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1.
Mem Inst Oswaldo Cruz ; 116: e200528, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33656141

RESUMO

Panstrongylus geniculatus (Latreille, 1811) is the triatomine with the largest geographic distribution in Latin America. It has been reported in 18 countries from southern Mexico to northern Argentina, including the Caribbean islands. Although most reports indicate that P. geniculatus has wild habitats, this species has intrusive habits regarding human dwellings mainly located in intermediate deforested areas. It is attracted by artificial light from urban and rural buildings, raising the risk of transmission of Trypanosoma cruzi. Despite the wide body of published information on P. geniculatus, many knowledge gaps exist about its biology and epidemiological potential. For this reason, we analysed the literature for P. geniculatus in Scopus, PubMed, Scielo, Google Scholar and the BibTriv3.0 databases to update existing knowledge and provide better information on its geographic distribution, life cycle, genetic diversity, evidence of intrusion and domiciliation, vector-related circulating discrete taxonomic units, possible role in oral T. cruzi transmission, and the effect of climate change on its biology and epidemiology.


Assuntos
Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Panstrongylus/genética , Panstrongylus/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi , Animais , Biologia , Ecologia , Genes de Insetos , Variação Genética/genética , Genótipo , Geografia , Humanos , Insetos Vetores/genética , América Latina , Panstrongylus/fisiologia , Filogenia , Trypanosoma cruzi/isolamento & purificação
2.
Mem Inst Oswaldo Cruz ; 116: e200571, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33681890

RESUMO

Leishmania infantum chagasi is the causative agent and Lutzomyia longipalpis is the main vector of visceral leishmaniasis in the Americas. We investigated the expression of Leishmania genes within L. longipalpis after artificial infection. mRNAs from genes involved in sugar and amino acid metabolism were upregulated at times of high parasite proliferation inside the insect. mRNAs from genes involved in metacyclogenesis had higher expression in late stages of infection. Other modulated genes of interest were involved in immunomodulation, purine salvage pathway and protein recycling. These data reveal aspects of the adaptation of the parasite to the microenvironment of the vector gut and reflect the preparation for infection in the vertebrate.


Assuntos
Insetos Vetores/parasitologia , Leishmania infantum/genética , Leishmania/isolamento & purificação , Leishmaniose Visceral/transmissão , Psychodidae/parasitologia , Animais , Brasil , Expressão Gênica , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Estágios do Ciclo de Vida , Psychodidae/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
3.
Geospat Health ; 15(2)2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33461273

RESUMO

Visceral Leishmaniasis (VL) is a neglected disease with increasing incidence in Brazil, particularly in the North-eastern. The aim of this study was to analyze the spatial and spatiotemporal dynamics of VL in an endemic region of North-eastern Brazil, between 2009 and 2017. Using spatial analysis techniques, an ecological and time series study was made regarding VL cases in Sergipe filed as notifiable disease events. With data from the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística, IBGE), a digital population and cartographic baseline was established. Segmented linear regression was used to examine the temporal trends. The statistical analysis methods of Global and Local Moran' I, local Bayesian empirical methodology and spatial-temporal scanning were used to produce thematic maps. High instances were found among adults, males, urban residents, non-Whites and persons with low levels of education. A decrease in the recovery rate and an increase in the proportion of urban cases and lethality was found. A heterogeneous VL distribution with spatiotemporal agglomeration on the seaside of the state was seen in Sergipe. To better manage the disease, new research is encouraged together with development of public health strategies. Further, improving health care networks, especially primary care, is suggested as this approach has a key role in health promotion, prevention and monitoring of the most prevalent diseases.


Assuntos
Insetos Vetores/parasitologia , Leishmaniose Visceral/epidemiologia , População Urbana/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Teorema de Bayes , Brasil/epidemiologia , Meio Ambiente , Sistemas de Informação Geográfica , Humanos , Leishmaniose Visceral/parasitologia , Pessoa de Meia-Idade , Distribuição por Sexo , Análise Espacial , Análise Espaço-Temporal
4.
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
5.
Parasit Vectors ; 14(1): 35, 2021 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-33422133

RESUMO

BACKGROUND: Peri-urban and urban settings have recently gained more prominence in studies on vector-borne transmission of Trypanosoma cruzi due to sustained rural-to-urban migrations and reports of urban infestations with triatomines. Prompted by the finding of Triatoma infestans across the rural-to-urban gradient in Avia Terai, an endemic municipality of the Argentine Chaco, we assessed selected components of domestic transmission risk in order to determine its variation across the gradient. METHODS: A baseline vector survey was conducted between October 2015 and March 2016, following which we used multistage random sampling to select a representative sample of T. infestans at the municipal level. We assessed T. cruzi infection and blood-feeding sources of 561 insects collected from 109 houses using kinetoplast DNA-PCR assays and direct enzyme-linked immunosorbent assays, respectively. We stratified triatomines according to their collection site (domestic or peridomestic), and we further categorized peridomestic sites in ecotopes of low- or high-risk for T. cruzi infection. RESULTS: The overall adjusted prevalence of T. cruzi-infected T. infestans was 1.8% (95% confidence interval [CI] 1.3-2.3) and did not differ between peri-urban (1.7%) and rural (2.2%) environments. No infection was detected in bugs captured in the urban setting; rather, infected triatomines were mainly collected in rural and peri-urban domiciles, occurring in 8% of T. infestans-infested houses. The main blood-feeding sources of domestic and peridomestic triatomines across the gradient were humans and chickens, respectively. The proportion of triatomines that had fed on humans did not differ between peri-urban (62.5%) and rural (65.7%) domiciles, peaking in the few domestic triatomines collected in urban houses and decreasing significantly with an increasing proportion of chicken- and dog- or cat-fed bugs. The relative odds ratio (OR) of having a T. cruzi infection was nearly threefold higher in bugs having a blood meal on humans (OR 3.15), dogs (OR 2.80) or cats (OR: 4.02) in a Firth-penalized multiple logistic model. CONCLUSIONS: Trypanosoma cruzi transmission was likely occurring both in peri-urban and rural houses of Avia Terai. Widespread infestation in a third of urban blocks combined with high levels of human-triatomine contact in the few infested domiciles implies a threat to urban inhabitants. Vector control strategies and surveillance originally conceived for rural areas should be tailored to peri-urban and urban settings in order to achieve sustainable interruption of domestic transmission in the Chaco region.


Assuntos
Doença de Chagas/epidemiologia , Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Triatoma , Trypanosoma cruzi , Adulto , Animais , Argentina/epidemiologia , Gatos , Galinhas , Cães , Ensaio de Imunoadsorção Enzimática , Comportamento Alimentar , Feminino , Cabras , Humanos , Masculino , Camundongos , Fatores de Risco , População Rural
6.
PLoS Negl Trop Dis ; 14(12): e0008967, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33370303

RESUMO

Phlebotomine sand flies employ an elaborate system of pheromone communication wherein males produce pheromones that attract other males to leks (thus acting as an aggregation pheromone) and females to the lekking males (sex pheromone). In addition, the type of pheromone produced varies among populations. Despite the numerous studies on sand fly chemical communication, little is known of their chemosensory genome. Chemoreceptors interact with chemicals in an organism's environment to elicit essential behaviors such as the identification of suitable mates and food sources. Thus, they play important roles during adaptation and speciation. Major chemoreceptor gene families, odorant receptors (ORs), gustatory receptors (GRs) and ionotropic receptors (IRs) together detect and discriminate the chemical landscape. Here, we annotated the chemoreceptor repertoire in the genomes of Lutzomyia longipalpis and Phlebotomus papatasi, major phlebotomine vectors in the New World and Old World, respectively. Comparison with other sequenced Diptera revealed a large and unique expansion where over 80% of the ~140 ORs belong to a single, taxonomically restricted clade. We next conducted a comprehensive analysis of the chemoreceptors in 63 L. longipalpis individuals from four different locations in Brazil representing allopatric and sympatric populations and three sex-aggregation pheromone types (chemotypes). Population structure based on single nucleotide polymorphisms (SNPs) and gene copy number in the chemoreceptors corresponded with their putative chemotypes, and corroborate previous studies that identified multiple populations. Our work provides genomic insights into the underlying behavioral evolution of sexual communication in the L. longipalpis species complex in Brazil, and highlights the importance of accounting for the ongoing speciation in central and South American Lutzomyia that could have important implications for vectorial capacity.


Assuntos
Células Quimiorreceptoras/metabolismo , Proteínas de Insetos/genética , Leishmaniose/prevenção & controle , Leishmaniose/transmissão , Phlebotomus/parasitologia , Atrativos Sexuais/química , Animais , Brasil , Feminino , Insetos Vetores/parasitologia , Leishmania , Masculino , Phlebotomus/genética , Phlebotomus/fisiologia , Polimorfismo de Nucleotídeo Único/genética
7.
PLoS Negl Trop Dis ; 14(12): e0009015, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33370305

RESUMO

Trypanosoma rangeli is a non-pathogenic protozoan parasite that infects mammals, including humans, in Chagas disease-endemic areas of South and Central America. The parasite is transmitted to a mammalian host when an infected triatomine injects metacyclic trypomastigotes into the host's skin during a bloodmeal. Infected mammals behave as parasite reservoirs for several months and despite intensive research, some major aspects of T. rangeli-vertebrate interactions are still poorly understood. In particular, many questions still remain unanswered, e.g. parasite survival and development inside vertebrates, as no parasite multiplication sites have yet been identified. The present study used an insect bite transmission strategy to investigate whether the vector inoculation spot in the skin behave as a parasite-replication site. Histological data from the skin identified extracellular parasites in the dermis and hypodermis of infected mice in the first 24 hours post-infection, as well as the presence of inflammatory infiltrates in a period of up to 7 days. However, qPCR analyses demonstrated that T. rangeli is eliminated from the skin after 7 days of infection despite being still consistently found on circulating blood and secondary lymphoid tissues for up to 30 days post-infection. Interestingly, significant numbers of parasites were found in the spleen and mesenteric lymph nodes of infected mice during different periods of infection and steady basal numbers of flagellates are maintained in the host's bloodstream, which might behave as a transmission source to insect vectors. The presence of parasites in the spleen was confirmed by fluorescent photomicrography of free and cell-associated T. rangeli forms. Altogether our results suggest that this organ could possibly behave as a T. rangeli maintenance hotspot in vertebrates.


Assuntos
Doença de Chagas/transmissão , Linfonodos/parasitologia , Pele/parasitologia , Baço/parasitologia , Trypanosoma rangeli/isolamento & purificação , Animais , América Central/epidemiologia , Doença de Chagas/epidemiologia , Modelos Animais de Doenças , Interações Hospedeiro-Parasita , Humanos , Mordeduras e Picadas de Insetos/parasitologia , Insetos Vetores/parasitologia , Camundongos , Rhodnius/parasitologia , Sepse/parasitologia , América do Sul/epidemiologia
8.
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
9.
Artigo em Inglês | MEDLINE | ID: mdl-33206861

RESUMO

The etiological agent of American trypanosomiasis is the protozoan Trypanosoma cruzi , typically transmitted by triatomines. The aim of this study was to investigate the triatomine fauna and trypanosomiasis infections in Acre State , Western Brazilian Amazon. Insect collection was performed by dissecting palm trees and installing traps. We found that T. cruzi infection rate was 24.5% and Rhodnius pictipes (57.1%) was the most abundant triatomine species. Health education as well as epidemiological and entomological surveillance are necessary to diagnose and prevent new cases of Chagas disease in the region.


Assuntos
Doença de Chagas , Insetos Vetores/parasitologia , Rhodnius/parasitologia , Trypanosoma cruzi , Animais , Brasil/epidemiologia , Doença de Chagas/epidemiologia , Doença de Chagas/transmissão
10.
PLoS Negl Trop Dis ; 14(9): e0008712, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970687

RESUMO

BACKGROUND: Several studies addressed changes on the insect vector behavior due to parasite infection, but little is known for triatomine bugs, vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. We assessed infection rates and metacyclogenesis of T. cruzi (TcVI) in fifth-instar nymphs of Triatoma rubrovaria comparing with the primary vector Triatoma infestans. Also, biological parameters related to feeding-excretion behavior were evaluated aiming to identify which variables are most influenced by T. cruzi infection. METHODOLOGY/PRINCIPAL FINDINGS: Fifth-instar nymphs of T. rubrovaria and T. infestans were fed on mice infected with T. cruzi (TcVI). We compared the presence and the number of parasite evolutive forms in excreta of both triatomine species at 30, 60 and 90 days post-infection (dpi) with traditional statistical analyses. Moreover, both species were analyzed through generalized linear models and multinomial logistic regression hypotheses for seven behavioral parameters related to host-seeking and feeding-excretion. Triatoma rubrovaria and T. infestans had similar overall infection and metacyclogenesis rates of T. cruzi TcVI in laboratory conditions. Regarding vector behavior, we confirmed that the triatomine's tendency is to move away from the bite region after a blood meal, probably to avoid being noticed by the vertebrate host. Interspecific differences were observed on the volume of blood ingested and on the proportion of individuals that excreted after the blood meal, revealing the higher feeding efficiency and dejection rates of T. infestans. The amount of ingested blood and the bite behavior of T. rubrovaria seems to be influenced by TcVI infection. Infected specimens tended to ingest ~25% more blood and to bite more the head of the host. Noteworthy, in two occasions, kleptohematophagy and coprophagy behaviors were also observed in T. rubrovaria. CONCLUSIONS/SIGNIFICANCE: Laboratory infections revealed similar rate of T. cruzi TcVI trypomatigotes in excreta of T. rubrovaria and T. infestans, one of the most epidemiological important vectors of T. cruzi. Therefore, TcVI DTU was able to complete its life cycle in T. rubrovaria under laboratory conditions, and this infection changed the feeding behavior of T. rubrovaria. Considering these results, T. rubrovaria must be kept under constant entomological surveillance in Rio Grande do Sul, Brazil.


Assuntos
Comportamento Alimentar , Insetos Vetores/fisiologia , Insetos Vetores/parasitologia , Triatoma/fisiologia , Triatoma/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Brasil , Doença de Chagas/transmissão , Modelos Animais de Doenças , Interações Hospedeiro-Parasita , Mordeduras e Picadas de Insetos , Modelos Logísticos , Camundongos , Ninfa , Eliminação Renal , Trypanosoma cruzi/patogenicidade
11.
PLoS Negl Trop Dis ; 14(9): e0008696, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970689

RESUMO

Gambiense Human African Trypanosomiasis (g-HAT) is a neglected tropical disease caused by trypanosomes transmitted by tsetse flies. 70% of cases in 2019 (604/863) occurred in the Democratic Republic of Congo (DRC). The national programme for g-HAT elimination in DRC includes a large-scale deployment of Tiny Targets which attract and kill tsetse. This intervention is directed by vector-control specialists with small teams, moving in canoes, deploying Tiny Targets along riverbanks where tsetse concentrate. While the targets are deployed in communal areas, and the method is cheap and easy-to-use, local people have little involvement. This study aimed to evaluate if a community-led vector control programme was feasible in the context of DRC's g-HAT elimination programme. In 2017, a community-led intervention was implemented in three villages in the Kwilu province of DRC. This intervention was evaluated through an Action Research with qualitative data collected through 21 focus group discussions and 289 hours of observation. Also the geographical location and quality of each Tiny Targets were collected (total number deployed = 2429). This research revealed that community-based approach largely worked: people were motivated and proactive, showed a good application of the acquired knowledge resulting in an effective deployment of Tiny Targets. In addition, our study provided evidence that acceptability of the targets by the community can improve deployment quality by reducing target loss and damage. The approach was feasible in places where canoe-based teams could not reach. Against these advantages, a community-based approach was time-consuming and had to adapt to the seasonal and daily rhythms of the community. A community-based approach for tsetse control is technically feasible and recommended but limits to the speed and scale of the approach restraints its application as a standalone strategy in a large-scale national programme aiming to eliminate g-HAT in a short timeframe.


Assuntos
Controle de Insetos/métodos , Insetos Vetores , Doenças Negligenciadas/prevenção & controle , Animais , República Democrática do Congo/epidemiologia , Erradicação de Doenças , Estudos de Viabilidade , Feminino , Humanos , Insetos Vetores/parasitologia , Insetos Vetores/fisiologia , Masculino , Doenças Negligenciadas/parasitologia , Projetos Piloto , Trypanosoma , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/transmissão , Moscas Tsé-Tsé/parasitologia , Moscas Tsé-Tsé/fisiologia
12.
Am J Trop Med Hyg ; 103(4): 1563-1568, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32748783

RESUMO

Human landing collections (HLCs) have been the standard method for the collection of black flies that serve as vectors for Onchocerca volvulus, the causative agent of onchocerciasis or river blindness. However, HLCs are inefficient and may expose collectors to vector-borne pathogens. The Esperanza window trap (EWT) has been shown to be a potential alternative to HLCs for the collection of Simulium damnosum, the principal vector of O. volvulus in Africa. To improve the performance of the EWT, sweat from individuals highly attractive or less attractive to S. damnosum sensu stricto was examined by gas chromatography and mass spectroscopy. Twelve compounds were identified which were solely present or present in increased amounts in the sweat of the highly attractive individuals. Two of these compounds (naphthalene and tert-hexadecyl mercaptan) were found to be attractive to S. damnosum s.s. in behavioral assays. Traps baited with these compounds outperformed those baited with the current standard bait of worn socks. Using these newly identified compounds as baits will make the EWT more efficient in collecting vector black flies and may enhance the potential utility of the EWT as a local vector control measure.


Assuntos
Insetos Vetores/parasitologia , Onchocerca volvulus/fisiologia , Oncocercose/transmissão , Simuliidae/parasitologia , Animais , Feminino , Humanos , Oncocercose/epidemiologia , Oncocercose/parasitologia , Suor/parasitologia , Uganda/epidemiologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-32844905

RESUMO

This study aimed to describe the spatial distribution and assess entomological indicators of synanthropic triatomines in Piaui State, Northeastern Brazil. We used surveillance data on the detection, identification and assessment of natural infection with trypanosomatids from triatomines in the State from 2014 to 2017. The State was divided into four macroregions. In relation to the dispersion rates of triatomines, they were much lower in the North, when compared to Southwest, Southeast and Central North macroregions. Infestation rates were higher in the Southwest and Southeast and intradomicile infestation rates varied during the study period, reaching high values in all regions. Insects belonging to the species Triatoma brasiliensis complex, Triatoma pseudomaculata, Triatoma sordida, and to the genus Panstrongylus spp. and Rhodnius spp. were collected during this period. T. brasiliensis was collected from all four regions of the State, but more frequently in those located in the Southeast. A similar pattern was observed for T. pseudomaculata. T. sordida was detected in the municipalities in the Southeast and Southwest regions, and less frequently in the Central North municipalities. Rhodnius spp. was detected in the Central North and North regions, and Panstrongylus spp. in the Central North and Southeast regions. The highest trypanosomatid-positivity rate of T. brasiliensis and Panstrongylus spp. was in the Southeast region. A significant proportion of the municipalities of Piaui State presents entomological parameters that indicate a risk of Chagas disease by vector transmission.


Assuntos
Doença de Chagas , Insetos Vetores/parasitologia , Triatoma/parasitologia , Triatominae/classificação , Trypanosoma cruzi/isolamento & purificação , Animais , Brasil , Doença de Chagas/diagnóstico , Doença de Chagas/transmissão , Triatominae/parasitologia
14.
Trends Parasitol ; 36(9): 785-795, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32713762

RESUMO

Leishmania parasites have the capacity to rapidly adapt to changing environments in their digenetic life cycle which alternates between a vertebrate and an invertebrate host. Emergence of resistance following drug exposure can evoke phenotypic alterations that affect several aspects of parasite fitness in both hosts. Current studies of the impact of resistance are mostly limited to interactions with the mammalian host and characterization of in vitro parasite growth and differentiation. Development in the vector and transmission capacity have been largely ignored. This review reflects on the impact of drug resistance on its spreading potential with specific focus on the use of the sand fly infection model to evaluate parasite development in the vector and the ensuing transmission potential of drug-resistant phenotypes.


Assuntos
Resistência a Medicamentos , Insetos Vetores/parasitologia , Leishmaniose/transmissão , Psychodidae/parasitologia , Animais , Antiparasitários/farmacologia , Humanos , Leishmania/efeitos dos fármacos , Leishmania/crescimento & desenvolvimento , Leishmaniose/parasitologia , Estágios do Ciclo de Vida/fisiologia
15.
Am J Trop Med Hyg ; 103(3): 967-969, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32602437

RESUMO

In the United States, Chagas disease is diagnosed in less than 1% of the estimated > 300,000 people who have the disease. However, the actual prevalence remains unknown, and these estimates may be wide of the mark (too high or too low). The greater part of those living with the disease acquired the infection in an endemic region of Latin America, but autochthonous transmission in the United States is increasingly being described. These cases are considered rare, and the transmission routes are largely unknown. Although triatomines or "kissing bugs" harbor Trypanosoma cruzi in North America, most autochthonous cases are presumed rather than confirmed exposures to naturally infected kissing bugs. Public knowledge of Chagas is growing, and efforts are underway to provide greater awareness, but what are the risk factors for human transmission of Chagas disease in the United States?


Assuntos
Doença de Chagas/epidemiologia , Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Doença de Chagas/parasitologia , Transmissão de Doença Infecciosa , Humanos , América Latina/epidemiologia , Prevalência , Trypanosoma cruzi/patogenicidade , Incerteza , Estados Unidos/epidemiologia
16.
Parasitol Res ; 119(10): 3517-3522, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32617725

RESUMO

The parasite-vector interaction of Chagas disease is still poorly understood and the understanding of this relationship can help in the development of new strategies to control Trypanosoma cruzi transmission, which is the etiological agent of this disease. Considering the need to know if T. cruzi can cause some pathology in the reproductive system of the Chagas disease vectors, we investigated the spermatogenesis of Triatoma infestans infected by T. cruzi through histological and cytogenetic analysis. Trypanosoma cruzi Bolivia strain infection was not pathogenic for the reproductive system of T. infestans, because all the analyzed males had normal spermatogenesis, with all phases (spermatocytogenesis, meiosis and spermiogenesis) happening without any change. Thus, we demonstrated that the presence of T. cruzi Bolivia strain does not have influence in the spermatogenesis of T. infestans and we suggest that the influences on reproductive system observed for other species were a result of the action of the parasite on gametogenesis of females.


Assuntos
Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Espermatogênese/fisiologia , Triatoma/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Doença de Chagas/parasitologia , Interações Hospedeiro-Parasita , Insetos Vetores/fisiologia , Masculino , Triatoma/fisiologia
17.
Am J Trop Med Hyg ; 103(4): 1496-1501, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32618254

RESUMO

In the United States, phlebotomine sand flies carrying Leishmania (Leishmania) mexicana are endemic along the southern border. However, relatively little is known about the enzootic and zoonotic transmission of L. (L.) mexicana within the United States, and autochthonous cases of the consequent disease are rarely reported. We investigated an atypical case of cutaneous leishmaniasis (CL) caused by L. (L.) mexicana in a patient from central Texas which did not respond to a typical antileishmanial chemotherapy. We also investigated sand fly vectors around the patient's residence. PCR followed by DNA sequencing was used for determination of Leishmania spp., sand fly species, and host blood meal source. The L. (L.) mexicana genotype from the patient was identical to one found in a positive sand fly. Moreover, this genotype presented the same single-nucleotide polymorphisms as other historical CL cases acquired in Texas over the last 10 years, but distinct from those originating in Mexico and Central America. Three sand fly species were identified among the samples analyzed (n = 194), the majority of which were Lutzomyia (Dampfomyia) anthophora (n = 190), of which four specimens tested positive for Leishmania and two blood-fed specimens showed the presence of a human blood meal. This study highlights the complexity of clinical management of CL in a setting where the disease is infrequently encountered. The detection of human blood in Lu. (D.) anthophora is the first documentation of anthropophagy in this species. This is the first report of wild-caught, naturally infected sand flies found in association with an autochthonous case of human leishmaniasis and the specific strain of Leishmania (Leishmania) mexicana in the United States.


Assuntos
Insetos Vetores/parasitologia , Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Phlebotomus/parasitologia , Idoso , Animais , Humanos , Leishmania mexicana/genética , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Masculino , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Texas
18.
PLoS One ; 15(7): e0236253, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32692759

RESUMO

INTRODUCTION: Understanding the feeding behavior and host choice of sand flies provides valuable information on vector-host relationships and elucidates the epidemiological patterns of leishmaniasis transmission. Blood meal analysis studies are essential for estimating the efficiency of pathogen transmission, assessing the relative human disease risk, and assist in identifying the other potential hosts of leishmaniasis. In Sudan and most of East Africa, there are large remaining gaps in knowledge regarding the feeding habits of phlebotomine vectors. The study aimed to identify the blood meal sources and, therefore, the host preferences of the principal vectors Phlebotomus orientalis and Ph. papatasi in leishmaniasis endemic areas of eastern and central Sudan. MATERIALS AND METHODS: Sand flies were collected from two endemic villages in eastern and central Sudan using CDC light traps and sticky traps. The phlebotomine sand flies were morphologically and then molecularly identified. The source of blood meal of the engorged females was determined using a multiplex PCR methodology and specific primers of cytochrome b gene of mitochondrial DNA for human, goat, cow, and dog. The detection of the Leishmania parasite was done using PCR. RESULTS: The total number of collected female phlebotomine sand flies was 180. Morphological identification revealed the abundance of Ph. orientalis 103 (57.2%), Ph. papatasi 42 (23.3%), Ph. bergeroti 31 (17.2%), Ph. rodhaini 2 (1.1%) and Ph. duboscqi 2 (1.1%) in the study sites. Out of the 180 collected, 31 (17%) were blood-fed flies. Three species were blood-fed and molecularly identified: Ph. papatasi (N = 7, 22.6%), Ph. bergeroti (N = 9, 26%), and Ph. orientalis (N = 15, 48.4%). Blood meal analysis revealed human DNA in two Ph. orientalis (6.4%), hence, the anthropophilic index was 13.3%. CONCLUSIONS: Multiplex PCR protocol described here allowed the identification of blood meal sources of many vertebrate species simultaneously. The results indicate that wild-caught Ph. orientalis are anthropophilic in the study areas. Further studies on larger blood-fed sample size are required to validate the potential applications of this technique in designing, monitoring and evaluating control programs, particularly in investigating the potential non-human hosts of leishmaniasis.


Assuntos
Interações Hospedeiro-Patógeno , Insetos Vetores/parasitologia , Leishmaniose/parasitologia , Phlebotomus/fisiologia , Animais , DNA/genética , Feminino , Geografia , Sudão
19.
PLoS One ; 15(6): e0234445, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579586

RESUMO

This study aimed to describe the sand fly fauna and detect trypanosomatids in these insects from Casa Branca, state of Minas Gerais, Brazil, an endemic area of both visceral (VL) and tegumentary leishmaniasis (TL). Sand flies were collected bimonthly from May 2013 to July 2014, using automatic light traps exposed for three consecutive nights in peridomiciliary areas of nine houses with previous reports of VL and TL. ITS1-PCR and DNA sequencing were performed for trypanosomatids identification. A total of 16,771 sand flies were collected belonging to 23 species. The most abundant species was Nyssomyia whitmani (Antunes & Coutinho, 1939) (70.9%), followed by Lutzomyia longipalpis (Lutz & Neiva, 1912) (15.2%) and Migonemyia migonei (França, 1920) (9.1%). Leishmania amazonensis DNA was detected in Ny. whitmani (four pools) and Le. braziliensis DNA was detected in Psychodopygus lloydi (one pool). In seven pools of Ny. whitmani and in one pool of Lu. longipalpis positive for Leishmania DNA, the parasite species was not determined due to the low quality of the sequences. Moreover, DNA of Herpetomonas spp. was detected in Ny. whitmani (two pools) and Cortelezzii complex (one pool). DNA of Crithidia spp. was detected in Ny. whitmani and Ps. lloydi (both one pool). Our results suggest that Ny. whitmani may be involved in the transmission of Le. amazonensis in the study area. The molecular detection of Le. amazonensis suggests the presence of this species in a sylvatic cycle between vertebrate and invertebrate hosts in the region of Casa Branca. Our data also reveal the occurrence of other non-Leishmania trypanosomatids in sand flies in Casa Branca District.


Assuntos
Biodiversidade , Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Phlebotomus/parasitologia , Psychodidae/parasitologia , Animais , Brasil/epidemiologia , DNA de Protozoário/isolamento & purificação , Doenças Endêmicas/prevenção & controle , Feminino , Humanos , Leishmania/genética , Leishmaniose/epidemiologia , Leishmaniose/parasitologia , Leishmaniose/prevenção & controle , Leishmaniose/transmissão , Análise de Sequência de DNA
20.
Am J Trop Med Hyg ; 103(1): 428-436, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32458775

RESUMO

Trypanosoma cruzi is the etiological agent of Chagas disease that infects more than seven million people in Latin America. The parasite is transmitted by triatomine insects, of which some species are often associated with palms. The establishment of oil palm plantations (Elaeis guineensis) in the Orinoco region (Colombia) has been rapidly growing, possibly constituting a new environment for the establishment and increase in triatomine populations. In this study, the potential of Rhodnius prolixus to colonize E. guineensis plantations and maintain T. cruzi transmission was assessed. Fieldwork was conducted in two areas located in the department of Casanare for sampling E. guineensis and Attalea butyracea palms, sampling for triatomines to determine their abundance and prevalence of T. cruzi infection. To assess T. cruzi transmission potential in the area, sylvatic and domestic mammals were sampled. Results showed that palm infestation with triatomines was higher in A. butyracea than in E. guineensis palms and T. cruzi infection in triatomines varied between habitats for one study area, but was constant in the other site. Trypanosoma cruzi-infected mammals in the E. guineensis plantations were mainly generalist rodents, suggesting that these mammals could have an important role in T. cruzi transmission in plantations. In conclusion, E. guineensis plantations in the Orinoco region are suitable habitats for R. prolixus and T. cruzi transmission.


Assuntos
Arecaceae , Doença de Chagas/veterinária , Insetos Vetores/parasitologia , Rhodnius/parasitologia , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Doença de Chagas/transmissão , Quirópteros/parasitologia , Colômbia/epidemiologia , Cães/parasitologia , Florestas , Gambás/parasitologia , Óleo de Palmeira , Roedores/parasitologia , Sus scrofa/parasitologia , Trypanosoma cruzi
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