Among the major sources that supply drinkable water are the aquifers which are geological formations that store water and act as a deposit and reserve, being in the entire terrestrial surface. Their exploitation is performed by artesian wells and the increasing demand for drinkable water in densely populated areas has forced the installation of these wells. The aim of this study was to determine the degree of contamination expressed by the concentration of fecal, total coliforms and aerobic mesophilic bacteria in samples of water from artesian wells from the Central and Cordillera departments and the capital city, within the limits of the Patiño aquifer outcrop. We evaluated 57 water samples from artesian wells of 20 to 130 m depth, treated and untreated, that were sent to INTN by owners of artesian wells and water sellers in 2008. We used the multiple tube technique for the determination of total and fecal coliforms and the most probable number for aerobic mesophiles. Of the samples, 58% (33/57) were classified as contaminated. In treated water, 12.5, 40.0 and 31.2% of fecal coliforms, aerobic mesophiles and total coliforms respectively had values outside the permitted limits.In untreated water,19.5,61.5 and 48.8 % of fecal coliforms, aerobic mesophiles and total coliforms respectively had values outside the permitted limits by the provisions of the Paraguayan Standard 24 001 80 (5th edition). It is important to detect microbiological contamination in groundwater, as they are sources of drinkable water.

Entre las fuentes principales que suministran agua para consumo humano se encuentran los acuíferos, que son formaciones geológicas que almacenan agua y actúan como depósito y reserva y se encuentran en toda la superficie terrestre. La explotación se realiza mediante pozos artesianos. La demanda creciente de consumo de agua potable en zonas densamente pobladas han requerido su instalación. El objetivo de este estudio fue determinar el grado de contaminación expresado en la concentración de coliformes fecales, totales y aerobios mesófilos en muestras de agua de pozo del departamento Central, Cordillera y municipio Capital, dentro del límite de afloramiento del acuífero Patiño. Se evaluaron 57 muestras de agua de pozo artesiano de 20 a 130 m de profundidad, tratadas y no tratadas remitidas por propietarios de pozos particulares y aguaterias al INTN durante el año 2008. Se usó la técnica de tubos múltiples para la determinación de coliformes totales y fecales y la de número más probable para aerobios Mesófilos. Fueron clasificadas como contaminadas el 58%(33/57) de las muestras. En las aguas tratadas el 12,5; 40 y 31,2% tenían valores fuera de lo permitido para coliformes fecales, aerobios mesófilos y coliformes totales respectivamente. En aguas no tratadas el 19,5; 61,5 y 48,8% tenían coliformes fecales, aerobios mesófilos y coliformes totales, respectivamente, en niveles fuera de lo permitido de acuerdo a lo establecido en la Norma Paraguaya NP 24 001 80 (5ª edición). Es importante detectar la contaminación microbiológica en las aguas subterráneas, ya que constituyen fuentes de agua potable.

A white Shannon-type trap was used for captures of female sand flies in the search for natural infection with flagellates, however, due to its low productivity and as a large number of phlebotomines settled on the researchers' black clothes, we decided to compare the relative attractiveness of black and white Shannon-type traps for sand flies. Several pairs of black and white traps were placed side by side in front of caves in four areas in the Serra da Bodoquena, Bonito county, State of Mato Grosso do Sul, Brazil, for a total of 12 observations and 44 h of capture. The experiment resulted in 889 phlebotomines captured, 801 on the black and 88 on the white trap, representing 13 species. The hourly Williams' means were 8.67 and 1.24, respectively, and the black/white ratio was 7.0:1.0. Lutzomyia almerioi, an anthropophilic species closely associated with caves, was predominant (89%). Only two other species, Nyssomyia whitmani and Psathyromyia punctigeniculata, also anthropophilic, were significantly attracted to the black rather than to the white trap (chi2 test; p <= 0.01). The difference between the diversity index of the two traps was not significant at level 0.05. The black trap in these circumstances was much more productive than the white, especially for anthropophilic species.