Hantavirus antibodies among phyllostomid bats from the arc of deforestation in Southern Amazonia, Brazil.

In order to determine whether southern Amazonian bats could harbour hantaviruses we, serologically and molecularly, screened blood, saliva, excreta and organ tissues of 47 bats captured from September to December 2015. We found that only phyllostomid bats presented antibodies against hantavirus. The seropositive bats belonged to two species of Phyllostomid bats: the greater spear-nosed bat Phyllostomus hastatus (omnivorous) and the gnome fruit-eating bat Dermanura gnoma. The overall seroprevalence was of 4.2%. Therefore, we show here that hantaviruses are circulating among phyllostomid bats in the Amazonian arc of deforestation.

Estimaciones de la distribución espacial del riesgo relativo de mortalidad por las principales zoonosis en Chile: enfermedad de Chagas, hidatidosis, síndrome cardiopulmonar por hantavirus y leptospirosis / Estimates of the spatial distribution of the relative risk of mortality of the main zoonoses in Chile: Chagas disease, hydatidosis, Hantavirus cardiopulmonary syndrome and leptospirosis

Resumen Introducción: Las zoonosis son enfermedades o infecciones causadas por todo tipo de agentes etiológicos transmisibles desde animales vertebrados a humanos. Durante las últimas décadas, el riesgo para la salud ocasionado por diferentes zoonosis, ha sido generado por la distribución natural de los distintos agentes etiológicos y por la emergencia y reemergencia de estas enfermedades. Objetivo: Estudiar la distribución del riesgo de mortalidad de las cuatro principales zoonosis en Chile continental, basados en datos nacionales de mortalidad, con el objetivo de visualizar geográficamente donde focalizar los esfuerzos de control de estas enfermedades. Metodología: Se estima el riesgo relativo de las principales zoonosis en Chile, mediante estadística Bayesiana. Resultados: Se obtuvo la distribución de las cuatro principales zoonosis de Chile. Discusión/Conclusión: Se obtuvo la distribución de las cuatro principales zoonosis de Chile. Los mapas de riesgo obtenidos muestran una enfermedad parasitaria transmitida por vectores de alto riesgo en el norte, la enfermedad de Chagas; una enfermedad parasitaria de comunidades biológicas en que el hombre es un hospedero accidental, asociada a zonas ganaderas, prevalente en el sur, la hidatidosis; una enfermedad bacteriana transmitida por vertebrados, especialmente por roedores, donde el agua es un vehículo importante, dominante en el centro, la leptospirosis; y una enfermedad viral transmitida por roedores, muy dominante en el sur, la infección por hantavirus.

Background: Zoonoses are infections caused by all types of etiological transmissible agents from vertebrate animals to humans. During the last decades, the risk to health caused by different zoonoses has been a consequence of the natural distribution of the different etiological agents and by the emergence and reemergence of these diseases. Aim: To study the distribution of the risk of mortality of the four main zoonoses in continental Chile, based on national mortality data, with the objective of visualizing geographically where to focus the control efforts of these diseases. Methods: Relative risk was estimated by means of Bayesian Statistics. Results: The distribution in Chile of the main zoonoses was obtained. Discussion/Conclusion: The risk maps obtained show a parasitic disease transmitted by high-risk vectors in the north, Chagas disease; a parasitic disease of biological communities in which man is an accidental host, associated with livestock areas, more prevalent in the south, hydatidosis; a bacterial disease transmitted by vertebrates, especially by rodents, where water is an important vehicle, dominant in the center, leptospirosis; and a viral disease transmitted by rodents, very dominant in the south, the hantavirus infection.

Factores de riesgo socio-demográficos del síndrome cardiopulmonar por hantavirus / Sociodemographic risk factors of hantavirus cardiopulmonary syndrome

Resumen Introducción: El síndrome cardiopulmonar por hantavirus (SCPH) es causado en Chile y en el sur de Argentina por el Andes hantavirus (ANDV), el que es endémico en esta zona. La enfermedad causada por ANDV produce un aumento de permeabilidad vascular y filtración de plasma con una alta tasa de letalidad (35%), debido principalmente a insuficiencia respiratoria por edema pulmonar y al desarrollo en los casos graves de compromiso miocárdico, hipoperfusión y shock. Aunque se sabe que los factores socio-demográficos del hospedero pueden influir en el curso y el resultado de la enfermedad, estos no se han caracterizado previamente en la población chilena. Objetivo: Evaluar la relación entre los factores socio-demográficos y la gravedad del SCPH. Pacientes y Métodos: Período de análisis 2004-20013, pacientes atendidos en ocho centros colaboradores, diagnóstico etiológico serológico o por biología molecular, se comparan SCPH leve y grave. Se analizaron 139 pacientes chilenos, 64 (46%) con enfermedad grave, entre los cuales 12 murieron (19%). Resultados: La etnia europea tuvo un riesgo 5,1 veces mayor de desarrollar un SCPH grave que la etnia amerindia, gravedad mayor que también se asoció a una residencia urbana. Conclusiones: Se observó una asociación estadísticamente significativa entre etnia, lugar de residencia y evolución de SCPH. Se discuten hipótesis que expliquen estos hallazgos.

Background: Hantavirus cardiopulmonary syndrome (HCPS) is caused by new world hantaviruses, among which Andes hantavirus (ANDV) is endemic to Chile and Southern Argentina. The disease caused by ANDV produces plasma leakage leading to enhanced vascular permeability and has a high case fatality rate (35%), mainly due to respiratory failure, pulmonary edema and myocardial dysfunction, hypoperfusion and shock. Host sociodemographic and genetic factors might influence the course and outcome of the disease. Yet, they have not been thoroughly characterized. Aim: To evaluate sociodemographic factors as risk factors in severity of HCPS. Patients and Methods: Study period: 2004-20013, attending in eight collaborative centers, etiological diagnosis was performed by serology or molecular biology, mild and severe HCPS were compared.139 Chilean patients were analyzed, 64 (46%) with severe disease among which 12 (19 %) died. Results: European ethnicity had 5,1 times higher risk than Amerindian ethnic group to develop a severe HCPS, greater seriousness that was also associated with an urban residence. Conclusion: It was observed that ethnicity and type of residence were significant risk factors for HCPS severity. Hypotheses explaining these findings are discussed.

Hantavirus infection among children hospitalized for febrile illness suspected to be dengue in Barbados.

Emerging picture of hantavirus infection in the South America is characterized by greater proportion of childhood infection and wider spectrum of disease from mild asymptomatic to lethal cardiopulmonary disease. Barbados is endemic for dengue and leptospirosis, both of which share clinical features with hantavirus infection and in many cases neither of these diagnosis could be confirmed. We investigate whether some of the children hospitalized with suspected dengue could indeed have been hantavirus infections. In this prospective study children hospitalized with suspected dengue were tested for hantavirus infection using ELISA for the IgM antibodies. Thirty-eight children tested positive for hantavirus infection. They presented with fever, headache and mild respiratory and gastrointestinal symptoms and signs. None of them had features suggestive of hantavirus cardiopulmonary syndrome. Blood count values ranged from low to normal to high for their age. There were no deaths. Hantavirus infection is prevalent in this Caribbean country. It predominantly presents with milder disease and is responsible for some of the nonspecific febrile illnesses in children.

Expression of a hantavirus N protein and its efficacy as antigen in immune assays

Hantavirus cardiopulmonary syndrome (HCPS) has been recognized as an important public heath problem. Five hantaviruses associated with HCPS are currently known in Brazil: Juquitiba, Araraquara, Laguna Negra-like, Castelo dos Sonhos, and Anajatuba viruses. The laboratory diagnosis of HCPS is routinely carried out by the detection of anti-hantavirus IgM and/or IgG antibodies. The present study describes the expression of the N protein of a hantavirus detected in the blood sample of an HCPS patient. The entire S segment of the virus was amplified and found to be 1858 nucleotides long, with an open reading frame of 1287 nucleotides that encodes a protein of 429 amino acids. The nucleotide sequence described here showed a high identity with the N protein gene of Araraquara virus. The entire N protein was expressed using the vector pET200D and the Escherichia coli BL21 strain. The expression of the recombinant protein was confirmed by the detection of a 52-kDa protein by Western blot using a pool of human sera obtained from HCPS patients, and by specific IgG detection in five serum samples of HCPS patients tested by ELISA. These results suggest that the recombinant N protein could be used as an antigen for the serological screening of hantavirus infection.