Dietary Habits of the Common Rodents in an Agrecosystem in Argentina

Dietary habits of five common rodents in agroecosystems on the central Argentine Pampa were studied for 15 months using microhistological analysis of stomach contents. All five rodent species were omnivorous, but proportions of major dietary items (arthropods, dicot leaves and seeds, monocot leaves and seeds) varied among species and seasons. Akodon azarae largely was entomophagous; arthropods formed 41-62% of the diet in all seasons. The other four species (Calomys musculinus, Calomys laucha, Bolomys obscurus, and Oligoryzomys flavescens) consumed most diet items throughout the year, but relative proportions varied among seasons. Leaves formed a relatively minor proportion of the diet (12- 16% overall for all species) throughout the year. All species except A. azarae consumed higher quantities of seeds (50-73% of stomach volume) than arthropods (15-35%) during autumn and winter but switched to higher quantities of arthropods (30-53%) in spring and summer. Diet breadth was narrower and overlap generally highest during winter when all species were forced to subsist on a reduced set of available resources. Of 28 plant species with \u3e2% cover in the environment, 25 were identified in stomachs of one or more of the five rodent species. The most important plant species in the diet were corn and soybeans (mostly grain), seed of Johnson grass (Sorghum halepense), chickweed (Stellaria media), and Amaranthus. High consumption of arthropods, especially by A. azarae, contraindicates the broad-scale use of rodenticides until the role of that rodent species in the control of pest insects can be ascertained

Dietary Habits of the Common Rodents in an Agrecosystem in Argentina

Dietary habits of five common rodents in agroecosystems on the central Argentine Pampa were studied for 15 months using microhistological analysis of stomach contents. All five rodent species were omnivorous, but proportions of major dietary items (arthropods, dicot leaves and seeds, monocot leaves and seeds) varied among species and seasons. Akodon azarae largely was entomophagous; arthropods formed 41-62% of the diet in all seasons. The other four species (Calomys musculinus, Calomys laucha, Bolomys obscurus, and Oligoryzomys flavescens) consumed most diet items throughout the year, but relative proportions varied among seasons. Leaves formed a relatively minor proportion of the diet (12- 16% overall for all species) throughout the year. All species except A. azarae consumed higher quantities of seeds (50-73% of stomach volume) than arthropods (15-35%) during autumn and winter but switched to higher quantities of arthropods (30-53%) in spring and summer. Diet breadth was narrower and overlap generally highest during winter when all species were forced to subsist on a reduced set of available resources. Of 28 plant species with \u3e2% cover in the environment, 25 were identified in stomachs of one or more of the five rodent species. The most important plant species in the diet were corn and soybeans (mostly grain), seed of Johnson grass (Sorghum halepense), chickweed (Stellaria media), and Amaranthus. High consumption of arthropods, especially by A. azarae, contraindicates the broad-scale use of rodenticides until the role of that rodent species in the control of pest insects can be ascertained

Hantavirus Infection in Humans and Rodents, Northwestern Argentina

We initiated a study to elucidate the ecology and epidemiology of hantavirus infections in northern Argentina. The northwestern hantavirus pulmonary syndrome (HPS)–endemic area of Argentina comprises Salta and Jujuy Provinces. Between 1997 and 2000, 30 HPS cases were diagnosed in Jujuy Province (population 512,329). Most patients had a mild clinical course, and the death rate (13.3%) was low. We performed a serologic and epidemiologic survey in residents of the area, in conjunction with a serologic study in rodents. The prevalence of hantavirus antibodies in the general human population was 6.5%, one of the highest reported in the literature. No evidence of interhuman transmission was found, and the high prevalence of hantavirus antibody seemed to be associated with the high infestation of rodents detected in domestic and peridomestic habitats

Indigenous Dengue Fever, Buenos Aires, Argentina

Fil: Natiello, Marcela. Hospital de Infecciosas “Francisco Javier Muñiz”; Argentina.Fil: Ritacco, Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Morales, María Alejandra. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas "Dr. Julio Maiztegui"; Argentina.Fil: Deodato, Bettina. Hospital de Infecciosas “Francisco Javier Muñiz”; Argentina.Fil: Picollo, Marisa. Hospital de Infecciosas “Francisco Javier Muñiz”; Argentina.Fil: Dinerstein, Edith. Hospital Interzonal de Agudos “Evita”; Argentina.Fil: Enria, Delia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas "Dr. Julio Maiztegui" Argentina

Estudio cualicuantitativo de las variables sociales que definen escenarios de transmisión de la fiebre hemorrágica argentina en las provincias de Buenos Aires y Santa Fe, 2001-2010

The aim of this paper was to characterize transmission scenarios of Argentine Hemorrhagic Fever in the post-vaccination period (2001-2010). The study was made up of three phases. The first consisted of a quantitative analysis using the database of the Dr. Julio I. Maiztegui National Institute of Human Viral Diseases [Instituto Nacional de Enfermedades Virales Humanas] regarding the confirmed cases in the period of study (221 cases). Taking into account the transmission site and the known endemic area, cases were grouped into three hypothetical transmission scenarios, identified as: a) classical, b) emerging-reemerging, c) traveling. In the second phase, in order to test these hypotheses, in-depth interviews were carried out from August to September 2011 within an intentionally selected sample of patients distributed proportionally among the three hypotheses. Finally, in the third stage, the data obtained for each hypothetical scenario were grouped into three spatiotemporal scales: the microscale (subject), the mesoscale (locality) and macroscale (region). The results show that new transmission sites are associated with the social dynamics of cereal production and port-bound routes.El objetivo de este artículo es caracterizar los escenarios de transmisión de fiebre hemorrágica argentina (FHA) en el período de vacunación (2001-2010). El estudio constó de tres etapas. En la primera, se realizó un análisis cuantitativo de la base de datos del Instituto Nacional de Enfermedades Virales Humanas "Dr. Julio I. Maiztegui" (INEVH) de casos de FHA confirmados en el período (221 casos) que, sobre la base del lugar de transmisión y la zona endémica conocida, se agruparon según tres hipótesis de escenario: clásico, emergente-reemergente, y viajero. En la segunda etapa, para poner a prueba las hipótesis, se realizaron entrevistas en campo, entre agosto y octubre de 2011, a una muestra de selección intencional de pacientes distribuida proporcionalmente entre las tres hipótesis. Finalmente, en una tercera etapa, los datos generados para cada hipótesis de escenario se agruparon en tres escalas espacio-temporales: microescala (sujeto), mesoescala (localidad) y macroescala (región). Los resultados muestran que los nuevos lugares de transmisión estarían asociados a las dinámicas socioproductivas del cereal y las rutas al puerto

Vector competence of Aedes aegypti for different strains of zika virus in Argentina

The importance of Zika virus (ZIKV) has increased noticeably since the outbreak in the Americas in 2015, when the illness was associated with congenital disorders. Although there is evidence of sexual transmission of the virus, the mosquito Aedes aegypti is believed to be the main vector for transmission to humans. This species of mosquito has not only been found naturally infected with ZIKV, but also has been the subject of study in many vector competence assays that employ different strains of ZIKV around the world. In Argentina, the first case was reported in February 2016 and a total of 278 autochthonous cases have since been confirmed, however, ZIKV virus has not been isolated from any mosquito species yet in Argentina. In order to elucidate if Argentinian Ae. aegypti populations could be a possible vector of ZIKV, we conducted vector competence studies that involved a local strain of ZIKV from Chaco province, and a Venezuelan strain obtained from an imported case. For this purpose, Ae. aegypti adults from the temperate area of Argentina (Buenos Aires province) were fed with infected blood. Body, legs and saliva were harvested and tested by plaque titration on plates of Vero cells for ZIKV at 7, 11 and 14 days post infection (DPI) in order to calculate infection, transmission, and dissemination rates, respectively. Both strains were able to infect mosquitoes at all DPIs, whereas dissemination and transmission were observed at all DPIs for the Argentinian strain but only at 14 DPI for the Venezuelan strain. This study proves the ability of Ae. aegypti mosquitoes from Argentina to become infected with two different strains of ZIKV, both belonging to the Asian lineage, and that the virus can disseminate to the legs and salivary glands.Fil: Bonica, Melisa Berenice. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Goenaga, Silvina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martin, María Laura. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Feroci, Mariel. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; ArgentinaFil: Luppo, Victoria. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; ArgentinaFil: Muttis, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Fabbri, Cintia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; ArgentinaFil: Morales, Maria Alejandra. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; ArgentinaFil: Enria, Delia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; ArgentinaFil: Micieli, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Levis, Silvana del Carmen. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Virales Humanas; Argentin

Laboratory Surveillance of Dengue in Argentina, 1995–2001

Local transmission of dengue fever virus in Argentina is increased by the presence of Aedes aegypti mosquitoes and dengue outbreaks in neighboring countries. From 1995 to 2001, a laboratory-based active surveillance program detected 922 dengue cases. Indigenous transmission involving dengue-1 and -2 serotypes was confirmed only in subtropical areas in northern Argentina

Clusters of Hantavirus Infection, Southern Argentina

Person-to-person transmission should be suspected when Andes virus case-patients are linked

Hantavirus infection in humans and rodents, northwestern Argentina

We initiated a study to elucidate the ecology and epidemiology of hantavirus infections in northern Argentina. The northwestern hantavirus pulmonary syndrome (HPS)–endemic area of Argentina comprises Salta and Jujuy Provinces. Between 1997 and 2000, 30 HPS cases were diagnosed in Jujuy Province (population 512,329). Most patients had a mild clinical course, and the death rate (13.3%) was low. We performed a serologic and epidemiologic survey in residents of the area, in conjunction with a serologic study in rodents. The prevalence of hantavirus antibodies in the general human population was 6.5%, one of the highest reported in the literature. No evidence of interhuman transmission was found, and the high preva-lence of hantavirus antibody seemed to be associated with the high infestation of rodents detected in domestic and peridomestic habitats.Fil: Pini, Noemi. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina.Fil: Levis, Silvana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina.Fil: Calderón, Gladys. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina.Fil: Ramirez, Josefina. Hospital San Miguel; Argentina.Fil: Bravo, Daniel. Hospital Oscar Orias; Argentina.Fil: Lozano, Elena. Hospital San Miguel; Argentina.Fil: Ripoll, Carlos. Dirección de Epidemiología; Argentina.Fil: St. Jeor, Stephen. University of Nevada; Estados Unidos.Fil: Ksiazek, Thomas G. Centers for Disease Control and Prevention; Estados Unidos.Fil: Barquez, Rubén. Universidad Nacional de Tucumán; Argentina.Fil: Enria, Delia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio Maiztegui; Argentina