[Molecular identification and genetic analysis of an echovirus 19-associated epidemic of aseptic encephalitis].

Objective: To ascertain the pathogen of aseptic encephalitis epidemic in Long-Yan city in Fujian, and to find out the genetic characteristics of the virus.

Methods: Rapid detection of enteroviral RNA by reverse transcription polymerasechain reaction (RT-PCR) was directly carried out in cerebrospinal fluid(CSF) to isolate and identify the viruses from CSF at the same time, and to detect the neutralization antibody in two serum specimens collected in acute and convalescence phase. Nucleotides of VP1 region was also analyzed by constructing phylogenetic tree.

Results: ECHO 19 infection was rapidly diagnosed and sequence analysed by RT-PCR, and then echovirus type 19 from 16 of 30 CSF samples (53.33%) was isolated and detected using RD and Hep-2 cells simultaneity. The titer of ECHO 19 neutralization antibody became positive or increased by 4 times from acute to convalescence phase in 4 of the 5 patients. Phylogenetic analyses of the VP1 genes of these isolates showed that their nucleotides identity were 98.9% -100.0% which were different from those ECHO 19 from GeneBank database by 13.0%-22.4%.

Conclusion: The etiology of the epidemic of aseptic encephalitis was attributed to ECHO 19. The method of molecular identification not only provided rapid diagnosis of enterovirus infections, but also information about the genetic character of the viruses.