(Eh) y metanólico (Em) de Pera distichophylla sobre un aislado de ...

técnicas de microscopía para el estudio de los quistes ameboides y Giardia sp. quistes en muestras de agua
y los huevos de Ascaris sp. en muestras de suelo podría estar asociada. El ELISA, cuando se compara con
las técnicas microscópicas, presenta un mayor número de muestras positivas protozoos investigado, tanto
en agua y suelo. Estos resultados sugieren el uso de inmunoensayo enzimático para controlar los parásitos
de calidad del agua o para investigar la contaminación ambiental.
Palabras clave: Muestras ambientales, Técnicas parasitológicas, Inmunoensayo enzimático.
INTRODUCTION
Many parasites, including protozoa and helminths,
may be water and soil-borne, transmitting
diseases to the population. It is worth to mention
that the presence of intestinal parasites in soil, water
or food, in addition to its importance specifically
related to the development of pathogenies, is a significant
biological indicator of fecal contamination,
pointing to the possible transmission of pathogenic
agents (Silva et al., 1991). Investigations on soil
and water contamination by parasites constitute an
important part of public health studies because of
the possibility transmission (Silva et al., 2009).
The detection of evolutionary forms of protozoa
and helminths in water is performed by few laboratories
of supply companies, which attribute this
fact to the lack of standardization, technical complexity
and high cost (Lima and Stamford, 2009).
Until 2007, at least 325 water-associated outbreaks
of parasitic protozoan disease have been reported in
the world (Karanis, 2007).
According to the OPAS report, it is estimated
that two billion people in the world are infected by
some form of parasite acquired through the contact
with the soil, 800 million of which are infected
children (40%), with about 20-30% occurring in
Latin America populations (Ehrenberg, 2002). In
soil, the detection of these evolutionary forms is
typically performed in epidemiological researches,
chiefly in samples collected in gardens, amusement
parks, public squares and beaches (Santos et al.,
2006; Rocha et al., 2011).
Different diagnostic techniques have been employed
for the detection of parasites in environmental
samples, usually the same ones used in clinical
fecal samples. Each technique has its own advantages
and disadvantages, but there is no one universally
accepted as the gold standard in the survey
of evolutionary forms of protozoa and helminths in
Rev. Ibero-Latinoam. Parasitol. (2012); 71 (1): 90-96
COMPARISON OF TECHNIQUES IN ENVIRONMENTAL SAMPLES
water and soil samples (Smith, 1998).
Owing to the diversity of existing laboratory
techniques and the importance of the water and soil
in the transmission of intestinal parasites, it becomes
relevant for the performance of studies which aim
to compare the efficiency of the parasitological
techniques and the enzyme immunoassay in
environmental samples.
The aim of this study was to compare the degree
of agreement in the detection of evolutionary forms
of parasites in water samples and soil collected in
Guarani Indian Villages using the Ritchie et al.,
parasitological technique (1948) modified by Young
et al., (1979), Sheather’s parasitological technique
(1923) modified by Huber et al., (2003) and the
enzyme immunoassay for the survey of Giardia
lamblia, Cryptosporidium sp. and Entamoeba
histolytica.
MATERIAL AND METHODS
Collection of the samples: The survey was
performed in four Guarani Indian Villages in the
cities of Angra dos Reis (Sapukai Village) Paraty
(Araponga, Rio Pequeno and Paraty Mirim
Villages) in the State of Rio de Janeiro.
Quadruplicate samples were collected over the
period from February to November, 2010. In the
end, there were 48 samples of water of the supply
systems of the Guarani Indian Villages, divided in
24 raw water samples and 24 treated water samples
from six different systems, thus distributed: three
systems in Sapukai Village, the single system of
Araponga Village, one in Rio Pequeno Village and
one in Paraty Mirim Village, totaling eight samples
of water for each system. For the soil, a total of
64 samples were collected in four different points
of the places allowed by the caciques, using the
greatest concentration of human and/or domestic
91