Experimental infection of Rio Mamore hantavirus in Sigmodontinae rodents

This study shows an experimental spillover infection of Sigmodontinae rodents with Rio Mamore hantavirus (RIOMV). Necromys lasiurus and Akodon sp were infected with 103 RNA copies of RIOMV by intraperitoneal administration. The viral genome was detected in heart, lung, and kidney tissues 18 days after infection (ai), and viral excretion in urine and faeces began at four and six ai, respectively. These results reveal that urine and faeces of infected rodents contain the virus for at least 18 days. It is possible that inhaled aerosols of these excreta could transmit hantavirus to humans and other animals.

Pinhal virus, a new arenavirus isolated from calomys tener in Brazil

Arenavirus Sabiá was originally isolated from a fatal human infection in Brazil, and after the occurrence of the second fatal human case in São Paulo state, epidemiologic and virologic studies were performed in the area where the patient lived, aiming at the identification of the Sabiá natural rodent reservoir. A broadly cross-reactive enzyme-linked immunosorbent assay (ELISA) was used to screen for antibody-positive samples. Antibodies to arenavirus were detected in two of the 55 samples of Calomys tener, and from these results, samples of rodents were analyzed by a broad RT-PCR assay. RT-PCR amplification detected arenavirus sequences in five of the 55 C. tener samples, and sequencing showed that this virus is a distinct form of Sabiá virus. Thus, we describe here the evidence for the circulation of a new arenavirus in Brazil (proposed name Pinhal virus) and its genetic characterization compared to other arenaviruses. This study also suggests C. tener as a probable rodent reservoir for this virus and associates this new virus with the lineage C of New World arenaviruses. Although we have defined some characteristics of this virus, so far, there is no evidence of its involvement in human disease.

Condiciones para la transmision del hantavirus en zona andina de Río negro, Argentina

El Síndrome Pulmonar por Hantavirus (SPH) es una enfermedad de etiología viral que causa en el hombre un cuadro respiratorio grave. En Patagonia, la enfermedad es causada por el virus Andes Sur (AND), transmitido por el roedor Oligoryzomys longicaudatus. El objetivo del presente trabajo fue identificar las actividades del hombre que favorecen su exposición a roedores, denominados escenarios de contagio. Se realizó un estudio retrospectivo a partir de información recolectada en investigaciones de casos ocurridos en Río Negro, mediante Fichas Clínico-Epidemiológicas e informes de evaluación ecológico/ambiental. Se definieron como variables a ser consideradas: edad, sexo, época del año, grado de urbanización, localización geográfica, integración del hombre al hábitat de roedores, fuente probable de exposición, actividad humana y nivel de saneamiento. Se estudiaron 32 casos. La exposición rural se verificó en 18 (56.2%) de los casos y 10 (31.3%) en paraje rural (grupo de viviendas en zona rural). En relación al ambiente antropogénico 24 (75%) resultaron en ambientes modificados por el hombre y 8 (25%) en áreas poco modificadas. El sitio de exposición de mayor importancia en El Bolsón fue el interior de edificaciones en 8 de los 18 casos allí registrados (44.5%), mientras que en Bariloche fueron ambientes de exterior con 8/14 (57.1%) casos. La actividad de riesgo fue laboral en 23 (71.9%) de los casos y recreacional en 7 (28.1%). Determinar los escenarios de contagio a nivel local ha aportado información para aplicar todos los recursos disponibles en materia de prevención y educación sanitaria.

Hantavirus Pulmonary Syndrome (HPS) is a disease of viral etiology that affects humans causing severe acute respiratory symptoms. In Patagonia the disease is caused by the Andes Virus (AND) and transmitted by the rodent Oligoryzomys longicaudatus. The aim of this study was to identify those human activities that increase the risk of exposure to rodents, what we call "contagious scenarios". A retrospective study was performed with data obtained from cases in Rio Negro, which included clinic-epidemiological records and ecological/environmental assessment reports. The following variables were considered: age, sex, season, percentage of urbanization, geographic location, human settlements in rodent infested areas, probable source of exposure, type of activity and level of sanitary development. In total 32 cases were studied. Exposure was verified in 18 (56.2 %) cases in rural areas and 10 cases (31.3%) in small rural towns. In relation to anthropogenic environment, 24 (75%) cases were reported in developed settlements and 8 cases (25%) were related to slightly modified areas. Major exposition in El Bolson identified 8 cases of indoor activities of the total 18 reported in the area (44.5%), while in Bariloche 8 (57.1%) cases out of 14 were reported in outdoor surroundings. In general, activities that generated greater risk were work-related, accounting for 23 (71.9%) cases while 7 were related to recreational activities (28.1%). The identification of "contagious scenarios" at local level provided information for an effective application of available resources in terms of prevention and sanitary education.

Evidencia serológica de infección por hantavirus (Bunyaviridae: Hantavirus) en roedores del Departamento de Sucre, Colombia / Serological evidence of hanta virus infection (Bunyaviridae: Hantavirus) in rodents from the Sucre Department in Colombia

Objetivo Determinar la frecuencia de anticuerpos específicos a hantavirus en roedores del municipio de San Marcos, departamento de Sucre. Métodos Se capturaron 144 roedores con trampas Sherman® en áreas urbanas y rurales del municipio de San Marcos, desde diciembre de 2007 hasta julio de 2009. Los anticuerpos Ig G específicos contra el Virus Sin Nombre (VSN) fueron detectados en muestras de plasma mediante ELISA indirecto. Resultados La seroprevalencia de anticuerpos contra hantavirus fue del 8,3 % (12/144 capturas). Los porcentajes de seropositividad específicos por especie variaron entre 6,8 % (3/44, Zygodontomys brevicauda) y 50 % (1/2, Neacomys spinosus). No se encontró diferencia estadística en la seroprevalencia con respecto al área de muestreo, sexo y etapa reproductiva (p>0,05); sin embargo, hubo un mayor número de machos adultos seropositivos. Conclusiones Se evidenció por primera vez seropositividad a hantavirus en roedores de la subfamilia Murinae en Colombia. La detección de anticuerpos contra el virus refuerza la hipótesis que sugiere la circulación de al menos un hantavirus en roedores del norte colombiano.

Objective The main goal of this research was to determine the frequency of hantavirus-specific antibodies in rodents from the municipality of San Marcos in the Sucre department of Colombia. Methods 144 rodents were captured in San Marcos' urban and rural areas using Sherman traps between December 2007 and July 2009. "Virus sin Nombre" (SNV)-specific antibodies were detected in plasma samples by an indirect ELISA immunoassay. Results An 8.3 % (12/144) seroprevalence rate was found. Specific seropositivity rates ranged from 6.8 % (3/44, Zygodontomysbrevicauda) to 50 % (1/2, Neacomysspinosus). No significant differences were found in seroprevalence according to capture area, gender and/or reproductive stage (p>0.05); however, there were more seropositive adult males. Conclusion This is the first evidence of hanta virus seropositivity in rodents from the Murinae subfamily in Colombia. The presence of SNV antibodies in rodents in San Marcos supported the hypothesis that at least one hantavirusis circulating in rodents from northern Colombia.

Detection of the first incidence of Akodon paranaensis naturally infected with the Jabora virus strain (Hantavirus) in Brazil

We characterised hantaviruses circulating in different Akodon rodent species collected in midwestern Santa Catarina (SC), southern Brazil, where the Jabora hantavirus (JABV) strain was first identified in Akodon montensis. Genetic and phylogenetic analyses based on a partial S segment indicated that, in SC, Akodon paranaensis and A. montensis carried the same type of hantavirus. Additionally, we conducted the first genomic characterisation of the complete S segment from the Brazilian JABV strain. This is the first report of A. paranaensis infected with the JABV.

Características de Oligoryzomys longicaudatus asociadas a la presencia del virus Andes (Hantavirus) / Oligoryzomys longicaudatus characteristics' associated with the presence of Andes virus (Hantavirus)

Oligoryzomys longicaudatus is the main reservoir of Andes virus (AND), which causes hantavirus pulmonary syndrome in Patagonia. The factors associated with the presence of antibodies against AND in this species are unknown. This study used a logistic regression model to analyze which characteristics of O. longicaudatus, captured in northern Argentinean Patagonia, led to an increased probability of an animal having antibodies against AND and to relate these characteristics to possible mechanisms of transmission of the virus within the population. Sex, age, body mass, and wounds were important predictors regarding the presence of antibodies against AND within O. longicaudatus populations. The probability of a wounded male O. longicaudatus adult having AND antibodies increased in parallel with the body mass. The probability of having antibodies was more than 80% in individuals with body masses above 44 gram. However, the possible transmission mechanism of AND within O. longicaudatus population is still uncertain and further studies involving a larger number of individuals and prolonged monitoring including the process of seroconversion are needed.

Oligoryzomys longicaudatus es el principal reservorio del virus Andes Sur (AND) causante del síndrome pulmonar por hantavirus en la Patagonia. Aún se desconoce qué características individuales están asociadas a una mayor presencia de anticuerpos contra AND en esta especie. En este estudio, mediante un modelo de regresión logística evaluamos qué características de O. longicaudatus, capturados en la Patagonia norte de Argentina, incrementan la probabilidad de un individuo de presentar anticuerpos contra AND para relacionarlos con posibles mecanismos de transmisión del virus dentro de la población. El sexo, la edad, la masa corporal y las heridas resultaron factores importantes para la circulación y persistencia del virus dentro de la población de O. longicaudatus. La probabilidad de que un O. longicaudatus, macho, adulto con heridas presente anticuerpos contra AND aumentó con el incremento de la masa corporal, siendo esta probabilidad mayor al 80% en individuos con masas corporales mayores a 44 g. Sin embargo, el posible mecanismo de transmisión de AND dentro de la población de O. longicaudatus queda aún incierto, por lo que son necesarios estudios futuros que involucren un mayor número de individuos y un tiempo prolongado de seguimiento en su proceso de seroconversión.

Primera evidencia serológica de infección por Hantavirus en roedores, en Colombia / First serological evidence of Hantavirus infection in rodents in Colombia

OBJETIVO: Determinar la prevalencia de infección por hantavirus en roedores del Departamento de Córdoba, Colombia. METODOLOGIA: Captura de roedores con trampas tipo Sherman live-capture traps (8x9x23 cm; Sherman Traps, Inc., Tallahassee, FL) en áreas domésticas y peridomésticas en el departamento de Córdoba. Analisis de anticuerpos IgG por ELISA, empleando como antígeno una proteína recombinante de la nucleocapside del Sin Nombre Virus (SNV) (CDC, Atlanta, Georgia, USA). RESULTADOS: Durante los meses de enero de 2003 a noviembre de 2004, en 79 noches de trampeo fueron capturados 336 roedores en once municipios del departamento de Córdoba (Murinae: 249; Sigmodontinae: 68; Heteromyidae: 17; Echimyidae: 2) (éxito de captura del 8,5 por ciento). La seroprevalencia de anticuerpos contra hantavirus fue del 2,1 por ciento (7 de 336 capturas). Los porcentajes de seropositividad específicos por género oscilaron entre 5,9 por ciento (1 de 17, Heteromys) a 50 por ciento (1 de 2, Proechimys). CONCLUSIONES: La prevalencia de anticuerpos contra el SNV en roedores de Córdoba, Colombia; indica que al menos un hantavirus es endémico en roedores del norte colombiano y esta frecuentemente trasmitido a residentes rurales.