Autochthonous Outbreak and Expansion of Canine Visceral Leishmaniasis, Uruguay.

We report an outbreak of canine visceral leishmaniasis in Uruguay. Blood specimens from 11/45 dogs tested positive for Leishmania spp. Specimens of Lutzomyia longipalpis sand flies were captured; typing revealed Leishmania infantum. Our findings document an expansion of visceral leishmaniasis to southern South America and risk for vectorborne transmission to humans.

Genetic variability highlights the invasion route of the Lutzomyia longipalpis complex, the main vector of Visceral Leishmaniasis in Uruguay.

In the Americas, the sandfly Lutzomyia longipalpis is the main vector of the parasitic protozoa Leishmania infantum, the etiological agent of visceral leishmaniasis (VL). The Lu. longipalpis species complex is currently discontinuously distributed across the Neotropical region, from Mexico to the north of Argentina and Uruguay. During its continental spreading, it must have adapted to several biomes and temperature amplitudes, when founder events should have contributed to the high genetic divergence and geographical structure currently observed, reinforcing the speciation process. The first report of Lu. longipalpis in Uruguay was in 2010, calling the attention of Public Health authorities. Five years later, the parasite Le. infantum was recorded and in 2015 the first case of VL in canids was reported. Hitherto seven human cases by VL have been reported in Uruguay. Here, we publish the first DNA sequences from the mitochondrial genes ND4 and CYTB of Lu. longipalpis collected in Uruguay, and we used these molecular markers to investigate their genetic variability and population structure. We described four new ND4 haplotypes in a total of 98 (4/98) and one CYTB in a total of 77 (1/77). As expected, we were able to establish that the Lu. longipalpis collected in two localities (i.e. Salto and Bella Unión) from the north of Uruguay are closely related to the populations from neighbouring countries. We also propose that the possible route for the vector arrival to the region may have been through vegetation and forest corridors of the Uruguay River system, as well as it may have benefited from landscape modifications generated by commercial forestation. The ecological-scale processes shaping Lu. longipalpis populations, the identification of genetically homogeneous groups and the gene flow among them must be carefully investigated by using highly sensible molecular markers (i.e. genome wide SNPs) since it will help to the understanding of VL transmission and contribute to the planification of public policies on its control.

Trypanosoma cruzi Isolates Naturally Adapted to Congenital Transmission Display a Unique Strategy of Transplacental Passage.

Chagas disease is mainly transmitted by vertical transmission (VT) in nonendemic areas and in endemic areas where vector control programs have been successful. For the present study, we isolated natural Trypanosoma cruzi strains vertically transmitted through three generations and proceeded to study their molecular mechanism of VT using mice. No parasitemia was detected in immunocompetent mice, but the parasites were able to induce an immune response and colonize different organs. VT experiments revealed that infection with different strains did not affect mating, pregnancy, or resorption, but despite low parasitemia, VT strains reached the placenta and resulted in higher vertical transmission rates than strains of either moderate or high virulence. While the virulent strain modulated more than 2,500 placental genes, VT strains modulated 150, and only 29 genes are shared between them. VT strains downregulated genes associated with cell division and replication and upregulated immunomodulatory genes, leading to anti-inflammatory responses and tolerance. The virulent strain stimulated a strong proinflammatory immune response, and this molecular footprint correlated with histopathological analyses. We describe a unique placental response regarding the passage of T. cruzi VT isolates across the maternal-fetal interphase, challenging the current knowledge derived mainly from studies of laboratory-adapted or highly virulent strains. IMPORTANCE The main findings of this study are that we determined that there are Trypanosoma cruzi strains adapted to transplacental transmission and completely different from the commonly used laboratory reference strains. This implies a specific strategy for the vertical transmission of Chagas disease. It is impressive that the strains specialized for vertical transmission modify the gene expression of the placenta in a totally different way than the reference strains. In addition, we describe isolates of T. cruzi that cannot be transmitted transplacentally. Taken together, these results open up new insights into the molecular mechanisms of this insect vector-independent transmission form.

Leishmania infantum isolates exhibit high infectivity and reduced susceptibility to amphotericin B.

Leishmaniasis is a neglected disease caused by a protozoan parasite of the Leishmania species in over 98 countries in five continents. Visceral leishmaniasis is one of the main forms of the disease and is mainly caused by Leishmania infantum, whose main vector is the dipteran Lutzomyia longipalpis. The presence of the vector in Uruguay was recorded for the first time in 2010 and an autochthonous outbreak of canine visceral leishmaniasis occurred in the northern locality of the country in 2015. We report the isolation in blood-free FBS-supplemented defined media of five isolates responsible for the referred outbreak, and characterize them in terms of their growth as promastigotes, infectivity and replication in human derived monocytes and drug resistance. Results indicate similar promastigote growth among the strains, enhanced infectivity and replication for the five strains isolated from the Uruguayan outbreak when compared with reference strains from South America, equivalent drug susceptibility for miltefosine and nifurtimox and a significant difference in IC50 values for amphotericin B between the Uruguayan strains, 3-4 fold higher than the reference strain.

Toxocariasis: manifestaciones clínicas y de laboratorio en niños asistidos en un prestador integral de salud privado de Montevideo, Uruguay (2014-2018) / Toxocariasis: clinical and laboratory manifestations in children assisted in a private comprehensive healthcare provider of Montevideo, Uruguay. 2014-2018 / Toxocaríase: manifestações clínicas e de laboratório em crianças atendidas em uma instituição privada de assistência integral de saúde em Montevidéu, Uruguai. 2014-2018

Resumen: Introducción: la toxocariasis humana es una parasitosis de amplia distribución en el mundo cuyos agentes etiológicos son Toxocara canis y, en menor medida, Toxocara cati. Objetivo: describir las características clínicas y paraclínicas de toxocariasis en menores de 15 años asistidos en un prestador integral privado de Montevideo entre 2014 y 2018. Material y método: estudio descriptivo, retrospectivo, de los menores de 15 años derivados a la policlínica de infectología entre el 1 de enero de 2014 y el 31 de diciembre de 2018 con diagnóstico de toxocariasis confirmada por ELISA. Variables: edad, sexo, motivo de consulta, manifestaciones clínicas, recuento leucocitario y de eosinófilos, parasitosis asociadas, tratamiento y evolución. Resultados: fueron asistidos 20 niños de los cuales 11 eran asintomáticos, cinco presentaron síndrome de larva migrans visceral (LMV) y cuatro síndrome de larva migrans ocular (LO). Veinte niños recibieron albendazol y uno, además, mebendazol. Aquellos con compromiso ocular recibieron también corticoides vía oral. Se constató pérdida de agudeza visual en dos pacientes. Discusión y conclusiones: la mayorías de los niños eran asintomáticos, la cuarta parte consultaron por alteraciones visuales cuyas secuelas representan un grave problema de salud potencialmente prevenible. Debería realizarse la búsqueda de la infección mediante serología en niños que presenten eosinofilia con y sin síntomas respiratorios o disminución de la agudeza visual causada por lesión intraocular y en niños con factores de riesgo para esta parasitosis.

Summary: Introduction: human toxocariasis is a widely distributed parasitosis around the world. Its etiological agents are Toxocara canis and Toxocara cati in a smaller proportion. Objective: to describe the clinical and paraclinical manifestations of toxocariasis in children younger than 15 years old who were assisted in a private comprehensive healthcare provider in Montevideo between 2014 and 2018. Method: descriptive, retrospective study of children under 15 years old who were referred to the infectology service between January 1, 2014 and December 31, 2018 with a diagnosis of toxocariasis confirmed by ELISA. Variables were age, sex, reason of consultation, clinical manifestations, leukocyte and eosinophils count and associated parasitosis, treatment and evolution. Results: 20 children were assisted, 11 of them were asymptomatic, 5 evidenced visceral larva migrans (VLM) syndrome and 4 of them presented larva migrans ocular (LMO). 20 patients received albendazon and one of them also received mebendazol. Those whose eyes were compromised also received oral corticoids. Two patients presented loss of visual acuity. Discussion and conclusions: Most children were asymptomatic, 25% of them consulted for visual alterations whose sequelae represented a potentially preventable severe health problem. We need to make a greater effort to insist on eye control for children since alterations may be detected, avoiding sequelae with an early diagnosis and the right treatment.

Resumo: Introdução: a toxocaríase humana é uma parasitose com ampla distribuição em todo o mundo; seus agentes etiológicos são o Toxocara canis e menos frequentemente Toxocara cati. Objetivo: descrever as características clínicas e de laboratório de toxocaríase em menores de 15 anos atendidos em uma instituição privada de assistência integral de saúde em Montevidéu no período 2014-2018. Materiais e métodos: estudo descritivo, retrospectivo, dos menores de 15 anos referidos ao ambulatório de infectologia no período 1 de janeiro de 2014 - 31 de dezembro de 2018 com diagnóstico de toxocaríase confirmado por ELISA. Variáveis: idade, sexo, motivo de consulta, manifestações clínicas, contagem de leucócitos e de eosinófilos, parasitoses associadas, tratamento e evolução. Resultados: vinte crianças foram atendidas sendo: 11 assintomáticos, 5 com síndrome de larva migrans visceral (LMV) e 4 síndrome de síndrome de larva migrans ocular (LO). Todas foram medicadas com albendazol e uma recebeu também mebendazol. Aquelas com compromisso ocular tomaram também corticoides por via oral. Dois pacientes apresentaram perda da acuidade visual. Discussão e conclusões: a maioria das crianças eram assintomáticas, sendo que um quarto consultou por alterações visuais cujas sequelas representam um problema grave de saúde potencialmente previnivel. Devemos melhorar os esforços para insistir na realização de controle oftalmológico das crianças nos controles de saúde, pois com um diagnóstico precoce e tratamento adequado é possível detectar alterações e evitar sequelas.

Evolutionary and dispersal history of Triatoma infestans, main vector of Chagas disease, by chromosomal markers.

Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known as Andean and non-Andean chromosomal groups, that are highly differentiated by the amount of heterochromatin and genome size. Analyses with nuclear and mitochondrial sequences are not conclusive about resolving the origin and spread of T. infestans. The present paper includes the analyses of karyotypes, heterochromatin distribution and chromosomal mapping of the major ribosomal cluster (45S rDNA) to specimens throughout the distribution range of this species, including pyrethroid-resistant populations. A total of 417 specimens from seven different countries were analyzed. We show an unusual wide rDNA variability related to number and chromosomal position of the ribosomal genes, never before reported in species with holocentric chromosomes. Considering the chromosomal groups previously described, the ribosomal patterns are associated with a particular geographic distribution. Our results reveal that the differentiation process between both T. infestans chromosomal groups has involved significant genomic reorganization of essential coding sequences, besides the changes in heterochromatin and genomic size previously reported. The chromosomal markers also allowed us to detect the existence of a hybrid zone occupied by individuals derived from crosses between both chromosomal groups. Our genetic studies support the hypothesis of an Andean origin for T. infestans, and suggest that pyrethroid-resistant populations from the Argentinean-Bolivian border are most likely the result of recent secondary contact between both lineages. We suggest that vector control programs should make a greater effort in the entomological surveillance of those regions with both chromosomal groups to avoid rapid emergence of resistant individuals.

5-Nitro-2-furyl derivative actives against Trypanosoma cruzi: preliminary in vivo studies.

Ten 5-nitro-2-furyl derivatives, with good to excellent in vitro anti-Trypanosoma cruzi activity, and nifurtimox were tested oral and intraperitoneally on healthy animals for its acute toxicity on murine models. According to animals' survival percentage, organ histological results, biochemical and haematological findings, three new derivatives, with toxicity like nifurtimox, were selected to test in vivo as antichagasic agents. Clearly, dependences between chemical structure and both acute toxicity and in vivo anti-T. cruzi activity were observed. 4-Hexyl-1-[3-(5-nitro-2-furyl)-2-propenylidene]semicarbazide displayed good profile as anti-T. cruzi agent and better acute toxicity profile than nifurtimox.

Triatoma delpontei Romaña & Abalos, 1947 (Hemiptera, Triatominae) en el estado brasileño de "Rio Grande do Sul" / Triatoma delpontei Romaña & Abalos, 1947 (Hemiptera, Tratominae) in the Brazilian State of Rio Grande do Sul

Triatoma delpontei (Romaña & Abalos, 1947) (Hemiptera, Triatominae) is an ornithophilic sylvatic with a particular association to the psittacid Myiopsitta monachus (Boaddert, 1783). It is found in the continental biogeographical province of the Chaco, where it inhabits the nests or M. monachus, in subtropical xerophytic forests. The authors report the first finding of T. delpontei in Brasil, in the "campanha" region of the State or Rio Grande do Sul (Barra do Quarai, Uruguaiana), on the right bank of the River Cuareim, not far from de Uruguayan border.

Actualización clínico-epidemiológica y terpéutica de la enfermedad del Chagas en Uruguay / Epidemiologic and therapeutic update of Chagas disease in Uruguay

La situación epidemiológica de la transmisión de la enfermedad de Chagas y su encare terapéutico han sufrido cambios importantes tanto a nivel regional como a nivel nacional. Los cambios socioeconómicos producidos en las últimas décadas y las acciones de control antivectorial sostenidas redujeron el área de dispersión del vector y la densidad de infestación en Uruguay, modificando las condiciones de la transmisión. La encuesta realizada en 1985 a nivel nacional en adultos y escolares de 12 años mostró una prevalencia serológica de 3,4 por ciento, aproximadamente 40.000 infectados. En 1997, basados en los datos de infestación vectorial y de la encuesta de prevalencia realizada en 1994, un grupo de expertos de OPS/OMS declaró interrumpida la transmisión vectorial de Trypanosoma cruzi en Uruguay. Esta situación ha modificado las características epidemiológicas de la transmisión, cobrando mayor importancia los restantes mecanismos. La transmisión transfusional, segundo mecanismo de infección en zonas endémicas y principal mecanismo en zonas libres del vector, no lo es en Uruguay debido al control en bancos de sangre. Queda como principal mecanismo de transmisión el congénito. La miocardiopatía chagasica crónica constituye la forma clínica más frecuente de la etapa crónica sintomática en Uruguay. Se actualizan las pautas de diagnóstico, de tratamiento etiopatológico y de seguimiento de los infectados

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.

Seroprevalencia de la infección por trypanosoma cruzi en escolares de seis y doce años de edad de tres departamentos endémicos de Uruguay / Seroprevalence of trypanosoma cruzi infection in 6 and 12 years old schoolchildren from 3 Uruguayan endemic departaments

The last national survey on seroprevalence of T. cruzi human infection in Uruguay, showed a 3,4 percent 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 representive sampling of rural and urban population was undertaken, to include six and twelve year-old schoolchildren from three departments: Artigas, Rivera and Tacuarembo. The whole sample included 4,722 school children, evaluated by the indirect inmunofluorescense (IFI) test for Chagasïdisease. The seroprevalence of T. cruzi infection in the six year-old group was 0,3 percent in Artigas, 0,6 percent in Rivera and 1,0 percent in Tacuarembo. The seropositive children with seropositive mothers support the possible congenital transmission

Perfil alimentario de Triatoma rubrovaria (Blanchard, 1843) (Hemiptera, Triatominae) en ambitos peridomiciliares, de una localidad rural de Uruguay / Feeding patterns of Triatoma rubrovaria (Blanchard, 1843) (Hemiptera, Triatominae in peridomestic habitats, in a rural area of Uruguay

En una localidad con poblacion rural dispersa ("La Bolsa", 3ª seccional, dpto. de Artigas, Uruguay) se estudio, en ambitos peridomiciliarios, el perfil alimentario de T. rubrovaria (triatomineo silvestre y potencial vector secundario de colonizacion intradomiciliaria), utilizandose la tecnica de doble difusion en agar, enfrentando contenido promesenterico frente a un panel de 13 sueros. Se pudo detectar en 120 insectos 251 identificaciones de fuente hematofagica con alimentacion predominante en mamiferos (73 per cent), pero marcado eclectismo alimentario (mamiferos, aves, reptiles y cucarachas), incluyendo hematofagia sobre seres humanos en un 8 per cent de las identificaciones totales....

Description of a new chromatomorph of Triatoma infestans (KLUG) and its genetic characteristics

En el presente trabajo se describen especímenes de Triatoma infestans, procedentes del Departamento de Soriano (Uruguay), que presentan variaciones en el patrón de colonización respecto a la forma estándar de la especie. Ellos presentan manchas ocráceas que se encuentran en posiciones particulares, constantes en todos los ejemplares estudiados, y que difieren en distribución y tamaño con las que se observaran en la forma común. Los individuos atípicos fueron estudiados morfológicamente (morfometría y chaetotaxia) y genéticamente (citogenética e inmunoelectroforesis de isoenzimas) y comparadas con las formas estándares. Los resultados tienden a rechazar cualquier evidencia de especiación entre las variantes cromáticas y los individuos típicos de T. infestans

Revisión de temas: Diagnóstico de histoplasmosis

Trata del diagnostico de Histoplamosis

Revisión de temas: Diagnóstico de histoplasmosis

Trata del diagnostico de Histoplamosis.