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

Abstract

BackgroundCoxsackievirus 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.Methods and FindingsSterile 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.ConclusionsThis 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.

Etiology of Acute Conjunctivitis Due to Coxsackievirus A24 Variant, Human Adenovirus, Herpes Simplex Virus, and Chlamydia in Beijing, China

“…It is well known that CA24v is highly contagious, especially due to the incredible mobility of populations worldwide (29). Several recent CA24v outbreaks have been reported in south China (Guangdong province in 2010 and Yunnan province in 2007) (30,31) (13)(14)(15)(16)29). When CA24v as a single causative agent of AHC was taken into account, the positive rate in this study was 3z.…”

“…CA24v and EV70 were identified using a real-time one-step RT-PCR kit (Qiagen) using 2 pairs of previously described primers (20). Complete nucleotide sequences of VP1 genes of CA24v-positive specimens were amplified using a one-step RT-PCR kit (Qiagen) with specific primers as described previously (14,21). PCR products of 915 bp were purified and sequenced using an ABI PRISM310 Genetic Analyzer (Applied Biosystems, Foster City, CA, USA).…”

“…CA24v epidemics were initially limited to India and Southeast Asian before 1985. Since then, CA24v outbreaks have spread worldwide (13)(14)(15)(16). Chlamydia is also a causative agent of conjunctivitis that can cause focal corneal scarring, neovascularization, and chronic inclusion conjunctivitis, which may lead to otitis media and pneumonitis in neonates.…”

A major outbreak of conjunctivitis caused by coxsackievirus A24, Réunion, January to April 2015

“…CV-A24v belonging to genotype IV was identified in all the samples by sequencing of the VP1 coding region (Figure 4). The 10 VP1 partial nt sequences shared a 99.1 to 100% nt identity and had 95.1 to 97.9% nt similarity with sequences from genotype IV isolates previously identified in AHC outbreaks in Egypt (2010) [21], Japan (2011) [22], China (2007 and 2010) [23][24][25], Brazil (2009) [26], India (2007) and Singapore (2005) [27] (Figure 4). They also grouped in a larger cluster containing the VP1 sequence from a genotype IV isolate detected in a traveller returning from Comoros to France in 2012 (Figure 4; accession number JX196594).…”

Inhibition of Coxsackievirus A24 in permissive Hep2 cells by small interfering RNA (siRNA)

“…In past few decades CA24 emerged as major pathogen responsible for several AHC outbreaks not only in India but other countries like, Spain, Brazil, China, Cuba, Taiwan [2,3,4,5,6,7]. Attempts were made to develop anti-CA24 therapeutics, still, no effective medication is available to treat CA24 infections.…”