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1.
Artigo em Inglês | MEDLINE | ID: mdl-32520213

RESUMO

Although the chemical control against leishmaniasis began in 1953 in Brazil, little information is available on how this strategy has affected populations of phlebotomine sandflies in the field. The objective of this study was to analyze the susceptibility profile of four populations of phlebotomine sandflies to the insecticide alpha-cypermethrin. Sandflies collected in field in four Brazilian municipalities were evaluated using CDC bottles in different concentrations of alpha-cypermethrin. A total of 1,186 phlebotomine sandflies were used in the bioassays. The LD50 ranged from 1.48 to 2.57 ug/mL in the field populations. For a dose of 5 ug/mL of alpha-cypermethrin, the LT50 and LT95 ranged from 17.9 to 27.5 minutes, and LT95 from 39.7 to 61.5 minutes, respectively. All the populations studied were highly susceptible to the insecticide alpha-cypermethrin. Routine studies are needed to detect changes in sandflies susceptibility to insecticides.


Assuntos
Insetos Vetores/efeitos dos fármacos , Inseticidas/farmacologia , Psychodidae/efeitos dos fármacos , Piretrinas/farmacologia , Animais , Brasil , Doenças Endêmicas , Feminino , Insetos Vetores/classificação , Leishmaniose/transmissão , Psychodidae/classificação
2.
PLoS Negl Trop Dis ; 14(5): e0008324, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32463829

RESUMO

Local anomalies in rainfall and temperature induced by El Niño and La Niña episodes could change the structure of the vector community. We aimed to estimate the effect of the El Niño-La Niña cycle in the potential distribution of cutaneous leishmaniasis (CL) vector species in Colombia and to compare the richness of the vectors with the occurrence of CL in the state of Norte de Santander. The potential distributions of four species were modeled using a MaxEnt algorithm for the following episodes: La Niña 2010-2011, Neutral 2012-2015 and El Niño 2015-2016. The relationship between the potential richness of the vectors and the occurrence of CL in Norte de Santander was evaluated with a log-binomial regression model. During the El Niño 2015-2016 episode, Lutzomyia ovallesi and Lutzomyia panamensis increased their distribution into environmentally suitable areas, and three vector species (Lutzomyia gomezi, Lutzomyia ovallesi and Lutzomyia panamensis) showed increases in the range of their altitudinal distribution. During the La Niña 2010-2011 episode, a reduction was observed in the area suitable for occupation by Lutzomyia gomezi and Lutzomyia spinicrassa. During the El Niño 2015-2016 episode, the occurrence of at least one CL case was related to a higher percentage of rural localities showing a richness of vectors = 4. The anomalies in rainfall and temperature induced by the episodes produced changes in the potential distribution of CL vectors in Colombia. In Norte de Santander, during Neutral 2012-2015 and El Niño 2015-2016 episodes, a higher probability of at least one CL case was related to a higher percentage of areas with a greater richness of vectors. The results help clarify the effect of the El Niño-La Niña cycle in the dynamics of CL in Colombia and emphasize the need to monitor climate variability to improve the prediction of new cases.


Assuntos
El Niño Oscilação Sul , Insetos Vetores/crescimento & desenvolvimento , Leishmaniose Cutânea/epidemiologia , Psychodidae/crescimento & desenvolvimento , Animais , Colômbia/epidemiologia , Humanos
3.
An Acad Bras Cienc ; 92(1): e20181093, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236298

RESUMO

Larvae of Psychodidae develop in a variety of breeding sites, including vertebrate feces. As searching for the larvae can be an extremely difficult task, immatures of many species are little known, with descriptions of coprophagous moth flies all from outside the Neotropics. In an attempt to mitigate this challenge, we tested an oviposition trap using cattle dung as attractant, measured the efficiency and specificity of the traps and the most efficient period of exposition in the field. With 60 traps installed in one fragment of ombrophilous forest, 344 immatures were collected, distributed in four species of Psychoda and one of Feuerborniella. Psychodidae accounted for 75% of the collected Diptera. The high specificity of the trap to Psychodidae contrasts with other studies on coprophagous fauna where they appear in low abundance. Based on the metrics in this study, the most efficient period of trapping exposition was between five to eight days, but the difference was not significant probably due to the high number of zero observations among the traps. Many questions pertaining to coprophagous moth flies remain unanswered. Further research is needed to improve trapping efficiency, elucidate the effects of attractants and determine how environmental factors influence the attractiveness of bait.


Assuntos
Controle de Insetos/instrumentação , Oviposição , Psychodidae/fisiologia , Animais , Bovinos , Fezes , Feminino , Psychodidae/classificação
4.
Parasit Vectors ; 13(1): 193, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32293524

RESUMO

BACKGROUND: For long time, canine leishmaniosis (CanL) was considered endemic in the southern, central, and insular regions of Italy, whereas heartworm disease (HW) caused by Dirofilaria immitis was considered endemic in the northern region and in the swampy Po Valley. Following the reports of new foci of both diseases, in this study we update the distribution patterns and occurrence of new foci of CanL and HW discussing the main drivers for the changes in the epidemiology of these two important zoonotic canine vector-borne diseases. METHODS: Based on the statistical analyses of serological assays (n = 90,633) on L. infantum exposure and D. immitis infection performed by two reference diagnostic centres in Italy over a ten-year period (2009-2019) irrespective of the anamnesis of dogs. The distribution patterns of both parasites are herein presented along with the occurrence of new foci. RESULTS: Results highlighted the changing distribution patterns of L. infantum vs D. immitis infection in Italy. CanL is endemic in some areas of northern regions and HW has endemic foci in central and southern regions and islands. Significant differences in L. infantum exposure and HW infection prevalence among the study macroareas were detected. The overall results of the positive tested samples were 28.2% in southern Italy and islands, 29.6% in central Italy and 21.6% in northern Italy for L. infantum and 2.83% in northern Italy, 7.75% in central Italy and 4.97% in southern Italy and islands for HW. HW positivity significantly varied over years (χ2 = 108.401, df = 10, P < 0.0001), gradually increasing from 0.77% in 2009 to 8.47% in 2016-2017. CONCLUSIONS: New potential epidemiological scenarios are discussed according to a range of factors (e.g. environmental modifications, occurrence of competent insect vectors, transportation of infected animals to non-endemic areas, chemoprophylaxis or vector preventative measures), which may affect the current distribution. Overall, the results advocate for epidemiological surveillance programmes, more focussed preventative and control measures even in areas where few or no cases of both diseases have been diagnosed.


Assuntos
Dirofilaria immitis/parasitologia , Dirofilariose/epidemiologia , Doenças do Cão/epidemiologia , Leishmania infantum/parasitologia , Leishmaniose/veterinária , Animais , Dirofilariose/prevenção & controle , Cães , Insetos Vetores/parasitologia , Itália/epidemiologia , Leishmaniose/epidemiologia , Psychodidae/parasitologia , Testes Sorológicos , Zoonoses
5.
Zootaxa ; 4732(2): zootaxa.4732.2.6, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32230263

RESUMO

Two new moth fly species, Australopericoma onofrei sp. nov. and Australopericoma xavierae sp. nov., are described from the Atlantic Rainforest in the state of Bahia, Brazil. A new record of Australopericoma dissimilis Bravo from the state of Sergipe, Brazil and an updated species list are also provided.


Assuntos
Dípteros , Psychodidae , Distribuição Animal , Animais , Brasil , Floresta Úmida
6.
Zootaxa ; 4728(2): zootaxa.4728.2.2, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-32230572

RESUMO

Tonnoiriella Vaillant, 1971 was one of the genera not treated by F. Vaillant for his revision in Die Fliegen der paläartktischen Region. Here we provide a genus diagnosis, re-describe known species based mainly on type material, and provide descriptions and figures of the West-Palearctic species. New species described are T. aurasica sp. nov., T. italiae sp. nov., T. ikariae sp. nov., T. andradei sp. nov., T. rhodesica sp. nov., and T. goncalvesi sp. nov.; T. androsica Vaillant, 1978, T. orientalis Vaillant, 1978, and T. pallidipenis Vaillant, 1978 are nomina nuda; finally 21 species are known to date from Europe and North Africa. The ejaculatory apodeme (basiphallus) is asymmetric and bilobed, lobes are stacked; one or both lobes are connected with asymmetric, cross positioned (distiphallus) sclerites. Operating of the open-close mechanism of the aedeagus is explained. Information on larval ecology is provided and the systematic position of the genus is discussed.


Assuntos
Dípteros , Psychodidae , Distribuição Animal , Animais , Ecologia , Larva
7.
Rev Soc Bras Med Trop ; 53: e20190538, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32267459

RESUMO

INTRODUCTION: Leishmaniasis constitutes a serious but neglected tropical disease. Recently, socio-environmental, biological and physical changes have altered the range of leishmaniasis, causing it to spread into urban areas. In Minas Gerais, the disease is endemic, exhibiting regional differences and reaching urban centers. The purpose of this study was to evaluate entomological aspects related to the ecoepidemiology of leishmaniasis in Itaúna. METHODS: Monthly catches with HP traps were carried out from June 2017 to May 2018, in three ecological areas (urban, rural, and forest). The adaptability of the species to anthropic environments was assessed using the synanthropy index (SI). RESULTS: We collected 1306 specimens of phlebotomine sand flies. Of the species of medical importance, Lutzomyia longipalpis, the vector of Leishmania infantum, represented 90.4% of the specimens identified at species level (n=1260). Nyssomyia whitmani, the vector of Leishmania braziliensis, represented 1.6% of the total. Lu. longipalpis displayed an SI of +95.8, a value that denotes a marked preference for human environments. For Ny. whitmani, the SI was -25, expressing the tendency of this species to occupy uninhabited areas. The population of the three most numerous species captured increased with rain, high temperatures, and high relative humidity. Although captured at low numbers, Ny. whitmani showed a different profile concerning the climate variables analyzed. CONCLUSIONS: Understanding the epidemiology of the disease may assist the health services in formulating effective control measures for improving community health and contributing to the establishment of a dynamic relationship and a global awareness of the health/disease process.


Assuntos
Insetos Vetores/classificação , Psychodidae/classificação , Distribuição Animal , Animais , Brasil , Feminino , Leishmaniose/transmissão , Masculino , População Rural , Estações do Ano , População Urbana
8.
Parasitol Res ; 119(4): 1177-1199, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32246259

RESUMO

A few data are related to the anthropophily of Malagasy Phlebotomine sandflies. Prior studies focussed mainly to inventories and description of new species. Our goal was to emphasize the anthropophily of Malagasy Phlebotomine sandflies. We worked in the Makira region, using two simultaneous methods: human landing catches (HLC) and CDC light traps. We collected sandflies in three rural communities adjacent to the Makira Natural Park. In each community, three different biotopes were sampled: within community settlements; at the edge of forest, typically in agricultural land; and within the forest. We collected 61 sandflies belonging to two new species presently described: Phlebotomus artemievi sp. nov. and Sergentomyia maroantsetraensis sp. nov. These sandflies were caught exclusively in the forest edge biotope. None were captured within communities or within forests. HLC provided 97% of the collected sandflies, corresponding to a human-biting rate of 15 females per human per night. CDC provided only two females. Ph. artemievi sp. nov. was predominantly captured by HLC and appears to be highly anthropophilic. Here, we update the behavioural ecology of sandflies and describe two new species. Further research is required to understand their vector competence and their ability to transmit arboviruses and other pathogens such as Leishmania.


Assuntos
Florestas , Phlebotomus , Psychodidae , Animais , Vetores de Doenças , Ecossistema , Feminino , Madagáscar , Masculino , Phlebotomus/classificação , Psychodidae/classificação
9.
PLoS Negl Trop Dis ; 14(4): e0008253, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32324738

RESUMO

BACKGROUND: In the Mediterranean basin, Leishmania infantum is the causative agent of visceral leishmaniasis (VL), a zoonosis in which the dog is the primary domestic reservoir, although wildlife may have a leading role in the sylvatic cycle of the disease in some areas. Infections without disease are very frequent. There is limited information regarding the role that VL patients and asymptomatic infected individuals could be playing in the transmission of L. infantum. Xenodiagnosis of leishmaniasis has been used in this descriptive study to explore the role of symptomatic and asymptomatic infected individuals as reservoirs in a recent focus of leishmaniasis in southwestern Madrid, Spain. METHODOLOGY AND MAIN FINDINGS: Asymptomatic blood donors (n = 24), immunocompetent patients who were untreated (n = 12) or treated (n = 11) for visceral leishmaniasis (VL), and immunocompromised patients with VL (n = 3) were enrolled in the study. Their infectivity to Phlebotomus perniciosus was studied by indirect xenodiagnosis on peripheral blood samples. Quantitative polymerase chain reaction of blood samples from immunocompetent patients untreated for VL and immunocompromised untreated, treated and under secondary prophylaxis for VL was performed. Antibodies against Leishmania were studied by indirect fluorescent antibody and rK39-immunochromatographic tests. A lymphoproliferative assay with a soluble Leishmania antigen was used to screen for leishmaniasis infection in the healthy population. Sixty-two xenodiagnostic tests were carried out and 5,080 sand flies were dissected. Positive xenodiagnosis was recorded in four patients, with different sand fly infection rates: 1 immunosuppressed HIV / L. infantum coinfected asymptomatic patient, 1 immunosuppressed patient with multiple myeloma and symptomatic active VL, and 2 immunocompetent patients with untreated active VL. All blood donors were negative for both xenodiagnosis and conventional PCR. CONCLUSIONS / SIGNIFICANCE: There is no consensus amongst authors on the definition of an 'asymptomatic case' nor on the tools for screening; we, therefore, have adopted one for the sake of clarity. Immunocompetent subjects, both infected asymptomatics and those treated for VL, are limited in number and appear to have no epidemiological relevance. The impact is limited for immunocompetent patients with untreated active VL, whilst immunosuppressed individuals undergoing immunosuppressive therapy and immunosuppressed individuals HIV / L. infantum coinfected were the most infectious towards sand flies. It is noteworthy that the HIV / L. infantum coinfected patient with asymptomatic leishmaniasis was easily infectious to sand flies for a long time, despite being under continuous prophylaxis for leishmaniasis. Accordingly, screening for latent Leishmania infection in HIV-infected patients is recommended in scenarios where transmission occurs. In addition, screening for VL in HIV-infected patients who have spent time in VL-endemic areas should also be implemented in non-endemic areas. More research is needed to better understand if some asymptomatic coinfected individuals contribute to transmission as 'super-spreaders'.


Assuntos
Reservatórios de Doenças , Transmissão de Doença Infecciosa , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Doenças Assintomáticas/epidemiologia , DNA de Protozoário/sangue , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Psychodidae/parasitologia , Espanha/epidemiologia
10.
PLoS Negl Trop Dis ; 14(3): e0008014, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32126078

RESUMO

BACKGROUND: Leishmaniasis is a vector-borne neglected disease. Inside the natural sand fly vector, the promastigote forms of Leishmania undergo a series of extracellular developmental stages to reach the infectious stage, the metacyclic promastigote. There is limited information regarding the expression profile of L. infantum developmental stages inside the sand fly vector, and molecular markers that can distinguish the different parasite stages are lacking. METHODOLOGY/PRINCIPAL FINDINGS: We performed RNAseq on unaltered midguts of the sand fly Lutzomyia longipalpis after infection with L. infantum parasites. RNAseq was carried out at various time points throughout parasite development. Principal component analysis separated the transcripts corresponding to the different Leishmania promastigote stages, the procyclic, nectomonad, leptomonad and metacyclics. Importantly, there were a significant number of differentially expressed genes when comparing the sequential development of the various Leishmania stages in the sand fly. There were 836 differentially expressed (DE) genes between procyclic and long nectomonad promastigotes; 113 DE genes between nectomonad and leptomonad promastigotes; and 302 DE genes between leptomonad and metacyclic promastigotes. Most of the DE genes do not overlap across stages, highlighting the uniqueness of each Leishmania stage. Furthermore, the different stages of Leishmania parasites exhibited specific transcriptional enrichment across chromosomes. Using the transcriptional signatures exhibited by distinct Leishmania stages during their development in the sand fly midgut, we determined the genes predominantly enriched in each stage, identifying multiple potential stage-specific markers for L. infantum. CONCLUSIONS: Overall, these findings demonstrate the transcriptional plasticity of the Leishmania parasite inside the sand fly vector and provide a repertoire of potential stage-specific markers for further development as molecular tools for epidemiological studies.


Assuntos
Expressão Gênica , Marcadores Genéticos , Leishmania infantum/crescimento & desenvolvimento , Leishmania infantum/genética , Psychodidae/parasitologia , Animais , Feminino , Trato Gastrointestinal/parasitologia , Perfilação da Expressão Gênica , Análise de Sequência de RNA
11.
PLoS One ; 15(3): e0220268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155153

RESUMO

Caves are extreme and inhospitable environments that can harbor several species of vertebrate and invertebrate animals. Among these animals are phlebotomine sand flies, vectors of parasites of the genus Leishmania that cause leishmaniasis. This study aimed to evaluate the species composition of sand flies of four caves, a cave located at Moeda Sul (MS) and three at Parque Estadual Serra do Rola Moça (PESRM), in the region of the Quadrilátero Ferrífero in the state of Minas Gerais, southeastern Brazil. Sand flies were collected with automatic light traps. Non-Metric Multidimensional Scaling, using a dissimilarity matrix calculated with the Jaccard index, and Multivariate Permutation Analysis were used to evaluate sand fly species composition among entrance, interior, and the surrounding environments of each sampled cave and to infer biological mechanisms from patterns of distribution among these different cave environments. A total of 375 phlebotomine sand flies representing 14 species and six genera were collected. The most abundant species were Evandromyia tupynambai (54.7%), Brumptomyia troglodytes (25.6%), Evandromyia edwardsi (6.1%), Psathyromyia brasiliensis (4.8%) and Lutzomyia longipalpis (4.3%). Thirty individuals were collected at MS, 16 inside the cave and 14 from its surroundings. At PESRM, five individuals were collected from the surroundings of cave RM38, 190 individuals from cave RM39 (48 in the cave and 142 from its surroundings) and 150 individuals from cave RM40 (42 in the cave and 108 from its surroundings). The results revealed a rich sand fly fauna with similar species compositions among the entrance, interior, and surrounding environments of each sampled cave, suggesting that both caves and their surroundings are important for maintaining sand fly communities.


Assuntos
Cavernas , Psychodidae/fisiologia , Animais , Brasil , Geografia , Phlebotomus/fisiologia , Especificidade da Espécie
12.
PLoS One ; 15(3): e0230537, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32208452

RESUMO

During the blood feeding, sand fly females inject saliva containing immunomodulatory and anti-haemostatic molecules into their vertebrate hosts. The saliva composition is species-specific, likely due to an adaptation to particular haemostatic pathways of their preferred host. Research on sand fly saliva is limited to the representatives of two best-studied genera, Phlebotomus and Lutzomyia. Although the members of the genus Sergentomyia are highly abundant in many areas in the Old World, their role in human disease transmission remains uncertain. Most Sergentomyia spp. preferentially attack various species of reptiles, but feeding on warm-blooded vertebrates, including humans and domestic animals, has been repeatedly described, especially for Sergentomyia schwetzi, of which salivary gland transcriptome and proteome is analyzed in the current study. Illumina RNA sequencing and de novo assembly of the reads and their annotation revealed 17,293 sequences homologous to other arthropods' proteins. In the sialome, all proteins typical for sand fly saliva were identified-antigen 5-related, lufaxin, yellow-related, PpSP15-like, D7-related, ParSP25-like, and silk proteins, as well as less frequent salivary proteins included 71kDa-like, ParSP80-like, SP16-like, and ParSP17-like proteins. Salivary enzymes include apyrase, hyaluronidase, endonuclease, amylase, lipase A2, adenosine deaminase, pyrophosphatase, 5'nucleotidase, and ribonuclease. Proteomics analysis of salivary glands identified 631 proteins, 81 of which are likely secreted into the saliva. We also compared two S. schwetzi lineages derived from the same origin. These lineages were adapted for over 40 generations for blood feeding either on mice (S-M) or geckos (S-G), two vertebrate hosts with different haemostatic mechanisms. Altogether, 20 and 40 annotated salivary transcripts were up-regulated in the S-M and S-G lineage, respectively. Proteomic comparison revealed ten salivary proteins more abundant in the lineage S-M, whereas 66 salivary proteins were enriched in the lineage S-G. No difference between lineages was found for apyrase activity; contrarily the hyaluronidase activity was significantly higher in the lineage feeding on mice.


Assuntos
Proteínas de Insetos/genética , Psychodidae/genética , Glândulas Salivares/metabolismo , Transcriptoma , Animais , Apirase/análise , Apirase/genética , Apirase/metabolismo , Hialuronoglucosaminidase/análise , Hialuronoglucosaminidase/genética , Hialuronoglucosaminidase/metabolismo , Proteínas de Insetos/análise , Proteínas de Insetos/metabolismo , Lagartos , Camundongos , Filogenia , Psychodidae/metabolismo , Receptores Odorantes/análise , Receptores Odorantes/genética , Receptores Odorantes/metabolismo
13.
PLoS One ; 15(3): e0229536, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155171

RESUMO

In this study, the presence of Leishmania DNA and blood feeding sources in phlebotomine sand fly species commonly present in Sicily were investigated. A total of 1,866 female sand flies including 176 blood fed specimens were sampled over two seasons in five selected sites in Sicily (southern Italy). Sergentomyia minuta (n = 1,264) and Phlebotomus perniciousus (n = 594) were the most abundant species at all the sites, while three other species from the genus Phlebotomus (i.e., P. sergenti n = 4, P. perfiliewi n = 3 and P. neglectus n = 1) were only sporadically captured. Twenty-eight out of the 1,866 (1.5%) sand flies tested positive for Leishmania spp. Leishmania tarentolae DNA was identified in 26 specimens of S. minuta, while the DNA of Leishmania donovani complex was detected in a single specimen each of S. minuta and P. perniciosus. Interestingly, seven S. minuta specimens (0.4%) tested positive for reptilian Trypanosoma sp. Blood sources were successfully identified in 108 out of 176 blood fed females. Twenty-seven out of 82 blood sources identified in fed females of P. perniciosus were represented by blood of wild rabbit, S. minuta mainly fed on humans (16/25), while the sole P. sergenti fed specimen took a blood meal on rat. Other vertebrate hosts including horse, goat, pig, dog, chicken, cow, cat and donkey were recognized as blood sources for P. perniciosus and S. minuta, and, surprisingly, no reptilian blood was identified in blood-fed S. minuta specimens. Results of this study agree with the well-known role of P. perniciosus as vector of L. infantum in the western Mediterranean; also, vector feeding preferences herein described support the hypothesis on the involvement of lagomorphs as sylvatic reservoirs of Leishmania. The detection of L. donovani complex in S. minuta, together with the anthropophilic feeding-behaviour herein observed, warrants further research to clarify the capacity of this species in the transmission of pathogens to humans and other animals.


Assuntos
Psychodidae/genética , Psychodidae/patogenicidade , Animais , DNA/genética , Comportamento Alimentar , Insetos Vetores , Leishmania/genética , Psychodidae/classificação , Estações do Ano , Sicília , Especificidade da Espécie , Trypanosomatina/genética
14.
Infect Dis Poverty ; 9(1): 30, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32183909

RESUMO

BACKGROUND: As of 2015 thousands of refugees are being hosted in temporary refugee camps in Greece. Displaced populations, travelling and living under poor conditions with limited access to healthcare are at a high risk of exposure to vector borne disease (VBD). This study sought to evaluate the risk for VBD transmission within refugee camps in Greece by analyzing the mosquito and sand fly populations present, in light of designing effective and efficient context specific vector and disease control programs. METHODS: A vector/pathogen surveillance network targeting mosquitoes and sand flies was deployed in four temporary refugee camps in Greece. Sample collections were conducted bi-weekly during June-September 2017 with the use of Centers for Disease Control (CDC) light traps and oviposition traps. Using conventional and molecular diagnostic tools we investigated the mosquito/sand fly species composition, population dynamics, pathogen infection rates, and insecticide resistance status in the major vector species. RESULTS: Important disease vectors including Anopheles sacharovi, Culex pipiens, Aedes albopictus and the Leishmania vectors Phlebotomus neglectus, P. perfiliewi and P. tobbi were recorded in the study refugee camps. No mosquito pathogens (Plasmodium parasites, flaviviruses) were detected in the analysed samples yet high sand fly Leishmania infection rates are reported. Culex pipiens mosquitoes displayed relatively high knock down resistance (kdr) mutation allelic frequencies (ranging from 41.0 to 63.3%) while kdr mutations were also detected in Ae. albopictus populations, but not in Anopheles and sand fly specimens. No diflubenzuron (DFB) mutations were detected in any of the mosquito species analysed. CONCLUSIONS: Important disease vectors and pathogens in vectors (Leishmania spp.) were recorded in the refugee camps indicating a situational risk factor for disease transmission. The Cx. pipiens and Ae. albopictus kdr mutation frequencies recorded pose a potential threat against the effectiveness of pyrethroid insecticides in these settings. In contrast, pyrethroids appear suitable for the control of Anopheles mosquitoes and sand flies and DFB for Cx. pipiens and Ae. albopictus larvicide applications. Targeted actions ensuring adequate living conditions and the establishment of integrated vector-borne disease surveillance programs in refugee settlements are essential for protecting refugee populations against VBDs.


Assuntos
Insetos Vetores/efeitos dos fármacos , Insetos Vetores/genética , Resistência a Inseticidas/genética , Leishmania , Controle de Mosquitos , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/genética , Dinâmica Populacional , Campos de Refugiados , Aedes/efeitos dos fármacos , Aedes/genética , Animais , Anopheles/efeitos dos fármacos , Anopheles/genética , Culex/efeitos dos fármacos , Culex/genética , Feminino , Grécia , Leishmania/genética , Leishmania/patogenicidade , Leishmaniose/epidemiologia , Phlebotomus/efeitos dos fármacos , Phlebotomus/genética , Psychodidae
15.
PLoS Negl Trop Dis ; 14(2): e0008011, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069283

RESUMO

BACKGROUND: Visceral leishmaniasis (VL) is a deadly disease transmitted by the sand fly Phlebotomus argentipes on the Indian subcontinent, with a promising means of vector control being orally treating cattle with fipronil-based drugs. While prior research investigating the dynamic relationship between timing of fipronil-based control schemes and the seasonality of sand flies provides insights into potential of treatment on a large scale, ecological uncertainties remain. We investigated how uncertainties associated with sand fly ecology might affect our ability to assess efficacy of fipronil-based control schemes. To do this, we used a previously-described, individual-based, stochastic sand fly model to quantify how uncertainties associated with 1) the percentage of female sand flies taking blood meals from cattle, and 2) the percentage of female sand flies ovipositing in organic matter containing feces from treated cattle might impact the efficacy of fipronil-based sand fly control schemes. PRINCIPAL FINDINGS: Assuming no prior knowledge of sand fly blood meal and oviposition sites, the probabilities of achieving effective sand fly population reduction with treatments performed 3, 6 and 12 times per year were ≈5-22%, ≈27-36%, and ≈46-54%, respectively. Assuming ≥50% of sand flies feed on cattle, probabilities of achieving efficacious control increased to ≈8-31%, ≈15-42%, and ≈52-65%. Assuming also that ≥50% of sand flies oviposit in cattle feces, the above probabilities increased further to ≈14-53%, ≈31-81%, and ≈89-97%. CONCLUSIONS: Our assessments of the efficacy of fipronil-based cattle treatments in controlling sand fly populations depend on our assumptions regarding key aspects of sand fly ecology. Assessments are most sensitive to assumptions concerning the percentage of sand flies ovipositing in feces of treated cattle, thus emphasizing the importance of identifying sand fly oviposition sites. Our results place the evaluation of fipronil-based cattle treatment within a broader ecological context, which could aid in the planning and execution of a largescale field trial.


Assuntos
Doenças dos Bovinos/prevenção & controle , Controle de Insetos/métodos , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/prevenção & controle , Psychodidae/efeitos dos fármacos , Pirazóis/farmacologia , Administração Oral , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Simulação por Computador , Ecossistema , Índia , Mordeduras e Picadas de Insetos/prevenção & controle , Inseticidas/farmacologia , Modelos Biológicos , Pirazóis/administração & dosagem , Incerteza
16.
PLoS Negl Trop Dis ; 14(2): e0008079, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32078634

RESUMO

Visceral leishmaniasis (VL) is a neglected tropical disease, caused by Leishmania (Kinetoplastida, Trypanosomatidae) species. In Brazil, the transmission of this parasite essentially occurs through the bite of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) previously infected with Leishmania infantum. Aiming at preventing VL expansion over the country, integrated control actions have been implemented through a Visceral Leishmaniasis Surveillance and Control Program (VLSCP). Among the actions currently adopted by the program, the screening-culling of seropositive dogs for canine VL (CVL) is particularly polemic. Dogs with negative or divergent serology for CVL remain in their owner's domicile and are monitored by public health agents. In the present study, we determined the prevalence of CVL and analyzed the implementation of the VLSCP screening-culling action, in an area in Brazil where there has been a recent expansion of VL. Canine census surveys were conducted semiannually for two years (Aug/2015 to Feb/2017). Serological diagnosis of CVL was performed in accordance with current VLSCP protocol: immunochromatography (TR-DPP) followed by enzyme-linked immunosorbent assay (ELISA EIE). 6,667 dogs were serologically screened for CVL, of which 567 (8.5%) were positive in both tests and 641 (9.6%) had divergent results. A variable percentage (6.3% to 65.4%) of the dogs in the latter group became positive within nine months from the first result. Xenodiagnosis was conducted in canine samples belonging to any of the three possible serological statuses for CVL-positive, divergent or negative. Leishmania spp. DNA was detected in Lu. longipalpis that fed on 50.0% (5/10) of dogs with positive serology and on 29.4% (5/17) of dogs with divergent serological status for CVL. Therefore, dogs with divergent serology for CVL may be as Leishmania-infective to Lu. longipalpis as seropositive ones. Even with the adoption of euthanasia for seropositive dogs, part of the canine population will continue to serve as a source of Leishmania infection for phlebotomine sand flies.


Assuntos
Doenças do Cão/parasitologia , Leishmaniose Visceral/veterinária , Psychodidae/parasitologia , Animais , Brasil/epidemiologia , Reservatórios de Doenças/veterinária , Doenças do Cão/epidemiologia , Cães , Comportamento Alimentar , Feminino , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Testes Sorológicos
17.
Am J Trop Med Hyg ; 102(4): 758-767, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32043439

RESUMO

Kala azar occurs among seasonal and migrant agricultural workers in northwest Ethiopia and accounts for almost 60% of the disease burden in the country. We conducted a quantitative study on the level of knowledge and practice of this vulnerable group in relation to kala azar transmission and acceptability of its vector control tools. A total of 403 workers were randomly selected from eight farms using a purposive sampling technique. Knowledge and practice scores were calculated based on 12 and 9 core questions, respectively. Binary logistic regression was used to identify factors associated with knowledge and practice. A large gap in knowledge of the disease and the vector was evident with 61.8%, 24.6%, and 13.6% of the workers having poor, moderate, and good levels of knowledge scores, respectively. Similarly, 95% of the seasonal workers reported poor level of use of protective measures against the bite of the sand fly vector. Good level of knowledge about kala azar and its sand fly vector was statistically associated with formal education (adjusted odds ratio [AOR] = 2.11; 95% CI = 1.17, 3.80; P < 0.05) and previous exposure to health education (AOR = 4.72; 95% CI = 1.99, 11.16; P < 0.001). Despite poor current knowledge and practice, a large proportion of the study participants showed interest in using vector control tools if made available, with 78% of the seasonal and migrant workers expressing some willingness to pay for different measures that can protect against sand fly bites. Therefore, we strongly recommend that comprehensive health education and vector control programs should be provided to these workers.


Assuntos
Agricultura , Leishmaniose Visceral/prevenção & controle , Estações do Ano , Migrantes , Adulto , Animais , Etiópia/epidemiologia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Mordeduras e Picadas de Insetos/prevenção & controle , Repelentes de Insetos/economia , Repelentes de Insetos/farmacologia , Mosquiteiros Tratados com Inseticida , Masculino , Pessoa de Meia-Idade , Roupa de Proteção/economia , Psychodidae , Adulto Jovem
18.
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
19.
Mem Inst Oswaldo Cruz ; 115: e190284, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049097

RESUMO

Despite some phlebotomines being well recognised as vectors of leishmaniasis agents, vector importance of those belonging to the genus Trichophoromyia has not been extensively studied. The present study provides evidence regarding the putative vector role played by some species of Trichophoromyia on leishmanine enzootics, based on literature reports and findings obtained from field experiments conducted in the ecotopes of Pará State, Brazil. The species Th. ubiquitalis, Th. velascoi, Th. auraensis, Th. ininii and Th. brachipyga possess minimal criteria to be included in the list of suspected leishmanine vectors. However, knowledge on man-biting behavior, substantiation of vector competence and determination of epidemiological implications are limited for all of the above mentioned species. Published studies together with present data draw attention to prioritize these phlebotomine species in entomological surveillance programs and studies on experimental susceptibility to Leishmania spp. infection.


Assuntos
Insetos Vetores/parasitologia , Leishmania/classificação , Psychodidae/parasitologia , Animais , DNA de Protozoário/genética , Leishmania/genética , Leishmaniose/transmissão , Reação em Cadeia da Polimerase
20.
BMC Infect Dis ; 20(1): 10, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906924

RESUMO

BACKGROUND: A visceral leishmaniasis outbreak was reported from a village in a low-endemic district of Bihar, India. METHODS: Outbreak investigation with house-to-house search and rapid test of kala-azar suspects and contacts was carried out. Sandfly collection and cone bio-assay was done as part of entomological study. RESULTS: A spatially and temporally clustered kala-azar outbreak was found at Kosra village in Sheikhpura district with 70 cases reported till December 2018. Delay of more than a year was found between diagnosis and treatment of the index case. The southern hamlet with socio-economically disadvantaged migrant population was several times more affected than rest of the village (attack rate of 19.0% vs 0.5% respectively, ORMH = 39.2, 95% CI 18.2-84.4). The median durations between onset of fever to first contact with any health services, onset to kala-azar diagnosis, diagnosis to treatment were 10 days (IQR 4-18), 30 days (IQR 17-73) and 1 day (IQR 0.5 to 3), respectively, for 50 kala-azar cases assessed till June 2017. Three-fourths of these kala-azar cases had out-of-pocket medical expenditure for their condition. Known risk factors for kala-azar such as illiteracy, poverty, belonging to socially disadvantaged community, migration, residing in kutcha houses, sleeping in rooms with unplastered walls and non-use of mosquito nets were present in majority of these cases. Only half the dwellings of the kala-azar cases were fully sprayed. Fully gravid female P. argentipes collected post indoor residual spraying (IRS) and low sandfly mortality on cone-bioassay indicated poor effectiveness of vector control. CONCLUSIONS: There is need to focus on low-endemic areas of kala-azar. The elimination programme should implement a routine framework for kala-azar outbreak response. Complete case-finding, use of quality-compliant insecticide and coverage of all sprayable surfaces in IRS could help interrupt transmission during outbreaks.


Assuntos
Surtos de Doenças , Leishmaniose Visceral/epidemiologia , Migrantes , Animais , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Incidência , Índia/epidemiologia , Controle de Insetos/estatística & dados numéricos , Inseticidas/administração & dosagem , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/terapia , Leishmaniose Visceral/transmissão , Psychodidae/fisiologia , Fatores de Risco
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