Dengue is considered to be the most important mosquito-borne viral disease in the world. The Aedes aegypti mosquito, its vector, is highly anthropophilic and is very well adapted to urban environments. Although several vaccine candidates are in advanced stages of development no licensed dengue vaccine is yet available. As a result, controlling the spread of dengue still requires that mosquitoes be targeted directly. We review the current methods of dengue vector control focusing on recent technical advances. We first examine the history of Brazil’s National Dengue Control Plan in effect since 2002, and we describe its establishment and operation. With the persistent recurrence of dengue epidemics, current strategies should be reassessed to bring to the forefront a discussion of the possible implementation of new technologies in Brazil’s mosquito control program.

Background: Dengue is a major public health problem worldwide, especially in the tropical and subtropical regions of the world. Infection with a single Dengue virus (DENV) serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients experiencing secondary infection with a different serotype progresses to the severe form of the disease, dengue hemorrhagic fever/dengue shock syndrome. Currently, there are no licensed vaccines or antiviral drugs to prevent or treat dengue infections. Biodegradable nanoparticles coated with proteins represent a promising method for in vivo delivery of vaccines. Findings: Here, we used a murine model to evaluate the IgG production after administration of inactivated DENV corresponding to all four serotypes adsorbed to bovine serum albumin nanoparticles. This formulation induced a production of anti-DENV IgG antibodies (p < 0.001). However, plaque reduction neutralization assays with the four DENV serotypes revealed that these antibodies have no neutralizing activity in the dilutions tested. Conclusions: Our results show that while the nanoparticle system induces humoral responses against DENV, further investigation with different DENV antigens will be required to improve immunogenicity, epitope specicity, and functional activity to make this platform a viable option for DENV vaccines.

The global economic cost of Aedes-borne diseases, such as dengue, is estimated to be in the billions of dollars annually. In this scenario, a sustained vector control strategy is the only alternative to control dengue, as well as other diseases transmitted by Aedes, including Zika and chikungunya. The use of transgenic mosquitoes is a promising weapon in the improvement of approaches currently applied in Aedes aegypti control. Field trials using genetically modified mosquitoes for population control have been conducted and offer an excellent opportunity to evaluate what can be improved. In a mass-rearing mosquito facility, the absence of a transgenic line that produces male-only progeny is undoubtedly a limiting factor; thus, being able to manipulate sex determination in this species is a fundamental step for the success of this strategy. Likewise, the possibility of manipulation of the sex determination pathway opens-up a new opportunity for disease control.

Hemocytes are insect immune cells which are responsible for processes of phagocytosis, encapsulation, and coagulation. This study aim to characterize the hemocyte cells in two species amazon blackflies: Ectemnaspis rorotaense (Floch & Abonnenc) and Ectemnaspis trombetense (Hamada, Py-Daniel & Adler). Black fly larvae and pupae were collected from streams in Presidente Figueiredo Municipality, Amazonas State, Brazil. Hemolymph of 36 individuals of E. rorotaense (12 larvae, 12 pupae and 12 adults) and 38 of E. trombetense (12 larvae, 12 pupae and 14 adults) were collected and the cells were characterized by light microscopy; 200 adults of each species were used to transmission electron microscopy study. In this work were showed, by the first time, the hemocyte cells of black flies amazon. Four cell types were identified: prohemocytes, granulocytes, oenocytoids, and plasmatocytes. Prohemocytes were the smallest cells and they exhibited a high nuclear-cytoplasmic ratio. Granulocytes possessed large, eccentric nuclei, and they were characterized by the presence of granules that differed in size and shape. Oenocytoids presented poorly developed nucleus with localization in central region. Plasmatocytes showed more morphological variations and large projections in the cytoplasmic membrane. The prohemocytes were the most frequent in E. rorotaense, with nearby 45% of total cells, whereas plasmatocytes and granulocytes, each one with 38%, were the most abundant in E. trombetense. This study showed that prohemocytes, granulocytes, oenocytoids, and plasmatocytes were present in the hemolymph of E. rorotaense and E. trombetense during all stages. Caracterização Morfológica de Hemócitos em Ectemnaspis rorotaense (Floch & Abonnenc) e Ectemnaspis trombetense (Hamada, Py-Daniel & Adler) (Diptera: Simuliidae) Resumo. Os hemócitos são células do sistema imune dos insetos responsáveis pelos processos de fagocitose, encapsulação e coagulação. O objetivo desse trabalho foi caracterizar os hemócitos nos simulídeos amazônicos, Ectemnaspis rorotaense (Floch & Abonnenc)e Ectemnaspis trombetense (Hamada, Py-Daniel & Adler). Larvas e pupas de simulídeos foram coletadas em igarapés no município de Presidente Figueiredo, Amazonas, Brasil. Para caracterização celular através da microscopia óptica, foi coletada a hemolinfa de 36 espécimes (12 larvas, 12 pupas e 12 adultos) de E. rorotaense e 38 espécimes (12 larvas, 12 pupas e 14 adultos) de E. trombetense. Para o estudo com microscopia eletrônica de transmissão, 200 adultos de cada espécie foram utilizados. Neste trabalho foram descritos, pela primeira vez, os hemócitos de simulídeos amazônicos. Foram identificados quatro tipos celulares em larvas, pupas e adultos: prohemócitos, plasmatócitos, granulócitos e oenocitóides. Os prohemócitos, com um núcleo volumoso em relação ao citoplasma, se mostraram as menores células. Os granulócitos foram caracterizados pela presença de grânulos de diferentes tamanhos e formas e um núcleo grande e excêntrico. Os oenocitóides revelaram núcleo pouco desenvolvido, geralmente localizado na região central. Os plasmatócitos apresentaram grandes projeções da membrana citoplasmática e maior variação morfológica. Os prohemócitos foram as células mais frequentes em E. rorotaense com 45% do total das células, enquanto os plasmatócitos e granulócitos, ambas com 38% cada, foram as mais abundantes em E. trombetense. Esse estudo mostrou que prohemócitos, granulócitos, oenocitóides e plasmatócitos são presentes na hemolinfa de E. rorotaense and E. trombetense durante todos os estágios.

Since the Zika outbreaks are unprecedented human threat in relation to congenital malformations and neurological/autoimmune complications as well as its high potential to spread in regions presenting the vectors, improvements in mosquito control is a top priority. Thus, Aedes aegypti laboratory strains will be fundamental to support studies in different research fields implicated on Zika-mosquito interactions which are the basis for the development of innovative control methods. In this sense, we determined the main infection aspects of the Brazilian Zika strain in reference Aedes aegypti laboratory mosquitoes. We orally exposed Rockefeller, Higgs and Rexville mosquitoes to a Brazilian ZIKV (ZIKV ^BR ) and qRT-PCR was applied to determine the infection and dissemination rates, and viral levels in mosquito tissues as well as in the saliva. The ZIKV ^BR kinetics was monitored during the infection in Rockefeller mosquitoes. Rockefeller strain was the most susceptible at 7 days post-infection but all strains presented similar infection levels at 14 days post-infection. Although variations in the saliva detection rates were observed, we confirmed that ZIKV ^BR was present in saliva from Rockefeller, Higgs and Rexville females at detectable levels at 14 days post-infection. The ZIKV ^BR kinetics in Rockefeller mosquitoes showed that the virus could be detected in the heads at 4 days post-infection but was more consistently detected late in infection. The viral levels peaked at 11 days post-infection in the mosquito bodies, remaining stable until 14 days post-infection, in contrast to the heads, where the mean viral levels only peaked at 14 days post-infection. Our study presents the first evaluation on how Brazilian Zika virus behaves in reference Aedes aegypti strains and shed light on how the infection evolves over time. Vector competence and basic hallmarks of the ZIKV ^BR development were revealed in laboratory mosquitoes. This study provides additional information to accelerate studies focusing on ZIKV-mosquito interactions.