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1.
Nat Commun ; 12(1): 215, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431825

RESUMO

Leishmaniasis is widely regarded as a vaccine-preventable disease, but the costs required to reach pivotal Phase 3 studies and uncertainty about which candidate vaccines should be progressed into human studies significantly limits progress in vaccine development for this neglected tropical disease. Controlled human infection models (CHIMs) provide a pathway for accelerating vaccine development and to more fully understand disease pathogenesis and correlates of protection. Here, we describe the isolation, characterization and GMP manufacture of a new clinical strain of Leishmania major. Two fresh strains of L. major from Israel were initially compared by genome sequencing, in vivo infectivity and drug sensitivity in mice, and development and transmission competence in sand flies, allowing one to be selected for GMP production. This study addresses a major roadblock in the development of vaccines for leishmaniasis, providing a key resource for CHIM studies of sand fly transmitted cutaneous leishmaniasis.


Assuntos
Leishmania major/fisiologia , Leishmaniose Cutânea/parasitologia , Animais , Modelos Animais de Doenças , Humanos , Insetos Vetores/parasitologia , Israel , Leishmania major/genética , Leishmania major/crescimento & desenvolvimento , Leishmaniose Cutânea/transmissão , Camundongos Endogâmicos BALB C , Parasitos/genética , Filogenia , Psychodidae/parasitologia , Sequenciamento Completo do Genoma
2.
Artigo em Inglês | MEDLINE | ID: mdl-33374115

RESUMO

Illegal waste disposal represents a risk health factor for vector-borne diseases by providing shelter for rodents and their ectoparasites. The presence of the Phlebotomus papatasi vector of Leishmania major, an etiologic agent of zoonotic cutaneous leishmaniasis (ZCL), was assessed at illegal waste sites located at the vicinity of villages in endemic areas of Central Tunisia. The study was performed over a two-year period over three nights from July to September 2017, and over three nights in September 2018. Household waste is deposited illegally forming dumpsites at the vicinity of each village and contains several rodent burrows of Psammomys obesus, the main reservoir host of L. major. Sandflies were collected from rodent burrows in the natural environment and in dumpsites using sticky traps and were identified at species level. Female sandflies were tested for the presence of L. major by PCR. Our entomological survey showed that Phlebotomus papatasi is the most abundant sandfly species associated with rodent burrows in these waste sites. The densities of P. papatasi in dumpsites are significantly higher compared to the natural environment. The minimum infection rate of P. papatasi with L. major in these illegal waste sites is not significantly different compared to the natural environment. Considering the short flight range of P. papatasi, increases in its densities, associated with burrows of P. obesus in illegal waste sites located at the edge of villages, expands the overlap of infected ZCL vectors with communities. Thus, illegal waste sites pose a high risk of spreading ZCL to neighboring home ranges. Waste management is an environmentally friendly method of controlling sandfly populations and should be included in an integrated management program for controlling ZCL in endemic countries.


Assuntos
Leishmaniose Cutânea/transmissão , Phlebotomus/parasitologia , Instalações de Eliminação de Resíduos , Animais , Feminino , Gerbillinae , Leishmania major , Leishmaniose Cutânea/epidemiologia , Masculino , Tunísia/epidemiologia
3.
Mem Inst Oswaldo Cruz ; 115: e200157, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33206821

RESUMO

BACKGROUND: In Acre state, Brazil, the dissemination of cutaneous leishmaniasis has increased in recent years, with limited knowledge of the potential Leishmania spp. vectors involved. OBJECTIVES: Here, data concerning the sandfly fauna of Brasiléia municipality, Leishmania DNA-detection rates and the identification of blood meal sources of insects captured in 2013-2015 are presented. METHODS: Parasite detection in female sandflies was performed individually by multiplex polymerase chain reaction (PCR) (Leishmania kDNA/sandfly cacophony-gene), with the identification of Leishmania spp. by hsp70-PCR and sequencing. The identification of blood gut-content from fed females was performed by cyt b-PCR and sequencing. FINDINGS: A total of 4,473 sandflies were captured. A subgroup of 864 non-blood-fed females evaluated for the presence of Leishmania DNA showed 2.9% positivity for Leishmania (Viannia) braziliensis and L. (V.) guyanensis. The identification of blood meal sources was performed in 96 blood-fed females, allowing the identification of 13 vertebrate species. In nine/96 fed females, DNA from L. (V.) shawi, L. (V.) guyanensis, L. (V.) braziliensis and Endotrypanum sp. was detected. MAIN CONCLUSIONS: In Brumptomyia sp. and Evandromyia termitophila, the first report of Leishmania DNA-detection is provided in Acre; Nyssomyia shawi is implicated as potential vector of L. (V.) braziliensis and L. (V.) guyanensis for the first time in Brazil.


Assuntos
DNA/análise , Insetos Vetores/genética , Leishmania/genética , Psychodidae/parasitologia , Animais , Brasil , DNA de Protozoário/análise , Feminino , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Leishmaniose Cutânea/transmissão , Reação em Cadeia da Polimerase , Psychodidae/classificação
4.
Am J Trop Med Hyg ; 103(5): 1934-1937, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32901597

RESUMO

The period between the infective sandfly bites and appearance of cutaneous leishmaniasis (CL) lesions is still hypothetical and little studied. This work aimed at assessing the incubation time of zoonotic CL (ZCL) due to Leishmania major using a standardized methodology. The retrospective analysis used the epidemiological, clinical, and biological information available in the database recording all the CL cases diagnosed at the Parasitology Department of the Pasteur Institute of Tunis during 2015-2019. It allowed for the selection of 92 privileged observations 1) of confirmed CL cases with presentation suggestive of ZCL form 2) living in northern regions free of ZCL 3) with a single infective trip of less than a week to ZCL foci during transmission season and 4) with accurate dates of travel and onset of lesions. Incubation length computed in this population ranged from 1 to 21 weeks, with a median of 5 weeks (interquartile range: 3-8.5 weeks).


Assuntos
Período de Incubação de Doenças Infecciosas , Leishmania major/fisiologia , Leishmaniose Cutânea/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Feminino , Geografia , Humanos , Lactente , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/transmissão , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tunísia/epidemiologia , Adulto Jovem , Zoonoses
5.
Korean J Parasitol ; 58(3): 229-236, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32615736

RESUMO

Cutaneous leishmaniosis (CL) is the most common form of leishmaniasis.CL caused by L. major and L. tropica is endemic in 17 provinces of Iran. This study was carried out to elucidate situation of CL in Ardabil province and to predict distribution of Phlebotomus papatasi and Phlebotomus sergenti (Diptera: Psychodidae) as vectors of CL in the region. In this cross-sectional study, data on CL patients were collected from local health centers of Ardabil province, Iran during 2006-2018 to establish a geodatabase using ArcGIS10.3. A total of 20 CL cases were selected randomly and skin samples were collected and analyzed by PCR method. MaxEnt 3.3.3 model was used to determine ecologically suitable niches for the main vectors. A total, 309 CL human cases were reported and the highest incidence rate of disease was occurred in Bilasavar (37/100,000) and Germi (35/100,000). A total of 2,794 sand flies were collected during May to October 2018. The environmentally suitable habitats for P. papatasi and P. sergenti were predicted to be present in northern and central areas of Ardabil province. The most variable that contributed ratio in the modeling were Isothermality and slope factors. Ardabil province is possibly an endemic are for CL. The presence of P. papatasi and P. sergenti justifies local transmission while the vectors of CL are existing in the northern and central areas of the province.


Assuntos
Insetos Vetores , Leishmaniose Cutânea/epidemiologia , Phlebotomus , Animais , Estudos Transversais , Ecossistema , Feminino , Humanos , Incidência , Irã (Geográfico)/epidemiologia , Leishmaniose Cutânea/transmissão , Masculino , Fatores de Tempo
6.
PLoS Negl Trop Dis ; 14(4): e0008149, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32251455

RESUMO

BACKGROUND: Individual behavior, particularly choices about prevention, plays a key role in infection transmission of vector-borne diseases (VBDs). Since the actual risk of infection is often uncertain, individual behavior is influenced by the perceived risk. A low risk perception is likely to diminish the use of preventive measures (behavior). If risk perception is a good indicator of the actual risk, then it has important implications in a context of disease elimination. However, more research is needed to improve our understanding of the role of human behavior in disease transmission. The objective of this study is to explore whether preventive behavior is responsive to risk perception, taking into account the links with disease knowledge and controlling for individuals' socioeconomic and demographic characteristics. More specifically, the study focuses on malaria, dengue fever, Zika and cutaneous leishmaniasis (CL), using primary data collected in Guyana-a key country for the control and/or elimination of VBDs, given its geographic location. METHODS AND FINDINGS: The data were collected between August and December 2017 in four regions of the country. Questions on disease knowledge, risk perception and self-reported use of preventive measures were asked to each participant for the four diseases. A structural equation model was estimated. It focused on data collected from private households only in order to control for individuals' socioeconomic and demographic characteristics, which led to a sample size of 497 participants. The findings showed evidence of a bidirectional association between risk perception and behavior. A one-unit increase in risk perception translated into a 0.53 unit increase in self-reported preventive behavior for all diseases, while a one-unit increase in self-reported preventive behavior (i.e. the use of an additional measure) led to a 0.46 unit decrease in risk perception for all diseases (except CL). This study also showed that higher education significantly improves knowledge and that better knowledge increases the take up of preventive measures for malaria and dengue, without affecting risk perception. CONCLUSIONS: In trying to reach elimination, it appears crucial to promote awareness of the risks and facilitate access to preventive measures, so that lower risk perception does not translate into lower preventive behavior.


Assuntos
Comportamento , Conhecimentos, Atitudes e Prática em Saúde , Doenças Transmitidas por Vetores/prevenção & controle , Doenças Transmitidas por Vetores/transmissão , Demografia , Dengue/prevenção & controle , Dengue/transmissão , Características da Família , Feminino , Guiana , Humanos , Leishmaniose Cutânea/prevenção & controle , Leishmaniose Cutânea/transmissão , Malária/prevenção & controle , Malária/transmissão , Masculino , Fatores de Risco , Autorrelato , Fatores Socioeconômicos , Inquéritos e Questionários , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/transmissão
7.
PLoS Negl Trop Dis ; 14(3): e0007947, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32196501

RESUMO

BACKGROUND: Cutaneous leishmaniasis (CL) is a major public health concern in Ethiopia. However, knowledge about the complex zoonotic transmission cycle is limited, hampering implementation of control strategies. We explored the feeding behavior and activity of the vector (Phlebotomus pedifer) and studied the role of livestock in CL transmission in southwestern Ethiopia. METHODS: Blood meal origins of engorged sand flies were determined by sequencing host DNA. A host choice experiment was performed to assess the feeding preference of P. pedifer when humans and hyraxes are equally accessible. Ear and nose biopsies from livestock were screened for the presence of Leishmania parasites. Sand flies were captured indoor and outdoor with human landing catches and CDC light traps to determine at which time and where P. pedifer is mostly active. PRINCIPAL FINDINGS: A total of 180 P. pedifer sand flies were found to bite hosts of 12 genera. Humans were the predominant blood meal source indoors (65.9%, p < 0.001), while no significant differences were determined outdoors and in caves. In caves, hyraxes were represented in blood meals equally as humans (45.5% and 42.4%, respectively), but the host choice experiment revealed that sand flies have a significant preference for feeding on hyraxes (p = 0.009). Only a single goat nose biopsy from 412 animal samples was found with Leishmania RNA. We found that P. pedifer is predominantly endophagic (p = 0.003), but occurs both indoors and outdoors. A substantial number of sand flies was active in the early evening, which increased over time reaching its maximum around midnight. CONCLUSION: In contrast to earlier suggestions of exclusive zoonotic Leishmania transmission, we propose that there is also human-to-human transmission of CL in southwestern Ethiopia. Livestock does not play a role in CL transmission and combined indoor and outdoor vector control measures at night are required for efficient vector control.


Assuntos
Reservatórios de Doenças/parasitologia , Comportamento Alimentar , Leishmania/isolamento & purificação , Gado/parasitologia , Phlebotomus/fisiologia , Phlebotomus/parasitologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Transmissão de Doença Infecciosa , Etiópia , Feminino , Humanos , Leishmaniose Cutânea/transmissão , Masculino , Pessoa de Meia-Idade , Adulto Jovem
8.
Am J Trop Med Hyg ; 102(4): 768-776, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32043444

RESUMO

After the first autochthonous case of cutaneous leishmaniasis was reported in the Atlántico department in the Caribbean region of Colombia, entomological sampling was conducted in the specific areas where the infection might have occurred. CDC traps were installed inside and outside dwellings in the peri-urban and rural areas of a settlement in the municipality of Luruaco. Sampling was performed during the night with protected human bait, and phlebotomine sand flies were actively sampled from potential diurnal resting sites within dwellings. Ten species of the genus Lutzomyia were identified; Lutzomyia evansi was the dominant species (78%) in the rural and peri-urban areas as well as in the different sampled habitats, followed by Lutzomyia panamensis and Lutzomyia gomezi. There was a 100% household infestation by Lu. evansi, and its indoor mean abundance was 13.3 sand flies/CDC trap/night. The indoor mean abundance of Lu. panamensis and Lu. gomezi was only 0.9 and 0.8 sand flies/CDC trap/night, respectively. Female Lu. evansi were collected with protected human bait, mostly in the peridomestic area, with sustained activity during the night and a slight increase in the activity from 19:00 to 23:00 hours. Of the total sand flies captured in the diurnal resting sites, 73.1% were collected from the walls of bedrooms and corresponded to Lu. evansi, Lutzomyia cayennensis cayennensis, and Lutzomyia trinidadensis. Owing to their vectorial importance, the species on which entomological surveillance should be focused are Lu. evansi, Lu. panamensis, and Lu. gomezi. The biting and resting behavior reported in this study will help guide vector prevention and the control of leishmaniasis within the study area.


Assuntos
Comportamento Animal/fisiologia , Insetos Vetores/fisiologia , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/transmissão , Psychodidae/fisiologia , Animais , Colômbia/epidemiologia , Ecossistema , Feminino , Humanos , Masculino
9.
BMC Infect Dis ; 20(1): 163, 2020 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-32087701

RESUMO

BACKGROUND: American tegumentary leishmaniasis (ATL) is a widespread anthropozoonosis caused by protozoa of the genus Leishmania and is considered a serious public health problem. The aim of this study was to provide a descriptive analysis of confirmed ATL cases and evaluate the spatial distribution of ATL in high-risk transmission areas from the state of Minas Gerais, Brazil. METHODS: An ecological, analytical, and retrospective study of the confirmed cases of ATL in Minas Gerais from 2007 to 2017 was conducted. To characterize these cases, multiple correspondence analysis and georeferencing of the ATL prevalence rates in the municipalities were conducted based on variables obtained at Sistema Nacional de Agravos de Notificação and Instituto Brasileiro de Geografia e Estatística databases. RESULTS: There were 13,025 confirmed cases of ATL from 74.4% (635) municipalities of Minas Gerais, corresponding to a prevalence rate of 66.5 cases for every 100,000 inhabitants. Males aged 20 to 59 years and individuals who attended elementary school were most affected with ATL. Multiple correspondence analysis presented an accumulated qui-squared value of 44.74%, proving that there was a relationship between the variables, including ethnicity, age, pregnancy status, zone of infection, and number of cases. CONCLUSION: We confirmed that ATL is endemic to Minas Gerais, and there is high risk of infection within the municipalities due to a high rate of parasite transmission. The occurrence of infection in children, pregnant women, and the indigenous population demonstrates the need for the government to expand social policies aimed at vulnerable groups.


Assuntos
Leishmania/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/transmissão , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Cidades/epidemiologia , Doenças Endêmicas , Feminino , Humanos , Lactente , Leishmania/genética , Leishmania/imunologia , Leishmaniose Cutânea/parasitologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gravidez , Prevalência , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
10.
Acta Trop ; 204: 105332, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31926144

RESUMO

Urbanization may influence the transmission of leishmaniasis, which is as a serious public health issue in Palestine. Semi urban environments can provide suitable habitats for the reservoir host species and the vector sand flies to create favorable condition for disease transmission. This study was aimed to evaluating the effect of distance from hyrax (reservoir host) colonies on sand fly (vector) abundance and its relationship to Leishmania infection within a semi urban landscape. In the Aleskan neighborhood the town of Tubas, sand flies were collected in July and September of 2016. Five trapping transects were set running from a rocky area containing hyrax dwelling habitats into an area of inhabited houses. 1051 Phlebotomus sand flies from 9 species were captured. The numbers of Phlebotomus sergenti, the vector species, correlated negatively with the distance from hyrax. Infected, blood engorged female sand flies were captured closer to hyrax colonies than infected, non-fed females. The risk of disease transmission to humans increased with a high density of reservoirs, closer proximity of reservoir hosts, and high densities of sand flies near houses. These results must be taken into account when implementing future interventions to reduce CL in urban environments.


Assuntos
Reservatórios de Doenças , Leishmania tropica , Leishmaniose Cutânea/transmissão , Phlebotomus , Animais , Ecologia , Feminino , Humanos , Leishmaniose Cutânea/epidemiologia , Masculino , Densidade Demográfica , Urbanização
11.
PLoS One ; 15(1): e0227697, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31971945

RESUMO

BACKGROUND: Cutaneous leishmaniasis is a neglected disease known to cause significant morbidity among the poor. We investigated a suspected outbreak to determine the magnitude of cases, characterize the cases and identify risk factors of cutaneous leishmaniasis in Gilgil, a peri-urban settlement in Central Kenya. METHODS: Hospital records for the period 2010-2016 were reviewed and additional cases were identified through active case search. Clinical diagnosis of cutaneous leishmaniasis was made based on presence of ulcerative, nodular or papular skin lesion. The study enrolled 58 cases matched by age and neighbourhood to 116 controls in a case control study. Data was collected using structured questionnaires and simple proportions, means and medians were computed, and logistic regression models were constructed for analysis of individual, indoor and outdoor risk factors. RESULTS: Of the 255 suspected cases of cutaneous leishmaniasis identified, females constituted 56% (142/255) and the median age was 7 years (IQR 7-21). Cases occurred in clusters and up to 43% of cases originated from Gitare (73/255) and Kambi-Turkana (36/255) villages. A continuous transmission pattern was depicted throughout the period under review. Individual risk factors included staying outside the residence in the evening after sunset (OR 4.1, CI 1.2-16.2) and visiting forests (OR 4.56, CI 2.04-10.22). Sharing residence with a case (OR 14.4, CI 3.8-79.3), residing in a thatched house (OR 7.9, CI 1.9-45.7) and cracked walls (OR 2.3, CI 1.0-4.9) were identified among indoor factors while sighting rock hyraxes near residence (OR 5.3, CI 2.2-12.7), residing near a forest (OR 7.8, CI 2.8-26.4) and having a close neighbour with cutaneous leishmaniasis (OR 6.8, CI 2.8-16.0) were identified among outdoor factors. CONCLUSIONS: We identify a large burden of cutaneous leishmaniasis in Gilgil with evidence of individual, indoor and outdoor factors of disease spread. The role of environmental factors and rodents in disease transmission should be investigated further.


Assuntos
Leishmaniose Cutânea/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos de Casos e Controles , Criança , Pré-Escolar , Vetores de Doenças , Feminino , Habitação , Humanos , Quênia/epidemiologia , Leishmaniose Cutânea/transmissão , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Doenças Negligenciadas/epidemiologia , Características de Residência , Fatores de Risco , População Urbana , Adulto Jovem
12.
Parasitol Res ; 119(2): 365-384, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31897789

RESUMO

We performed a systematic review of the literature published since 1900 about leishmaniasis a neglected vector-borne disease, focused on environmental and social risk factors for visceral (VL) and cutaneous leishmaniasis (CL) to better understand their impact on the incidence of disease. The search terms were "leishmaniasis" AND "risk factors" using Google Scholar, PudMed, and Scielo. We reviewed 177 articles, 95 studies for VL, 75 for CL, and 7 on both forms. We identified 14 categories of risk factors which were divided into three groups: socioeconomic (7), environmental (5), and climate (2) variables. Socioeconomic factors were also associated with disease incidence in vulnerable human populations of arid and tropical developing regions. Environmental and climate factors showed significant associations with the incidence of VL and CL in all the studies that considered them. Proximity to natural vegetation remnants increased disease risk in both the New and Old World while the climate conditions favorable for disease transmission differed among regions. We propose a common conceptual framework for both clinical forms that highlights networks of interaction among risk factors. In both clinical forms, the interplay of these factors played a major role in disease incidence. Although there are similarities in environmental and socioeconomic conditions that mediate the transmission cycle of tropical, arid, and Mediterranean regions, the behavior of vector and reservoirs in each region is different. Special attention should be given to the possibility of vector adaptation to urban environments in developing countries where populations with low socioeconomic status are particularly vulnerable to the disease.


Assuntos
Clima , Meio Ambiente , Leishmaniose Cutânea/epidemiologia , Leishmaniose Visceral/epidemiologia , Fatores Socioeconômicos , Animais , Vetores de Doenças , Humanos , Incidência , Leishmaniose Cutânea/transmissão , Leishmaniose Visceral/transmissão , Fatores de Risco
13.
PLoS Negl Trop Dis ; 14(1): e0007939, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31899767

RESUMO

Cutaneous leishmaniasisis a vector-borne disease transmitted by Leishmania infected sand flies. PpSP15 is an immunogenic salivary protein from the sand fly Phlebotomus papatasi. Immunization with PpSP15 was shown to protect against Leishmania major infection. Lactococcus lactis is a safe non-pathogenic delivery system that can be used to express antigens in situ. Here, the codon-optimized Ppsp15-egfp gene was cloned in pNZ8121 vector downstream of the PrtP signal peptide that is responsible for expression and secretion of the protein on the cell wall. Expression of PpSP15-EGFP recombinant protein was monitored by immunofluorescence, flow cytometry and Western blot. Also, expression of protein in cell wall compartment was verified using whole cell ELISA, Western blot and TEM microscopy. BALB/c mice were immunized three times with recombinant L. lactis-PpSP15-EGFPcwa, and the immune responses were followed up, at short-term (ST, 2 weeks) and long-term (LT, 6 months) periods. BALB/c mice were challenged with L. major plus P. papatasi Salivary Gland Homogenate. Evaluation of footpad thickness and parasite burden showed a delay in the development of the disease and significantly decreased parasite numbers in PpSP15 vaccinated animals as compared to control group. In addition, immunized mice showed Th1 type immune responses. Importantly, immunization with L. lactis-PpSP15-EGFPcwa stimulated the long-term memory in mice which lasted for at least 6 months.


Assuntos
Lactococcus lactis/metabolismo , Leishmania major , Proteínas e Peptídeos Salivares/metabolismo , Animais , Feminino , Proteínas de Insetos/imunologia , Lactococcus lactis/genética , Leishmaniose Cutânea/transmissão , Camundongos Endogâmicos BALB C , Phlebotomus/genética , Proteínas Recombinantes/imunologia , Proteínas e Peptídeos Salivares/genética
14.
J Med Entomol ; 57(1): 281-288, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31550368

RESUMO

In urban ecotourism parks, the life cycle of American cutaneous leishmaniasis (ACL) agents can remain established, where phlebotomines may comprise potential risks for visitors. The present study aimed to survey the phlebotomine fauna of a forest park 'Bosque Rodriques Alves-Jardim Botânico da Amazônia' (BRAJBA), in the urban area of Belém, Brazil. The park was monthly surveyed in 2018 using CDC light traps placed in ground and canopy strata. Leishmania spp. isolated from dissected females were characterized by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP) analysis. Fluctuations in specimen capture were correlated with rainfall. Nyssomyia antunesi (Coutinho, 1939) was predominant for all surveyed ecotopes and capture methods in both areas. Females of Ny. antunesi resting on tree bases were observed attempting to bite researchers during early morning. One Bichromomyia flaviscutellata (Mangabeira, 1942) and one Trichophoromyia brachipyga (Mangabeira, 1942) were found naturally infected by flagellates. Only the strain from Th. brachipyga was isolated and characterized as Leishmania (Viannia) lainsoni Silveira, Shaw, Braga and Ishikawa, 1987. Monthly fluctuations of the three most abundant species, Ny. antunesi, Trichophoromyia ubiquitalis (Mangabeira, 1942) and Th. brachypiga, had statistically significant negative correlations with rainfall. The present study provided further information to better understand ACL ecology in the Belém urban area, where the urban parks surveyed appeared to offer potential risk of contracting the disease, thus requiring environmental management. These observations highlighted the need for including Ny. antunesi, Bi. flaviscutellata, Th. ubiquitalis, and Th. brachypiga in the priority list for continuous entomological surveillance.


Assuntos
Leishmania/isolamento & purificação , Leishmaniose Cutânea/transmissão , Psychodidae/fisiologia , Animais , Brasil , Cidades , Insetos Vetores/parasitologia , Insetos Vetores/fisiologia , Parques Recreativos , Psychodidae/parasitologia , Especificidade da Espécie
15.
Acta Trop ; 202: 105224, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629825

RESUMO

Phlebotomines are important vectors of bacteria, viruses and protozoan parasites. Protozoans of the genus Leishmania which cause visceral and cutaneous leishmaniases, are among the most important etiologic agents transmitted by sand flies. Different blends of human and animal volatiles have been evaluated for use in surveillance and/or control of hematophagous insects. With regard to phlebotomine sand flies there are few records of attraction under laboratory and field conditions. This study was carried out at two collecting sites located in a Brazilian town with a high prevalence of cutaneous leishmaniasis. The aim of the present study was to evaluate the effect of adding two kinds of commercial bait which mimic human odors to light traps to attract sand flies and compare the results with those of light traps without any additional bait. The commercial baits, BG-Lure® and BG-Sweetscent®, were developed to catch anthropophilic mosquitoes. Three treatments were evaluated: 1 - HP light trap with BG-Lure® added; 2 - HP light trap with BG-Sweetscent® added and 3- HP light trap without any attractant. A total of 3,682 sand flies were collected during the study. Constrained correspondence analysis was applied to perform ordination of the captured community of sand fly species that could be explained by attractant, sampling site and sex. The most abundant species: Pintomyia nevesi, Nyssomyia whitmani and Nyssomyia antunesi were further investigated by fitting generalized linear mixed models. Only Ny. whitmani showed a slight indication of an increase in catches with BG-Lure®.


Assuntos
Controle de Insetos/métodos , Phlebotomus , Animais , Feminino , Humanos , Leishmaniose Cutânea/transmissão , Masculino
17.
Acta Trop ; 203: 105287, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31790649

RESUMO

By employing protected human bait landing and modified Shannon light trap, a total of 1924 phlebotomine sand fly Lutzomyia spp. were captured in an area from which L. (V.) guyanensis was reported as the causative parasite of cutaneous leishmaniasis (CL). The sand flies captured alive were dissected and identified at species level, based mainly on their spermathecae. At the same time, the sand flies dissected were searched for the Leishmania parasites by microscopic-test, and later on by PCR-test. No positive sand flies were detected by both tests, while considerable numbers of anthropophilic sand fly species of the genus Lutzomyia were observed as probable vectors of the Leishmania parasite in the areas. Those were eight species, Lu. robusta, Lu. trapidoi, Lu. maranonensis, Lu. gomezi, Lu. shannoni, Lu. migonei, Lu. punctigeniculata and Lu. spathotrichia. Among them, the first two species Lu. robusta and Lu. trapidoi were most dominant, suggesting probable vectors of the Leishmania parasite prevailing in the area. Lu. punctigeniculata and Lu. spathotrichia were for the first time recorded for the Manabí province, Ecuador. These findings provide basic information useful for future planning of the control and management of the disease in the areas, though further study to incriminate the vector sand fly remains.


Assuntos
Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Phlebotomus/parasitologia , Animais , Equador/epidemiologia , Humanos , Leishmaniose Cutânea/transmissão
18.
Acta Trop ; 203: 105315, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31866337

RESUMO

American cutaneous leishmaniasis is a public health concern in Colombia, its incidence being sustained or focally increased principally by the emergence of domestic transmission concomitantly with the adaptation of the phlebotomine vectors to habitat transformation around households. The objective of the study is to scale up a rapid characterization methodology for evaluating the relationship of land use around the house to the composition and abundance of phlebotomines. Five sites with a history of domestic leishmaniasis transmission in the Andean area of Colombia were selected. The peri-domestic habitat was evaluated at 10 m intervals along eight radial transects, centered on each house, at 45° intervals using a web pattern. Phlebotomines were captured by placing three CDC light traps over two nights both indoors and outdoors (10 m from the house). Blood source and infection were determined by PCR. Spearman rank correlation coefficients and negative binomial regression were used to quantify associations between the phlebotomine abundance and habitat categories. The study demonstrated that the vectors were largely anthropophagic (62% of 79 were human blood) and that a single species in each site was favored by the pertaining agriculture monoculture. Specifically, Pintomyia (Pifanomyia) quasitownsendi was associated with sugar cane in Novillero and La Esmeralda; while Pi. (Pif.) longiflocosa was associated with coffee plantations in Agua Bonita and El Cucal. Honda Alta had a more diverse array of land use and forest coverage with a lower number of specimens but higher species diversity. In terms of distance from the house to an area of a given land use, the abundance of Pi. (Pif.) quasitownsendi was inversely related to the distance to sugar cane plantation (Spearman correlation coefficient, ρ = -0.56, p < 0.001 for outdoor catches, and ρ = -0.50, p < 0.001 indoors). A similar inverse relationship was observed for Pi. (Pif.) longiflocosa with regard to technified coffee (ρ = -0.51, p < 0.001 outdoors, and ρ = -0.48, p < 0.001 indoors). This rapid characterization methodology could guide public heath decision makers in identifying those houses at higher risk of domestic transmission, and also educate farmers to increase the distance between their crops and any neighboring houses.


Assuntos
Insetos Vetores , Leishmaniose Cutânea/transmissão , Phlebotomus , Psychodidae , Agricultura , Animais , Colômbia/epidemiologia , Ecossistema , Características da Família , Humanos
19.
Acta Trop ; 203: 105321, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31877283

RESUMO

To elucidate the transmission mode of Andean cutaneous leishmaniasis (Andean-CL), natural Leishmania infection and biting activity of sand flies were tested in a selected sylvatic focus of the endemic area of the Ecuadorian Andes. Monthly sand fly collections and dissections were conducted during 12 months from July 2018 to June 2019. The Leishmania positive specimens/slides with innumerable amounts of actively mobile flagellates made us easy to detect positive sand flies. The promastigotes observed located in the anterior and posterior midgut, without the hindgut localization. The parasite isolated was identified as L. (L.) mexicana by cytochrome b gene analysis. No other Leishmania or flagellate species parasitic in sand flies was observed in the area. Only Lu. ayacuchensis was caught throughout. Monthly microscopic examination of Lu. ayacuchensis revealed 0.75-8.33% of natural L. (L.) mexicana infection rates. Higher Leishmania infection months were present at the end of the wet season of the Andes, while higher sand fly numbers occurred during the dry season. Diurnal biting (blood meal seeking) activity of sand flies started around 17:30 before sunset, increased between 18:00 and 19:30, and thereafter decreased drastically probably because of low temperature (15-18 °C) in the area. The results provide information important for the planning of vector control strategy and management of the disease in the Andean-CL endemic area of Ecuador.


Assuntos
Mordeduras e Picadas de Insetos , Insetos Vetores/parasitologia , Leishmaniose Cutânea/transmissão , Psychodidae/parasitologia , Animais , Equador/epidemiologia , Humanos , Leishmania mexicana/genética , Leishmania mexicana/isolamento & purificação
20.
PLoS Negl Trop Dis ; 13(10): e0007712, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31626654

RESUMO

BACKGROUND: Phlebotomus (Larroussius) guggisbergi is among the confirmed vectors for cutaneous leishmaniasis (CL) transmission in Kenya. This scarring and stigmatizing form of leishmaniasis accounts for over one million annual cases worldwide. Most recent CL epidemics in Kenya have been reported in Gilgil, Nakuru County, where the disease has become a public health issue. However, little is known about the factors that drive its transmission. Here, we sought to determine the occurrence, distribution and host blood feeding preference of the vectors, and to identify Leishmania species and infection rates in sandflies using molecular techniques. This information could lead to a better understanding of the disease transmission and improvement of control strategies in the area. METHODOLOGY/ PRINCIPAL FINDINGS: An entomological survey of sandflies using CDC light traps was conducted for one week per month in April 2016, and in June and July 2017 from five villages of Gilgil, Nakuru county; Jaica, Sogonoi, Utut, Gitare and Njeru. Sandflies were identified to species level using morphological keys and further verified by PCR analysis of cytochrome c oxidase subunit I (COI) gene. Midguts of female sandflies found to harbour Leishmania were ruptured and the isolated parasites cultured in Novy-MacNeal-Nicolle (NNN) media overlaid with Schneider's insect media to identify the species. Leishmania parasite screening and identification in 198 randomly selected Phlebotomus females and parasite cultures was done by PCR-RFLP analysis of ITS1 gene, nested kDNA-PCR and real-time PCR-HRM followed by sequencing. Bloodmeal source identification was done by real-time PCR-HRM of the vertebrate cytochrome-b gene. A total of 729 sandflies (males: n = 310; females: n = 419) were collected from Utut (36.6%), Jaica (24.3%), Sogonoi (34.4%), Njeru (4.5%), and Gitare (0.1%). These were found to consist of nine species: three Phlebotomus spp. and six Sergentomyia spp. Ph. guggisbergi was the most abundant species (75.4%, n = 550) followed by Ph. saevus sensu lato (11.3%, n = 82). Sandfly species distribution across the villages was found to be significantly different (p<0.001) with Jaica recording the highest diversity. The overall Leishmania infection rate in sandflies was estimated at 7.07% (14/198). Infection rates in Ph. guggisbergi and Ph. saevus s.l. were 9.09% (12/132) and 3.57% (2/56) respectively. L. tropica was found to be the predominant parasite in Gilgil with an overall infection rate of 6.91% (13/188) in Ph. guggisbergi (n = 11) and Ph. saevus s.l. (n = 2) sandflies. However, PCR analysis also revealed L. major infection in one Ph. guggisbergi specimen. Bloodmeal analysis in the 74 blood-fed sandflies disclosed a diverse range of vertebrate hosts in Ph. guggisbergi bloodmeals, while Ph. saevus s.l. fed mainly on humans. CONCLUSIONS/ SIGNIFICANCE: The high infection rates of L. tropica and abundance of Ph. guggisbergi in this study confirms this sandfly as a vector of L. tropica in Kenya. Furthermore, isolation of live L. tropica parasites from Ph. saevus s.l. suggest that there are at least three potential vectors of this parasite species in Gilgil; Ph. guggisbergi, Ph. aculeatus and Ph. saevus s.l. Molecular identification of L. major infections in Ph. guggisbergi suggested this sandfly species as a potential permissive vector of L. major, which needs to be investigated further. Sandfly host preference analysis revealed the possibility of zoonotic transmissions of L. tropica in Gilgil since the main vector (Ph. guggisbergi) does not feed exclusively on humans but also other vertebrate species. Further investigations are needed to determine the potential role of these vertebrate species in L. tropica and L. major transmission in the area.


Assuntos
Leishmania major/fisiologia , Leishmania tropica/fisiologia , Leishmaniose Cutânea/transmissão , Phlebotomus/parasitologia , Psychodidae/parasitologia , Animais , Entomologia , Feminino , Humanos , Quênia/epidemiologia , Leishmaniose Cutânea/epidemiologia , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
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