RESUMO
Orthohantaviruses are emerging rodent-borne pathogens that cause Hantavirus Pulmonary Syndrome in humans. They have a wide range of rodent reservoir hosts and are transmitted to humans through aerosolized viral particles generated by the excretions of infected individuals. Since the first description of HPS in Argentina, new hantaviruses have been reported throughout the country, most of which are pathogenic to humans. We present here the first HPS case infected with Alto Paraguay virus reported in Argentina. Until now, Alto Paraguay virus was considered a non-pathogenic orthohantavirus since it was identified in a rodent, Holochilus chacarius. In addition to this, with the goal of identifying potential hantavirus host species in the province of Santa Fe, we finally describe a novel orthohantavirus found in the native rodent Scapteromys aquaticus, which differed from other hantaviruses described in the country so far. Our findings implicate an epidemiological warning regarding these new orthohantaviruses circulating in Central Argentina as well as new rodent species that must be considered as hosts from now on.
Assuntos
Reservatórios de Doenças/virologia , Síndrome Pulmonar por Hantavirus/virologia , Orthohantavírus/isolamento & purificação , Sigmodontinae/virologia , Adolescente , Animais , Anticorpos Antivirais/sangue , Argentina , Feminino , Orthohantavírus/classificação , Orthohantavírus/genética , Humanos , Masculino , Filogenia , Sigmodontinae/sangueRESUMO
Rodents are reservoirs of various types of hantavirus, some of which are agents of hantavirus pulmonary syndrome in humans. Each hantavirus is associated with a single rodent host species but successive spill-over events may eventually lead to host-switching and new species' becoming host of a given pathogen. This study aims to gain an understanding of the spatial ecology of two hantavirus-host species, Akodon azarae, and Oligoryzomys flavescens, by identifying factors modulating their home range sizes and stability, and by evaluating intra- and interspecific spatial aggregation for these species and a third one-Oxymycterus rufus-living in sympatry. For this, eleven capture-mark-recapture surveys were carried out, spanning 22 months. We found that A. azarae males have larger and more mobile home ranges than females, independently of the season. Consequently, males could likely have a more relevant role in the transmission of hantavirus because of their greater exposure both to a higher number of contacts between individuals and viral contamination of the environment. Contrasting, O. flavescens individuals showed negligible displacements of their home range through time, which could limit the range of hantavirus spread in host populations. Since O. flavescens is host to Lechiguanas hantavirus (pathogenic to humans) this result encompasses epidemiological relevance, for it may imply the existence of local foci of infection. Additionally, individuals of both species performed excursions outside their home ranges. These events could enable hantavirus spread over distances beyond the normal range of movements and lead to new hantavirus outbreaks in formerly non-infected rodent populations, favoring the persistence of the virus in nature.
Assuntos
Ecossistema , Comportamento de Retorno ao Território Vital , Sigmodontinae/fisiologia , Animais , Argentina , Comportamento Animal , Reservatórios de Doenças , Feminino , Orthohantavírus , Infecções por Hantavirus/transmissão , Masculino , Estações do Ano , Sigmodontinae/virologiaRESUMO
Hantavirus pulmonary syndrome (HPS) is a severe emerging endemic disease of the Americas. Because hantavirus reservoirs are sylvatic rodents, HPS risk has been associated with occupational and recreational activities in natural and rural environments. The aim of this study was to analyze the risk of HPS in an endemic province of Argentina. For this, we explored the relationship between HPS cases occurring in Entre Ríos province between 2004 and 2015 and climate, vegetation, landscape, reservoir population, and rodent community characteristics by means of generalized linear models. We modeled HPS occurrence at each site, and both the incidence and number of cases grouped by department. The resulting best model of each analysis was applied in a GIS to build HPS risk maps. Risk of occurrence of HPS increased with tree cover and decreased with distance to rivers. We identified the south of Entre Ríos as the area with higher HPS risk, and therefore, where HPS prevention measures should be more urgently applied. Risk maps based on data available in the public domain are a useful tool that should be used by decision makers to concentrate surveillance and control efforts in those areas with highest HPS risk.
Assuntos
Meio Ambiente , Síndrome Pulmonar por Hantavirus/epidemiologia , Doenças dos Roedores/epidemiologia , Sigmodontinae/virologia , Animais , Argentina/epidemiologia , Clima , Reservatórios de Doenças/virologia , Mapeamento Geográfico , Orthohantavírus , Humanos , Plantas , Dinâmica Populacional , Fatores de Risco , Fatores Socioeconômicos , Estrigiformes/virologia , ZoonosesRESUMO
The Hepacivirus genus comprises single-stranded positive-sense RNA viruses within the family Flaviviridae. Several hepaciviruses have been identified in different mammals, including multiple rodent species in Africa, Asia, Europe, and North America. To date, no rodent hepacivirus has been identified in the South American continent. Here, we describe an unknown hepacivirus discovered during a metagenomic screen in Akodon montensis, Calomys tener, Oligoryzomys nigripes, Necromys lasiurus, and Mus musculus from São Paulo State, Brazil. Molecular detection of this novel hepacivirus by RT-PCR showed a frequency of 11.11% (2/18) in Oligoryzomys nigripes. This is the first identification of hepavivirus in sigmondonine rodents and in rodents from South America. In sum, our results expand the host range, viral diversity, and geographical distribution of the Hepacivirus genus.
Assuntos
Reservatórios de Doenças/virologia , Genoma Viral , Hepacivirus/classificação , Hepacivirus/isolamento & purificação , Sigmodontinae/virologia , Animais , Especificidade de Hospedeiro , Filogenia , RNA Viral/genética , América do SulRESUMO
BACKGROUND: Hantavirus pulmonary syndrome (HPS) is an infection endemic in Chile and Argentina, caused by Andes hantavirus (ANDV). The rodent Oligoryzomys longicaudatus is suggested as the main reservoir, although several other species of Sigmodontinae are known hosts of ANDV. Here, we explore potential ANDV transmission risk to humans in southern South America, based on eco-epidemiological associations among: six rodent host species, seropositive rodents, and human HPS cases. METHODS: We used ecological niche modeling and macroecological approaches to determine potential geographic distributions and assess environmental similarity among rodents and human HPS cases. RESULTS: Highest numbers of rodent species (five) were in Chile between 35° and 41°S latitude. Background similarity tests showed niche similarity in 14 of the 56 possible comparisons: similarity between human HPS cases and the background of all species and seropositive rodents was supported (except for Abrothrix sanborni). Of interest among the results is the likely role of O. longicaudatus, Loxodontomys micropus, Abrothrix olivaceus, and Abrothrix longipilis in HPS transmission to humans. CONCLUSIONS: Our results support a role of rodent species' distributions as a risk factor for human HPS at coarse scales, and suggest that the role of the main reservoir (O. longicaudatus) may be supported by the broader rodent host community in some areas.
Assuntos
Reservatórios de Doenças/virologia , Ecossistema , Infecções por Hantavirus/epidemiologia , Orthohantavírus/isolamento & purificação , Animais , Argentina/epidemiologia , Chile/epidemiologia , Infecções por Hantavirus/diagnóstico , Infecções por Hantavirus/transmissão , Humanos , Sigmodontinae/virologiaRESUMO
The nearly complete genome sequence of a novel polyomavirus from blood samples of Akodon montensis and Calomys tener collected in Brazil was determined by high-throughput sequencing. This virus showed a typical polyomaviruses genome organization, and it was classified as a member of the genus Betapolyomavirus. Our results expand the host range and viral diversity of the family Polyomaviridae.
Assuntos
Antígenos Virais de Tumores/genética , Genoma Viral/genética , Polyomaviridae , Sigmodontinae/virologia , Sequência de Aminoácidos/genética , Animais , Brasil , Especificidade de Hospedeiro , Filogenia , Polyomaviridae/classificação , Polyomaviridae/genética , Polyomaviridae/isolamento & purificaçãoRESUMO
Argentine hemorrhagic fever (AHF) is a serious endemic disease in Argentina, produced by Junín virus, whose host is the Sigmodontinae rodent Calomys musculinus. Within the endemic area, human incidence and proportion of infected rodents remains high for 5-10 years after the first appearance of the disease (epidemic [E] zone) and then gradually declines to sporadic cases (historic [H] zone). We tested the hypothesis that host populations within the E zone are large and well connected by gene flow, facilitating the transmission and maintenance of the virus, whereas those in the H and nonendemic (NE) zones are small and isolated, with the opposite effect. We estimated parameters affected by levels of gene flow and population size in 14 populations of C. musculinus: population effective size (Ne), genetic variability, and mean relatedness. Our hypothesis was not supported: the lowest levels of variability and of Ne and the highest genetic relatedness among individuals were found in the H zone. Populations from the NE zone displayed opposite results, whereas those in the E zone showed intermediate values. If we consider that populations are first NE, then E, and finally H, a correlative decrease in Ne was observed. Chronically infected females have a low reproductive success. We propose that this would lower Ne because each cohort would originate from a fraction of females of the previous generation, and affect other factors such as proportion of individuals that develop acute infection, probability of viral transmission, and evolution of virulence, which would explain, at least partly, the changing incidence of AHF.
Assuntos
Reservatórios de Doenças/virologia , Febre Hemorrágica Americana/epidemiologia , Sigmodontinae/genética , Sigmodontinae/virologia , Animais , Argentina/epidemiologia , Doenças Endêmicas , Fluxo Gênico , Variação Genética , Genética Populacional , Humanos , Incidência , Vírus Junin/isolamento & purificação , Densidade DemográficaRESUMO
Hantavirus cardiopulmonary syndrome is an emerging serious disease in the Americas, transmitted from wild rodents to humans through inhalation of aerosol containing virus. Herein, we characterized two distinct hantaviruses circulating in rodent species form Central Plateau, Midwestern region of Brazil in the Cerrado (savanna-like) biome, an area characterized by small trees and grasses adapted to climates with long dry periods. In this study, we identified the co-circulation of the Araraquara virus and a possible new lineage of the Juquitiba virus (JUQV) in Oligoryzomys nigripes. The implications of co-circulation are still unknown, but it can be the key for increasing viral diversity or emergence of new species through spillover or host switching events leading to co-infection and consequently recombination or reassortment between different virus species. Phylogenetic analyses based on the complete S segment indicated that, alongside with Oligoryzomys mattogrossae rodents, O. nigripes species could also have a whole as JUQV reservoir in the Cerrado biome. Although these rodents' species are common in the Cerrado biome, they are not abundant demonstrating how complex and different hantavirus enzootic cycles can be in this particular biome.
Assuntos
Coinfecção/virologia , Reservatórios de Doenças/veterinária , Infecções por Hantavirus/transmissão , Orthohantavírus/classificação , Filogenia , Sigmodontinae/virologia , Animais , Brasil , Coinfecção/genética , Doenças Transmissíveis/virologia , Reservatórios de Doenças/virologia , Ecossistema , Genoma Viral , Orthohantavírus/genética , Orthohantavírus/isolamento & purificação , Orthohantavírus/patogenicidade , Infecções por Hantavirus/epidemiologia , Humanos , Recombinação Genética , Doenças dos Roedores/epidemiologia , Doenças dos Roedores/virologia , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
Hantavirus pulmonary syndrome is a severe cardio pulmonary disease transmitted to humans by sylvan rodents found in natural and rural environments. Disease transmission is closely linked to the ecology of animal reservoirs and abiotic factors such as habitat characteristics, season or climatic conditions. The main goals of this research were: to determine the biotic and abiotic factors affecting richness and abundance of rodent species at different spatial scales, to evaluate different methodologies for studying population of small rodents, and to describe and analyze an ecologically-based rodent management experience in a highly touristic area. A 4-year study of small rodent ecology was conducted between April 2007 and August 2011 in the most relevant habitats of El Palmar National Park, Argentina. Management involved a wide range of control and prevention measures, including poisoning, culling and habitat modification. A total of 172 individuals of 5 species were captured with a trapping effort of 13 860 traps-nights (1.24 individuals/100 traps-nights). Five rodent species were captured, including 2 hantavirus-host species, Oligoryzomys nigripes and Akodon azarae. Oligoryzomys nigripes, host of a hantavirus that is pathogenic in humans, was the most abundant species and the only one found in all the studied habitats. Our results are inconsistent with the dilution effect hypothesis. The present study demonstrates that sylvan rodent species, including the hantavirus-host species, have distinct local habitat selection and temporal variation patterns in abundance, which may influence the risk of human exposure to hantavirus and may have practical implications for disease transmission as well as for reservoir management.
Assuntos
Ecossistema , Controle de Roedores/métodos , Roedores/fisiologia , Roedores/virologia , Sigmodontinae/fisiologia , Sigmodontinae/virologia , Animais , Argentina , Reservatórios de Doenças/virologia , Orthohantavírus , Síndrome Pulmonar por Hantavirus/prevenção & controle , Parques Recreativos , Dinâmica Populacional , Doenças dos Roedores/virologiaRESUMO
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.