RESUMO
Nesotriatoma confusa sp. nov. (Hemiptera, Reduviidae, Triatominae) is described based on specimens from Cuba. From one male, one female, and eleven nymphs of a then-undescribed species of Nesotriatoma collected in Cuba, a colony was formed and its specimens were used to describe N. confusa sp. nov. Characters were observed on the head, thorax, abdomen, female external genitalia, and male genitalia with optical microscopy and scanning electron microscopy. We concluded that N. bruneri (Usinger, ) was indeed a synonym of N. flavida (Neiva, ) as previously proposed.
Assuntos
Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Insetos Vetores/patogenicidade , Triatominae/parasitologia , Triatominae/patogenicidade , Animais , Cuba , Feminino , Masculino , MicroscopiaRESUMO
In southeast Amazon, Lutzomyia (Nyssomyia) flaviscutellata is the incriminated vector of Leishmania (Leishmania) amazonensis, a causative agent of zoonotic cutaneous leishmaniasis (CL). The optimal methods for surveying Lu. flaviscutellata were investigated in the Bragança region, northeast Pará State, Brazil, selected for the presence of Le. amazonensis. The performances of modified Disney traps and CDC light traps were compared in four ecotopes within and around four village transects during the wet and dry seasons. The physiological age of female sand flies was estimated and natural infection by flagellates was evaluated by dissection. Disney traps were better for detecting the presence of Lu. flaviscutellata, while CDC traps performed well for detecting Lutzomyia (Nyssomyia) antunesi, suspected vector of Leishmania lindenbergi. The former was more abundant during the wet season, when female flies were naturally infected with Le. amazonensis. These findings identified the environments of local transmission. In order to improve surveys of Lu. flaviscutellata as part of integrated epidemiological surveillance of CL, our recommendations include focusing vector surveys with Disney traps on forest fragments where people work, during the seasonal peak of the vector. Further field studies are required to make model-based predictions of seasonal variations in the vectorial capacity of vector populations.
Assuntos
Insetos Vetores/parasitologia , Insetos Vetores/patogenicidade , Leishmaniose Cutânea/transmissão , Psychodidae/parasitologia , Psychodidae/patogenicidade , Animais , Brasil , Entomologia , Leishmania/patogenicidade , Leishmaniose Cutânea/parasitologia , Estações do AnoRESUMO
Previous studies have shown that the negative effects of density of Ae. albopictus on Ae. aegypti exceed those of Ae. aegypti on Ae. albopictus for population growth, adult size, survivorship, and developmental rate. This competitive superiority has been invoked to explain the displacement of Ae. aegypti by Ae. albopictus in the southeastern USA. In Brazil, these species coexist in many vegetated suburban and rural areas. We investigated a related, but less-well-studied question: do effects of Ae. albopictus on Ae. aegypti larval development and survival occur under field conditions at realistic densities across multiple seasons in Brazil? We conducted additive competition experiments in a vegetated area of Rio de Janeiro where these species coexist. We tested the hypothesis that Ae. aegypti (the focal species, at a fixed density) suffers negative effects on development and survivorship across a gradient of increasing densities of Ae. albopictus (the associate species) in three seasons. The results showed statistically significant effects of both season and larval density on Ae. aegypti survivorship, and significant effects of season on development rate, with no significant season-density interactions. Densities of Aedes larvae in these habitats differed among seasons by a factor of up to 7x. Overall, Spring was the most favorable season for Ae. aegypti survivorship and development. Results showed that under natural conditions the negative competitive effects of Ae. albopictus on Ae. aegypti were expressed primarily as lower survivorship. Coexistence between Ae. aegypti and Ae. albopictus in vegetated areas is likely affected by seasonal environmental differences, such as detrital resource levels or egg desiccation, which can influence competition between these species. Interactions between these Aedes are important in Brazil, where both species are well established and widely distributed and vector dengue, Zika and chikungunya viruses.
Assuntos
Aedes/virologia , Dengue/transmissão , Insetos Vetores/patogenicidade , Infecção por Zika virus/transmissão , Aedes/crescimento & desenvolvimento , Aedes/patogenicidade , Animais , Brasil , Dengue/epidemiologia , Estações do Ano , Zika virus/patogenicidade , Infecção por Zika virus/epidemiologiaRESUMO
A fundamental question to be clarified concerning the host cell invasion by Trypanosoma cruzi is whether the insect-borne and mammalian-stage parasites use similar mechanisms for invasion. To address that question, we analysed the cell invasion capacity of metacyclic trypomastigotes (MT) and tissue culture trypomastigotes (TCT) under diverse conditions. Incubation of parasites for 1 h with HeLa cells in nutrient-deprived medium, a condition that triggered lysosome biogenesis and scattering, increased MT invasion and reduced TCT entry into cells. Sucrose-induced lysosome biogenesis increased HeLa cell susceptibility to MT and resistance to TCT. Treatment of cells with rapamycin, which inhibits mammalian target of rapamycin (mTOR), induced perinuclear lysosome accumulation and reduced MT invasion while augmenting TCT invasion. Metacylic trypomastigotes, but not TCT, induced mTOR dephosphorylation and the nuclear translocation of transcription factor EB (TFEB), a mTOR-associated lysosome biogenesis regulator. Lysosome biogenesis/scattering was stimulated upon HeLa cell interaction with MT but not with TCT. Recently, internalized MT, but not TCT, were surrounded by colocalized lysosome marker LAMP2 and mTOR. The recombinant gp82 protein, the MT-specific surface molecule that mediates invasion, induced mTOR dephosphorylation, nuclear TFEB translocation and lysosome biogenesis/scattering. Taken together, our data clearly indicate that MT invasion is mainly lysosome-dependent, whereas TCT entry is predominantly lysosome-independent.
Assuntos
Doença de Chagas/genética , Interações Hospedeiro-Patógeno/genética , Lisossomos/parasitologia , Trypanosoma cruzi/patogenicidade , Animais , Doença de Chagas/parasitologia , Suscetibilidade a Doenças/metabolismo , Suscetibilidade a Doenças/parasitologia , Células HeLa , Humanos , Insetos Vetores/genética , Insetos Vetores/parasitologia , Insetos Vetores/patogenicidade , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Lisossomos/metabolismo , Sirolimo/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Técnicas de Cultura de Tecidos , Trypanosoma cruzi/metabolismoRESUMO
Since chikungunya virus (CHIKV) was introduced into the Americas in 2013, its geographic distribution has rapidly expanded. Of 119 serum samples collected in 2014 from febrile patients in southern Mexico, 79% were positive for CHIKV or IgM against CHIKV. Sequencing results confirmed CHIKV strains closely related to Caribbean isolates.
Assuntos
Febre de Chikungunya/epidemiologia , Vírus Chikungunya/patogenicidade , Surtos de Doenças/estatística & dados numéricos , Febre de Causa Desconhecida/etiologia , Animais , Anticorpos Antivirais/sangue , Febre de Chikungunya/patologia , Culicidae/virologia , Febre de Causa Desconhecida/epidemiologia , Humanos , Insetos Vetores/patogenicidade , Insetos Vetores/virologia , México/epidemiologia , Dados de Sequência MolecularRESUMO
In 2009, the WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the International Development Research Centre (IDRC) launched a call for innovative community-based ecosystem management research projects for dengue and Chagas disease prevention in low and middle income countries in Latin America and the Caribbean. Eight research institutions were selected. The outputs of these projects led to a better understanding of the interaction between ecological, biological, social and economic (eco-bio-social) determinants of dengue and Chagas disease in Latin America and the Caribbean. Both diseases are considered highly relevant in the regional health agendas.
Assuntos
Doença de Chagas/prevenção & controle , Serviços de Saúde Comunitária/organização & administração , Dengue/prevenção & controle , Insetos Vetores/patogenicidade , Animais , Região do Caribe/epidemiologia , Doença de Chagas/transmissão , Mudança Climática , Análise Custo-Benefício , Dengue/transmissão , Reservatórios de Doenças , Ecossistema , Humanos , América Latina/epidemiologia , Doenças Negligenciadas , Inovação Organizacional , Urbanização , Microbiologia da Água/normas , Abastecimento de Água/normasRESUMO
BACKGROUND: This study intended to implement a novel intervention strategy, in Brazil, using an ecohealth approach and analyse its effectiveness and costs in reducing Aedes aegypti vector density as well as its acceptance, feasibility and sustainability. The intervention was conducted from 2012 to 2013 in the municipality of Fortaleza, northeast Brazil. METHODOLOGY: A cluster randomized controlled trial was designed by comparing ten intervention clusters with ten control clusters where routine vector control activities were conducted. The intervention included: community workshops; community involvement in clean-up campaigns; covering the elevated containers and in-house rubbish disposal without larviciding; mobilization of schoolchildren and senior inhabitants; and distribution of information, education and communication (IEC) materials in the community. RESULTS: Differences in terms of social participation, commitment and leadership were present in the clusters. The results showed the effectiveness of the intervention package in comparison with the routine control programme. Differences regarding the costs of the intervention were reasonable and could be adopted by public health services. CONCLUSIONS: Embedding social participation and environmental management for improved dengue vector control was feasible and significantly reduced vector densities. Such a participatory ecohealth approach offers a promising alternative to routine vector control measures.
Assuntos
Serviços de Saúde Comunitária/organização & administração , Dengue/prevenção & controle , Reservatórios de Doenças/parasitologia , Controle de Mosquitos/organização & administração , Aedes/parasitologia , Animais , Atitude Frente a Saúde , Brasil/epidemiologia , Análise por Conglomerados , Ecossistema , Entomologia , Estudos de Viabilidade , Conhecimentos, Atitudes e Prática em Saúde , Promoção da Saúde/organização & administração , Habitação , Humanos , Insetos Vetores/patogenicidade , Participação SocialRESUMO
Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.
Assuntos
DNA de Protozoário/isolamento & purificação , Insetos Vetores/parasitologia , Leishmania/genética , Leishmaniose Visceral/transmissão , Psychodidae/classificação , Animais , Biodiversidade , Aves/sangue , Brasil , Cães , Ensaio de Imunoadsorção Enzimática , Comportamento Alimentar/fisiologia , Pradaria , Humanos , Soros Imunes , Insetos Vetores/patogenicidade , Leishmaniose Visceral/parasitologia , Mephitidae/sangue , Reação em Cadeia da Polimerase , Psychodidae/parasitologia , Psychodidae/patogenicidade , Roedores/sangue , Tempo (Meteorologia)RESUMO
Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.