Wild birds as hosts of ticks (Acari: Ixodidae) and Anaplasmataceae (Rickettsiales) in the Atlantic rainforest ecoregion, Argentina.

This study aimed to assess the presence of Anaplasma, Ehrlichia and Rickettsia species infecting wild birds and their associated ticks in two localities: Moconá Provincial Park (MPP) and Piñalito Provincial Park (PPP), within the Atlantic rainforest ecoregion of Argentina. A total of 142 birds were captured representing 34 species, 28 genera, 15 families and five orders. Ticks were collected from 33 of these birds, comprising 19 species, 14 genera and one order.

Anaplasmataceae presence in Amblyomma calcaratum associated with anteaters (Tamandua tetradactyla) in the rainforest ecoregion, Argentina.

Bacteria of the sister genera Ehrlichia and Anaplasma (Anaplasmataceae) are obligate intracellular Alphaproteobacteria that are transmitted mostly through arthropod vectors. These agents can infect different vertebrate cells, depending on the species involved, and can cause diseases in animals and humans. In this study, we evaluated the presence of Anaplasmataceae bacteria in Amblyomma calcaratum ticks collected from a road-killed Tamandua tetradactyla in the Rainforest ecoregion in Argentina.

Analyses of Early ZIKV Genomes Are Consistent with Viral Spread from Northeast Brazil to the Americas.

The Americas, particularly Brazil, were greatly impacted by the widespread Zika virus (ZIKV) outbreak in 2015 and 2016. Efforts were made to implement genomic surveillance of ZIKV as part of the public health responses. The accuracy of spatiotemporal reconstructions of the epidemic spread relies on the unbiased sampling of the transmission process.

Acute-Phase Levels of CXCL8 as Risk Factor for Chronic Arthralgia Following Chikungunya Virus Infection.

The immunopathogenesis of chikungunya virus (CHIKV) infection and the role of acute-phase immune response on joint pain persistence is not fully understood. We investigated the profile of serum chemokine and cytokine in CHIKV-infected patients with acute disease, compared the levels of these biomarkers to those of patients with other acute febrile diseases (OAFD) and healthy controls (HC), and evaluated their role as predictors of chronic arthralgia development. Chemokines and cytokines were measured by flow Cytometric Bead Array.

Risk of chronic arthralgia and impact of pain on daily activities in a cohort of patients with chikungunya virus infection from Brazil.

Objectives: To investigate risk factors for persistent arthralgia in patients with chikungunya, and describe its impact on daily activities.

Methods: From September 2014 to July 2016, a surveillance study enrolled patients with acute febrile illness in Salvador, Brazil, and detected those with chikungunya virus infection using IgM enzyme-linked immunosorbent assay or reverse transcriptase polymerase chain reaction. Telephone follow-ups were performed to ascertain the progression of disease.

Autochthonous circulation of Saint Louis encephalitis and West Nile viruses in the Province of La Rioja, Argentina.

St. Louis encephalitis (SLEV) and West Nile (WNV) arboviruses, which circulate in Argentina, are maintained in enzootic transmission cycles involving Culex mosquitoes (vectors) and birds belonging to orders Passeriformes and Columbiformes (amplifier hosts). The objective of this work was to determine the circulation of both viruses among wild birds in a semiarid ecosystem in the Province of La Rioja through a serologic survey.

Evaluation of two commercially available chikungunya virus IgM enzyme-linked immunoassays (ELISA) in a setting of concomitant transmission of chikungunya, dengue and Zika viruses.

Objective: To evaluate the diagnostic performance of the Inbios (Seattle, US) and Euroimmun (Luebeck, Germany) chikungunya virus (CHIKV) IgM enzyme-linked immunoassays (ELISAs).

Methods: We evaluated the tests' accuracy on sera from 372 patients enrolled in an acute febrile illness surveillance study performed in Salvador, Brazil from Sept/2014 to Jul/2016, a period of simultaneous CHIKV, dengue (DENV), and Zika (ZIKV) virus transmission. We assessed the sensitivity on acute and paired convalescent sera from RT-PCR-confirmed CHIKV cases (collected at median one and 19 days post-onset of symptoms, respectively), and the specificity on sera of RT-PCR-confirmed DENV and ZIKV cases, and on negative patients.

Molecular survey of flaviviruses and orthobunyaviruses in Amblyomma spp. ticks collected in Minas Gerais, Brazil.

Due to anthropic environmental changes, vector-borne diseases are emerging worldwide. Ticks are known vectors of several pathogens of concern among humans and animals. In recent decades, several examples of tick-borne emerging viral diseases have been reported (Crimean Congo hemorrhagic fever virus, Powassan virus, encephalitis virus, heartland virus, severe fever with thrombocytopenia syndrome virus).

Genomic characterization of orthobunyavirus of veterinary importance in America.

During 2013, in Argentina, three new isolates of serogroup Bunyamwera virus (genus Orthobunyavirus, family Peribunyaviridae) were recovered from two horses with encephalitis, and from an aborted equine fetus. In the present study, we report the complete genome sequence, genetic characterization, and phylogenetic analysis of three new strains isolated in Argentina to clarifying their relationship within the Bunyamwera serogroup virus and to investigate the evolutionary history of viruses with segmented genomes.

A localized outbreak of Chikungunya virus in Salvador, Bahia, Brazil.

A localized Chikungunya virus (CHIKV; East/Central/South African genotype) outbreak (50 cases, 70% laboratory-confirmed; attack rate: 5.3 confirmed cases/100 people) occurred in a Salvador, Brazil neighborhood, between Apr-Jun/2017. Highly clustered cases in space and time, mostly along a single street, highlight an increased risk of CHIKV transmission among pockets of susceptible populations.

Accuracy of the SD BIOLINE Dengue Duo for rapid point-of-care diagnosis of dengue.

Background: Rapid diagnosis tests (RDTs) are easy to carry out, provide fast results, and could potentially guide medical treatment decisions. We investigated the performance of a commercially available RDT, which simultaneously detects the non-structural 1 (NS1) dengue virus (DENV) antigen, and IgM and IgG DENV antibodies, using representative serum samples from individuals in a dengue endemic area in Salvador, Brazil.

Methodology/principal Findings: We evaluated the accuracy of the SD BIOLINE Dengue Duo RDT (Abbott, Santa Clara, USA; former Alere Inc, Waltham, USA) in a random collection of sera.

Concomitant Transmission of Dengue, Chikungunya, and Zika Viruses in Brazil: Clinical and Epidemiological Findings From Surveillance for Acute Febrile Illness.

Background: Since their emergence in the Americas, chikungunya (CHIKV) and Zika (ZIKV) viruses co-circulate with dengue virus (DENV), hampering clinical diagnosis. We investigated clinical and epidemiological characteristics of arboviral infections during the introduction and spread of CHIKV and ZIKV through northeastern Brazil.

Methods: Surveillance for arboviral diseases among febrile patients was performed at an emergency health unit of Salvador, Brazil, between September 2014 and July 2016.

Diagnostic performance of commercial IgM and IgG enzyme-linked immunoassays (ELISAs) for diagnosis of Zika virus infection.

Background: Serologic detection of Zika virus (ZIKV) infections is challenging because of antigenic similarities among flaviviruses.

Objective: To evaluate the sensitivity and specificity of commercial ZIKV IgM and IgG enzyme-linked immunoassay (ELISA) kits.

Methods: We used sera from febrile patients with RT-PCR-confirmed ZIKV infection to determine sensitivity and sera from RT-PCR-confirmed dengue cases and blood donors, both of which were collected before ZIKV epidemics in Brazil (2009-2011 and 2013, respectively) to determine specificity.

Neuronal Degeneration in Mice Induced by an Epidemic Strain of Saint Louis Encephalitis Virus Isolated in Argentina.

Saint Louis encephalitis virus (SLEV) is a neglected flavivirus that causes severe neurological disorders. The epidemic strain of SLEV, CbaAr-4005, isolated during an outbreak in Córdoba city (Argentina), causes meningitis and encephalitis associated with neurological symptoms in a murine experimental model. Here, we identified the affected brain areas and the damage triggered by this neurotropic arbovirus.

Tissue tropism of Saint Louis encephalitis virus: Histopathology triggered by epidemic and non-epidemic strains isolated in Argentina.

Saint Louis encephalitis virus (SLEV) reemerged in South America, and caused encephalitis outbreaks at the beginning of the 21st century. To enhance our knowledge about SLEV virulence, we performed comparative pathogenesis studies in Swiss albino mice inoculated with two different variants, the epidemic strain CbaAr-4005 and the non-epidemic strain CorAn-9275. Only the infection of mice with SLEV strain CbaAr-4005 resulted in high viremia, invasion of peripheral tissues including the lungs, kidney, and spleen, and viral neuroinvasion.

Unrecognized Emergence of Chikungunya Virus during a Zika Virus Outbreak in Salvador, Brazil.

Background: Chikungunya virus (CHIKV) entered Brazil in 2014, causing a large outbreak in Feira de Santana, state of Bahia. Although cases have been recorded in Salvador, the capital of Bahia, located ~100 km of Feira de Santana, CHIKV transmission has not been perceived to occur epidemically, largely contrasting with the Zika virus (ZIKV) outbreak and ensuing complications reaching the city in 2015.

Methodology/principal Findings: This study aimed to determine the intensity of CHIKV transmission in Salvador between November 2014 and April 2016.

Distinct Zika Virus Lineage in Salvador, Bahia, Brazil.

Sequencing of isolates from patients in Bahia, Brazil, where most Zika virus cases in Brazil have been reported, resulted in 11 whole and partial Zika virus genomes. Phylogenetic analyses revealed a well-supported Bahia-specific Zika virus lineage, which indicates sustained Zika virus circulation in Salvador, Bahia's capital city, since mid-2014.

Coinfections of Zika and Chikungunya Viruses in Bahia, Brazil, Identified by Metagenomic Next-Generation Sequencing.

Metagenomic next-generation sequencing (mNGS) of samples from 15 patients with documented Zika virus (ZIKV) infection in Bahia, Brazil, from April 2015 to January 2016 identified coinfections with chikungunya virus (CHIKV) in 2 of 15 ZIKV-positive cases by PCR (13.3%). While generally nonspecific, the clinical presentation corresponding to these two CHIKV/ZIKV coinfections reflected infection by the virus present at a higher titer.

First isolation of Bunyamwera virus (Bunyaviridae family) from horses with neurological disease and an abortion in Argentina.

Bunyamwera virus (BUNV) is the prototype virus for both the Orthobunyavirus genus and the Bunyaviridae family. Different strains of BUNV have been associated with clinical diseases in domestic animals, mainly ruminants. During 2013, in Argentina's Santa Fe Province, three new isolates of BUNV were recovered from the brain and spleen of two horses with encephalitis, and from the brain of an aborted equine fetus.

Ticks (Acari: Ixodidae) on wild birds in north-central Argentina.

Ixodid ticks were collected from wild birds in five ecoregions in north-central Argentina, namely: Selva de las Yungas, Esteros del Iberá, Delta e Islas del Paraná, Selva Paranaense and Chaco Seco. A total of 2199 birds belonging to 139 species, 106 genera, 31 families and 11 orders were captured, but ticks were collected only from 121 birds (prevalence=5.5%) belonging to 39 species (28.

Virulence variation among epidemic and non-epidemic strains of Saint Louis encephalitis virus circulating in Argentina.

Saint Louis encephalitis virus caused an outbreak of febrile illness and encephalitis cases in Córdoba, Argentina, in 2005. During this outbreak, the strain CbaAr-4005 was isolated from Culex quinquefasciatus mosquitoes. We hypothesised that this epidemic variant would be more virulent in a mouse model than two other non-epidemic strains (78V-6507 and CorAn-9275) isolated under different epidemiological conditions.