Astrovirus Infection in Cattle with Nonsuppurative Meningoencephalitis in South Korea.

Neurological diseases in cattle can be caused by several infectious agents. Astroviruses are increasingly recognized as the causative agent of encephalitis in various animals, including humans. In this study, a neuroinvasive astrovirus (BoAstV 20B05) was discovered in the brain tissues of an 81-month-old Korean native cattle with neurological symptoms. Lymphocyte infiltration and multifocal perivascular cuffing were observed in the cerebrum and brain stem, and viral antigens were also detected in the meninges. In particular, the concentration of the astroviral genome was high in the brain tissues. Korean BoAstV 20B05 was classified into the CH13/NeuroS1 clade and was closely related to the Neuro-Uy and KagoshimaSR28-462 strains. Our evolutionary analysis showed that Korean BoAstV 20B05 belongs to the sub-lineage NeuroS1 and evolved independently of BoAstV KagoshimaSR28-462. These results suggest that neuroinvasive astroviruses were first introduced in Korea. However, analysis is limited by the lack of reference astrovirus sequences reported in various countries within Asia, and further analysis should be performed using more strains. In this study, we identified a neuroinvasive astrovirus infection with neurological symptoms for the first time in South Korea and confirmed that BoAstV 20B05 may have been introduced in South Korea a long time ago.

A review of the epidemiology and surveillance of viral zoonotic encephalitis and the impact on human health in Australia.

Human encephalitis in Australia causes substantial mortality and morbidity, with frequent severe neurological sequelae and long-term cognitive impairment. This review discusses a number of highly pathogenic zoonotic viruses which have recently emerged in Australia, including Hendra virus and Australian bat lyssavirus which present with an encephalitic syndrome in humans. Encephalitis surveillance currently focuses on animals at sentinel sites and animal disease or definitive diagnosis of notifiable conditions that may present with encephalitis. This is inadequate for detecting newly emerged viral encephalatides. Hospital-based sentinel surveillance may aid in identifying increases in known pathogens or emergence of new pathogens that require a prompt public health response.

[Influenza-associated encephalopathy].

Acute encephalopathy is one of the most serious complications of pediatrics viral infections including influenza. It is characterized clinically by rapidly progressive brain damage following viral infection, and pathologically by brain edema in the absence of direct invasion of the virus and inflammatory cells. Recently, it has been classified into several categories according to the clinical characteristics and pathogenesis. In 2009, an outbreak of AH1N1 (swine) influenza was discovered in North America and quickly spread worldwide. During this pandemic, a number of patients with acute encephalopathy have been reported from all over the world. This article reviews the pathogenesis and classification of acute encephalopathy in general and the epidemiological, clinical and pathological features of pandemic flu-associated encephalopathy in comparison with those of seasonal flu-associated encephalopathy.

Spectrum of movement disorders in encephalitis.

To study the frequency and type of movement disorders and correlate these with MRI findings and outcome. Consecutive patients having encephalitis with movement disorders were included. The encephalitides were categorized into Japanese encephalitis (JE), herpes simplex, dengue, mumps, measles and nonspecific, depending on respective ELISA or CSF PCR. The movement disorders were recorded and severity was graded into mild, moderate, severe and markedly severe. Cranial MRI was done on a 1.5 T scanner acquiring T1, T2 and FLAIR sequence, and the location of MRI changes was noted. Outcome was defined at 6 months on the basis of functional status into complete, partial or poor. The type and severity of movement disorders and their relation to outcome was evaluated. Seventy-four out of 209 encephalitis patients had movement disorders; 67.6% of the patients had JE, 51.2% nonspecific and 11.3% dengue encephalitis. Their median age was 19 years and 16 were females. Parkinsonian features were present in 36, dystonia in six and both in 32 patients. The severity of movement disorders ranged between 2 and 4 (scale: none = 0, mild = 1, moderate = 2, severe = 3, markedly severe = 4). Movement disorders were common in males (P = 0.0001), and more frequent in JE (P = 0.03) and those having substantia nigra involvement on MRI (P = 0.03). Dystonia was associated with worse outcome than parkinsonian features only (P = 0.01). Movement disorders are common and severe in JE and are related to typical anatomical involvement.

Analysis of the surveillance situation for viral encephalitis and meningitis in Europe.

Infective processes in the brain, spinal cord and meninges are considered to be the main causes of encephalitis, myelitis and meningitis. However, most cases remain unexplained. The incidence of different viral aetiologies (zoonotic and non-zoonotic) is especially poorly estimated, due to the lack of a standard case definition and of agreed diagnostic algorithms, including harmonised diagnostic methods and sample collection. It is important to clarify the incidence of viral encephalitis/meningitis and to optimise the diagnosis of infectious neurological illness, particularly to ensure early recognition of outbreaks or emerging infectious such a West Nile encephalitis. The European Network for Diagnostics of 'Imported' Viral Diseases (ENIVD) has analysed the present surveillance situation for viral encephalitis/meningitis in Europe. Here we give an overview of the existing epidemiological sources of information in European Union (EU) Member States, mapping the laboratory capacity and identifying key requirements for a possible future surveillance study at European level. The data presented will help design a harmonised/standardised Europe-wide surveillance study investigating patients with encephalitis and/or meningitis in order to obtain more information on the role of infections in these rarely analysed syndromes, both from a clinical and an epidemiological perspective.

[Acute encephalitis: report on 32 consecutive pediatric cases observed in one hospital]. / Encéphalite aiguë: à propos de 32 enfants vus consécutivement dans un même service de pédiatrie.

We report 32 cases of acute encephalitis consecutively hospitalized in one hospital, from January 1991 to December 2002. The causative agent was identified in 26 cases (81%). The main associated viruses were varicella-zoster (10 children; 31%), Herpes simplex (6 children; 19%), and enteroviruses (4 children; 13%). At the acute phase, the most relevant biological findings were electroencephalogram results and CSF analysis. The initial encephalic imaging was primarily helpful to exclude other acute neurological diseases whereas long-term imaging was a prognostic factor for necrotizing encephalitis. The microbiological diagnosis required several days or weeks to be determined. It did not influence the initial management. In addition to the 6 cases of herpetic encephalitis, 19 children (78% altogether) were then treated by acyclovir before a definitive diagnosis was made. Twenty-two children (69%) had a favorable outcome, 2 (6%) had moderate sequels, 2 (6%) had important ones, and 5 (16%) had major ones. One (3%) child died. The outcome was highly dependant on the causative agent and the mechanism of encephalitis. This series gives information on the epidemiology of encephalitis in children in our region over a period of 12 years.

HHV-6 encephalopathy with cluster of convulsions during eruptive stage.

The features of a characteristic type of encephalopathy caused by human herpesvirus-6 are presented. All patients have clusters of brief convulsions during the stage of skin eruptions. Sometimes the encephalopathy resulted in hemiplegia or mental retardation. Because the clinical course is similar, we propose a subtype of encephalopathy "human herpesvirus-6 encephalopathy with cluster of convulsions in eruptive stage" for further studies of pathophysiology and treatment.

Mycoplasma pneumoniae encephalitis in childhood.

Mycoplasma pneumoniae is an important etiologic agent of acute childhood encephalitis. We retrospectively reviewed 17 cases of M. pneumoniae encephalitis at the Pediatric Department of the National Taiwan University Hospital from April 1997 through March 2000. These cases were diagnosed as having positive immunoglobulin M antibodies (94%), a minimum 4-fold change of complement-fixation antibody titers (47%), or nested polymerase chain reaction. The ages of these patients ranged from 1.5 to 10.9 years (mean, 5.3 years) with a male-to-female ratio of 8:9. The clinical manifestations included fever (94%), altered consciousness (65%), seizure (41%), personality or behavior changes (29%), meningeal sign (24%), visual hallucination (24%), ataxia (12%), Guillain-Barré syndrome (6%), blurred vision (6%), and aphasia (6%). Respiratory symptoms and signs were found in 76% of the patients. Abnormal electroencephalogram and neuroimage were observed in all cases, while abnormal cerebrospinal fluid examination was noted in about one-third of the patients. Five (29%) patients required intensive care because of intractable seizure or respiratory failure. Fourteen (82%) patients recovered completely, but 3 (18%) had sequelae including epilepsy, hydrocephalus, and global neurologic deficits with brain stem dysfunction. In Taiwan, M. pneumoniae should be considered an etiologic pathogen of acute childhood encephalitis if fever and respiratory symptoms and signs are observed with or without abnormal cerebrospinal fluid findings. Supportive treatment is the basis of management.

[Viral encephalitis caused by biowarfare agents].

Many viruses may cause encephalitis. Three such viruses of the Alpha genus (Venezuelan equine encephalitis (VEE), Western equine encephalitis (WEE) and Eastern equine encephalitis (EEE)) may be used as biological warfare agents. The clinical course of the diseases caused by these viruses is not specific, and resembles a broad range of bacterial and viral diseases. Several attenuated and inactivated vaccines were developed, but their efficacy in the biological warfare scenario is questionable. There is no effective drug therapy for the treatment of these diseases, and treatment is mainly supportive. Several VEE outbreaks were reported in humans and horses in South America and southern United States. This virus usually causes a febrile illness, which might be complicated with encephalitis, mainly in the cases of children and elderly patients. The EEE virus causes the most severe form of disease, with severe encephalitis and high proportion of sequel. It is prevalent mainly in the eastern parts of Northern America. The WEE virus, which is hybridization between the Sindbis virus and the EEE virus, causes encephalitis mainly in children. The severity of the disease caused by WEE and the sequel rate is much lower than that of EEE.

Serial magnetic resonance imaging in children with postinfectious encephalitis.

We analyzed follow-up magnetic resonance images (MRI) in eight children with clinical postinfectious encephalitis (PIE), and discussed their pathogeneses. Three categories of MRI findings were apparent: (1) multifocal lesions in the white matter with/without basal ganglia involvement consistent with acute disseminated encephalomyelitis (ADEM) (three patients); (2) single or multifocal lesions localized only in the gray matter (two patients); and (3) localized lesions in the brain stem, basal ganglia or cerebellum. Some lesions in the patients in Categories 1 and 2 migrated or were resolved quickly, sometimes within 10 days. Gadolinium caused linear or spotty enhancement in the patients in Category 2. These findings suggest that Categories 1 and 2 are a self-limiting allergic angiopathy without demyelination. In contrast, the lesions in the patients in Category 3 were fixed, and not resolved within 6 months (three patients). The pathogenesis of Category 3 is not known. All except one patient had no prednisolone (PSL) therapy, however; all lesions were resolved completely or markedly reduced in size, which indicates PSL therapy is not always necessary in patients with PIE.

Acute herpes simplex encephalitis: clinical assessment and prognostic data.

Acute herpes simplex encephalitis (HSE) has a grave outcome, and detection of prognostic features is of clinical importance. Thirty patients with HSE were assessed in a retrospective study. Diagnosis was confirmed by serological methods using the indirect immunofluorescence technique (IFT). Antiviral treatment was given to 23 of the patients. Focal convulsions were more frequent in patients below 18 years of age, while confusion and memory disturbances were prevalent among patients above 18. The final outcome was influenced by the degree of severity of the disease at the peak and the state of consciousness and duration of disease prior to the initiation of anti-viral treatment. No correlation was found between antibody levels in serum or in CSF and the outcome. We conclude that the clinical degree of severity the duration of illness prior to treatment and state of consciousness at the initiation of anti-viral treatment are of prognostic importance.