Updates on Enterovirus Surveillance in Korea

ABSTRACT

PURPOSE: We identified the causative viruses from patients with aseptic meningitis, acute hemorrhagic conjunctivitis and other enterovirus-related diseases to understand the epidemiological patterns and prevailing strains of enterovirus infections each year. MATERIALS AND METHODS: During 1999-2003, we examined 3,260 specimens from 2,939 patients with aseptic meningitis or other clinical manifestations for the presence of enteroviruses by using both cell culture/ neutralisation test and reverse transcription-polymerse chain reaction-sequencing. To investigate the etiological agents which caused an epidemic of acute haemorrhagic conjunctivitis, conjunctival swab samples from acute haemorrhagic conjunctivitis patients showing cytopathic effects in HEp2 cells were tested by enteroviral specific PCR. RESULTS: We identified 603 isolates of enteroviruses (20.5%) among 2,939 cases and 22 serotypes of human enteroviruses were isolated during this 5 year period. Echovirus 13 and coxsackievirus A24 in 2002 and coxsackievirus A9 in 2003 were the first enterovirus to be indentified in Korea since we began the enterovirus surveillance in 1993. While an epidemic of echovirus 13 infection in Korea began in Gwangju and Jeolla province in 2002 and spread to Seoul, Gyunggi, Busan, Ulsan and other regions, echovirus 6 isolates in 2002 were mainly detected in Busan specimens and some Gwangju samples. From the nucleotide sequencing of enteroviral PCR products of conjunctival swab specimens, we found 85% nucleotide homology to coxsackievirus A24 (D90457). CONCLUSIONS: We isolated 603 enteroviral isolates among 2939 cases during 1999-2003. Echovirus 13 and coxsackievirus A24 were the first enterovirus to be identified in Korea and caused nationwide epidemics in 2002.