Molecular Characterization and Phylogenetic Study of Coxsackievirus A24v Causing Outbreaks of Acute Hemorrhagic Conjunctivitis (AHC) in Brazil

Coxsackievirus A24 variant (CA24v) is the most prevalent viral pathogen associated with acute hemorrhagic conjunctivitis (AHC) outbreaks. Sixteen years after its first outbreak in Brazil, this agent reemerged in 2003 in Brazil, spread to nearly all states and caused outbreaks until 2005. In 2009, a new outbreak occurred in the northeast region of the country. In this study, we performed a viral isolation in cell culture and characterized clinical samples collected from patients presenting symptoms during the outbreak of 2005 in Vitória, Espírito Santo State (ES) and the outbreak of 2009 in Recife, Pernambuco State (PE). We also performed a phylogenetic analysis of worldwide strains and all meaningful Brazilian isolates since 2003.Sterile cotton swabs were used to collect eye discharges, and all 210 clinical samples were used to inoculate cell cultures. Cytopathic effects in HEp-2 cells were seen in 58 of 180 (32%) samples from Vitória and 3 of 30 (10%) samples from Recife. Phylogenetic analysis based on a fragment of the VP1 and 3C gene revealed that the CA24v causing outbreaks in Brazil during the years 2003, 2004 and 2005 evolved from Asian isolates that had caused the South Korean outbreak of AHC during the summer of 2002. However, the 2009 outbreak of AHC in Pernambuco was originated from the reintroduction of a new CA24v strain that was circulating during 2007 in Asia, where CA24v outbreaks has been continuously reported since 1970.This study is the first phylogenetic analysis of AHC outbreaks caused by CA24v in Brazil. The results showed that Asian strains of CA24v were responsible for the outbreaks since 1987 and were independently introduced to Brazil in 2003 and 2009. Phylogenetic analysis of complete VP1 gene is a useful tool for studying the epidemiology of enteroviruses associated with outbreaks

Produção de anticorpos monoclonais através de imunização genética para o diagnóstico dos lentivírus de pequenos ruminantes, maedi-visna e artrite encefalite caprina

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Produção de anticorpos monoclonais através de imunização genética para o diagnóstico dos lentivírus de pequenos ruminantes, maedi-visna e artrite encefalite caprina

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Geographic distribution of CA24v outbreaks in Brazil, 2003–2009.

<p>Geographic distribution of CA24v outbreaks in Brazil, 2003–2009.</p

Oligonucleotide primer sequences for VP1 and 3C amplification of CA24v.

<p>*Nucleotide position according CA24v reference strain EH24/70.</p

Origin and number of CA24v isolates from Brazilian AHC outbreaks that were used for phylogenetic study.

<p>*Samples received previously isolated in cell culture.</p

Phylogenetic analysis based on a 473-nucleotide region of the VP1 gene.

<p>This phylogenetic tree was constructed by the neighbor joining method using Kimura-two parameter model from MEGA4 software, with 1000 replicates. Thirty-seven sequences were compared to those strains reported from others countries in previous years available in GenBank. Only bootstrap values >70% are shown at the node. Geometric shapes indicate the years of the Brazilian isolates.</p