Objective: To summarize the clinical characteristics, diagnosis and treatment of forest encephalitis, and provide basis for revising relevant diagnostic criteria. Methods: From January to December 2020, the clinical characteristics, diagnosis and treatment of forest encephalitis cases in the data of China National Knowledge Infrastructure (CNKI) and Wanfang Chinese journals from 2009 to 2020 were retrospectively analyzed. The measurement data are expressed in Mean±SD, numbers, and the counting data of gender, region and occupation are expressed in numbers and composition ratio. Descriptive analysis of relevant data is carried out. Results: There were 1 153 confirmed cases of forest encephalitis reported in domestic literature, including 910 males and 243 females. Age: 16-78 years old; Cases were mainly distributed in Jilin Province, Inner Mongolia Autonomous Region and Heilongjiang Province. The cases included forest rangers (112/518), freelancers (104/518) and loggers (88/518). The common symptoms and signs were fever 81.2% (936/1153), headache 70.3% (811/1153), meninges irritation 29.0% (334/1153), vomiting 25.3% (292/1153), nausea 21.8% (251/1153), etc. Only 48.1% (555/1153) of the patients obtained positive pathogenic test results from blood and/or cerebrospinal fluid specimens. 42.1% (485/1153) had definite diagnosis grade, 354 cases were mild, 58 cases were moderate, and 73 cases were severe. Among 730 patients with forest encephalitis who received complete treatment, 511 cases were cured, 148 cases were improved, 48 cases were not cured, and 23 cases died. Conclusion: The epidemic of forest encephalitis has strict regional, seasonal and occupational characteristics. Early diagnosis and treatment can reduce the mortality and disability rate.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Aged ; Retrospective Studies ; Encephalitis, Tick-Borne ; Encephalitis/epidemiology* ; Headache ; Fever

The prevalence of tick-borne encephalitis virus (TBEV) in southern Korea was determined by collecting ticks using tick drags. A total of 4,077 of 6,788 ticks collected were pooled (649 pools) according to collection site, species, and developmental stage and assayed for TBEV. The TBEV protein E and NS5 gene fragments were detected using RT-nested PCR in six pools of nymphs collected from Jeju Island (2,491 ticks). The minimum field detection rates for TBEV were 0.17% and 0.14% for Haemaphysalis longicornis and Haemayphysalis. flava nymphs, respectively. The 252 bp NS5 and 477 bp protein E gene amplicons were sequenced. Phylogenetic analysis showed that the NS5 and protein E genes of the Jeju strain were clustered with Western subtype (98.0% and 99.4% identity, respectively). The Western subtype of TBEV is endemic in Korea, including Jeju Island. The study of vector and zoonotic host susceptibility to TBEV is required to better understand its potential impact on public health.
Animals ; Arachnid Vectors/*virology ; Base Sequence ; DNA Primers/genetics ; Encephalitis Viruses, Tick-Borne/classification/*genetics ; Encephalitis, Tick-Borne/*epidemiology ; Molecular Sequence Data ; *Phylogeny ; Prevalence ; Republic of Korea/epidemiology ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Ticks/*virology ; Viral Envelope Proteins/genetics