Coxsackievirus B3-associated aseptic meningitis: an emerging infection in Hong Kong

Enterovirus (EV) infection is a common disease of childhood and associated not uncommonly with aseptic meningitis. In the summer of 2008, laboratory surveillance has detected increased number of coxsackievirus B3 (CVB3) associated aseptic meningitis in Hong Kong, constituting 11.6% of those infected. This study analyzed the epidemiology, circulating pattern, and clinical presentations of CVB3 in Hong Kong over the last 10 years with reference to the circulation of EV in the locality. Enteroviruses (EV) were isolated from respiratory, cerebrospinal fluid (CSF), stool, and vesicular samples using human rhabdomyosarcoma, human laryngeal carcinoma (HEp2-C), human lung fibroblast (MRC-5), and African green monkey kidney (Vero) cell lines. Virus isolates were identified and characterized by indirect immunofluorescence (IF) using monoclonal antibodies (mAB), neutralization test as well as partial VP1 sequencing. Different from previous years, IF test result showed that majority of the isolates from 2008 were untypeable by the mAB suggesting antigenic change. Sequence analysis revealed that these isolates were clustered with recent isolate from Fuyang, China. Review of data from 1999 to 2008 showed increased activity of CVB3 in the years 2005 and 2008, and isolates in these 2 years displayed an amino acid change from threonine to alanine at codon 277 of the VP1 gene, which may be associated with central nervous system (CNS) disease.