in 16 species, and 3259 in the canopy, with eight species. One of these species was labeled as Pintomia (Pifanomyia) nevesi, although certain morphological features allowed us to doubt that it was that taxon. To define the identity of this sand fly, a re-evaluation (this work) was recently carried out through morphological analyses and measurements of the available specimens mounted on Euparal, previously labeled as Pi. (Pif.) nevesi. RESULTS: Based on the morphological traits and measurements, the re-evaluated specimens were definitively identified as a new sand fly species, Pintomyia (Pifanomyia) veintemillasi, closely related to Pi. (Pif.) nevesi and Pintomyia (Pifanomyia) maranonensis within the Evansi series. This new sand fly was the third most numerous anthropophilic species at the floor (6.2%) and the second most numerous anthropophilic at the canopy (35.1%). CONCLUSIONS: A new anthropophilic sand fly species is described as Pi. (Pif.) veintemillasi n. sp. This sand fly species was caught at about 900 m altitude in the Marimonos mountain range, a highly endemic area for cutaneous and mucosal leishmaniasis due to Leishmania (Viannia) braziliensis. Therefore, this species could be involved in the leishmaniasis transmission in the sub-Andean foothills of Alto Beni, Department of La Paz, Bolivia.


Assuntos
Leishmania braziliensis , Leishmaniose , Phlebotomus , Psychodidae , Animais , Bolívia , Humanos , Insetos Vetores , Psychodidae/anatomia & histologia , Inquéritos e Questionários
13.
PLoS Negl Trop Dis ; 16(9): e0010628, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36099245

RESUMO

BACKGROUND: Zoonotic cutaneous leishmaniasis (ZCL) is endemic in Palestine and transmitted by Phlebotomus sand flies. They inhabit dens of hyraxes, the reservoir animal. Control measures were implemented since 1996 but cases still occur. We estimated the effect of insecticide thermal fogging inside hyrax dens on sand fly density and leishmania infection. METHODOLOGY/PRINCIPAL FINDINGS: During July-September 2019, we conducted a 12-week controlled interrupted time series study in two control and one intervention sites containing three hyrax dens each. We implemented Permethrin thermal fogging in the intervention site at week 6. We measured weekly and 36hrs post-intervention sand fly abundance inside dens using CDC light traps. We performed Next-Generation Sequencing to identify sand fly Leishmania spp. infection. We calculated the abundance reduction (AR) using Mulla's formula and negative binomial regression. Among 11427 collected sand flies, 7339 (64%) were females and 1786 (16%) were Phlebotomus spp. comprising ten species; P. sergenti was the dominant (n = 773, 43%). We report P. arabicus (n = 6) for the first time in Palestine. After fogging, Phlebotomus spp. AR was 93% at 36hrs, 18% and 38% at two and five weeks respectively and 41% during the complete post-intervention period. In the regression models, Phlebotomus spp. density in the intervention site decreased by 74% (IRR: 0.26, 95%CI: 0.11-0.57) at two weeks, 34% (IRR: 0.66, 95%CI: 0.48-0.90) at five weeks and 74% (IRR: 0.26, 95%CI: 0.12-0.59) during the complete period. The density of Leishmania infected sand flies decreased by 65% (IRR: 0.35, 95%CI: 0.26-0.48) at five weeks and 82% (IRR: 0.18, 95%CI: 0.07-0.42) for the complete period (zero infections until week two). Leishmania infection prevalence in the intervention site was 14% pre-intervention and 3.9% post-intervention. CONCLUSIONS/SIGNIFICANCE: Fogging hyrax dens reduced sand fly abundance and leishmania infection during the 5-week post-intervention period and especially the first two weeks suggesting it could be an effective source-reduction measure for ZCL vectors. Future randomized controlled trials are needed to confirm the effectiveness of fogging hyrax dens on decreasing ZCL incidence.


Assuntos
Procaviídeos , Inseticidas , Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Feminino , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/prevenção & controle , Masculino , Estudos Prospectivos
14.
ScientificWorldJournal ; 2022: 9382154, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36132438

RESUMO

An entomological survey was carried out in the locality of Aichoune to conduct a study on sand flies, species composition, and monthly relative abundance. This study is essential for the implementation of integrated vector management control. Insects collection was carried out twice a month from January 2013 to December 2014 by means of adhesive and CDC-type light traps. A total of 5441 sand flies were collected with the predominance of males (a sex ratio = 1.89). The sampled specimens consist of seven species divided into two genera: Phlebotomus (99.55%) and Sergentomyia (0.44%). Phlebotomus sergenti was the dominant species with an average annual proportion of 47.38%, followed by P. perniciosus (37.32%), P. longicuspis (8,56%), P. papatasi (6.23%), and P. ariasi (0.05%). The genus Sergentomyia was less common (0.44%). S.minuta was represented only by 0.36% and S. fallax by 0.07%. The species dynamics showed a unimodal evolution for P. sergenti and P. papatasi. They were active from May to October. P. perniciosus presents a trimodal trend showing the most relevant peak in August. The highest number of specimens was collected in June, when the temperature reaches an annual average value of 25.5°C. The obtained results will help us better understand the leishmaniasis transmission dynamics in the Aichoune locality and will contribute to the design of a surveillance strategy.


Assuntos
Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Feminino , Leishmaniose Cutânea/epidemiologia , Masculino , Marrocos/epidemiologia , Temperatura
15.
J Med Entomol ; 59(6): 2170-2175, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-35980597

RESUMO

Visceral leishmaniasis is not endemic in West Africa, but prevalence of canine leishmaniasis and seroprevalence of Leishmania infantum infection in humans are high in the Mont Rolland community (Thiès region, Senegal). Previous studies in this area showed that Sergentomyia schwetzi could be the potential vector of Le. infantum. To precisely describe the biology and population structure of this potential vector, we identified eight novel microsatellite loci to characterize Se. schwetzi populations. We tested these loci in Se. schwetzi populations from five locations at Mont Rolland (Thiès, Senegal). All the loci were polymorphic, with a mean of 17.25 alleles (observed heterozygosity: 0.455). We did not detect any evidence of scoring errors due to stuttering and large allele dropout. Moreover, several of these loci were also amplified in six other sand fly species (Sergentomyia magna, Sergentomyia dubia, Sergentomyia minuta, Phlebotomus duboscqi, Phlebotomus perniciosus, and Phlebotomus ariasi). These preliminary results demonstrate the utility of these microsatellite markers for Se. schwetzi (and for the other sand fly species) population genetic studies.


Assuntos
Repetições de Microssatélites , Phlebotomus , Animais , Cães , Humanos , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Insetos Vetores/genética , Insetos Vetores/parasitologia , Leishmania infantum/genética , Leishmaniose , Phlebotomus/genética , Phlebotomus/parasitologia , Senegal/epidemiologia , Estudos Soroepidemiológicos
16.
PLoS Negl Trop Dis ; 16(8): e0010650, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35943980

RESUMO

The trypanosomatid protist Leishmania tarentolae is a saurian-associated parasite vectored by the Sergentomyia minuta sand fly. This study aimed to confirm the circulation of L. infantum and L. tarentolae in sand flies, reptiles and dogs and to isolate new strains of these protists. Reptilian and sheltered dog blood samples were collected, and sand flies were captured. Samples were tested for Leishmania spp. using duplex real-time PCR (dqPCR) and real-time PCR (qPCR); the origin of blood meal was identified in engorged sand flies by conventional PCR. The reptilian blood and intestinal content of sand fly females were cultured. Dog sera were tested by IFAT using both Leishmania species. Four Tarentola mauritanica geckoes were molecularly positive for L. infantum or L. tarentolae, with no co-infections; moreover, amastigote-like forms of L. infantum were observed in the bone marrow. 24/294 sand flies scored positive for Leishmania spp. by dqPCR, 21 S. minuta and two Phlebotomus perniciosus were positive for L. tarentolae, while only a single Ph. perniciosus was positive for L. infantum. Blood meal analysis confirmed reptile and dog in S. minuta, dog and human in Ph. perniciosus and dog in Phlebotomus neglectus. Two axenic strains of L. tarentolae were obtained. Twelve of 19 dogs scored positive for L. infantum and L. tarentolae by IFAT and three of them also for L. infantum by dqPCR, and six by qPCR. These data confirm the sympatric circulation of L. infantum and L. tarentolae in geckoes, sand flies, and dogs, and suggest that geckoes may be infected with L. infantum.


Assuntos
Leishmania infantum , Lagartos , Phlebotomus , Psychodidae , Animais , Cães , Feminino , Humanos , Leishmania infantum/genética , Phlebotomus/parasitologia , Reação em Cadeia da Polimerase , Psychodidae/parasitologia
17.
Acta Trop ; 235: 106628, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35952923

RESUMO

As land use intensifies in tropical forests, it is expected that species assemblages will be modified and that key functions of these ecosystems will be affected. The latter scenario is important from a public health perspective, because the land use change has been linked the outbreaks of vector-borne diseases. In this study, we evaluated the response of Phlebotominae (Diptera: Psychodidae) assemblages and their pattern of co-occurrence in four sites with different land use in an emerging cutaneous leishmaniasis focus in Yucatan, Mexico. Our hypothesis is that the conservation status (as forest cover) will positively influence the structure and composition of sand flies' assemblages. Using three different traps over a period of five months, a sampling effort of 1, 440 night-traps was performed. A total of 7, 897 sand fly specimens belonging to six genera and 10 species were collected. Our hypothesis was partially achieved since sand fly diversity increased as forest cover increased and vice versa, however random patterns of co-occurrence in assemblages were detected among sites. Even though the high abundance of sand flies in the forest fragment suggests an amplification effect, our results show that different vector species directly dominate in each site. We discuss the potential implications of the nestedness of species dominance. We suggest that in this emerging focus and under the land use gradient, Lutzomyia cruciata and Psathyromyia cratifer could play a pivotal role in maintaining the transmission cycles of Leishmania. The apparent generalist or colonialist profile of Lu. cruciata in disturbed areas deserves attention, due to the potential risk of leishmaniasis "domiciliation". This information is essential to understand the eco-epidemiology of leishmaniasis and the factors associated with its emergence in Yucatan, Mexico.


Assuntos
Leishmaniose Cutânea , Phlebotomus , Psychodidae , Animais , Ecossistema , Insetos Vetores , Leishmaniose Cutânea/epidemiologia , México/epidemiologia
18.
Emerg Microbes Infect ; 11(1): 2080-2092, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35916448

RESUMO

Phlebotomus chinensis sandfly is a neglected insect vector in China that is well-known for carrying Leishmania. Recent studies have expanded its pathogen repertoire with two novel arthropod-borne phleboviruses capable of infecting humans and animals. Despite these discoveries, our knowledge of the general pathogen diversity and overall microbiome composition of this vector species is still very limited. Here we carried out a meta-transcriptomics analysis that revealed the actively replicating/transcribing RNA viruses, DNA viruses, bacteria, and eukaryotic microbes, namely, the "total microbiome", of several sandfly populations in China. Strikingly, "microbiome" made up 1.8% of total non-ribosomal RNA and comprised more than 87 species, among which 70 were novel, including divergent members of the genera Flavivirus and of the family Trypanosomatidae. Importantly, among these microbes we were able to reveal four distinguished types of human and/or mammalian pathogens, including two phleboviruses (hedi and wuxiang viruses), one novel Spotted fever group rickettsia, as well as a member of Leishmania donovani complex, among which hedi virus and Leishmania each had > 50% pool prevalence rate and relatively high abundance levels. Our study also showed the ubiquitous presence of an endosymbiont, namely Wolbachia, although no anti-viral or anti-pathogen effects were detected based on our data. In summary, our results uncovered the much un-explored diversity of microbes harboured by sandflies in China and demonstrated that high pathogen diversity and abundance are currently present in multiple populations, implying disease potential for exposed local human population or domestic animals.


Assuntos
Phlebotomus , Phlebovirus , Psychodidae , Animais , Bactérias/genética , Eucariotos/genética , Humanos , Mamíferos , Phlebotomus/genética , Phlebovirus/genética , Psychodidae/genética , RNA , Análise de Sequência de RNA
19.
Parasit Vectors ; 15(1): 289, 2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-35953873

RESUMO

BACKGROUND: Species belonging to the subgenus Sauroleishmania are parasites of reptiles, and traditionally considered to be non-pathogenic to mammals. Knowledge of the development of these parasites in sand flies and their mechanism of transmission is currently lacking. The main aim of this study was to test the susceptibility of various sand fly species to infection by two Sauroleishmania species, focusing on the localization of parasites in the sand fly intestinal tract. METHODS: The development of Leishmania (Sauroleishmania [S.]) adleri and Leishmania (S.) hoogstraali was studied in six sand fly species (Phlebotomus orientalis, P. argentipes, P. sergenti, P. papatasi, P. duboscqi, Sergentomyia schwetzi). Sand flies were fed through a chick-skin membrane on blood containing Sauroleishmania promastigotes, and they were dissected at various time intervals post blood meal (PBM). Guts were examined microscopically for the presence of parasites, and the intensity and localizations of infections were recorded. Morphological forms of both Sauroleishmania species developing in P. orientalis were analyzed. Experimental infections of geckos using sand fly-derived promastigotes were also performed, and the reptiles were repeatedly examined for Sauroleishmania infection by xenodiagnosis and PCR analysis. RESULTS: High infection rates for both Sauroleishmania species were observed in P. orientalis and P. argentipes, with the parasites migrating anteriorly and undergoing a peripylarian type of development, including colonization of the stomodeal valve. Conversely, the development of L. (S.) adleri in P. sergenti, P. papatasi and Se. schwetzi was restricted to the sand fly hindgut (hypopylarian type of development). Five morphological forms were distinguished for both Sauroleishmania species developing in P. orientalis. All experimentally infected geckos scored negative for Sauroleishmania based on xenodiagnosis and molecular analysis. CONCLUSIONS: The results showed that Sauroleishmania promastigotes can undergo either a peripylarian or hypopylarian type of development in the sand fly intestinal tract, depending on the sand fly species infected. We demonstrated that P. argentipes and P. orientalis, two sand fly species known as permissive vectors for mammalian parasites of subgenus Leishmania, are also highly susceptible to Sauroleishmania as the parasites developed mature late-stage infections, including colonization of the sand fly stomodeal valve. Thus, the role of Phlebotomus sand flies in transmission of Sauroleishmania should be reconsidered and further investigated.


Assuntos
Leishmania , Lagartos , Phlebotomus , Psychodidae , Animais , Mamíferos , Phlebotomus/parasitologia , Psychodidae/parasitologia , Xenodiagnóstico
20.
J Nepal Health Res Counc ; 20(1): 194-201, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35945875

RESUMO

BACKGROUND: Visceral leishmaniasis is transmitted to humans by Leishmania donovani infected Phlebotomus argentipes sandflies. Nepal has successfully met the elimination target of less than 1 case per 10,000, although recently this threshold has been surpassed demonstrating ongoing transmission. The main objective of the present study was to investigate transmission of visceral leishmaniasis in 4 visceral leishmaniasis endemic districts of Nepal including Palpa, Morang, Saptari and Sarlahi. METHODS: Human blood samples (331), domestic animals blood samples [goats (n =67), dogs (n =1), cows (n = 6), buffaloes (n = 16), and ox (n = 10)] and sandflies samples (3976 from 142 households) were collected from the villages of these 4 districts. Human blood samples were tested for VL antibodies using the rK39 rapid diagnostic test (InBios International, Seattle, WA). kDNA of L.donovani was amplified by PCR from DNA extracted from human blood, animal blood and sandfly samples. RESULTS: Out of 331 screened across 4 districts,32 were positive on rK39 serology and 16 were positive by PCR amplification of kDNA from L. donovani. The majority of the positive serology and PCR tests were from the Ishworpur village in the Sarlahi district where there was an outbreak of 18 cases of VL. This study also revealed the presence of L. donovani DNA in female P. argentipes sandflies collected from the Ishworpur village of Sarlahi, 6 villages in the Saptari,10 villages in the Palpa, and from 9 villages in the Morang. Blood samples from domestic animals in the same villages were negative for kDNA detection by PCR. CONCLUSIONS: The results of human and sandfly findings strongly point towards local transmission of visceral leishmaniasis in these 4 districts of Nepal. Notably, there is a significant level of transmission in the Ishworpur village in the Sarlahi district. The observations from this study suggest that domestic animals are not a reservoir host for L. donovani in these districts in Nepal. Ongoing surveillance is needed to identify new outbreaks such as in the Sarlahi district.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Phlebotomus , Animais , Bovinos , DNA de Cinetoplasto , Cães , Feminino , Humanos , Leishmania donovani/genética , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Nepal/epidemiologia , Phlebotomus/genética
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