Distribution and preference for oviposition sites of Aedes albopictus (Skuse) in the metropolitan area of Belém, in the Brazilian Amazon.

The mosquito Aedes albopictus is a vector of several arboviruses transmitted to humans. They have a sylvatic behavior, occurring in rural areas. However, reports of their adaptation to anthropic environments have been increasing. The aim of this study is to investigate the presence and distribution of Ae. albopictus in the Metropolitan Region of Belém in the Brazilian Amazon and evaluate its preference for either natural or artificial breeding sites under the weather conditions of the Amazon. Ovitraps (artificial breeding sites) and bamboo internodes (natural breeding sites) were deployed in neighborhood peridomiciles during the dry and rainy seasons. The results showed that the presence of Ae. albopictus was recorded in 71.4% of the neighborhoods during the dry season and in 69.2% neighborhoods during the rainy season, thus indicating a wide distribution in the region. A significant increase in the frequency of the capture of mosquitoes in areas with higher vegetation cover was observed during the dry season (R2 = 0.2995; p=0.018) but not during the rainy season (R2 = 0.044; p=0.43). Comparing the weekly frequency of Ae. albopictus on positive bamboos and OVT, no significant difference was observed between them (t= 0.559; df= 23; p=0.58). A significant increase in the number of positive breeding sites was observed with increased rainfall for both bamboo (R2 = 0.33; p= 0.002) and OVT (R2 = 0.24; p= 0.013). This is the first report of Ae. albopictus in the metropolitan area of Belém. The findings suggest a wide distribution in the studied area, preferably in areas with more extensive vegetation cover. Additionally, the mosquito population showed the ability to use both natural and artificial habitats.

Improve protective efficacy of a TB DNA-HSP65 vaccine by BCG priming.

Vaccines are considered by many to be one of the most successful medical interventions against infectious diseases. But many significant obstacles remain, such as optimizing DNA vaccines for use in humans or large animals. The amount of doses, route and easiness of administration are also important points to consider in the design of new DNA vaccines. Heterologous prime-boost regimens probably represent the best hope for an improved DNA vaccine strategy. In this study, we have shown that heterologous prime-boost vaccination against tuberculosis (TB) using intranasal BCG priming/DNA-HSP65 boosting (BCGin/DNA) provided significantly greater protection than that afforded by a single subcutaneous or intranasal dose of BCG. In addition, BCGin/DNA immunization was also more efficient in controlling bacterial loads than were the other prime-boost schedules evaluated or three doses of DNA-HSP65 as a naked DNA. The single dose of DNA-HSP65 booster enhanced the immunogenicity of a single subcutaneous BCG vaccination, as evidenced by the significantly higher serum levels of anti-Hsp65 IgG2a Th1-induced antibodies, as well as by the significantly greater production of IFN-gamma by antigen-specific spleen cells. The BCG prime/DNA-HSP65 booster was also associated with better preservation of lung parenchyma. The improvement of the protective effect of BCG vaccine mediated by a DNA-HSP65 booster suggests that our strategy may hold promise as a safe and effective vaccine against TB.