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.

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.

Assessing cross-reactivity of Junín virus-directed neutralizing antibodies.

Arenaviruses cause several viral hemorrhagic fevers endemic to Africa and South America. The respective causative agents are classified as biosafety level (BSL) 4 pathogens. Unlike for most other BSL4 agents, for the New World arenavirus Junín virus (JUNV) both a highly effective vaccination (Candid#1) and a post-exposure treatment, based on convalescent plasma transfer, are available.

[Spatial difference in the incidence of Argentine Hemorrhagic Fever and composition and abundance of rodents in the assemblage].

Background: The Argentine Hemorrhagic Fever (AHF) is a zoonotic disease endemic in a wide area of the humid pampa of Argentina. The etiologic agent is the Junin virus that is maintained in the wild by the rodent Calomys musculinus and transmitted to humans, mainly, through aerosols generated from secretions and excretions.

Aims: To characterize and compare the assemblages of small rodent composition and diversity inside the epidemic, historic and non-endemic zone of AHF and to register C.

[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.

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.

Monoclonal antibody therapy for Junin virus infection.

Countermeasures against potential biothreat agents remain important to US Homeland Security, and many of these pharmaceuticals could have dual use in the improvement of global public health. Junin virus, the causative agent of Argentine hemorrhagic fever (AHF), is an arenavirus identified as a category A high-priority agent. There are no Food and Drug Administration (FDA) approved drugs available for preventing or treating AHF, and the current treatment option is limited to administration of immune plasma.

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.

[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.

[Tenosynovitis due to Chikungunya virus].

We report the case of a man from Dominican Republic who consulted for a tenosynovitis of the right middle finger extensor; in the immediate convalescence second febrile curve, after 48 hours of no symptoms of an acute febrile illness, with marked fatigue, itchy rash, polyarthralgia, functional impairment and general stiffness. Biochemical tests did not provide useful data for diagnosis. Dengue virus serology was negative.

Complete genome sequences and phylogenetic analysis of two West Nile virus strains isolated from equines in Argentina in 2006 could indicate an early introduction of the virus in the Southern Cone.

The complete nucleotide sequences of two West Nile virus (WNV) strains isolated in Argentina were determined. Phylogenetic trees were constructed from the aligned nucleic acid sequences of these two strains along with other previously published complete WNV genome sequences. Phylogenetic data showed that both strains belonged to clade 1a of lineage 1 and clustered in a subclade with American strains isolated during 1999-2002.

Evaluation of commercially available diagnostic tests for the detection of dengue virus NS1 antigen and anti-dengue virus IgM antibody.

Commercially available diagnostic test kits for detection of dengue virus (DENV) non-structural protein 1 (NS1) and anti-DENV IgM were evaluated for their sensitivity and specificity and other performance characteristics by a diagnostic laboratory network developed by World Health Organization (WHO), the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the Pediatric Dengue Vaccine Initiative (PDVI). Each network laboratory contributed characterized serum specimens for the panels used in the evaluation. Microplate enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic test (RDT formats) were represented by the kits.

Quali-quantitative study of the social variables defining transmission scenarios of Argentine Hemorrhagic Fever in the provinces of Buenos Aires and 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.

New strains of Culex flavivirus isolated in Argentina.

Strains of Culex flavivirus (CxFV), an insect virus isolated initially from Japan, were isolated from different species of Culex sp. mosquitoes collected in Corrientes province, Argentina, during 2009. CxFV was detected by reverse transcription polymerase chain reaction and by isolation in C6/36 cell culture.

Hantaviruses and cardiopulmonary syndrome in South America.

Hantavirus (Bunyaviridae) cardiopulmonary syndrome (HCPS) is an emerging health problem in South America due to urban growth and to the expansion of agriculture and cattle-raising areas into ecosystems containing most of the species of Sigmodontinae rodents that act as hantavirus reservoirs. About 4000 HCPS cases have been reported in South America up to 2013, associated with the following hantaviruses: Andes, Anajatuba, Araraquara (ARQV), Paranoá, Bermejo, Castelo dos Sonhos, Juquitiba, Araucária, Laguna Negra, Lechiguanas, Maripa, Oran, Rio Mamore and Tunari. The transmission of hantavirus to man occurs by contact with or through aerosols of excreta and secretions of infected rodents.

Yellow fever vaccine-associated adverse events following extensive immunization in Argentina.

As a consequence of YF outbreaks that hit Brazil, Argentina, and Paraguay in 2008-2009, a significant demand for YF vaccination was subsequently observed in Argentina, a country where the usual vaccine recommendations are restricted to provinces that border Brazil, Paraguay, and Bolivia. The goal of this paper is to describe the adverse events following immunization (AEFI) against YF in Argentina during the outbreak in the northeastern province of Misiones, which occurred from January 2008 to January 2009. During this time, a total of nine cases were reported, almost two million doses of vaccine were administered, and a total of 165 AEFI were reported from different provinces.

Estimating hantavirus risk in southern Argentina: a GIS-based approach combining human cases and host distribution.

We use a Species Distribution Modeling (SDM) approach along with Geographic Information Systems (GIS) techniques to examine the potential distribution of hantavirus pulmonary syndrome (HPS) caused by Andes virus (ANDV) in southern Argentina and, more precisely, define and estimate the area with the highest infection probability for humans, through the combination with the distribution map for the competent rodent host (Oligoryzomys longicaudatus). Sites with confirmed cases of HPS in the period 1995-2009 were mostly concentrated in a narrow strip (~90 km × 900 km) along the Andes range from northern Neuquén to central Chubut province. This area is characterized by high mean annual precipitation (~1,000 mm on average), but dry summers (less than 100 mm), very low percentages of bare soil (~10% on average) and low temperatures in the coldest month (minimum average temperature -1.

Isolation of yellow fever virus from mosquitoes in Misiones province, Argentina.

Yellow fever (YF) is a viral hemorrhagic fever endemic to tropical regions of South America and Africa. From 2007 to 2009 an important epidemic/epizootic of YF was detected in different populations of howler monkeys (Alouatta species) in Misiones, a northeastern Argentinian province. Yellow fever virus (YFV) infection was researched and documented by laboratory tests in humans and in dead Alouatta carayá.

[Outbreak of St. Louis encephalitis in the Metropolitan Buenos Aires Area].

We describe the epidemiological and clinical findings of 13 patients with diagnosis of infection by St. Louis encephalitis virus, transmitted between January and March 2010 in Buenos Aires Metropolitan Area (AMBA). Thirteen patients, average age 38 years, had an acute onset with hyperthermia and headache.

[Perinatal dengue infection].

Dengue is a mosquito-borne viral disease, with worldwide distribution in tropical and subtropical areas. Argentina was certified free of Aedes aegypti in the sixties, however the vector reappered in 1984. In the nineties, small dengue outbreaks occurred with autocthonus diseases at first limited to the northern provinces.