Introduction: The etiology of encephalitis involves an enormous range and can be classified as infectious or immune-mediated. There are several factors influencing its prognosis and has been associated with significant morbidity and mortality. This study aims to evaluate the clinico-epidemiologic characteristics and outcomes of infectious and immune-mediated encephalitis among pediatric patients. Methodology: Retrospective descriptive cross-sectional study that included patients aged 6 months to 17 years old with encephalitis in a tertiary hospital between January 2010 to December 2020 Results: A total of 23 cases were reviewed and 60.87% were infectious while that of immune-mediated was 39.13%. Among those with identified infectious cause, Mycoplasma pneumonia was the most common (28.57%). Infectious encephalitis was more common among younger males (35.71%) while immune-mediated affected female adolescents more (55.56%). The most common neurologic manifestation was altered mental status and/or behavioral changes. Treatment such as antibiotics (78.26%), anticonvulsant therapy (78.26%), and steroids (43.48%) were given. All immune-mediated cases received steroids. More than half of patients had complete recovery (56.52%). Conclusion Pediatric encephalitis should be considered among patients with neurologic dysfunction with or without systemic involvement. Behavioral changes in an apparently well child should prompt clinicians to consider anti-NMDAR encephalitis, especially if viral studies are negative and with no other known cause. Viruses remain to be the most common etiology, but other possible causes should be highly considered such as anti-NMDAR and Mycoplasma. A normal CSF analysis, imaging and/or encephalography (EEG) may not totally exclude encephalitis. Prognosis is relatively good hence an early diagnosis and initiation of appropriate management is important.
Encephalitis ; Infectious Encephalitis ; Encephalitis, Viral ; Mycoplasma

Introduction: Coronavirus disease (COVID-19) is currently a global health crisis and is caused by a new strain of coronavirus. However, emerging literature of case reports noted possible extrapulmonary manifestations of the disease. Because COVID 19 is a relatively new disease, at present, little existing literature tackles the diagnosis and therapeutic management of COVID‐19‐related conditions outside the pulmonary system. Case: A 24-year-old male presented with sudden stiffening of all extremities but non-contrast computed tomography (CT) scan was unremarkable. Chest X-ray revealed interstitial pneumonia and SARS-CoV-2 RT-PCR (OPS/NPS) was positive. Electrocardiogram (ECG) findings showed supraventricular tachycardia and had elevated Troponin I levels. Pertinent physical findings noted were slurring of speech, dysmetria, and vertical nystagmus. The patient was initially treated as a case of Bacterial Abscess versus Viral encephalitis. Pericardial ultrasound revealed small pericardial effusion and was started on Colchicine. Repeat cranial CT scan noted unremarkable results but due to persistence of symptoms, the patient was started with Dexamethasone. On Day 16 of illness, the patient was noted to have full resolution of symptoms. Rapid antibody testing was done which revealed positive for both IgG and IgM hence the patient was discharged with the final diagnosis of Viral Myopericarditis resolved, Viral encephalitis resolved, COVID-19 pneumonia recovered. Conclusion Extrapulmonary manifestations have been reported increasingly as an atypical presentation of COVID 19 infection. Early recognition of viral myopericarditis and viral encephalitis as a manifestation of COVID 19 can lead to the initiation of proper treatment and management. More reports on these cases can aid future studies on diagnostics and therapeutic approaches during the COVID-19 pandemic.
COVID-19 ; Encephalitis, Viral ; SARS-CoV-2 ; Coronavirus Infections

In order to evaluate the immune effect of the genotype Ⅰ Japanese encephalitis virus prM-E DNA vaccine and the prM-EⅢ fusion protein subunit vaccine on mice using DNA prime-protein boost strategy, the prM-E gene was inserted into the pVAX1 eukaryotic expression vector. The recombinant expression vector prM-E-pVAX1 was constructed as a DNA vaccine for initial immunity, and the recombinant prM-EⅢ fusion protein was obtained using a prokaryotic expression system as a subunit vaccine for enhanced immunity. Thirty two female BALB/c mice aged 4-6 weeks were randomly divided into four groups, and a prM-E-pVAX1 DNA vaccine group, a DNA prime-protein boost immune group, a prM-EⅢ subunit vaccine group, and a pVAX1 vector control group were set up. The specific antibody level in serum was monitored by ELISA, the neutralizing antibody titer was detected by plaque reduction neutralization, and the cellular immune responses induced by different vaccine immune groups were analyzed by cytokine expression abundance and lymphocyte proliferation experiments. The results showed that the neutralizing antibody titers induced by mice immunized with the DNA prime-protein boost strategy were close to that of the group immunized with the single prM-EⅢ subunit vaccine, but significantly higher than that of the group immunized with the single prM-E-pVAX1 DNA vaccine. DNA prime-protein boost strategies induced effective Th1/Th2 immune responses in mouse models, in particular the Th1 cell-mediated immune responses. This study provides a new immune strategy that may facilitate the prevention of Japanese encephalitis.
Animals ; Antibodies, Neutralizing ; Antibodies, Viral ; DNA ; Disease Models, Animal ; Encephalitis Virus, Japanese/genetics* ; Female ; Mice ; Mice, Inbred BALB C ; Vaccines, DNA/genetics* ; Vaccines, Subunit

OBJECTIVES: Varicella-zoster virus (VZV) is one of the most common etiologies of viral meningitis/encephalitis. The early clinical manifestations and cerebrospinal fluid (CSF) changes of VZV meningitis/encephalitis lack specificity, and it is easy to be misdiagnosed as other viral encephalitides or tuberculous meningitis. This study aims to investigate whether the clinical characteristics, CSF analysis findings, and CSF cytokine levels could distinguish VZV meningitis/encephalitis from central nervous system (CNS) herpes simplex virus (HSV) and Mycobacterium tuberculosis (MTB) infections. METHODS: The medical records from 157 CNS infections, including 49 HSV (45 HSV-1, 4 HSV-2), 55 VZV, and 53 MTB infections between January 2018 and June 2021 in the Cytology Laboratory, Department of Neurology, Third Xiangya Hospital of Central South University were retrospectively reviewed. The data of 3 groups included demographic characteristics, laboratory results, radiographic findings, and outcomes. The levels of 12 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, IFN-γ, IFN-α, and TNF-α) in the CSF of 68 patients (13 HSV, 22 VZV, and 33 MTB infection cases) were quantified. Clinical and laboratory data were compared among the 3 groups. RESULTS: The most common clinical manifestations in the 3 groups were fever, headache, vomiting, and neck stiffness. The clinical manifestations of HSV and VZV CNS disease were similar, although fever and altered consciousness were less common in the VZV group than those in the HSV and MTB groups (63.6% vs 87.8% vs 96.2%, P<0.001, and 14.5% vs 26.5% vs 47.2%, P=0.004, respectively). Seven patients (7/55, 12.7%) presented cutaneous zoster in the VZV group. CSF leukocyte count was significantly higher in the VZV group (230×10⁶ cells/mL) and MTB groups (276×10⁶ cells/mL) than that in the HSV group (87×10⁶ cells/mL, P=0.002). CSF protein level was significantly higher in the VZV than that in the HSV group (1 034 mg/L vs 694 mg/L, P=0.011) but lower than that in the MTB group (1 744 mg/L, P<0.001). IL-6 (VZV vs HSV vs MTB: 2 855.93 pg/mL vs 2 128.26 pg/mL vs 354.77 pg/mL, P=0.029) and IL-8 (VZV vs HSV vs MTB: 4 001.46 pg/mL vs 1 578.11 pg/mL vs 1 023.25 pg/mL, P=0.046) levels were significantly different among the 3 groups and were elevated in the VZV group.Post hoc analysis revealed that IL-6 and IL-8 were significantly higher in the VZV group than those in the MTB group (P=0.002 and P=0.035, respectively), but not in the HSV group (P>0.05). CONCLUSIONS VZV meningitis/encephalitis presents with CSF hypercellularity and proteinemia, challenging the classical view of CSF profiles in viral encephalitis. CSF IL-6 and IL-8 levels are elevated in patients with VZV meningitis/encephalitis, indicating a more intense inflammatory response in these patients.
Humans ; Central Nervous System Infections ; Encephalitis ; Encephalitis, Varicella Zoster/diagnosis* ; Encephalitis, Viral/diagnosis* ; Herpesvirus 3, Human ; Interleukin-6 ; Interleukin-8 ; Meningitis ; Retrospective Studies

To screen the best genotypeⅠJapanese encephalitis virus subunit vaccine candidate antigens, the prMEIII gene, the polytope gene and the prMEIII-polytope fusion gene of the GenotypeⅠJapanese encephalitis virus GS strain were cloned into prokaryotic expression vector pET-30a. The recombinant proteins were obtained after the induction and purification. The prepared recombinant proteins were immunized to mice, and the immunogenicity of the subunit vaccine candidate antigens was evaluated through monitoring the humoral immune response by ELISA, detecting the neutralizing antibody titer by plaque reduction neutralization test, and testing the cell-mediated immune response by lymphocyte proliferation assay and cytokine profiling. The recombinant proteins with the molecular weights of 35 (prMEIII), 28 (polytope antigen) and 57 kDa (prMEIII-polytope) induced strong humoral and cellular immune responses in mice. Compared with prMEIII-polytope and polytope proteins, the prMEIII protein induced a significant expression of IL-2 and IFN-γ (P<0.05) and the significant lymphoproliferation of splenocytes (P<0.05). The neutralizing antibody titer induced by the prMEIII protein was close to that induced by the commercial attenuated vaccine SA14-14-2 (P>0.05). The study suggests that the prMEIII protein can be used for the development of the Japanese encephalitis virus subunit vaccine.
Animals ; Antibodies, Viral ; blood ; Antigens, Viral ; immunology ; Encephalitis Virus, Japanese ; immunology ; Encephalitis, Japanese ; immunology ; prevention & control ; Immunogenicity, Vaccine ; Mice ; Mice, Inbred BALB C ; Vaccines, Subunit ; immunology ; Viral Vaccines ; immunology

Pseudorabies virus (PRV), a veterinary pathogen that infects domestic animals as well as wild animals such as wild boar and feral swine, was recently reported to infect human and led to endophthalmitis and encephalitis. A retrospective seroepidemiologic survey was conducted using 1,335 serum samples collected from patients with encephalitis and ELISA positive rates were 12.16%, 14.25%, and 6.52% in 2012, 2013, and 2017, respectively. The virus neutralizing antibody titers of positive samples correlated well with ELISA results. The pseudorabies virus antibody positive rate of patients with encephalitis were higher than that of healthy people in 2017. The above results suggest that some undefined human encephalitis cases may be caused by PRV infection.
Adult ; Animals ; Antibodies, Viral ; blood ; China ; Encephalitis ; immunology ; virology ; Enzyme-Linked Immunosorbent Assay ; Female ; Herpesvirus 1, Suid ; immunology ; Humans ; Male ; Middle Aged ; Prevalence ; Pseudorabies ; blood ; immunology ; virology ; Retrospective Studies ; Seroepidemiologic Studies ; Young Adult

OBJECTIVE: Tick-borne encephalitis virus (TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis (TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease. METHODS: A reverse-transcription recombinase-aided amplification (RT-RAA) assay was developed. This assay can be completed in one closed tube at 39 °C within 30 minutes. The sensitivity and specificity of RT-RAA were validated using non-infectious synthetic RNA representing a fragment of the NS5 region of the wild-type (WT) TBEV genome and the Senzhang strain. Additionally, 10 batches of tick samples were used to evaluate the performance of the RT-RAA assay. RESULTS: The analytical limit of detection of the assay was 20 copies per reaction of the TBEV synthetic transcript and 3 plaque-forming units (pfu) per reaction of TBEV titers. With the specific assay, no signal due to other arboviruses was observed. Of the 10 batches of tick samples obtained from the Changbai Mountains of China, three were TBEV-positive, which was consistent with the results of the quantitative real-time PCR assay. CONCLUSION A rapid, highly sensitive, specific, and easy-to-use method was developed for the detection of the TBEV Far-Eastern subtype.
Encephalitis Viruses, Tick-Borne ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; RNA, Viral ; analysis

Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing viral encephalitis in humans and reproductive disorder in swine. JEV is prevalent throughout China in human; however, spatiotemporal analysis of JEV in Chinese swine herds has not been reported previously. Herein, we present serological and molecular epidemiological results and estimates of prevalence of JEV infections among swine herds in various regions of China. The results suggest that JEV infections are widespread and genotype I and III strains co-exist in the same regions. Therefore, there is an urgent need to monitor JEV infection status among swine herds in China.
Asian Continental Ancestry Group ; China ; Encephalitis Virus, Japanese ; Encephalitis, Japanese ; Encephalitis, Viral ; Flavivirus ; Genotype ; Humans ; Molecular Epidemiology ; Prevalence ; Spatio-Temporal Analysis ; Swine

Viral encephalitis can lead to serious neurological sequelae and death among younger children. It is also known that the mortality rate in encephalitis with cerebral edema or transtentorial brain herniation is higher. A 4-year-old boy visited our emergency department exhibiting mental change. The patient had a high fever for four and a whole-body rash for three days prior to his visit. He had displayed irritable symptoms and been vomiting for six hours before his visit, accompanied by seizure. After 13 hours of admission, the patient's right pupil became fixed and fully dilated, and the left pupil also became fixed and fully dilated within 30 minutes. Brain computed tomography (CT) was performed immediately, and severe brain swelling with transtentorial brain herniation was found. The mannitol dose was increased and dexamethasone was also added. Hyperventilation was performed through intubation to reach PaCO₂ levels of 25 to 30mmHg. Fifteen hours later, pupillary reflex was observed and the cerebral edema and transtentorial brain herniation was found to be improving in follow-up brain CT. He was transferred to a general ward after 11 days and discharged on the thirteenth hospital day without any neurological sequelae. Human herpesvirus type 6 (HHV-6) was detected in the serological polymerase chain reaction (PCR) examination.
Brain ; Brain Edema* ; Child ; Child, Preschool ; Dexamethasone ; Emergency Service, Hospital ; Encephalitis* ; Encephalitis, Viral ; Exanthema ; Fever ; Follow-Up Studies ; Humans* ; Hyperventilation ; Intubation ; Male ; Mannitol ; Mortality ; Patient Rights ; Patients' Rooms ; Polymerase Chain Reaction ; Pupil ; Reflex, Pupillary ; Seizures ; Vomiting

Objective: To investigate the distribution patterns of mosquitoes, midges and related arboviruses in Sichuan province. Methods: Blood-sucking insects were collected from houses and pens, using the ultraviolet lights. Mosquito samples were classified according to morphologic characteristics and then stored at liquid nitrogen. All samples were incubated with BHK-21 and C6/36 cells for virus isolation and then detected for their viral genes. Sequences of the virus were identified and analyzed by molecular biological software, such as BioEdit 7.0.5.3, MEGA 6.0. Results: In total, 17 019 mosquitoes from 3 genera and 4 species and 12 700 midges were collected from the southeast regions of Sichuan province in 2016 and 2017. Among them, 79.4% (13 519/17 019) belonged to Culex tritaeniorhynchus with 11.1% (1 897/17 019) as Armigeres subalbatus, 5.5% (930/17 019) were Anopheles sinensis and 4.0% (673/17 019) were Anopheles sinensis 3 virus strains that isolated from Culex tritaeniorhynchus were identified as typeⅠ Japanese encephalitis virus. Seven pools of mosquitoes isolated from Hejiang county were identified Japanese encephalitis virus gene positive through PCR amplification. With 4 pool midges were detected positive for Akabane virus through PCR gene amplification while midges samples didn't have virus isolates. Conclusions: Culex tritaeniorhynchus appeared the predominant species in the southeast regions of Sichuan. Japanese encephalitis virus transmitted by mosquitoes and Akabane virus by midges were prevalent in southeast Sichuan province.
Animals ; Arboviruses ; Culicidae ; Encephalitis Virus, Japanese/isolation & purification* ; Encephalitis, Japanese/diagnosis* ; Genes, Viral ; Nucleic Acid Amplification Techniques ; Phylogeny ; Polymerase Chain Reaction