Development and standardization of an enzyme-linked inmunosorbent for the detection of orthohantavirus infection in Argentina based on its bacterial-expressed nucleocapside protein.

We conducted a development and standardization of an IgG ELISA assay for serological detection of human orthohantavirus infections using the recombinant antigen rLECH13 produced in bacterial and derived from the LECHV. The evaluation and standardization were carried out by analyzing serum samples from a total of 50 patients with confirmed Hantavirus Pulmonary Syndrome (HPS) diagnosis through the reference technique, 50 negative sera, and 53 patients with other medical conditions. The data from the assay analysis showed a diagnostic sensitivity value of 95% and a diagnostic specificity of 80%.

[Co-circulation of Junín virus and other mammarenaviruses in a geographical area without confirmed cases of Argentine Hemorrhagic Fever].

Since the identification of Junin virus in the 1950s, many studies were carried out in wild rodents within the endemic area of the Argentine Hemorrhagic Fever (AHF) that recorded also the activity of the lymphocytic choriomeningitis virus (LCMV) and the Latino virus (LATV). The absence of confirmed cases of AHF since the 1990s in the department of Rio Cuarto, Córdoba province, promoted ecoepidemiological surveillance of infection of Calomys musculinus (Junin virus reservoir) and the search of reservoirs of the other mammarenaviruses. During two years of seasonal sampling, with a capture, mark and release system, 857 rodents were captured, corresponding 57.

Application of quantitative immunofluorescence assays to analyze the expression of cell contact proteins during Zika virus infections.

Zika Virus (ZIKV) is an RNA virus that belongs to the Flavivirus (FV) genus. In the last years, several unique characteristics of ZIKV among FV have been revealed, as the multiple routes of transmission and its ability to reach different human tissues, including the central nervous system. Thus, one of the most intriguing features of ZIKV biology is its ability to cross diverse complex biological barriers.

Development and Validation of Waste Decontamination Cycle in a Biosafety Level 3 Laboratory.

Introduction: Steam sterilization has been used for decades to effectively kill microbial contaminants in a variety of medical and commercial settings. One of the most critical aspects of safe operations in biosafety level 3 biocontainment laboratories (BSL-3) is the effective inactivation of biological select agents in the waste generated in these environments. The Instituto Nacional de Enfermedades Virales Humanas "Dr.

A Retrospective Survey of Rodent-borne Viruses in Rural Populations of Brazilian Amazon.

Introduction: The Amazon tropical rainforest has the most dense and diverse ecosystem worldwide. A few studies have addressed rodent-borne diseases as potential hazards to humans in this region.

Methods: A retrospective survey was conducted using enzyme-linked immunosorbent assay for detecting mammarenavirus and orthohantavirus antibodies in 206 samples collected from rural settlers of the Brazilian Western Amazonian region.

Superinfection exclusion studies using West Nile virus and Culex flavivirus strains from Argentina.

In Argentina, many Flavivirus were recognised including West Nile virus (WNV). During 2009 several strains of Culex Flavivirus (CxFV), an insect-specific flavivirus, were isolated in the same region where circulation of WNV was detected. Hence, the objective of this study was to analyse the effect of co-infection in vitro assays using CxFV and WNV Argentinean strains in order to evaluate if CxFV could affect WNV replication.

Use of an Argentinean Wildlife Tissue Collection for Epidemiological Studies of Histoplasmosis.

Histoplasmosis is a worldwide systemic endemic mycosis caused by several cryptic species included within the Histoplasma capsulatum complex. Domestic and wild mammals are susceptible to infection by this fungus and could be used as indicators of its presence in the environment. The aim of the study was to identify the natural reservoirs of H.

Seroprevalence of rodent-borne viruses in Afro-descendent communities in Brazil.

During the Brazilian slavery period, many African migrants were brought to the American continent. Historically, some of these migrants escaped from the Brazilian gold mines and farms to which they had been brought and settled in remote valleys and this was the main mode of resistance to the slavery system. These runaway-slave descendant communities are called quilombos, a group with distinct ethnic identity, specific behavioral habits, including geographic isolation and conservative practices.

Mechanisms of Hantavirus Transmission in Oligoryzomys longicaudatus.

The cricetid rodent Oligoryzomys longicaudatus is the species host of Andes virus (ANDV) which causes hantavirus pulmonary syndrome in southern Argentina and Chile. Population density, behavioral interactions, and spacing patterns are factors that affect viral transmission among wild rodents. We predict that the highest prevalence of hantavirus antibody positive would be found among wounded, reproductive males and that, at high population densities, wounded, reproductive males would be dispersers rather than resident individuals.

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.

Orthohantavirus genotype Lechiguanas in Oligoryzomys nigripes (Rodentia: Cricetidae): New evidence of host-switching.

To identify and predict situations of increased risk of orthohantavirus infection in humans, it is necessary to study the relationships between the virus and its rodent hosts. The present study investigated orthohantavirus infection in an assemblage of wild Sigmodontinae rodents of the Paraná Delta, Argentina, and providing new evidence of host-switching events. Rodents belonging to the species Oxymycterus rufus (n = 187), Akodon azarae (n = 82), Oligoryzomys flavescens (n = 80), Oligoryzomys nigripes (n = 47), Scapteromys aquaticus (n = 38), Deltamys kempi (n = 7) and Holochilus brasiliensis (n = 2) were captured at 4 sampling sites during 20 trapping sessions.

Rodent-borne viruses survey in rural settlers from Central Brazil.

Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.

Development of a serosurveillance assay for detection of Necoclí virus exposure.

Hantavirus cardiopulmonary syndrome (HPS) has gained importance in Latin America as an emerging disease, with reports of about 4000 HPS cases; however, this is probably an underestimate because of limited surveillance programs and diagnostic tools to confirm HPS. In order to address this issue and develop better serosurveillance capability, we evaluated three recombinant peptides from the Necoclí virus (NECV) nucleocapsid in antibody-capture ELISA. We cloned and expressed antigens representing the whole NECV nucleocapsid protein (NECV-rN), the immunodominant domain (NECV-rN100), and a serospecific domain (NECV-rN428), and then we compared these antigens in ELISA to detect IgG antibodies to NECV in human sera.

[Outbreak of hantavirus pulmonary syndrome in Tucumán, Argentina].

We describe an outbreak of hantavirus pulmonary syndrome in the Burruyacú Department, Province of Tucumán. The detection in 2016 of a case of hantavirosis affecting a 23-year-old woman, considered at that time to be the first case occurred in that province, promoted a thorough epidemiological study. The investigation allowed the retrospective detection of another case occurred one month earlier in a 5-year-old child in the same Department.

Vaccine-elicited receptor-binding site antibodies neutralize two New World hemorrhagic fever arenaviruses.

While five arenaviruses cause human hemorrhagic fevers in the Western Hemisphere, only Junin virus (JUNV) has a vaccine. The GP1 subunit of their envelope glycoprotein binds transferrin receptor 1 (TfR1) using a surface that substantially varies in sequence among the viruses. As such, receptor-mimicking antibodies described to date are type-specific and lack the usual breadth associated with this mode of neutralization.

Serum Cytokine Profiles Differentiating Hemorrhagic Fever with Renal Syndrome and Hantavirus Pulmonary Syndrome.

Hantavirus infection is an acute zoonosis that clinically manifests in two primary forms, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). HFRS is endemic in Europe and Russia, where the mild form of the disease is prevalent in the Tatarstan region. HPS is endemic in Argentina, as well as other countries of North and South American.

[First evidence of lymphocytic choriomeningitis virus (Arenavirus) infection in Mus musculus rodents captured in the urban area of the municipality of Sincelejo, Sucre, Colombia].

Introduction: The lymphocytic choriomeningitis virus is an Old World arenavirus that infects Mus musculus, and can cause congenital hydrocephalus, chorioretinitis and multisystemic failure in transplant human recipients. Although the disease has not been clinically diagnosed in Colombia yet, there have been reports of infection with the Pichindé virus in rodents from Cauca and Valle del Cauca departments, and with the Guanarito virus in rodents from Córdoba department.

Objective: To identify the lymphocytic choriomeningitis virus from Mus musculus captured in the municipality of Sincelejo.

Detection of the mosquito-borne flaviviruses, West Nile, Dengue, Saint Louis Encephalitis, Ilheus, Bussuquara, and Yellow Fever in free-ranging black howlers (Alouatta caraya) of Northeastern Argentina.

Several medically important mosquito-borne flaviviruses have been detected in Argentina in recent years: Dengue (DENV), St. Louis encephalitis (SLEV), West Nile (WNV) and Yellow Fever (YFV) viruses. Evidence of Bussuquara virus (BSQV) and Ilheus virus (ILHV) activity were found, but they have not been associated with human disease.

Development and validation of a point-of-care test for detecting hantavirus antibodies in human and rodent samples.

Hantaviruses are etiologic agents of a zoonotic disease transmitted mainly from wild rodents to humans, causing Hemorrhagic Fever with Renal Syndrome in Eurasia and the Hantavirus Cardiopulmonary Syndrome in the Americas (HCPS), reaching a lethality rate of 40% in Brazil. Hantavirus diagnostic and seroprevalence are often based on the presence of IgM and IgG antibodies against the virus. Here we propose a rapid test assay able to identify hantavirus antibodies with sensibility and specificity similar to ELISA assays.

Molecular Basis for Antibody-Mediated Neutralization of New World Hemorrhagic Fever Mammarenaviruses.

In the Western hemisphere, at least five mammarenaviruses cause human viral hemorrhagic fevers with high case fatality rates. Junín virus (JUNV) is the only hemorrhagic fever virus for which transfusion of survivor immune plasma that contains neutralizing antibodies ("passive immunity") is an established treatment. Here, we report the structure of the JUNV surface glycoprotein receptor-binding subunit (GP1) bound to a neutralizing monoclonal antibody.

Potential for Co-Infection of a Mosquito-Specific Flavivirus, Nhumirim Virus, to Block West Nile Virus Transmission in Mosquitoes.

Nhumirim virus (NHUV) is an insect-specific virus that phylogenetically affiliates with dual-host mosquito-borne flaviviruses. Previous in vitro co-infection experiments demonstrated prior or concurrent infection of Aedes albopictus C6/36 mosquito cells with NHUV resulted in a 10,000-fold reduction in viral production of West Nile virus (WNV). This interference between WNV and NHUV was observed herein in an additional Ae.

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.

[New transmission scenarios of the Argentine hemorrhagic fever since the introduction of the live attenuated junin virus vaccine (Candid #1): an experience in migrant workers].

The Argentine hemorrhagic fever (AHF) is a severe acute viral disease caused by the Junin virus of the Arenaviridae family. The AHF endemic area coincides geographically with the largest grain export agro-industrial complex of the country [Argentina]. Since the implementation of vaccination with the Candid #1 vaccine, a significant reduction in incidence was achieved and risk patterns were modified.