Integration of municipal state, society and university efforts for sanitary risk prevention associated with Aedes aegypti mosquito in the metropolitan area of Buenos Aires, Argentina.

The sanitary problem of Aedes aegypti mosquito acquires relevance around the world because it is the vector of dengue, zika, chikungunya and yellow fever. The vector is adapting to southern regions faster, and the propagation of these diseases in urban areas is a complex problem for society. We aimed to contribute to the risk prevention of disease transmission in the Metropolitan Area of Buenos Aires, through monitoring Aedes aegypti population levels and developing education campaigns with government agencies and society participation. Monitoring activities aimed to diagnose the presence of the vector and its ecology behaviour, and to generate education and prevention politics to avoid its propagation. The results show that (1) the mosquito is in the territory and it is spreading, (2) prevention activities of the municipalities are insufficient to generate an effective sanitary response and (3) it is necessary to improve the education programmes to the population about the life cycle of the vector. The integration of university, government and society improved the work of the team because it combined knowledge about vector ecology, diseases and territory characteristics.

Ecological meta-analysis of bloom-forming planktonic Cyanobacteria in Argentina.

The aim of the present research was to summarize the main reasons that explain the distribution of harmful blooms of cyanobacteria in Argentina. It is a large territory with climates ranging from humid tropical to cold temperate. We performed a meta-analysis of the published data and information in technical reports published from 1945 to 2015, and included additional data from personal non-published studies. A total of 122 water bodies affected by planktonic cyanobacterial blooms were recorded and geo-referenced. The analysis showed that blooms, defined as events exceeding 5000 cells/mL, occurred in different types of water bodies, including shallow lakes, rivers, streams, reservoirs, estuaries and storage facilities. Maximum bloom abundance and species and ecological strategies (dispersive, scum-forming, nitrogen fixer) responsible for each event were related to the geographic and climatologic characteristics and type and origin of water bodies. The Puna and the Andean Patagonia eco-regions were mostly free of blooms. The most impaired aquatic systems were shallow lakes and reservoirs (46.7 and 24.6%, respectively). Deep lakes had no reports of blooms and rivers were mainly affected at the regulated reaches, with intensities generally decreasing downstream the dams. Besides, 74.3% of the blooms reported in Argentina exceeded WHO Alert Level 2 for drinking and bathing waters (100,000 cells/mL). Thirty-nine species, identified by Komárek's polyphasic approach to taxonomy, were responsible for the blooms. Microcystis aeruginosa, Dolichospermum spiroides, Dolichospermum circinale, Raphidiopsis mediterranea and Cylindrospermopsis raciborskii were frequently found participating in either mixed or single species blooms. The species distribution was associated with the eco-region and aquatic system typologies and affected by seasonality and climatological and geographic variables. The eco-strategies of cyanobacterial species showed stronger associations with the qualitative and quantitative indicators used in the meta-analysis, and appeared as useful tools for management measures.

Dispersal of Aedes aegypti: field study in temperate areas using a novel method.

BACKGROUND & OBJECTIVES: Since Aedes aegypti was identified as vector of yellow fever and dengue, its dispersal is relevant for disease control. We studied the dispersal of Ae. aegypti in temperate areas of Argentina during egglaying, using the existing population and egg traps. METHODS: Two independent replicas of a unique experimental design involving mosquitoes dispersing from an urbanized area to adjacent non-urbanized locations were carried out and analyzed in statistical terms. RESULTS: We found relationship between stochastic variables related to the egg-laying mosquito activity (ELMA), useful to assess dispersal probabilities, despite the lack of knowledge of the total number of ovipositions in the zone. We propose to evaluate the egg-laying activity as minus the logarithm of the fraction of negative ovitraps at different distances from the buildings. INTERPRETATION & CONCLUSION: Three zones with different oviposition activity were determined, a corridor surrounding the urbanization, a second region between 10 and 25 m and the third region extending from 30 to 45 m from the urbanization. The landscape (plant cover) and the human activity in the area appear to have an influence in the dispersal of Ae. aegypti. The proposed method worked consistently in two different replicas.

Baseline water quality and macrophyte assemblages in Pampean streams: a regional approach.

Streams of the pampas region (central Argentina) are characterized by the lack of riparian forests and by low current velocities, and receive a large amount of industrial and domestic effluents. Intensive agriculture in the region has greatly increased during the last years; nevertheless, regional studies to determine baseline conditions are not available. Here, we characterized pampean streams considering physico-chemical water features and the composition of macrophyte communities, and we established if the regions proposed by an early hydrological regionalization show differentiated water chemistry and macrophyte assemblages. Forty-one streams were sampled in autumn, spring and summer. Streams were characterized by alkaline waters, with high conductivities and dissolved oxygen concentrations, and they can be classified as eutrophic. A good discrimination among regions was achieved based on streamwater features in all seasons; variables that most contribute to the discrimination were related to pH, eutrophication, and conservative ions. Regional differences may be due to variations in water availability, parent material, and land use practices. The aquatic plant communities reflected the eutrophic state of waters, but macrophyte composition was not useful to differentiate among regions because it is not affected by differences in water chemistry. Macrophyte species grouped according to their growth form and assemblage distribution were related to chemical variables (as conductivity and nitrate) and possibly to flow conditions.

Capsular polysaccharides secreted by building façade colonisers: characterisation and adsorption to surfaces.

Exopolymers secreted by algal and cyanobacterial strains isolated from building façades were imaged by microscopy techniques. They were extracted and characterised to investigate their possible contribution to interactions with solid surfaces. The polymers were polysaccharides, with anionic and hydrophobic properties varying between the various strains. Capsular polysaccharides extracted from a strain of Klebsormidium flaccidum adsorbed in higher amounts on hydrophobic than on hydrophilic surfaces. These results tend to confirm the hypothesis that exopolymers are important in the colonisation process of microorganisms to surfaces.

Factors involved in the colonisation of building façades by algae and cyanobacteria in France.

Algae and cyanobacteria are colonisers of building façades. A multivariate analysis of data gathered during a sampling campaign around France proved that precipitation, hygrometry, thermal amplitude, distance from the sea and proximity to vegetation were environmental parameters influencing this colonisation. Other influencing factors could be attributed to the nature of the façade coating, mineral substrata being more frequently colonised, and to the architecture, favouring in some cases the formation of damp conditions and thus the colonisation of the building envelope.

The assessment of water quality in the Lower Luján River (Buenos Aires, Argentina): phytoplankton and algal bioassays.

The monitoring of river phytoplankton and several hydrological, physical and chemical variables, in combination with bioassays using Selenastrum capricornutum Printz, allowed the characterisation of three distinct reaches of the Lower River Luján. The upstream stretch, characterised by the lowest depth and discharge, registered the highest nutrient, dissolved heavy metal and chlorophyll a concentrations in accordance with low phytoplankton diversity and the occurrence of several species typical of organically polluted lowland rivers. A downstream improvement, concomitant to increasing river discharge, is revealed by a progressive decrease of organic pollution parameters even though algal toxicity is registered through bioassays. The water input from the Parana River through the G. Arias Channel plays an important role in the regulation of the limnology of the Lower Luján River. As a result of marked increasing discharge, depth and width, there is a decrease in nutrient concentration and phytoplankton density and an increase in dissolved oxygen concentration. Likewise, algal growth rates in the bioassays showed less toxic effect.

Programa de salud animal y salud pública veterinaria en el área VI de OPS

Hechos más salientes, por país, en el campo de la salud animal y salud pública veterinaria ocurridos durante 1979. Brucelosis, garrapata en bovinus, sarna, hidatidosis, brucelosis bovina, tuberculosis bovina, rabia ectoparasitosis, en Argentina, Chile, Paraguay y Uruguay. Comparación entre los países del área VI en relación a programas de salud animal

Programa de salud animal y salud pública veterinaria en el área VI de OPS

Hechos más salientes, por país, en el campo de la salud animal y salud pública veterinaria ocurridos durante 1979. Brucelosis, garrapata en bovinus, sarna, hidatidosis, brucelosis bovina, tuberculosis bovina, rabia ectoparasitosis, en Argentina, Chile, Paraguay y Uruguay. Comparación entre los países del área VI en relación a programas de salud animal