ETIDIOH - NEW

  Abstract The spillover of highly pathogenic avian influenza (HPAI) A H5N1 virus to mammalian hosts raises major concerns due to its pandemic potential . Cats are frequently affected mammals, often succumbing to systemic and neurological disease . Here, we characterized the pathogenesis and transmissibility of two H5N1 genotypes, B3.13 and D1.1, in cats . Infected cats exhibited high-level viremia and virus shedding in nasal, oral, and fecal secretions were consistently detected. The virus replicated initially in the upper respiratory tract and lungs , followed by systemic dissemination and neuroinvasion . Notably, the virus crossed the blood-brain-barrier by infecting endothelial cells , spreading to astrocytes and neurons , causing multifocal encephalitis . D1.1-virus infection caused protracted disease with lower shedding and no transmissibility , whereas B3.13 virus caused rapid onset with efficient shedding and transmission. These findings reveal critical H5N1 neuropathogenes...

  Highlights •  Viremia in children with La Crosse Virus infection is transient; viral RNA was detected in only 3.2% of sera •  Detection of La Crosse Virus RNA in respiratory samples is slightly higher at 21.7% and may reflect the temporal distribution of the virus after infection •  NAAT has limited utility in routine diagnosis of La Crosse Virus encephalitis in children but may still be useful in cases with delayed seroconversion Abstract Background La Crosse virus (LACV), a member of family Peribunyaviridae, genus Orthobunyavirus , is the leading cause of neuroinvasive arboviral infection in children in the United States . Diagnosis relies on detecting specific antibodies (IgG or IgM), a 4-fold titer rise or seroconversion, in patients with compatible presentations. NAAT used for LACV detection has largely been limited to mosquito, animal models or postmortem brain tissue. There is a lack of data on the performance of NAATs in clinical specimens from living patie...

  Abstract Human non-polio enteroviruses (NPEVs) cause a plethora of infections in humans, ranging from mild to severe neurological diseases including aseptic meningitis . NPEVs are the leading cause of aseptic meningitis in both children and adults worldwide . In Russia , reports of NPEV infections have surged, especially in the post-COVID era starting in 2022, with elevated infection rates into 2023 . A comprehensive examination of the whole genome is crucial for understanding the evolution of NPEV genes and for predicting potential outbreaks. This study focused on identifying the circulating NPEV strains in the Ural Federal District and Western Siberia , using Sanger sequencing and next-generation sequencing (NGS) methodologies. Biological samples were collected from (n = 225) patients diagnosed with aseptic meningitis. Bioinformatics analysis targeted the nucleotide sequences of the major capsid protein (partial VP1) gene fragment, and the assembly of whole NPEV genomes. A tota...

  Abstract Influenza-associated encephalitis/encephalopathy (IAE) is a severe neurological complication characterized by central nervous system dysfunction and structural damage following influenza virus infection . Predominantly affecting infants and young children , IAE exhibits its highest incidence in those under five years of age . Key clinical manifestations of IAE include acute seizures, sudden high fever, and impaired consciousness , frequently progressing to coma . Neuroimaging , particularly magnetic resonance imaging (MRI), often reveals multifocal brain lesions involving multiple brain regions, including the cerebellum, brainstem, and corpus callosum . The prognosis of IAE is poor , with a mortality rate reaching 30%. Current diagnosis relies heavily on clinical presentation and characteristic neuroimaging findings, as the precise pathogenesis of IAE remains elusive . While various research models, including cell lines, brain organoids, and animal models , have been dev...

Abstract The H1N1 virus commonly causes symptoms such as fever, cough, sore throat, which have a self-limited course in most cases . Neurological complications are rare, especially in adults. This case illustrates H1N1-associated acute leukoencephalopathy in a young adult with a favorable outcome and no lasting neurological deficits . The initial presentation included fever, sore throat, and myalgia , evolving into neurological symptoms , including dysarthria, nystagmus, and left-sided motor weakness . Comprehensive laboratory tests ruled out common bacterial, viral, or autoimmune causes, while MRI findings suggested acute leukoencephalopathy of infectious or toxic etiology. Although the urine toxicology screen showed traces of phenol , clinical evidence did not correlate with toxic exposure and pointed towards an infectious origin. A throat swab for Influenza/H1N1 PCR confirmed the diagnosis. Treatment with oseltamivir and methylprednisolone led to symptomatic improvement with no sequ...

ABSTRACT Newly emerging or “re-emerging” influenza viruses have been regarded as a huge global threat to human public health . However, there are few reports of human deaths caused by newly emerging influenza viruses derived from pigs and poultry . Here, we described the clinical and virological features of a fatal encephalitis caused by a novel H3N2 reassortant virus generated from swine H3N2 and human H7N9 viruses. A 7-year-old boy was diagnosed with acute encephalitis in Yixing, China, in August 2022. Chest computed tomography (CT) showed mild pneumonia . Brain CT indicated acute encephalitis companied brain parenchyma swelling. Haematological examinations revealed a markedly elevation of lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, creatine kinase and cytokines . Pathogenic analysis confirmed that a novel H3N2 virus (A/Yixing/805/2022, YX805) was responsible for this case. Phylogenetic analysis showed that the surface protein-coding genes were origin...

Abstract In this report, we document and analyze a case in which the Irkut virus (IRKV) (Mononegavirales: Rhabdoviridae) caused a fatal human case following a bat bite in June 2021. Unfortunately, the available data did not permit a detailed taxonomic classification of the carrier bat ( Chiroptera ). The event occurred in the southwestern part of the Sikhote-Alin mountain region (Russian Far East) covered by the Ussuri taiga forest . The symptoms of the illness began with the following: fever ; pronounced psychomotor and motor agitation ; tremor of the lower jaw and tongue ; aphasia; dyslexia; and dysphagia . These rapidly developed, leading to a severe and fatal encephalitis . The patient was not vaccinated for rabies and did not receive rabies immunoglobulin. Using brain sections prepared from the deceased, molecular diagnostics were performed: immunofluorescence (polyclonal anti-rabies immunoglobulin) indicating the presence of the lyssavirus antigen ; and RT-PCR indicating traces o...

ABSTRACT Respiratory and encephalitic virus infections represent a significant risk to public health globally . Detailed investigations of immunological responses and disease outcomes during sequential virus infections are rare. Here, we define the impact of influenza virus infection on a subsequent virus encephalitis . We used a model system in which mice were given influenza A virus (IAV) infection 8 days prior to Semliki Forest virus (SFV) infection (IAV→SFV). IAV infection clearly attenuated the subsequent SFV infection with reduced titers of infectious SFV and lower levels of cytokines and chemokines in the central nervous system ( CNS ). In contrast, the SFV viremia in both IAV→SFV and SFV-only mice was comparable. Increased type I interferon (IFN) levels in the CNS after IAV infection might have contributed to some level of protection towards SFV infection in the CNS, suggesting that early control of SFV replication in the CNS during IAV→SFV infection led to reduced adaptive res...

Abstract The European subtype of tick-borne encephalitis virus (TBEV-Eur; species Orthoflavivirus encephalitidis , family Flaviviridae ) was the only tick-borne flavivirus present in central Europe known to cause neurologic disease in humans and several animal species . Here, we report a tick-borne flavivirus isolated from Alpine chamois (Rupicapra rupicapra rupicapra) with encephalitis and attached ticks , present over a wide area in the Alps . Cases were detected in 2017 in Salzburg, Austria , and 2023 in Lombardy and Piedmont, Italy . The virus strains exhibit 94.8–97.3% nucleotide identities to each other and are more closely related to Louping ill viruses (LIV; Orthoflavivirus loupingi ; 90–92% identities) than to TBEV-Eur (less than 88%). The chamois-derived virus strains, tentatively termed “ Alpine chamois encephalitis virus ”, form a well-supported independent genetic clade with Spanish goat encephalitis virus , clearly separated from other LIV. This supports its designation a...

Abstract Neurological manifestations associated with human parvovirus B19 (B19V) infections are rare and varied. Acute encephalitis and encephalopathy are the most common, accounting for 38.8% of all neurological manifestations associated with human B19V. Herein, we report on the clinical features of 13 laboratory-confirmed human cases of B19V-associated encephalitis in Senegal in the framework of a hospital-based surveillance of acute viral encephalitis conducted from 2021 to 2023. Overall, B19V was detected from 13 cerebrospinal fluid samples using specific real time PCR. The mean age was 16.7 years among B19V-positive patients, with a higher prevalence in 0–5-year-old children and the sex ratio (male/female) was 2.25. The B19V-positive patients mainly exhibited hypoleukocytosis, normal glycorrhachia, and normal proteinorrachia in the cerebrospinal fluid. While the main neurological symptoms included meningeal and infectious syndromes . Furthermore, three complete B19V genome sequenc...