-
Archives of Razi Institute Aug 2023Cutaneous leishmaniasis (CL) is a vector-borne disease widely distributed in tropical and subtropical areas of North and South America, Europe, Asia, and Africa....
Cutaneous leishmaniasis (CL) is a vector-borne disease widely distributed in tropical and subtropical areas of North and South America, Europe, Asia, and Africa. Considering the increasing number of CL cases in recent years and the fact that no study has been conducted to identify CL fauna and vectors in Alborz province, this study was carried out to identify sand flies and CL vectors in this region. Sand flies were collected from August to October 2021 from plain and mountainous indoor and outdoor areas of the region using sticky paper traps and were detected morphologically. DNA was extracted from the midguts of female sand flies. In this study, 1157 sand flies were collected and identified. The number of sand flies caught from indoor and outdoor places was 367 (31.72%) and 790 (68.28%), respectively. Overall, six species of flies were of the genus (Raynal, 1937), including (, 695 [60.07%]; Scopoli, 1786), (13 [1.12%]; Shchurenkova, 1926), (232 [20.05%]; Parrot, 1917), (14 [1.21%]; Annandale, 1910), (4 [0.35%]; Marzinowsky, 1917), (18 [1.56%]; Alexandri Sinton, 1920), and four were of the genus (Artemiev, 1978), including (109 [9.42%]; Adler, Theodor & Lourie, 1930), (53 [4.58%]), (14 [1.21%]; Sintoni Pringle, 1933), (5 [0.43%]). spp. were dominant in indoor and outdoor places, with a prevalence of 695 (60.07%). The () gene was identified in five samples of spp. This suggests that is the potential vector spp. in the study area. Moreover, was confirmed as the aetiological agent of CL cases in Alborz province. The identification of vectors and parasite spp. is very important for the treatment and operational planning of disease vectors.
Topics: Female; Animals; Iran; Insect Vectors; Phlebotomus; Leishmaniasis, Cutaneous; Psychodidae; Leishmania major
PubMed: 38226373
DOI: 10.32592/ARI.2023.78.4.1277 -
Ticks and Tick-borne Diseases Jul 2018Tick cell lines are increasingly used in many fields of tick and tick-borne disease research. The Tick Cell Biobank was established in 2009 to facilitate the development... (Review)
Review
Tick cell lines are increasingly used in many fields of tick and tick-borne disease research. The Tick Cell Biobank was established in 2009 to facilitate the development and uptake of these unique and valuable resources. As well as serving as a repository for existing and new ixodid and argasid tick cell lines, the Tick Cell Biobank supplies cell lines and training in their maintenance to scientists worldwide and generates novel cultures from tick species not already represented in the collection. Now part of the Institute of Infection and Global Health at the University of Liverpool, the Tick Cell Biobank has embarked on a new phase of activity particularly targeted at research on problems caused by ticks, other arthropods and the diseases they transmit in less-developed, lower- and middle-income countries. We are carrying out genotypic and phenotypic characterisation of selected cell lines derived from tropical tick species. We continue to expand the culture collection, currently comprising 63 cell lines derived from 18 ixodid and argasid tick species and one each from the sand fly Lutzomyia longipalpis and the biting midge Culicoides sonorensis, and are actively engaging with collaborators to obtain starting material for primary cell cultures from other midge species, mites, tsetse flies and bees. Outposts of the Tick Cell Biobank will be set up in Malaysia, Kenya and Brazil to facilitate uptake and exploitation of cell lines and associated training by scientists in these and neighbouring countries. Thus the Tick Cell Biobank will continue to underpin many areas of global research into biology and control of ticks, other arthropods and vector-borne viral, bacterial and protozoan pathogens.
Topics: Animals; Arachnid Vectors; Arthropods; Biological Specimen Banks; Cell Line; Disease Vectors; In Vitro Techniques; Mites; Psychodidae; Research; Research Design; Tick-Borne Diseases; Ticks
PubMed: 29886187
DOI: 10.1016/j.ttbdis.2018.05.015 -
Parasites & Vectors Oct 2022Phlebotomine sand flies are proven or suspected vectors of several pathogens of importance, including leishmaniasis, bartonellosis and sand fly fevers. Although sand...
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.
Topics: Animals; Humans; Insect Vectors; Leishmania; Leishmaniasis; Phlebotomus; Psychodidae
PubMed: 36199150
DOI: 10.1186/s13071-022-05464-8 -
PLoS Neglected Tropical Diseases Aug 2016As Bangladesh, India and Nepal progress towards visceral leishmaniasis (VL) elimination, it is important to understand the role of asymptomatic Leishmania infection... (Review)
Review
BACKGROUND
As Bangladesh, India and Nepal progress towards visceral leishmaniasis (VL) elimination, it is important to understand the role of asymptomatic Leishmania infection (ALI), VL treatment relapse and post kala-azar dermal leishmaniasis (PKDL) in transmission.
METHODOLOGY/ PRINCIPAL FINDING
We reviewed evidence systematically on ALI, relapse and PKDL. We searched multiple databases to include studies on burden, risk factors, biomarkers, natural history, and infectiveness of ALI, PKDL and relapse. After screening 292 papers, 98 were included covering the years 1942 through 2016. ALI, PKDL and relapse studies lacked a reference standard and appropriate biomarker. The prevalence of ALI was 4-17-fold that of VL. The risk of ALI was higher in VL case contacts. Most infections remained asymptomatic or resolved spontaneously. The proportion of ALI that progressed to VL disease within a year was 1.5-23%, and was higher amongst those with high antibody titres. The natural history of PKDL showed variability; 3.8-28.6% had no past history of VL treatment. The infectiveness of PKDL was 32-53%. The risk of VL relapse was higher with HIV co-infection. Modelling studies predicted a range of scenarios. One model predicted VL elimination was unlikely in the long term with early diagnosis. Another model estimated that ALI contributed to 82% of the overall transmission, VL to 10% and PKDL to 8%. Another model predicted that VL cases were the main driver for transmission. Different models predicted VL elimination if the sandfly density was reduced by 67% by killing the sandfly or by 79% by reducing their breeding sites, or with 4-6y of optimal IRS or 10y of sub-optimal IRS and only in low endemic setting.
CONCLUSION/ SIGNIFICANCE
There is a need for xenodiagnostic and longitudinal studies to understand the potential of ALI and PKDL as reservoirs of infection.
Topics: Animals; Asymptomatic Infections; Bangladesh; Coinfection; Humans; India; Leishmania donovani; Leishmaniasis, Visceral; Nepal; Psychodidae; Recurrence; Risk Factors
PubMed: 27490264
DOI: 10.1371/journal.pntd.0004896 -
PLoS Neglected Tropical Diseases Apr 2023Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the...
Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites.
Topics: Animals; Humans; Phlebotomus; Psychodidae; Leishmania; Leishmaniasis, Cutaneous; Genomics
PubMed: 37043542
DOI: 10.1371/journal.pntd.0010862 -
Infectious Diseases of Poverty Feb 2016After the existence of phlebotomine sand flies was first reported in China in 1910, the distribution of different species and their role in the transmission of visceral... (Review)
Review
After the existence of phlebotomine sand flies was first reported in China in 1910, the distribution of different species and their role in the transmission of visceral leishmaniasis (VL) have been extensively studied. Up until 2008, four species have been verified as vectors of VL, namely, Phlebotomus chinensis (Ph. sichuanensis), Ph. longiductus (Ph. chinensis longiductus), Ph. wui (Ph. major wui), and Ph. alexandri. The sand fly species vary greatly depending on the natural environments in the different geographic areas where they are endemic. Ph. chinensis is euryecious and adaptable to different ecologies, and is thus distributed widely in the plain, mountainous, and Loess Plateau regions north of the Yangtze River. Ph. longiductus is mainly distributed in ancient oasis areas south of Mt. Tianshan in the Xinjiang Uygur autonomous region. Ph. wui is the predominant species in deserts with Populus diversifolia and Tamarix vegetation in Xinjiang and the western part of the Inner Mongolia autonomous region. Finally, Ph. alexandri is steroecious and found only in stony desert areas, such as at the foot of the mountains in Xinjiang and the western Hexi Corridor, in Gansu province. This review summarized the relationship between the geographic distribution pattern of the four sand fly species and their geographical landscape in order to foster research on disease distribution and sand fly control planning. Furthermore, some problems that remained to be solved about vectors of VL in China were discussed.
Topics: Animal Distribution; Animals; China; Humans; Insect Vectors; Leishmania; Leishmaniasis, Visceral; Psychodidae
PubMed: 26906187
DOI: 10.1186/s40249-016-0107-z -
PLoS Neglected Tropical Diseases May 2022Insect-vectored Leishmania are responsible for loss of more disability-adjusted life years than any parasite besides malaria. Elucidation of the environmental factors... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Insect-vectored Leishmania are responsible for loss of more disability-adjusted life years than any parasite besides malaria. Elucidation of the environmental factors that affect parasite transmission by vectors is essential to develop sustainable methods of parasite control that do not have off-target effects on beneficial insects or environmental health. Many phytochemicals that inhibit growth of sand fly-vectored Leishmania-which have been exhaustively studied in the search for phytochemical-based drugs-are abundant in nectars, which provide sugar-based meals to infected sand flies.
PRINCIPLE FINDINGS
In a quantitative meta-analysis, we compare inhibitory phytochemical concentrations for Leishmania to concentrations present in floral nectar and pollen. We show that nectar concentrations of several flowering plant species exceed those that inhibit growth of Leishmania cell cultures, suggesting an unexplored, landscape ecology-based approach to reduce Leishmania transmission.
SIGNIFICANCE
If nectar compounds are as effective against parasites in the sand fly gut as predicted from experiments in vitro, strategic planting of antiparasitic phytochemical-rich floral resources or phytochemically enriched baits could reduce Leishmania loads in vectors. Such interventions could provide an environmentally friendly complement to existing means of disease control.
Topics: Animals; Insect Vectors; Leishmania; Parasites; Phlebotomus; Phytochemicals; Plant Nectar; Psychodidae
PubMed: 35551517
DOI: 10.1371/journal.pntd.0010373 -
Turkiye Parazitolojii Dergisi Mar 2022Human and canine leishmaniasis (CanL) are endemic in Turkey, and cutaneous leishmaniasis (CL) is a primary public health problem among vector-borne diseases, with...
Fauna, Seasonal Activity, and Altitudinal Distribution of Phlebotomine Sand Flies (Diptera: Psychodidae) in Leishmaniasis Endemic Area, Aydın Mountains, and Surroundings in Western Turkey.
OBJECTIVE
Human and canine leishmaniasis (CanL) are endemic in Turkey, and cutaneous leishmaniasis (CL) is a primary public health problem among vector-borne diseases, with 1500-2000 autochthonous cases per year. In this study, we aimed to perform a comprehensive entomological survey, including the detection of sand fly fauna, seasonal activity, and altitudinal distribution, together with the ecological features of Aydın Mountains and their surroundings that are endemic areas for CL caused by and CanL caused by MON-1.
METHODS
The survey was carried out from June 2009 to July 2010. Ten localities with different altitudes were selected. Sand fly collection was done every 15 days in July and August when sand flies are most active and every 30 days between September and June (14 months, 16 samplings) using CDC light traps and sticky traps. During the collection, the temperature, humidity, and ecological and environmental features were recorded. Sand fly specimens were dissected and identified at species level using written keys.
RESULTS
A total of 6712 sand fly specimens (3268 females and 3444 males) were collected from 10 localities throughout all study periods. Species identification revealed that nine and three species belonging to ( s.l. 30.38%, 22.93%, 5.88%, s.l. 4.51%, 4.26%, 3.50%, 0.63%, 0.45%, and spp. 0.28%) and ( 23.17%, 2.43%, and 1.58%) were found, respectively. The seasonal activities of these 12 sand fly species were determined, and s.l. and , which were probable vectors of VL and CanL, were present in the study area. s.l., a probable vector of CL, was also found in the region and was active for seven months between April and October. s.l. was found in the 400-600 m altitude in July, while and were found in high densities in the 200-400 m altitude in September.
CONCLUSION
Our results showed that leishmaniasis vectors are present in different altitudes in the Aydın mountains and surroundings. The findings revealed the time intervals of parasite transmission in the area and the period of applying protective measures, such as insecticide application.
Topics: Animals; Dogs; Female; Humans; Insect Vectors; Leishmaniasis, Cutaneous; Leishmaniasis, Visceral; Male; Phlebotomus; Psychodidae; Seasons; Turkey
PubMed: 35232708
DOI: 10.4274/tpd.galenos.2022.35119 -
The American Journal of Tropical... Oct 2021In this pilot comparative study, we investigated and compared the effects of existing vector control tools on sandfly densities and mortality to inform and support the...
In this pilot comparative study, we investigated and compared the effects of existing vector control tools on sandfly densities and mortality to inform and support the National Kala-azar Elimination Program (NKEP). The interventions included insecticidal wall painting (IWP), reduced-coverage insecticidal durable wall lining (DWL), insecticide-impregnated bednets (ITN), and indoor residual spraying with deltamethrin (IRS). Sakhua union with seven villages was the study area, which was the most highly endemic visceral leishmaniasis union in Trishal upazila, Bangladesh. Each cluster containing the different interventions included approximately 50 households. Study methods included random selection of clusters, collection of sandfly by CDC light trap and manual aspirator to determine sandfly density, and sandfly mortality determined by WHO cone bioassay test. Trained field research assistants interviewed household heads using structured questionnaires for sociodemographic information, as well as safety and acceptability of the interventions. Descriptive and analytical statistical methods measured interventions' effect and its duration on sandfly density reduction and mortality. We measured the relative efficacy of IWP on sandfly control against DWL, ITN, and IRS by the difference-in-difference regression model. We found that existing interventions were effective and safe for sandfly control with different duration of effect and acceptability. The relative efficacy of IWP for sandfly reduction varied by -59% to -91%, -75% to -81%, and -30% to -104% compared with DWL, ITN, and IRS, respectively, at different time points during the 12-month follow-up. These study results will guide the NKEP for selection of sandfly control tool(s) in its subsequent consolidation and maintenance phases.
Topics: Animals; Bangladesh; Construction Materials; Housing; Insect Control; Insect Vectors; Insecticide-Treated Bednets; Insecticides; Leishmaniasis, Visceral; Nitriles; Phlebotomus; Pilot Projects; Psychodidae; Pyrethrins
PubMed: 34695792
DOI: 10.4269/ajtmh.20-0997 -
PLoS Neglected Tropical Diseases Jun 2023Leishmaniases are vector borne diseases caused by Leishmania spp. parasites transmitted by female sandflies (Diptera: Psychodidae) whose geographic distribution is...
BACKGROUND
Leishmaniases are vector borne diseases caused by Leishmania spp. parasites transmitted by female sandflies (Diptera: Psychodidae) whose geographic distribution is influenced by environmental factors. Among the main tools for studying the distribution of vector species, modeling techniques are used to analyze the influence of climatic and environmental factors on the distribution of these insects and their association with human cases of the disease.
METHODOLOGY/PRINCIPAL FINDINGS
Here, we used a multiscale ecological niche modeling approach to assess the environmental suitability of sandfly vectors of the etiological agents of Visceral (VL) and American Cutaneous Leishmaniasis (ACL) in Piauí state, northeastern Brazil, and then evaluated their relationship with human disease incidence. For this, we obtained the geographic coordinates of the vector species Lutzomyia longipalpis and Nyssomyia whitmani through literature review, online databases and unpublished records. These data were used for the development of predictive models of the distribution of both sandflies species based on climatic and environmental variables. Finally, the environmental suitability for the presence of these vectors was compared with the incidence of both the diseases at the municipality level. The final models for each sandfly species showed good predictive powers with performance metric values of 0.889 for Lu. longipalpis and 0.776 for Ny. whitmani. The areas with greater environmental suitability for the presence of these species were concentrated in the central-north region of Piauí and coincide with the location of those municipalities presenting higher incidences of VL and ACL, situated in the central-north and extreme north of the state, respectively. The south and southeast regions of Piauí state have low incidence of these diseases and presented low environmental suitability for the presence of both vectors.
CONCLUSIONS/SIGNIFICANCE
We discuss how predictive modeling can guide entomological and epidemiological surveillances and recommend an increased supervision and control activities in Teresina (capital of the state of Piaui), Altos and Pedro II, in addition to other municipalities with similar social and environmental characteristics.
Topics: Animals; Female; Humans; Incidence; Brazil; Insect Vectors; Leishmaniasis, Cutaneous; Psychodidae; Phlebotomus
PubMed: 37276231
DOI: 10.1371/journal.pntd.0011388