Usefulness of nested PCR and sequence analysis in a nosocomial outbreak of neonatal enterovirus infection.

Abstract

Non-polio enterovirus infections are recognized in children during summer-fall seasons and they sometimes cause large outbreaks. We experienced a nosocomial infection in the neonatal nursery and echovirus type 7 was isolated from samples of four patients. We diagnosed the horizontal infection of four neonates by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) and the nucleotide sequence. Total RNA was extracted from clinical isolates, serum samples and cerebrospinal fluid (CSF). We amplified enterovirus genome in the 5'-noncoding region by nested PCR and determined the nucleotide sequences. Enterovirus genome was detected in all isolates, in the acute-phase sera in all four patients and in the CSF in one patient by the first PCR. By using nested PCR, the genome was detected from convalescent-phase sera in two patients. All enterovirus genome obtained from the nursery outbreak showed the same sequences with 100% homology. We demonstrated the clinical advantages of RT-nested PCR from serum samples and the analysis of nucleotide sequencing gave the supportive evidence of identification of transmission pathway.