Application of PCR technique in etiological diagnosis of children with enterovirus and herpesvirus encephalitis / 中华检验医学杂志

ABSTRACT

Objective:To examine the infection of the enterovirus and human herpes virus in children with suspected encephalitis.Methods:A total number of 365 suspected encephalitis cases were included in this study from August 2017 to December 2019 in Hunan Children′s Hospital. The clinical samples, the cerebrospinal fluid (CSF), serum, sputum, stool and urine were collected and preserved at-80 ℃condition. The enterovirus (EV) and human herpesvirus (HHV) were examined by a one-step nested reverse transcription PCR(RT-PCR) and a real-time fluorescent quantitative PCR (qPCR), respectively. The positive rate of the two viruses in clinical specimens of children with suspected encephalitis was examined. Among all cases, 132 cases were diagnosed with EV encephalitis or HHV encephalitis.Results:the EV encephalitis were identified in 20.5% (75/365) children with suspected viral encephalitis; whereas HHV encephalitis infection was identified as 15.6% (57/365). Among the 75 cases of EV encephalitis, echo 6 was the main sub-type of these diseases 52.0% (39/75) and others were EV71 (30.7%, 23/75), echo11 (6.7%, 5/75), Coxsackie virus A group 6(CA6, 4.0%, 3/75), echo30 (1.3%, 1/75), echo9 (1.3%, 1/75), echo4 (1.3%, 1/75),Coxsackie virus B group 1(CB1, 1.3%, 1/75))and poliovirus(1.3%, 1/75).Human herpes virus type 6 (HHV6) was the most common pathogen in 57 cases of HHV encephalitis, accounting for 35.1% (20/57).The other pathogens were Cytomegalovirus (CMV, 31.6%, 18/57), Epstein-Barr virus (8.8%, 7/57), Herpes simplex virus 1 (HSV1, 10.5%, 6/57), HSV2 (8.8%, 5/57), and Varicella zoster virus (VZV, 1.8%, 1/57) .The virus in CSF detected significantly earlier than that in serum after onset. Virus could be detected in CSF 2-7 days after onset,but 7-26 days in serum. Conclusions:This study uses nested PCR and qPCR to detect pathogens in clinical specimens of children. This not only expands our understanding of the clinical examination and diagnosis of viral encephalitis in children, but also promotes the method of this study to benefit more children.