Seroprevalence of MOG and AQP4 Antibodies and Outcomes in an Indian Cohort of Pediatric Acquired Demyelinating Syndromes.

This study aimed to determine the seropositivity of myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) and aquaporin-4 antibodies (AQP4-Ab) and outcomes in children with acquired demyelinating syndromes (ADSs). Children (6 months-15 years) with suspected ADS were enrolled and tested for MOG-Ab and AQP4-Ab prospectively over 18 months at a tertiary care hospital in North India. Children with proven nonimmune-mediated neurological disorders were enrolled as controls. Of 79 children with suspected ADS, 66 were enrolled. Among the enrolled children with ADS, acute demyelinating encephalomyelitis (ADEM) (25) was the most common first clinical event followed by optic neuritis (ON) (20) and transverse myelitis (TM) (19; one child had ON and TM simultaneously [neuromyelitis optica spectrum disorders [NMOSDs]]), while two children had clinically isolated syndrome (CIS) apart from ON and TM. Fourteen (21.2%, confidence interval [CI] 11.3-31.1) tested positive for one antibody (12 [18.1%; 95% CI 10.5-25.5%] for MOG-Ab and 2 [3%; 95% CI 0-7.2%] for AQP4-Ab). None of the 62 controls tested positive for any antibody. The final diagnosis in those with the monophasic ADS was ADEM (21), ON (13), TM (16), and other CIS (1) while that in children with recurrent events was multiphasic disseminated encephalomyelitis (MDEM) (2), NMOSD (3), ADEM-ON (4), recurrent ON (4), and MS (2). Among those with the first event, 4/51 (7.8%; 95% CI 0.5-15.2%) were MOG-Ab positive and 2 AQP4-Ab positive, whereas 8/15 (53.3% [95% CI 28.1-78.6%]) with recurrent events (MDEM [2], ADEM-ON [4], recurrent ON [1], and recurrent TM [1]) were MOG-Ab positive. Hence, MOG-Abs are the most common antibodies detected in one in five children with pediatric ADS, especially in relapsing disease. AQP4-Abs are rare in children with ADS.

Two novel porcine teschovirus strains as the causative agents of encephalomyelitis in the Netherlands.

BACKGROUND: Porcine teschovirus (PTV) circulates among wild and domesticated pig populations without causing clinical disease, however neuroinvasive strains have caused high morbidity and mortality in the past. In recent years, several reports appeared with viral agents as a cause for neurologic signs in weanling and growing pigs among which PTV and new strains of PTV were described. CASE PRESENTATION: On two unrelated pig farms in the Netherlands the weanling pig population showed a staggering gate, which developed progressively to paresis or paralysis of the hind legs with a morbidity up to 5%. After necropsy we diagnosed a non-suppurative encephalomyelitis on both farms, which was most consistent with a viral infection. PTV was detected within the central nervous system by qPCR. From both farms PTV full-length genomes were sequenced, which clustered closely with PTV-3 (98%) or PTV-11 (85%). Other common swine viruses were excluded by qPCR and sequencing of the virus. CONCLUSION: Our results show that new neuroinvasive PTV strains still emerge in pigs in the Netherlands. Further research is needed to investigate the impact of PTV and other viral agents causing encephalomyelitis within wild and domestic pig populations supported by the awareness of veterinarians.

Pathological, immunohistochemical, and molecular findings of equine protozoal myeloencephalitis due to Sarcocystis neurona infection in Brazilian horses.

Equine protozoal myeloencephalitis (EPM) is an important neurologic disease of horses in the American continent caused by Sarcocystis neurona and Neospora hughesi infection. This study describes the pathological, immunohistochemical, and molecular findings of fatal cases of EPM in southern Brazil. A review was performed on a total of 13 cases compatible with EPM, which were diagnosed by postmortem examination in the period of 2010-2017. Epidemiological information was obtained from necropsy reports. Gross and histological lesions were characterized, and cases were subjected to immunohistochemistry anti-Sarcocystis neurona, Toxoplasma gondii, and Neospora spp. Molecular search was performed using ITS-1 gene PCRs. Microscopic lesions were multifocal in all cases, and more frequently observed in the spinal cord segments and in the rhombencephalon. Intralesional protozoans were histologically detected in five horses, while a positive immunostaining for S. neurona was observed in eleven cases (11/13). Through molecular techniques, six positive cases for the ITS-1 gene were detected, and obtained sequences presented highest similarity with S. neurona. EPM due to S. neurona infection represents an important neurologic disease of horses in Brazil and this disease should be considered as a main differential diagnosis in horses presenting neurologic signs.

Enterovirus A71 Infection and Neurologic Disease, Madrid, Spain, 2016.

We conducted an observational study from January 2016 through January 2017 of patients admitted to a reference pediatric hospital in Madrid, Spain, for neurologic symptoms and enterovirus infection. Among the 30 patients, the most common signs and symptoms were fever, lethargy, myoclonic jerks, and ataxia. Real-time PCR detected enterovirus in the cerebrospinal fluid of 8 patients, nasopharyngeal aspirate in 17, and anal swab samples of 5. The enterovirus was genotyped for 25 of 30 patients; enterovirus A71 was the most common serotype (21/25) and the only serotype detected in patients with brainstem encephalitis or encephalomyelitis. Treatment was intravenous immunoglobulins for 21 patients and corticosteroids for 17. Admission to the pediatric intensive care unit was required for 14 patients. All patients survived. At admission, among patients with the most severe disease, leukocytes were elevated. For children with brainstem encephalitis or encephalomyelitis, clinicians should look for enterovirus and not limit testing to cerebrospinal fluid.

Outbreaks of Neuroinvasive Astrovirus Associated with Encephalomyelitis, Weakness, and Paralysis among Weaned Pigs, Hungary.

A large, highly prolific swine farm in Hungary had a 2-year history of neurologic disease among newly weaned (25- to 35-day-old) pigs, with clinical signs of posterior paraplegia and a high mortality rate. Affected pigs that were necropsied had encephalomyelitis and neural necrosis. Porcine astrovirus type 3 was identified by reverse transcription PCR and in situ hybridization in brain and spinal cord samples in 6 animals from this farm. Among tissues tested by quantitative RT-PCR, the highest viral loads were detected in brain stem and spinal cord. Similar porcine astrovirus type 3 was also detected in archived brain and spinal cord samples from another 2 geographically distant farms. Viral RNA was predominantly restricted to neurons, particularly in the brain stem, cerebellum (Purkinje cells), and cervical spinal cord. Astrovirus was generally undetectable in feces but present in respiratory samples, indicating a possible respiratory infection. Astrovirus could cause common, neuroinvasive epidemic disease.

Genetic characterization of equine herpesvirus 1 isolates from abortion outbreaks in India.

Equine herpesvirus 1 (EHV1) is a common pathogen of horses that causes upper respiratory tract disease, abortion, neonatal death and neurological disease. The neurological form of disease is called equine herpesvirus myeloencephalopathy (EHM). During the past decade, the incidence of EHM has been on the rise in Europe, North America, Australia and Asia. Some EHV1 isolates causing EHM exhibit a single-nucleotide polymorphism (SNP) in the DNA polymerase gene (ORF30) at position 2254 (A2254 to G2254). Further, based on polymorphism in the ORF68, EHV1 isolates have been classified into different groups. The aim of the present study was to estimate the genetic diversity of EHV1 and to determine the prevalence of the neuropathogenic genotype of EHV1 in India. Out of 133 clinical specimens from abortion cases in northern India, 56 were positive for EHV1 infection. Analysis of the A/G SNP by real-time PCR and sequence analysis revealed that 54 of 56 samples (96.43 %) were of the non-neuropathogenic genotype (A2254), while two (3.57 %) had the neuropathogenic marker (G2254). Sequence analysis of the polymorphic region of ORF68 of EHV1 isolates (n = 9) from India indicated that the Delhi/1998, Tohana-2/2013, Hisar-2/2014 and Hisar-15/1990 isolates belonged to group 4, while the Jind/1996, Rajasthan/1998, Delhi-3/2007 and Tohana-5/1996 isolates clustered within group 5. One isolate (Hisar-7/1990) exhibited SNPs at positions C710 and C713, forming a separate group. Here, we report for the first time the detection of neuropathogenic genotypes of EHV1 in India and show that Indian EHV1 isolates cluster within groups 4 and 5.

National Institutes of Health Pathways to Prevention Workshop: Advancing the Research on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

The National Institutes of Health (NIH) Pathways to Prevention Workshop: Advancing the Research on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome was cosponsored by the NIH Office of Disease Prevention and the Trans-NIH Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Research Working Group. A multidisciplinary working group developed the agenda, and an Evidence-based Practice Center prepared an evidence report through a contract with the Agency for Healthcare Research and Quality to facilitate the discussion. During the 1.5-day workshop, invited experts discussed the body of evidence and attendees had the opportunity to comment during open discussions. After weighing evidence from the evidence report, expert presentations, and public comments, an unbiased, independent panel prepared a draft report that identified research gaps and future research priorities. The report was posted on the NIH Office of Disease Prevention Web site for 4 weeks for public comment.

Spatial epidemiological analysis of bovine encephalomyelitis outbreaks caused by Akabane virus infection in western Japan in 2011.

Akabane disease, which is distributed in temperate and tropical regions in the world, is a vector-borne disease of ruminants caused by the Akabane virus, transmitted by Culicoides biting midges. In 2011, outbreaks of Akabane viral encephalomyelitis occurred in the Shimane Prefecture in western Japan. In this study, a spatial epidemiological analysis was conducted to understand environmental factors associated with the spread of Akabane disease. By applying a conditional autoregressive model, the relationship between infection and environmental variables was explored. The results showed that the dominance of farmlands and the presence of infected farms within a 3-km radius had a significant effect on infection. This result implies that land use, which would relate with the vector habitat, and the presence of neighboring infected farms as a source of infection may have influenced the spread of the disease in this region. These findings provide basic insights into the spread of Akabane disease and useful suggestions for developing a surveillance program and preventive measures against the disease.

Clinical presentation and medical management of melioidosis in children: a 24-year prospective study in the Northern Territory of Australia and review of the literature.

BACKGROUND: Melioidosis is less common in children than adults. The clinical spectrum of disease varies greatly between the 2 groups. Treatment guidelines are currently based on adult studies, and revision of existing guidelines is necessary to instruct specific pediatric management. METHODS: Culture-confirmed cases of melioidosis in the Northern Territory between 1989 and 2013 were identified from the Prospective Melioidosis Study. The epidemiology and clinical spectrum of disease for children aged ≤ 16 years were analyzed and compared with the adult data. RESULTS: Forty-five pediatric patients were identified, representing 5% of the total 820 melioidosis cases over 24 years. Most children (84%) had no recognized risk factors for melioidosis, and 80% presented during the wet season. Primary cutaneous melioidosis was the commonest presentation in children (60% vs 13%; P < .001), whereas pneumonia predominated in adults (54% vs 20%; P < .001). Bacteremia was less common in children than in adults (16% vs 59%; P < .001). Brainstem encephalitis occurred in 3 children without risk factors. Children were more likely to report an inoculating event (42%; P < .001). There was no difference in mortality between the groups (P = .178), with 3 children dying (7%); all had identifiable risk factors. Four children with cutaneous melioidosis were successfully treated with oral therapy alone, while 2 had skin lesions that resolved spontaneously. CONCLUSIONS: Pediatric melioidosis commonly manifests as localized cutaneous disease in immunocompetent hosts. The disease can be fatal, especially in individuals with risk factors for disease. Melioidosis with encephalomyelitis can result in severe residual disability. Prompt diagnosis requires a high index of clinical suspicion in endemic areas.

Glycine receptor antibodies in PERM and related syndromes: characteristics, clinical features and outcomes.

The clinical associations of glycine receptor antibodies have not yet been described fully. We identified prospectively 52 antibody-positive patients and collated their clinical features, investigations and immunotherapy responses. Serum glycine receptor antibody endpoint titres ranged from 1:20 to 1:60 000. In 11 paired samples, serum levels were higher than (n = 10) or equal to (n = 1) cerebrospinal fluid levels; there was intrathecal synthesis of glycine receptor antibodies in each of the six pairs available for detailed study. Four patients also had high glutamic acid decarboxylase antibodies (>1000 U/ml), and one had high voltage-gated potassium channel-complex antibody (2442 pM). Seven patients with very low titres (<1:50) and unknown or alternative diagnoses were excluded from further study. Three of the remaining 45 patients had newly-identified thymomas and one had a lymphoma. Thirty-three patients were classified as progressive encephalomyelitis with rigidity and myoclonus, and two as stiff person syndrome; five had a limbic encephalitis or epileptic encephalopathy, two had brainstem features mainly, two had demyelinating optic neuropathies and one had an unclear diagnosis. Four patients (9%) died during the acute disease, but most showed marked improvement with immunotherapies. At most recent follow-up, (2-7 years, median 3 years, since first antibody detection), the median modified Rankin scale scores (excluding the four deaths) decreased from 5 at maximal severity to 1 (P < 0.0001), but relapses have occurred in five patients and a proportion are on reducing steroids or other maintenance immunotherapies as well as symptomatic treatments. The glycine receptor antibodies activated complement on glycine receptor-transfected human embryonic kidney cells at room temperature, and caused internalization and lysosomal degradation of the glycine receptors at 37°C. Immunoglobulin G antibodies bound to rodent spinal cord and brainstem co-localizing with monoclonal antibodies to glycine receptor-α1. Ten glycine receptor antibody positive samples were also identified in a retrospective cohort of 56 patients with stiff person syndrome and related syndromes. Glycine receptor antibodies are strongly associated with spinal and brainstem disorders, and the majority of patients have progressive encephalomyelitis with rigidity and myoclonus. The antibodies demonstrate in vitro evidence of pathogenicity and the patients respond well to immunotherapies, contrasting with earlier studies of this syndrome, which indicated a poor prognosis. The presence of glycine receptor antibodies should help to identify a disease that responds to immunotherapies, but these treatments may need to be sustained, relapses can occur and maintenance immunosuppression may be required.

Molecular and pathological insights into Chlamydia pecorum-associated sporadic bovine encephalomyelitis (SBE) in Western Australia.

BACKGROUND: Despite its global recognition as a ruminant pathogen, cases of Chlamydia pecorum infection in Australian livestock are poorly documented. In this report, a C. pecorum specific Multi Locus Sequence Analysis scheme was used to characterise the C. pecorum strains implicated in two cases of sporadic bovine encephalomyelitis confirmed by necropsy, histopathology and immunohistochemistry. This report provides the first molecular evidence for the presence of mixed infections of C. pecorum strains in Australian cattle. CASE PRESENTATION: Affected animals were two markedly depressed, dehydrated and blind calves, 12 and 16 weeks old. The calves were euthanized and necropsied. In one calf, a severe fibrinous polyserositis was noted with excess joint fluid in all joints whereas in the other, no significant lesions were seen. No gross abnormalities were noted in the brain of either calf. Histopathological lesions seen in both calves included: multifocal, severe, subacute meningoencephalitis with vasculitis, fibrinocellular thrombosis and malacia; diffuse, mild, acute interstitial pneumonia; and diffuse, subacute epicarditis, severe in the calf with gross serositis. Immunohistochemical labelling of chlamydial antigen in brain, spleen and lung from the two affected calves and brain from two archived cases, localised the antigen to the cytoplasm of endothelium, mesothelium and macrophages. C. pecorum specific qPCR, showed dissemination of the pathogen to multiple organs. Phylogenetic comparisons with other C. pecorum bovine strains from Australia, Europe and the USA revealed the presence of two genetically distinct sequence types (ST). The predominant ST detected in the brain, heart, lung and liver of both calves was identical to the C. pecorum ST previously described in cases of SBE. A second ST detected in an ileal tissue sample from one of the calves, clustered with previously typed faecal bovine isolates. CONCLUSION: This report provides the first data to suggest that identical C. pecorum STs may be associated with SBE in geographically separated countries and that these may be distinct from those found in the gastrointestinal tract. This report provides a platform for further investigations into SBE and for understanding the genetic relationships that exist between C. pecorum strains detected in association with other infectious diseases in livestock.

Experimental infection with equine herpesvirus type 1 (EHV-1) induces chorioretinal lesions.

Equine herpesvirus myeloencephalitis (EHM) remains one of the most devastating manifestations of equine herpesvirus type 1 (EHV-1) infection but our understanding of its pathogenesis remains rudimentary, partly because of a lack of adequate experimental models. EHV-1 infection of the ocular vasculature may offer an alternative model as EHV-1-induced chorioretinopathy appears to occur in a significant number of horses, and the pathogenesis of EHM and ocular EHV-1 may be similar. To investigate the potential of ocular EHV-1 as a model for EHM, and to determine the frequency of ocular EHV-1, our goal was to study: (1) Dissemination of virus following acute infection, (2) Development and frequency of ocular lesions following infection, and (3) Utility of a GFP-expressing virus for localization of the virus in vivo. Viral antigen could be detected following acute infection in ocular tissues and the central nervous system (experiment 1). Furthermore, EHV-1 infection resulted in multifocal choroidal lesions in 90% (experiment 2) and 50% (experiment 3) of experimentally infected horses, however ocular lesions did not appear in vivo until between 3 weeks and 3 months post-infection. Taken together, the timing of the appearance of lesions and their ophthalmoscopic features suggest that their pathogenesis may involve ischemic injury to the chorioretina following viremic delivery of virus to the eye, mirroring the vascular events that result in EHM. In summary, we show that the frequency of ocular EHV-1 is 50-90% following experimental infection making this model attractive for testing future vaccines or therapeutics in an immunologically relevant age group.

Human rabies encephalomyelitis in the background of rabies outbreak in animals in Gelephu, Bhutan, 2023: a case report.

BACKGROUND: Rabies continues to pose significant public health challenges in many developing countries including Bhutan. A probable case of rabies was admitted to our hospital and its reporting led to the uncovering of an outbreak in domestic and wild animals. We discuss the challenges in the diagnosis and management of rabies in a resource-limited setting. CASE PRESENTATION: A 35-year-old male presented with intermittent fever, bilateral lower limb weakness that was rapidly progressive, urinary incontinence with episodes of palpitations and sweating. He had sustained a Category III bite on the right lower thigh with four bite marks, inflicted by a stray dog. He had received post-exposure prophylaxis with intra-dermal anti-rabies vaccine. On initial examination, the patient was in distress but cooperative for the interview. He had pulse rate ranging from 60 to 100/min with episodes of diaphoresis and palpitations, but with normal capillary blood glucose. In the lower limb, the muscle power was zero with absent tendon reflexes in the lower limb and impaired abdominal reflex below T10 level. He had hyperaesthesia below T8, hydrophobia, aerophobia and photophobia. He had multiple spontaneous fasciculations in both the thighs and right deltoid and these later involved the intercostal muscles, neck and face muscles. He had altered sensorium and desaturation for which he required mechanical ventilation. Polymerase chain reaction for rabies virus was negative in cerebrospinal fluid and saliva. Rabies virus neutralizing antibody was negative in cerebrospinal fluid but had high titres in the serum. He received Human Rabies Immunoglobulin after admission. He was managed in the intensive care unit and died 23 days later. After this case was notified, a rapid response team was deployed in the field, and uncovered rabies outbreak in animals in the locality. CONCLUSIONS: This case called for a serious evaluation of the country's efforts in achieving zero rabies deaths by 2030. The management of this case identified several critical areas of context-specific interventions in Bhutan. There is also an urgent need to improve diagnostic capabilities at the national reference laboratory and enhance the technical competencies of healthcare workers in the management of dog bite cases.

Association between covid-19 vaccination, SARS-CoV-2 infection, and risk of immune mediated neurological events: population based cohort and self-controlled case series analysis.

OBJECTIVE: To study the association between covid-19 vaccines, SARS-CoV-2 infection, and risk of immune mediated neurological events. DESIGN: Population based historical rate comparison study and self-controlled case series analysis. SETTING: Primary care records from the United Kingdom, and primary care records from Spain linked to hospital data. PARTICIPANTS: 8 330 497 people who received at least one dose of covid-19 vaccines ChAdOx1 nCoV-19, BNT162b2, mRNA-1273, or Ad.26.COV2.S between the rollout of the vaccination campaigns and end of data availability (UK: 9 May 2021; Spain: 30 June 2021). The study sample also comprised a cohort of 735 870 unvaccinated individuals with a first positive reverse transcription polymerase chain reaction test result for SARS-CoV-2 from 1 September 2020, and 14 330 080 participants from the general population. MAIN OUTCOME MEASURES: Outcomes were incidence of Bell's palsy, encephalomyelitis, Guillain-Barré syndrome, and transverse myelitis. Incidence rates were estimated in the 21 days after the first vaccine dose, 90 days after a positive test result for SARS-CoV-2, and between 2017 and 2019 for background rates in the general population cohort. Indirectly standardised incidence ratios were estimated. Adjusted incidence rate ratios were estimated from the self-controlled case series. RESULTS: The study included 4 376 535 people who received ChAdOx1 nCoV-19, 3 588 318 who received BNT162b2, 244 913 who received mRNA-1273, and 120 731 who received Ad26.CoV.2; 735 870 people with SARS-CoV-2 infection; and 14 330 080 people from the general population. Overall, post-vaccine rates were consistent with expected (background) rates for Bell's palsy, encephalomyelitis, and Guillain-Barré syndrome. Self-controlled case series was conducted only for Bell's palsy, given limited statistical power, but with no safety signal seen for those vaccinated. Rates were, however, higher than expected after SARS-CoV-2 infection. For example, in the data from the UK, the standardised incidence ratio for Bell's palsy was 1.33 (1.02 to 1.74), for encephalomyelitis was 6.89 (3.82 to 12.44), and for Guillain-Barré syndrome was 3.53 (1.83 to 6.77). Transverse myelitis was rare (<5 events in all vaccinated cohorts) and could not be analysed. CONCLUSIONS: No safety signal was observed between covid-19 vaccines and the immune mediated neurological events of Bell's palsy, encephalomyelitis, Guillain-Barré syndrome, and transverse myelitis. An increased risk of Bell's palsy, encephalomyelitis, and Guillain-Barré syndrome was, however, observed for people with SARS-CoV-2 infection.

Swine polioencephalomyelitis in Brazil: identification of Teschovirus A, Sapelovirus A, and Enterovirus G in a farm from Southern Brazil.

Porcine encephalomyelitis can be associated with many etiologies, including viral agents, such as Porcine teschovirus (PTV), Porcine sapelovirus (PSV), and Porcine astrovirus (PoAstV). In this study, we investigated the presence of these viruses in a neurological disease outbreak in a swine farm in Southern Brazil. The piglet production farm unity had 1200 weaning piglets, and 40 piglets with neurological signs such as motor incoordination, paresis, and paralysis of hind limbs, with an evolution time of approximately 4 days. Among these, 10 piglets were submitted to postmortem examination. Gross lesions were restricted to a mild enlargement of the nerve roots and ganglia of spinal cord segments. The microscopic lesions were characterized by nonsuppurative encephalomyelitis and ganglioneuritis with evident neuronal degeneration and necrosis. Samples of the central nervous system (CNS), cerebrospinal fluid, and feces were collected and submitted to molecular analysis. PTV was identified in all samples of the CNS, while eight of the piglets were also positive for PSV, and seven were positive for Porcine enterovirus (EV-G). PoAstV was identified in a pool of feces of healthy animals used as controls. This study demonstrates the occurrence of encephalomyelitis associated with PTV on a swine farm in Southern Brazil, as well as the presence of other viruses such as PSV, EV-G, and PoAstV in the swineherd. Sequences of the fragments that were previously amplified by PCR showed a high similarity to PTV 6. Herein, we describe the first case report of severe swine polioencephalomyelitis associated with PTV in South America.

Clinical, neuroradiological, diagnostic and prognostic profile of autoimmune glial fibrillary acidic protein astrocytopathy: A pooled analysis of 324 cases from published data and a single-center retrospective study.

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a recently defined autoimmune meningoencephalomyelitis, associated with GFAP-IgG antibody. A pooled analysis of 324 cases from published literature and a retrospective single-center study were performed, firstly reveals the possibility that patients with myelitic lesions respond better to initial immunotherapy, but are prone to relapse, suggesting a more aggressive and long-term immunosuppressive medication for them. Moreover, our results showed using tacrolimus at maintenance stage exhibited a less tendency to relapse, providing a possibly new choice to future clinical treatments.

Epidemiology of Viliuisk encephalomyelitis in Eastern Siberia.

BACKGROUND: Viliuisk encephalomyelitis is a disorder that starts, in most cases, as an acute meningoencephalitis. Survivors of the acute phase develop a slowly progressing neurologic syndrome characterized by dementia, dysarthria, and spasticity. An epidemic of this disease has been spreading throughout the Yakut Republic of the Russian Federation. Although clinical, neuropathologic, and epidemiologic data suggest infectious etiology, multiple attempts at pathogen isolation have been unsuccessful. METHODS: Detailed clinical, pathologic, laboratory, and epidemiologic studies have identified 414 patients with definite Viliuisk encephalomyelitis in 15 of 33 administrative regions of the Yakut Republic between 1940 and 1999. All data are documented in a Registry. RESULTS: The average annual Viliuisk encephalomyelitis incidence rate at the height of the epidemic reached 8.8 per 100,000 population and affected predominantly young adults. The initial outbreak occurred in a remote isolated area of the middle reaches of Viliui River; the disease spread to adjacent areas and further in the direction of more densely populated regions. The results suggest that intensified human migration from endemic villages led to the emergence of this disease in new communities. Recent social and demographic changes have presumably contributed to a subsequent decline in disease incidence. CONCLUSIONS: Based on the largest known set of diagnostically verified Viliuisk encephalomyelitis cases, we demonstrate how a previously little-known disease that was endemic in a small indigenous population subsequently reached densely populated areas and produced an epidemic involving hundreds of persons.

Genotyping of Porcine teschovirus from nervous tissue of pigs with and without polioencephalomyelitis in Indiana.

Porcine teschovirus (PTV) was isolated in cell culture and/or demonstrated by polymerase chain reaction in samples of brain and/or spinal cord in pigs in Indiana during the 2002-2007 period. Testing was initiated on pigs originating from populations exhibiting nervous clinical disease and/or pigs with microscopic lesions in central nervous tissues, indicating viral encephalitis and/or myelitis. Virus was demonstrated in pigs with and without lesions as well as with and without nervous clinical disease. Nucleotide sequence analysis of the 5'-nontranslated region of the viral genome revealed that these isolates had low-level genetic heterogeneity but were homologous to porcine PTV serotype 1 (PTV-1). These findings indicate that low-to-moderate virulence strains of PTV with some homology to PTV-1 are endemic in many swineherds of Indiana and are associated with subclinical and clinical nervous disease in weaned pigs.

[Encephalomyelitis caused by enterovirus type 71 in children].

Enterovirus type 71 (EV71) is a causative agent of large outbreaks of hand, foot, and mouth disease (HFMD) in Europe (Bulgaria, 1975; Hungary, 1978) and South-East Asia (Malaysia, 1977; Taiwan, 1998; Singapore, 2000-2007; People's Republic of China, 2007-2009). HFMD afflicted children less than 10 years of age and resulted in recovery within 3-7 days. In a small percentage of infants (aged 6 months to 3 years), HFMD was accompanied by acute neurological complications, such as serous meningitis, poliomyelitis-like syndrome (extremity pareses and muscle paralyses); brain stem encephalitis (myoclonic jerks, tremor, lethargy, swallowing and speech disorders, cardiopulmonary failure, pulmonary edema, shock, coma, death). X-ray study revealed pulmonary hemorrhages and edema. Mortality rates were as high as 82-94% in severe cases. Incapacitating motor, respiratory, and psychoemotional disorders persisted in some surviving children. Pathomorphologically, patients with central nervous system disease and cardiopulmonary failure were found to have acute inflammation of the grey matter of the brain stem (medulla oblongata, pons) and spinal cord. Inflammatory changes in the lung and myocardial tissues were negligible or absent. Fatal pulmonary edema was neurogenic in origin and resulted from damage to the respiratory and vasomotor centers of the brain stem.