ABSTRACT
To study the possibility that schistosomiasis might be able to spread into the basins of the Paraná and Uruguay rivers, 1,711 snails were experimentally exposed to infection with Schistosoma mansoni. These snails were laboratory-bred progeny of Biomphalaria tenagophila collected from 15 populations in the geographic area under consideration. Three strains of S. mansoni were used: BH2, adapted to B. glabrata, and SJ and SJ2 adapted to B. tenagophila. None of the 543 snails exposed to the BH2 strain became infected, nor did any of the 668 exposed to SJ. However, of the 500 exposed the SJ2, 4 of the 163 snails (2%) from Ayolas, a locality in the Paraná basin, were susceptible, as were 8 of 45 (18%) from Fuente, Salto, in the Uruguay basin. These findings are similar to those of studies done in other geographic areas, where some populations of B. tenagophila do not become infected with S. mansoni while others are susceptible. The results of this study signal the possibility of the expansion of schistosomiasis into a broad region of South America in which B. tenagophila is found.
Subject(s)
Biomphalaria/parasitology , Schistosoma mansoni/physiology , Schistosomiasis mansoni/transmission , Animals , Argentina , Biomphalaria/classification , Host-Parasite Interactions , Paraguay , Schistosoma mansoni/growth & development , Schistosomiasis mansoni/epidemiology , UruguayABSTRACT
An epidemiologic study was conducted in San Cayetano, a village in the province of Corrientes, Argentina, to determine the prevalence of intestinal parasitoses in children. Eighty-eight households were randomly selected. Stool samples were collected from 207 children (72% of the school-age population and 12% of the total village population) over a period of six consecutive days, and were subjected to microscopic examination. Of the samples examined, 170 (83%) contained one or more parasites, of which the most frequently found was Blastocystis hominis (in 43% of the samples). Other parasites and commensals detected included Giardia lamblia (29%), hookworms (27%), Entamoeba coli (27%), Enterobius vermicularis (4%), Strongyloides stercoralis (2%), and Ascaris lumbricoides, Trichuris trichiura, Taenia saginata, Isospora belli, Iodamoeba bütschlii, and Balantidium coli (each 0.5%). The high observed prevalence of intestinal parasitoses indicates active parasite transmission in San Cayetano as a result of poor environmental hygiene-ascribable largely to a lack of public water supply, sewerage, and waste removal services.
Subject(s)
Intestinal Diseases, Parasitic/epidemiology , Rural Health , Adolescent , Argentina/epidemiology , Child , Child, Preschool , Female , Humans , Incidence , Intestinal Diseases, Parasitic/etiology , Intestinal Diseases, Parasitic/prevention & control , Male , Sanitary EngineeringABSTRACT
Segun la presente investigacion, en la zona en donde se construira la represa hidroeletrica de Yacyreta-Apire existe una amplia apreciable magnitud en la transmision de la enfermedad de Chagas, de acuerdo con lo indicado por la alta prevalencia serologica de la dispersion de Triatoma infestans con, una ciable magnitud en la transmision de la enfermedad de Chagas, de acuerdo con lo indicado por la alta prevalencia serologica de la infeccion. A los cambios ambientales introducidos por la construccion de la obra, se sumaria el realojamiento de poblaciones en nuevas viviendas hasta las que podria llegar el vector transportado en forma pasiva por ignorancia de los habitantes. Por esta causa, se indica la necesidad de tomar en cuenta sus factores culturales para no favorecer las persistencias de la transmision