scholarly journals Leishmania infection and blood sources analysis in Phlebotomus chinensis (Diptera: Psychodidae) along extension region of the Loess Plateau, China

2020 ◽  
Author(s):  
Hanming Chen ◽  
Huiying Chen ◽  
Feng Tao ◽  
Jingpeng Gao ◽  
Kaili Li ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Rural Areas ◽  
Leishmania Donovani ◽  
Control Measures ◽  
Sand Fly ◽  
Leishmania Infection ◽  
Sand Flies ◽  
The Loess Plateau ◽  
Specific Antibodies ◽  
Asymptomatic Patients

Abstract Background Visceral leishmaniasis (VL) was one of the most important parasitic diseases in China, caused by Leishmania protozoans and transmitted by sand flies. Recently VL cases have reappeared in China, including the extension region of the Loess Plateau. The purpose of this study was to collect fundamental data on the host-vector VL system in the Loess Plateau to assist in the development of prevention and control measures.Methods Sand flies were collected by light traps from rural areas in Shanxian, Henan, China in 2015, as well as in Wuxiang and Yangquan, Shanxi, China in 2017. The blood sources of sand flies were analyzed by PCR detecting the host-specific mitochondrial cytochrome b (mtDNA Cyt b) gene fragments. Leishmania infection in sand flies was detected by amplifying and sequencing ribosomal DNA internal transcribed spacer 1 (ITS1). The Leishmania specific antibodies in the sera of local dogs were detected by ELISA kit. Results Blood sources showed diversity in the extension region of the Loess Plateau, including human, chicken, dog, cattle, pig and goat. Multiple blood sources within a sand fly were observed in samples from Yangquan (17/118, 14.4%) and Wuxiang (12/108, 11.1%). Leishmania DNA was detected in sand flies collected from Yangquan with minimum infection rate of 1.00%. The ITS1 sequences were conserved with the Leishmania donovani complex. The positive rate of Leishmania specific antibodies in dogs was 5.97%. Conclusions This study detected the blood sources and Leishmania parasites infection of sand flies by molecular methods in the extension region of Loess Plateau, China. A high epidemic risk of leishmaniasis is currently indicated by the results as the infection of Leishmania in sand flies, the extensive blood sources of sand flies including humans, and positive antibody of Leishmania in local dog sera. Given the recent increase of VL cases, asymptomatic patients, dogs and other potential infected animals should be screened and treated. Furthermore, the density of sand flies needs to be controlled and personal protection should be strengthened.

scholarly journals Investigation of Leishmania infection and blood sources analysis in Phlebotomus chinensis (Diptera: Psychodidae) along extension region of the Loess Plateau, China

2020 ◽  
Author(s):  
Hanming Chen ◽  
Huiying Chen ◽  
Feng Tao ◽  
Jingpeng Gao ◽  
Kaili Li ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Rural Areas ◽  
Control Measures ◽  
Sand Fly ◽  
Leishmania Infection ◽  
Sand Flies ◽  
The Loess Plateau ◽  
Specific Antibodies ◽  
Asymptomatic Patients ◽  
Mitochondrial Cytochrome B

Abstract Background Visceral leishmaniasis (VL) was one of the most important parasitic diseases in China, caused by Leishmania protozoans and transmitted by sand flies. Recently VL cases have reappeared in China, including the extension region of the Loess Plateau . The purpose of this study was trying to reveal the reason of reappearance to the developing the prevention and control measures. Methods Sand flies were collected by light traps from rural areas in Shanxian, Henan, China in 2015, as well as in Wuxiang and Yangquan, Shanxi, China in 2017. The blood sources of sand flies were analyzed by PCR detecting the host-specific mitochondrial cytochrome b (mtDNA Cyt b ) gene fragments. Leishmania infection in sand flies was detected by amplifying and sequencing ribosomal DNA internal transcribed spacer 1 ( ITS1 ). The Leishmania specific antibodies in the sera of local dogs were detected by ELISA kit. Results Blood sources showed diversity in the extension region of the Loess Plateau, including human, chicken, dog, cattle, pig and goat. Multiple blood sources within a sand fly were observed in samples from Yangquan (17/118, 14.4%) and Wuxiang (12/108, 11.1%). Leishmania DNA was detected in sand flies collected from Yangquan with minimum infection rate of 1.00%. The ITS1 sequences were conserved with the Leishmania donovani complex. The positive rate of Leishmania specific antibodies in dogs was 5.97%. Conclusion This study detected the blood sources and Leishmania parasites infection of sand flies by molecular methods in the extension region of Loess Plateau, China. A high epidemic risk of leishmaniasis is currently indicated by the results as the infection of Leishmania in sand flies, the extensive blood sources of sand flies including humans, and positive antibody of Leishmania in local dog sera. Given the recent increase of VL cases, asymptomatic patients, dogs and other potential infected animals should be screened and treated. Furthermore, the density of sand flies needs to be controlled and personal protection should be strengthened.

scholarly journals Investigation of Leishmania infection and blood sources analysis in Phlebotomus chinensis (Diptera: Psychodidae) along extension region of the Loess Plateau, China

2020 ◽  
Author(s):  
Hanming Chen ◽  
Huiying Chen ◽  
Feng Tao ◽  
Jingpeng Gao ◽  
Kaili Li ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Rural Areas ◽  
Leishmania Donovani ◽  
Control Measures ◽  
Leishmania Infection ◽  
The Loess Plateau ◽  
Specific Antibodies ◽  
Asymptomatic Patients ◽  
Positive Rate ◽  
Prevention And Control Measures

Abstract BackgroundVisceral leishmaniasis (VL) was one of the most important parasitic diseases in China, caused by Leishmania protozoans and transmitted by sandflies. Recently VL cases have reappeared in China, including the extension region of the Loess Plateau. The purpose of this study was to detect the infection rate of Leishmania and analyze the blood sources of the sandflies vectors to guide the development of prevention and control measures. MethodsSandflies were collected by light traps from rural areas in Shanxian, Henan, China in 2015, as well as in Wuxiang and Yangquan, Shanxi, China in 2017. The blood sources of sandflies were analyzed by PCR detecting the host-specific mitochondrial cytochrome b (mtDNA Cyt b) gene fragments. Leishmania infection in sandflies was detected by amplifying and sequencing ribosomal DNA internal transcribed spacer 1 (ITS1). The Leishmania specific antibodies in the sera of local dogs were detected by ELISA. ResultsBlood sources showed diversity in the extension region of the Loess Plateau, including human, chicken, dog, cattle, pig and goat. Multiple blood sources within a sandfly individual were observed in samples from Yangquan (17/118, 14.4%) and Wuxiang (12/108, 11.1%). Leishmania DNA was detected in sandflies collected from Yangquan, of which 8.5% pooled and 1.9% individual samples were positive. The ITS1 sequences were conserved with the Leishmania donovani complex. The positive rate of Leishmania specific antibodies in dogs was 5.97%. ConclusionThis study detected the blood sources and Leishmania parasites infection of sandflies by molecular methods in the extension region of Loess Plateau, China. A high epidemic risk of leishmaniasis is currently indicated by the results as the infection of Leishmania in sandflies, the extensive blood sources of sandflies including humans, and positive antibody of Leishmania in local dog sera. Given the recent increase of VL cases, asymptomatic patients, dogs and other potential infected animals should be screened and treated. Furthermore, the density of sandflies needs to be controlled and personal protection should be strengthened.

scholarly journals INVESTIGATION OF LEISHMANIASIS VECTORS IN EL-KADOBA VILLAGE, WHITE NILE STATE, SUDAN

2017 ◽  
Vol 5 (1) ◽  
pp. 430-441
Author(s):  
Belal Abdallah A. Adam ◽  
Moawia Mukhtar Hassan ◽  
Osman Mohammed Abd Elnour ◽  
Ahmed Hamid Awadallah
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Morphological Characters ◽  
Sand Fly ◽  
Leishmania Infection ◽  
Sand Flies ◽  
Kala Azar ◽  
Ecological Aspects ◽  
Binocular Microscope ◽  
White Nile

Visceral leishmaniasis (VL; kala-azar) is one of the most important parasitic tropical diseases in Sudan   and the Sudan is considered to be one of the most important foci in the world. The visceral leishmaniasis has been described in Sudan since the beginning of the twentieth century. In Sudan, VL is caused by Leishmania donovani complex: MON 18, MON 30 and MON 82 zymodemes and  The proven vector is Phlebotomus (Larroussius) orientalis, in this study a survey was carried out to identify the principal vector of VL based on Leishmania infection, morphological characters and to determine some ecological aspects of the sand flies prevalent in the area . Ten species of sand flies were recorded, three Phlebotomus species and seven Sergentomyia species of these sandflies, P. rodhaini was collected only from Acacia seyal/Balanities aegyptiaca at the Island whereas S. hunti was collected from the Acacia nilotica forest only of the total collections, P. orientalis representing 3.80% (248 specimens) of the total collection and P. papatasi were 3.11% of the collection. Sand flies identification was done under a binocular microscope at 40x (magnification). The main features used for sand flies identification were the sperm theca of the female, the termination of the male and the pharyngeal and the ciboria toothed structures of both sexes. According to results of this study we recommended the following:  more studies are needed in the future to determine the transmission season, and infection rates of Leishmania parasites in human and the animal host in this area. Annually Entomological surveys must be done to determine density of Sand fly Vectors and Encourage the use of personal protection tools (ITNs), repellents, and improving of houses to avoid bite of sand fly.

scholarly journals Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae): a review

2003 ◽  
Vol 75 (3) ◽  
pp. 301-330 ◽  
Author(s):  
Rodrigo P. P. Soares ◽  
Salvatore J. Turco
Keyword(s):  
Latin America ◽  
Rural Areas ◽  
New World ◽  
Control Measures ◽  
Sand Fly ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Recent Past ◽  
Leishmania Chagasi ◽  
Large Cities

Lutzomyia longipalpis is the most important vector of AmericanVisceral Leishmaniasis (AVL) due to Leishmania chagasi in the New World. Despite its importance, AVL, a disease primarily of rural areas, has increased its prevalence and became urbanized in some large cities in Brazil and other countries in Latin America. Although the disease is treatable, other control measures include elimination of infected dogs and the use of insecticides to kill the sand flies. A better understanding of vector biology could also account as one more tool for AVL control. A wide variety of papers about L. longipalpis have been published in the recent past years. This review summarizes our current information of this particular sand fly regarding its importance, biology, morphology, pheromones genetics, saliva, gut physiology and parasite interactions.

Entomological Studies in Itaúna, Brazil, an Area With Visceral Leishmaniasis Transmission: Fauna Survey, Natural Leishmania Infection, and Molecular Characterization of the Species Circulating in Phlebotomine Sand Flies (Diptera: Psychodidae)

2019 ◽  
Vol 56 (5) ◽  
pp. 1368-1376 ◽  
Author(s):  
Josiane V Lopes ◽  
Erika M Michalsky ◽  
Nathalia C L Pereira ◽  
Adão J V de Paula ◽  
Fabiana O Lara-Silva ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Natural Infection ◽  
Local Population ◽  
Influential Factor ◽  
Sand Fly ◽  
Health Concern ◽  
Leishmania Infection ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Phlebotomine Sand Flies

Abstract Among neglected tropical diseases, visceral leishmaniasis (VL) shows great relevance in global terms and is a serious public health concern due to the possibility of severe and lethal forms in humans. In this study, we evaluate entomological factors such as diversity and abundance of phlebotomine sand flies (Diptera:Psychodidae) and the Leishmania species circulating in these species in possible association with VL transmission in the Brazilian town Itaúna. The entomological collections were performed during three consecutive nights, always in the third week of each month, within a period of 12 mo. A total of 1,786 sand fly specimens were collected, from which 20% were collected inside houses. The influence of three local climatic variables (temperature, rainfall, relative humidity) on the population sizes of these insects was evaluated. Temperature was the most influential factor, with a significant positive correlation with the local population size of phlebotomine sand flies collected per month. Lutzomyia longipalpis (Lutz & Neiva, 1912) was the predominant species in the study area. Leishmania DNA was detected in nine out of 133 pools of sand fly females, using nested/PCR, which resulted in a minimal natural infection rate of 2.91%. DNA from Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatida), was detected in Evandromyia cortelezzii (Bréthes, 1923), Ev. evandroi (Costa, Lima & Antunes, 1936), Ev. lenti (Mangabeira, 1938), and Ev. termitophila (Martins, Falcão & Silva, 1964), besides Lu. longipalpis. Our study indicates favorable conditions for VL spreading in Itaúna due to the presence of Lu. longipalpis and Le. infantum-infected phlebotomine sand flies.

scholarly journals Morphological identification keys for adults of sand flies (Diptera: Psychodidae) in Sri Lanka

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Tharaka Wijerathna ◽  
Nayana Gunathilaka
Keyword(s):  
Sri Lanka ◽  
Species Abundance ◽  
Morphological Features ◽  
Control Measures ◽  
Sand Fly ◽  
Health Staff ◽  
Morphological Identification ◽  
Sand Flies ◽  
Identification Keys ◽  
Control Programmes

Abstract Background Phlebotomine sand flies are a medically important group of insects that is responsible for the transmission of leishmaniasis. Surveillance plays a major role in vector control programmes through exploring species abundance, potential entomological risk and designing appropriate control measures. In field surveillance programmes of such nature, morphological identification of vector species is of paramount importance. However, in Sri Lanka, there is no published taxonomic key available for the identification of leishmaniasis vectors. Method Identification keys for both male and females of the sand flies recorded in Sri Lanka were developed using morphological features. Main identification features were compared with the original observation of specimens collected from surveys and the use of published literature. Photographic illustrations of morphological features are included with the intention of making the keys user-friendly for non-taxonomists. Results A total of 22 sand fly species (Diptera: Psychodidae) of the genera Phlebotomus and Sergentomyia reported in Sri Lanka from 1910 to 2019 are included in the present work. Conclusion This simplified key, along with photographs taken from specimens would be beneficial to the health staff, entomologists and research staff who deal with leishmaniasis control programmes and vector-related studies.

scholarly journals Increased Transmissibility of Leishmania donovani From the Mammalian Host to Vector Sand Flies After Multiple Exposures to Sand Fly Bites

2017 ◽  
Vol 215 (8) ◽  
pp. 1285-1293 ◽  
Author(s):  
Joanna G. Valverde ◽  
Andrea Paun ◽  
Ehud Inbar ◽  
Audrey Romano ◽  
Michael Lewis ◽  
...  
Keyword(s):  
Leishmania Donovani ◽  
Sand Fly ◽  
Mammalian Host ◽  
Sand Flies ◽  
Multiple Exposures

scholarly journals Evaluation of molecular assays to detect Leishmania donovani in Phlebotomus argentipes fed on post-kala-azar dermal leishmaniasis patients

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Md Anik Ashfaq Khan ◽  
Khaledul Faisal ◽  
Rajashree Chowdhury ◽  
Rupen Nath ◽  
Prakash Ghosh ◽  
...  
Keyword(s):  
Leishmania Donovani ◽  
Control Strategies ◽  
Reference Method ◽  
Critical Factor ◽  
Sand Fly ◽  
Accurate Estimation ◽  
Limiting Factor ◽  
Sand Flies ◽  
Real Time Quantitative Pcr ◽  
Kala Azar

Abstract Background Post-kala-azar dermal leishmaniasis (PKDL) caused by Leishmania donovani (LD) is a skin disorder that often appears after treatment of visceral leishmaniasis (VL) patients. PKDL patients are potential reservoirs of LD parasites, which can initiate a new epidemic of anthroponotic VL. Therefore, host infectiousness to its sand fly vector is a critical factor for transmission, and its accurate estimation can facilitate control strategies. At present, conventional microscopy serves as the reference method to detect parasites in its vector. However, low sensitivity of microscopy can be a limiting factor. Methods In this study, real-time quantitative PCR (LD-qPCR) and recombinase polymerase amplification (LD-RPA) assays were evaluated against microscopy for the detection of LD DNA extracted from live sand flies five days after controlled feeding on PKDL cases. Results The sensitivity of LD-qPCR and LD-RPA assays were found to be 96.43 and 100%, respectively, against microscopy for the selected fed sand flies (n = 28), and an absolute specificity of both molecular tools for apparently unfed sand flies (n = 30). While the proportion of infectious cases among 47 PKDL patients was estimated as 46.81% as defined by microscopic detection of LD in at least one fed sand fly per case, LD-RPA assay evaluation of only the microscopy negative sand flies fed to those 47 PKDL cases estimated an even greater proportion of infectious cases (51.06%). In overall estimation of the infectious cases in retrospective manner, discordance in positivity rate was observed (p < 0.05) between LD-RPA (59.57%) assay and microscopy (46.81%), while LD-RPA had slightly better positivity rate than LD-qPCR (55.32%) as well. Conclusions Considering the sensitivity, cost, detection time, and field applicability, RPA assay can be considered as a promising single molecular detection tool for investigations pertaining to LD infections in sand flies and/or host infectiousness in PKDL, while it can also be useful in confirmation of microscopy negative sand fly samples. Graphical abstract

scholarly journals Notes on the sand fly fauna (Diptera: Psychodidae) in a region of Brazil

2021 ◽  
Vol 10 (14) ◽  
pp. e596101422480
Author(s):  
Paula Fassicolo Variza ◽  
Thiago Nunes Pereira ◽  
Joice Guilherme de Oliveira ◽  
Millena Fernandes ◽  
Daniel Moreira de Avelar ◽  
...  
Keyword(s):  
Urban Forest ◽  
Control Measures ◽  
Sand Fly ◽  
Sand Flies ◽  
Monitoring And Control ◽  
Santa Catarina ◽  
Leishmania Spp ◽  
The Tropics ◽  
And Control ◽  
First Time

The family Psychodidae has a cosmopolitan distribution with members that occur in many habitats, mainly in humid environments, and is most diverse in the tropics. Subfamilies Sycoracinae and Phlebotominae have females with hematophagous habits and the latter studied more due to medical and veterinary interest, since it includes species that can transmit diseases to animals and humans. The knowledge about the sand fly fauna in a region is extremely important for adequate monitoring and control measures for leishmaniasis. Thus, the objective of this study was to characterize Psychodidae fauna in relation to richness, abundance and molecular identification of Leishmania spp. in sand flies in southern Santa Catarina, Brazil. The ollections were carried out between 2015 and 2016 in three cities in Santa Catarina, Brazil. Samples were taken near feeding places for domestic animals, urban forest and peridomicile areas. The insects were identified and female sand flies were submitted to molecular analysis to detect the presence of Leishmania spp.. A total of 4,200 insects were collected, 4,193 from the Sycoracinae subfamily and 7 Phlebotominae from the Nyssomyia neivai and Pintomyia fisheri species. Of the studied municipalities, sandflies were registered in Tubarão and Imaruí and the most frequent habitat was the peridomicile areas. No samples were positive for Leishmania spp. In conclusion, the work highlights the presence of two species of sandflies, which were recorded for the first time in southern Santa Catarina.

scholarly journals Leishmania infection induces a limited differential gene expression in the sand fly midgut

2020 ◽  
Author(s):  
Iliano V. Coutinho-Abreu ◽  
Tiago D. Serafim ◽  
Claudio Meneses ◽  
Shaden Kamhawi ◽  
Fabiano Oliveira ◽  
...  
Keyword(s):  
Gene Expression ◽  
De Novo ◽  
Early Time ◽  
Differentially Expressed ◽  
Sand Fly ◽  
Leishmania Infection ◽  
Developmental Cycle ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Time Points

Abstract Background: Sand flies are the vectors of Leishmania parasites. To develop in the sand fly midgut, Leishmania multiplies and undergoes various stage differentiations giving rise to the infective form, the metacyclic promastigotes. To determine the changes in sand fly midgut gene expression caused by the presence of Leishmania, we performed RNA-Seq of uninfected and Leishmania infantum-infected Lutzomyia longipalpis midguts from seven different libraries corresponding to time points which cover the various Leishmania developmental stages. Results: The combined transcriptomes resulted in the de novo assembly of 13,841 sand fly midgut transcripts. Importantly, only 113 sand fly transcripts, about 1%, were differentially expressed in the presence of Leishmania parasites. Further, we observed distinct differentially expressed sand fly midgut transcripts corresponding to the presence of each of the various Leishmania stages suggesting that each parasite stage influences midgut gene expression in a specific manner. Two main patterns of sand fly gene expression modulation were noted. At early time points (days 1-4), more transcripts were down-regulated by Leishmania infection at large fold changes (> 32 fold). Among the down-regulated genes, the transcription factor Forkhead/HNF-3 and hormone degradation enzymes were differentially regulated on day 2 and appear to be the upstream regulators of nutrient transport, digestive enzymes, and peritrophic matrix proteins. Conversely, at later time points (days 6 onwards), most of the differentially expressed transcripts were up-regulated by Leishmania infection with small fold changes (< 32 fold). The molecular functions of these genes have been associated with the metabolism of lipids and detoxification of xenobiotics. Conclusion: Overall, our data suggest that the presence of Leishmania produces a limited change in the midgut transcript expression profile in sand flies. Further, Leishmania modulates sand fly gene expression early on in the developmental cycle in order to overcome the barriers imposed by the midgut, yet it behaves like a commensal at later time points where a massive number of parasites in the anterior midgut results only in modest changes in midgut gene expression.

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