Larvicidal activity of piperovatine and dichloromethane extract from Piper corcovadensis roots against mosquitoes Aedes aegypti L / Actividad larvicida de piperovatina y extracto de diclorometano de las raíces de Piper corcovadensis contra mosquitos vectores del dengue Aedes aegypti L

The research of new substances capable of controlling the Aedes aegypti mosquito is urgent due to the increase in the transmission of the diseases such as dengue, chikungunya and Zika virus by the vector. Thus, the aim of this study was to evaluate the larvicidal activity of crude extract of Piper corcovadensis roots, a native plant from Brazil, and of the isolated compound piperovatine against larvae of A. aegypti by the larval immersion test. The lethal concentration that killed 50% (LC50) and 99% (LC99) of larvae was determined by Probit analysis. The results indicated high larvicidal activity on A. aegypti larvae for crude extract of Piper corcovadensis roots with LC50 of 4.86 µg/mL and LC99 of 15.50 µg/mL and piperovatine with LC50 of 17.78 µg/mL and LC99 of 48.55 µg/mL. This work opens new perspectives to the development of future products with crude extract of Piper corcovadensis roots and piperovatine that can be applied to mosquito control.

La investigación de nuevas sustancias capaces de controlar el mosquito Aedes aegypti es urgente debido al aumento en la transmisión de enfermedades como el dengue, el chikungunya y el virus Zika por el vector. Por lo tanto, el objetivo de este estudio fue evaluar la actividad larvicida del extracto crudo de las raíces de Piper corcovadensis, una planta nativa de Brasil, y del compuesto aislado piperovatine contra larvas de A. aegypti mediante la prueba de inmersión larvaria. La concentración letal que mató al 50% (LC50) y al 99% (LC99) de larvas se determinó mediante análisis Probit. Los resultados indicaron una alta actividad larvicida en larvas de A. aegypti para extracto crudo de las raíces de Piper corcovadensis con LC50 de 4.86 µg/mL y LC99 de 15.50 µg/mL y piperovatine con LC50 de 17.78 µg/mL y LC99 de 48.55 µg/mL. Este trabajo abre nuevas perspectivas para el desarrollo de futuros productos con extracto crudo de las raíces de Piper corcovadensis y piperovatine que pueden aplicarse al control de mosquitos.

Keeping our immigrants healthy: hygienist doctrine in the Hospedaria de Imigrantes da Ilha das Flores. / Como manter saudáveis nossos imigrantes: preceitos higienistas na constituição da Hospedaria de Imigrantes da Ilha das Flores.

The Hospedaria de Imigrantes (Immigrant Lodgings) da Ilha das Flores was established in 1883 in accordance with the hygienist thinking of the time. Immigrants were isolated on the east coast of Guanabara Bay because of the epidemics of yellow fever which returned to the Imperial capital every summer since 1849-1850. Hygienists attributed the disease to the precarious health conditions in the city of Rio de Janeiro, which enabled germs to multiply and infect the atmosphere. As physicians reinterpreted the disease in light of Pasteurian theory, new procedures were adopted to receive immigrants, changing the structure and function of the facility on Ilha das Flores.

A criação da Hospedaria de Imigrantes da Ilha das Flores, em 1883, esteve de acordo com os preceitos higienistas vigentes na época. O isolamento de imigrantes na costa leste da baía de Guanabara ocorreu em virtude das epidemias de febre amarela que retornavam à capital do Império todo verão, desde 1849-1850. Higienistas atribuíam a doença à precária condição sanitária da cidade do Rio de Janeiro, que propiciava a multiplicação do germe e infeccionava a atmosfera. Na medida em que os médicos reinterpretavam a doença à luz da teoria pasteuriana, foram sendo adotados novos procedimentos para a recepção de imigrantes, alterando a estrutura e o funcionamento da Hospedaria da Ilha das Flores.

Como manter saudáveis nossos imigrantes: preceitos higienistas na constituição da Hospedaria de Imigrantes da Ilha das Flores / Keeping our immigrants healthy: hygienist doctrine in the Hospedaria de Imigrantes da Ilha das Flores

Resumo A criação da Hospedaria de Imigrantes da Ilha das Flores, em 1883, esteve de acordo com os preceitos higienistas vigentes na época. O isolamento de imigrantes na costa leste da baía de Guanabara ocorreu em virtude das epidemias de febre amarela que retornavam à capital do Império todo verão, desde 1849-1850. Higienistas atribuíam a doença à precária condição sanitária da cidade do Rio de Janeiro, que propiciava a multiplicação do germe e infeccionava a atmosfera. Na medida em que os médicos reinterpretavam a doença à luz da teoria pasteuriana, foram sendo adotados novos procedimentos para a recepção de imigrantes, alterando a estrutura e o funcionamento da Hospedaria da Ilha das Flores.

Abstract The Hospedaria de Imigrantes (Immigrant Lodgings) da Ilha das Flores was established in 1883 in accordance with the hygienist thinking of the time. Immigrants were isolated on the east coast of Guanabara Bay because of the epidemics of yellow fever which returned to the Imperial capital every summer since 1849-1850. Hygienists attributed the disease to the precarious health conditions in the city of Rio de Janeiro, which enabled germs to multiply and infect the atmosphere. As physicians reinterpreted the disease in light of Pasteurian theory, new procedures were adopted to receive immigrants, changing the structure and function of the facility on Ilha das Flores.

Immunogenicity and Protection After Vaccination With a Modified Vaccinia Virus Ankara-Vectored Yellow Fever Vaccine in the Hamster Model.

The highly efficacious live-attenuated 17D yellow fever (YF) vaccine is occasionally associated with rare life-threatening adverse events. Modified vaccinia virus Ankara (MVA), a non-replicating poxvirus, has been used as a vaccine platform to safely deliver various antigens. A MVA-based YF vaccine (MVA-BN-YF) was tested with and without a non-mineral oil adjuvant in a hamster model of lethal YF disease and protective efficacy of this vaccine was compared with the 17D vaccine. The vaccine candidate MVA-BN-YF generated a protective response in hamsters infected with YFV that was comparable to protection by the live 17D vaccine. Similar levels of neutralizing antibody were observed in animals vaccinated with either vaccine alone or vaccine with adjuvant. Significant improvement in survival, weight change, and serum alanine aminotransferase levels were observed in vaccinated hamsters when administered 42 and 14 days prior to challenge with Jimenez YF virus (YFV). Neutralizing antibodies induced by MVA-BN-YF were transferred to naïve hamsters prior to virus challenge. Passive administration of neutralizing antibody 24 h prior to virus infection resulted in significantly improved survival and weight change. A trend toward reduced liver enzyme levels was also observed. MVA-BN-YF, therefore, represents a safe alternative to vaccination with live-attenuated YFV.

Dopamine receptor antagonists as new mode-of-action insecticide leads for control of Aedes and Culex mosquito vectors.

BACKGROUND: New mode-of-action insecticides are sought to provide continued control of pesticide resistant arthropod vectors of neglected tropical diseases (NTDs). We previously identified antagonists of the AaDOP2 D1-like dopamine receptor (DAR) from the yellow fever mosquito, Aedes aegypti, with toxicity to Ae. aegypti larvae as leads for novel insecticides. To extend DAR-based insecticide discovery, we evaluated the molecular and pharmacological characteristics of an orthologous DAR target, CqDOP2, from Culex quinquefasciatus, the vector of lymphatic filariasis and West Nile virus. METHODS/RESULTS: CqDOP2 has 94.7% amino acid identity to AaDOP2 and 28.3% identity to the human D1-like DAR, hD1. CqDOP2 and AaDOP2 exhibited similar pharmacological responses to biogenic amines and DAR antagonists in cell-based assays. The antagonists amitriptyline, amperozide, asenapine, chlorpromazine and doxepin were between 35 to 227-fold more selective at inhibiting the response of CqDOP2 and AaDOP2 in comparison to hD1. Antagonists were toxic to both C. quinquefasciatus and Ae. aegypti larvae, with LC50 values ranging from 41 to 208 µM 72 h post-exposure. Orthologous DOP2 receptors identified from the African malaria mosquito, Anopheles gambiae, the sand fly, Phlebotomus papatasi and the tsetse fly, Glossina morsitans, had high sequence similarity to CqDOP2 and AaDOP2. CONCLUSIONS: DAR antagonists represent a putative new insecticide class with activity against C. quinquefasciatus and Ae. aegypti, the two most important mosquito vectors of NTDs. There has been limited change in the sequence and pharmacological properties of the DOP2 DARs of these species since divergence of the tribes Culicini and Aedini. We identified antagonists selective for mosquito versus human DARs and observed a correlation between DAR pharmacology and the in vivo larval toxicity of antagonists. These data demonstrate that sequence similarity can be predictive of target potential. On this basis, we propose expanded insecticide discovery around orthologous DOP2 targets from additional dipteran vectors.

Fresh, dried or smoked? Repellent properties of volatiles emitted from ethnomedicinal plant leaves against malaria and yellow fever vectors in Ethiopia.

BACKGROUND: In the search for plant-based mosquito repellents, volatile emanations were investigated from five plant species, Corymbia citriodora, Ocimum suave, Ocimum lamiifolium, Olea europaea and Ostostegia integrifolia, traditionally used in Ethiopia as protection against mosquitoes. METHODS: The behaviour of two mosquitoes, the malaria vector Anopheles arabiensis and the arbovirus vector Aedes aegypti, was assessed towards volatiles collected from the headspace of fresh and dried leaves, and the smoke from burning the dried leaves in a two-choice landing bioassay and in the background of human odour. RESULTS: Volatile extracts from the smoke of burning dried leaves were found to be more repellent than those from fresh leaves, which in turn were more repellent to mosquitoes than volatiles from dried leaves. Of all smoke and fresh volatile extracts, those from Co. citriodora (52-76%) and Oc. suave (58-68%) were found to be the most repellent, Os. integrifolia (29-56%) to be intermediate while Ol. europaea (23-40%) and Os. integrifolia (19-37%) were the least repellent. One volatile present in each of the fresh leaf extracts of Co. citriodora, Oc. suave and Os. integrifolia was ß-ocimene. The levels of ß-ocimene reflected the mosquito repellent activity of these three fresh leaf extracts. Female host-seeking mosquitoes responded dose-dependently to ß-ocimene, both physiologically and behaviourally, with a maximal behavioural repulsion at 14% ß-ocimene. ß-ocimene (14%) repels mosquitoes in our 6-minute landing assays comparable to the synthetic insect repellent N,N-diethyl-m-toluamide (10% DEET). CONCLUSIONS: Volatiles in the smoke of burning as well as fresh leaves of Co. citriodora and Oc. suave have significant repellent properties against host seeking An. arabiensis and Ae. aegypti mosquitoes. ß-ocimene, present in the fresh leaf headspace of Co. citriodora, Oc. suave and Os. integrifolia, is a significantly effective volatile mosquito repellent in the laboratory. In addition to its repellent properties, ß-ocimene has long approved safe for use in food and cosmetics, making this volatile an intriguing compound to pursue in further tests in the laboratory and field to validate its mosquito repellent activity and potential for use in a commercial product. Also, the landing bioassay with humanised membranes is a potentially useful repellent screening technique that does not require the exposure of humans to the vectors, however further tests in parallel with conventional techniques are advised.

[Combined (associated) vaccination against quarantinable infections]. / Kompleksnaia (assotsiirovannaia) vaktsinatsiia protiv karantinnykh infektsii.

The presence of several active foci of infection of different etiology is an indication for complex (combined) immunization against these diseases. The scheme of complex (combined) immunization against plague, cholera and yellow fever has been experimentally substantiated and successfully tested on volunteers.

Combate aos vetores da febre amarela e do dengue Aedes aegypti/Aedes albopictus: instruçöes para guardas, guardas-chefes e inspetores / Combat against vectors of yelow fever and dengue Aedes aegypti/Aedes Albopictus: instructions for guards, guard-chiefs and inspectors

O manual destina-se aos guardas, guardas-chefes e inspetores da SUCAM que trabalham no Programa de Controle da Febre Amarela e no combate ao Aedes Aegypti e Albopictus. Contém regulamento disciplinar e noçöes gerais sobre a doença e seu controle. (AMSB)