Detection and Phylogenetic Analysis of Coxsackievirus A24 Variant Causing Nation-wide Epidemic of Acute Hemorrhagic Conjunctivitis in Korea, 2002 / 감염과화학요법

ABSTRACT

BACKGROUND: Nation-wide outbreak of acute hemorrhagic conjunctivitis occurred in the summer, 2002 in South Korea. We identified the causative agent of this outbreak through virus culture and molecular biological techniques. METHODS: Polymerase chain reaction (PCR) was carried out with direct conjunctival swab samples and cell culture supernatants. Conjunctival swab was done at a community based-eye clinic in Seoul, September 2002. Initial screening for adenovirus and enterovirus was performed. Nested PCR for adenovirus was done with adenovirus common primers using direct swab sample, and reverse transcription PCR (RT-PCR) for enterovirus was done with enterovirus common primers. RT-PCR with primer 188/222 for VP1 region of enterovirus was done, if initial screening test was positive. PCR product was sequenced, and homology searching, compared to prototype strains, was done for serotyping. Protease 3C region of coxsackievirus A24v was amplified and sequenced with primer D1/U2. The sequence of this region was compared to those of viral isolates, which had been obtained from several Asian outbreaks since 1970. RESULTS: Conjunctival swabs were performed in 88 patients. Thirty nine (44%) samples out of the 88 were culture positive on HeLa or MRC-5 cells. Nine (100%) out of 9 culture supernatants, randomly selected from 39 culture positve samples, were positive for coxsackievirus A24v-specific RT-PCR. Phylogenetic analysis showed that sequences from 14 culture positive supernatants, randomly selected from 39 culture positive samples, clustered into a time-related, but distinct lineage, with Asian strains. CONCLUSIONS: We identified the causative agent of the epidemic hemorrhagic conjunctivits in year 2002 as coxsackievirus A24v.