BackgroundOf the nine human herpesviruses (HHVs), most viruses have neurovirulence. Clinical manifestations of central nervous system (CNS) complications caused by some of the HHVs are well examined in children and immunocompromised adults; however, information of EBV and β-herpesviruses in an immunocompetent adult is limited.MethodsBetween April 2013 and March 2018, 322 patients (median age; 51.6 years old, male/female; 196/126) suspected to CNS infection were enrolled in this study. Patients with unconsciousness or characteristic change lasting more than 24 hours and abnormal brain MRI or EEG were defined as encephalitis. Real-time PCRs for detection of the 7 HHVs DNA including HSV-1, HSV-2, VZV, CMV, EBV, HHV-6, and HHV-7 were carried out in DNA extracted from 200 μL CSF. HHV-6 was discriminated between HHV-6A and HHV-6B using RFLP analysis.ResultsHerpesviruses DNA was detected in 33 (10.2%) of the 322 patients. The most frequently detected HHVs was VZV (19 cases) and followed by HHV-6B (4 cases), HSV-1 (3 cases), HSV-2 (3 cases), and EBV (2 cases). Multiple HHVs DNAs were detected from the 2 patients (case A; HSV-2, HHV-6, and EBV, case B; EBV and HHV-6B). No CMV and HHV-7 DNAs were detected in any of the samples. Eleven cases were assigned as encephalitis, and other 22 cases were non-encephalitis. Although all 3 patients with positive HSV-1 DNA were encephalitis, all 3 patients with positive HSV-2 DNA were meningitis. Fourteen (13 patients had zoster) of the 19 patients with positive VZV DNA were meningitis, and the remaining 5 patients (4 patients had zoster) were encephalitis. Two of the 4 HHV-6B-positive patients were non-encephalitis, one patient was diagnosed Orbital apex syndrome and another patient was myelitis. One of the 2 encephalitis patient was chromosomally integrated (ci) HHV-6. Additionally, case B was also ciHHV-6.ConclusionApproximately 10% of the samples were positive of HHVs DNA. VZV was the most frequently detected viral DNA in this cohort. Thirty-three percent of the patients were encephalitis, remaining patients were non-encephalitis such as meningitis and myelitis. As suggested, ciHHV-6 can cause miss-diagnosis of patients suspected with CNS infection.Disclosures All authors: No reported disclosures.