Laboratório de Enterovírus, Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
PLoS One. 2011;6(8):e23206. doi: 10.1371/journal.pone.0023206. Epub 2011 Aug 16.
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.
柯萨奇病毒 A24 变体（CA24v）是与急性出血性结膜炎（AHC）暴发相关的最常见病毒病原体。该病毒于 1987 年在巴西首次暴发后 16 年，于 2003 年在巴西再次出现，传播到几乎所有州，并导致暴发直至 2005 年。2009 年，该国东北部地区发生了新的暴发。在这项研究中，我们进行了病毒分离培养，并对 2005 年在巴西 Espírito Santo 州 Vitória 和 2009 年在巴西 Pernambuco 州 Recife 暴发期间收集的有症状患者的临床样本进行了特征分析。我们还对来自世界各地的毒株和自 2003 年以来所有有意义的巴西分离株进行了系统发育分析。
使用无菌棉签收集眼分泌物，用 210 份临床样本中的 180 份（32%）样本接种细胞培养物。在 Vitória 的 180 份样本中的 58 份（32%）和 Recife 的 30 份样本中的 3 份（10%）可见 HEp-2 细胞中的细胞病变效应。基于 VP1 和 3C 基因片段的系统发育分析显示，导致巴西 2003、2004 和 2005 年暴发的 CA24v 源自 2002 年夏季导致韩国 AHC 暴发的亚洲分离株。然而，2009 年 Pernambuco 的 AHC 暴发源自于 2007 年在亚洲流行的新 CA24v 株的再次引入，自 1970 年以来，亚洲不断有 CA24v 暴发的报告。
这是巴西首例 CA24v 引起的 AHC 暴发的系统发育分析。结果表明，亚洲 CA24v 株自 1987 年以来一直是暴发的原因，并于 2003 年和 2009 年分别独立引入巴西。完整 VP1 基因的系统发育分析是研究与暴发相关的肠道病毒流行病学的有用工具。
