[Seroprevalence of T. cruzi infection in 6- and 12- year-old school children from three Uruguayan endemic departments]. / Seroprevalencia de la infección por Trypanosoma cruzi en escolares de seis y doce años de edad de tres departamentos endémicos de Uruguay.

The last national survey on seroprevalence of T. cruzi human infection in Uruguay, showed a 3.4% in adults from endemic areas. Since 1983, antivectorial actions of the control program have been carried out continually. In consequence, household infestation by Triatoma infestan, the main vector of T. cruzi in Uruguay, decreased in all endemic areas and was completely eliminated in some of them. The objectives of the present work are to evaluate the new seroepidemiological situation. A representative sampling of rural and urban population was undertaken, to include six and twelve year-old school children from three departments: Artigas, Rivera and Tacuarembo. The whole sample included 4,722 school children, evaluated by the indirect immunofluorescence (IFI) test for Chagas disease. The seroprevalence of T. cruzi infection in the six year-old group was 0.3% in Artigas, 0.6% in Rivera and 1.0% in Tacuarembo. The seropositive children with seropositive mothers support the possible congenital transmission.

Atlas of Chagas disease vectors in the Americas

Habitats of Triatominae bugs are important from an epidemiological point of view. Each species is related to certain environmental conditions, and its significance as a vector for Trypanosoma cruzi is often linked to its proximity to human dwellings or the infestation of houses, corrals, pigeon or chicken coops, woodpiles, and/or other peridomiciliary sites. The authors of this chapter have agreed to provide a general list of references, mostly devoted either to those publications compiling the scattered bibliography or to some specific papers where a single species was studied, giving compiled bibliography added to the original research. Despite this bibliographical condensation, the list is long enough to provide a general idea about some basic references to each species

Karyotype evolution in holocentric chromosomes of three related species of triatomines (Hemiptera-Reduviidae).

C-banded karyotypes, DNA content and the male meiiotic process of Triatoma platensis and Triatoma delpontei are compared with those of Triatoma infestans, the main vector of Chagas disease in South America. These three species present the same diploid chromosome number 2n = 22 (20 autosomes + XX male/XY female). They also have several cytogenetic traits that differ from all other triatomines: large autosomes, C-heterochromatic blocks and meiotic heteropycnotic chromocenters formed by autosomes and sex chromosomes. In spite of these similarities, each species presents different chromosomal behavior during male meiosis, distinct DNA content and a specific amount and localization of the C-heterochromatin. The differences in DNA content are mainly due to the variation in C-heterochromatin amount, which may be interpreted as loss and/or gain of C-regions. This interpretation is supported by the presence of meiotic and mitotic chromocenters that facilitate the transference of C-positive material. The cytogenetic data presented in this work suggest that T. infestans and T. platensis are more closely related to each other than to T. delpontei. It can also be inferred that the differences in distribution and amount of heterochromatin do not play a direct role in speciation in this group.

Ecology of Triatoma rubrovaria (Hemiptera, Triatominae) in wild and peridomestic environments of Uruguay.

This paper describes population structure, spatial distribution and habitat selection of wild and peridomestic populations of Triatoma rubrovaria (Blanchard, 1843). Field studies were carried out at Las Piedras and La Bolsa in the Northern Department of Artigas, Uruguay. A semicircular sampling area, divided in seven or eight triangular sectors was sequentially examined from October 1990 to November 1991. At Las Piedras (typical wild habitat) 1063 T. rubrovaria bugs were collected from 84% of the rocky outcroops ("pedregales"). Abundance varied by season peaking in October-November (spring). Throughout the year, most of the population was made up of third, fourth and fifth instar nymphs; adults were found from October to March. In the peridomestic environment of La Bolsa, however T. rubrovaria was less common and showed a more irregular instar distribution. Colonized ecotopes, were those close to houses. In both sites T. rubrovaria was mainly associated with the geckonid Homonota uruguayensis and the cockroach Blaptica dubia.

[Feeding pattern of Triatoma rubrovaria (Blanchard, 1843) (Hemiptera, Triatominae) in peridomiciliary habitats, of a rural area of Uruguay]. / Perfil alimentario de Triatoma rubrovaria (Blanchard, 1843) (Hemiptera, triatominae) en ámbitos peridomiciliarios, de una localidad rural de Uruguay.

It has been studied the feeding patterns of Triatoma rubrovaria (wild triatominae bug, and intradomiciliary secondary vector of T. cruzi) in a rural area of "La Bolsa" (Department of Artigas). Agar double diffusion test were used for analyze the blood meal, from 120 insects, which were confronted to 13 antisera. It has 251 identify blood meals, and the most frequently was mammalian host (73%), but it has a variable source of feeding (mammals, birds, reptiles and cockroach), including humans rate 8% of the total. The identify of haemolimphe as feed, place this triatominae bug as an intermediary vector between predator and haematophagous. The most usual mammals are dasypodides and bovines. The frequence of human blood meal near the dwellings, shows its potentiality as vectors. Therefore, the peridomicile is an area of interaction between, domestic, wild and sinantropic host. The trypanosomic infection's rate at peridomiciles was lesser those at wild areas.

Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae) en el estado brasileno de "Rio Grande do Sul" / Finding of Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae) in the Brazilian state of \"Rio Grande do Sul\"

Triatoma platensis Neiva 1913 (Hemiptera, Triatominae), especie ornitofila, con area de dispercion conocida en Argentina, Bolivia, Paraguay y Uruguay es notificada en um primer registro para Brasil. Hallada en el municipio de Uruguaiana (Rio Grande do Sul) en nidos de Anumbius annumbi (Vieillot, 1817) (Passeriformes, Furnariidae) donde cohabitaba con cricetidos de la especie Orizomys flavescens. Ningun ejemplar de los siete colectados se presento infectado por Trypanosoma cruzi.

[Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae) found in the Brazilian state of "Rio Grande do Sul"]. / Hallazgo de Triatoma platensis Neiva, 1913 (Hemiptera, Triatominae) en el Estado brasileno de "Rio Grande do Sul".

Triatoma platensis, an ornitophilic species, found in Argentina, Bolivia, Paraguay and Uruguay is reported for the first time in Brazil. It was found in the county of Uruguaiana (Rio Grande do Sul) in nests of Anumbius annumbi (Vieillot, 1817) (Passeriformes, Furnariidae) where it cohabited with cricetids belonging to the species Orizomys flavescens. None of the seven individuals collected were infected by Trypanosoma cruzi.

[Seroprevalence of antibodies against Trypanosoma cruzi in 13 departments of Uruguay]. / Seroprevalencia de anticuerpos contra Trypanosoma cruzi en 13 departamentos del Uruguay.

In 1985 a study was undertaken of the prevalence of Trypanosoma cruzi antibodies in 13 departments of Uruguay where transmission of the parasite by the vector Triatoma infestans persists. A total of 5,924 serum samples were selected using a probabilistic method--3,840 from individuals over the age of 12 (sample I) and 2,084 from subjects who were 12 years old (sample II). The population was classified according to place of residence (capital city, non-capital city, suburban area, and rural area). The percentage of positive sera detected by indirect immunofluorescence in the different departments ranged from 1 to 11%, and overall seroprevalence for the area was 3.4%. Based on the results obtained, it was possible to distinguish three areas: A, with seroprevalence from 6 to 11%; B, 2 to 3.2%, and C, 1 to 1.4%. In sample II from the Departments of Paysandú, Soriano, Flores, Florida, and Durazno, no cases of Chagas' disease were detected, which suggests that there is no active transmission of T. cruzi in this age group in the area studied. The number of persons estimated to have the disease was 36,952, or 1.3% of the total population of Uruguay and 4% of the population in the area surveyed. These seroprevalence figures are similar to those recorded in the province of Entre Ríos, Argentina, and in the neighboring municipalities of Rio Grande do Sul, Brazil.

Seroprevalencia de anticuerpos contra trypanosoma cruzi en 13 departamentos del Uruguay / Seroprevalence of trypanosoma cruzi in 13 deparments of Uruguay

In 1985 a study was undertaken of the prevalence of Trypanosoma cruzi antibodies in 13 departments of Uruguay where transmission of the parasite by the vector Triatoma infestans persists. A total of 5 924 serum samples were selected using a probabilistic method- 3 840 from individuals over the age of 12 (sample I) and 2 084 from subjects who where 12 years old (sample II). The population was classified acording to place of residence (capital city, non-capital city, suburban área, and rural área). The percentage of positive sera detected by indirect immunofluorescence in the different departments ranged from 1 to 11 percent, and overall seroprevalence for the área was 3.4 percent. Based on the results obtained, it was possible to distinguish three áreas: A, which seroprevalence from 6 to 11 percent; B, 2 to 3.2 percent, and C, 1 to 4 percent. In sample II from the Departments of Paysandu, Soriano, Flores, Florida, and Durazno, no cases of Chagas' disease were detected which suggests that there is no active transmission of T. cruzi in this age group in the área studied. The number of persons estimated to have the disease was 36 952, or 1.3 percent of the total population of Uruguay and 4 percent of the population in the área surveyed. These seroprevalence figures are similar to those recorded in the povince of Entre Rios, Argentina, and in the neighboring municipalities of Rio Grande do Sul, Brazil

Zelurus femoralis intermedius, Hemiptero entomofago, predador de triatomineos. / Zelurus femoralis intermedius, hemiptera, Redividae, as a predator of triatomidae

Os autores assinalam Zelurus femoralis intermedius (Hemiptera, Rediviidae) como predador de Triatoma infestans, T. rubrovaria e T. circunmaculata, observando que o hemiptero se encontra estreitamente associado aos triatomineos mencionados, em habitats naturais e artificiais no Uruguai Apos o registro de observacoes realizadas em campo e em laboratorio, os autores concluem que em virtude de capacidade predadora, abundancia com que pode ser encontrado no campo, ampla dispersao, seletividade para triatomineos como fonte de alimentacao e possibilidade de reproducao em laboratorio, o Z. femoralis intermedius representa um agente de valor potencial no controle biologico de triatomineos

Seroprevalencia de anticuerpos contra trypanosoma cruzi en 13 departamentos del Uruguay / Seroprevalence of trypanosoma cruzi in 13 deparments of Uruguay

In 1985 a study was undertaken of the prevalence of Trypanosoma cruzi antibodies in 13 departments of Uruguay where transmission of the parasite by the vector Triatoma infestans persists. A total of 5 924 serum samples were selected using a probabilistic method- 3 840 from individuals over the age of 12 (sample I) and 2 084 from subjects who where 12 years old (sample II). The population was classified acording to place of residence (capital city, non-capital city, suburban area, and rural area). The percentage of positive sera detected by indirect immunofluorescence in the different departments ranged from 1 to 11 percent, and overall seroprevalence for the area was 3.4 percent. Based on the results obtained, it was possible to distinguish three areas: A, which seroprevalence from 6 to 11 percent; B, 2 to 3.2 percent, and C, 1 to 4 percent. In sample II from the Departments of Paysandu, Soriano, Flores, Florida, and Durazno, no cases of Chagas' disease were detected which suggests that there is no active transmission of T. cruzi in this age group in the area studied. The number of persons estimated to have the disease was 36 952, or 1.3 percent of the total population of Uruguay and 4 percent of the population in the area surveyed. These seroprevalence figures are similar to those recorded in the povince of Entre Rios, Argentina, and in the neighboring municipalities of Rio Grande do Sul, Brazil