Pathological Characteristics of Echovirus 30 Infection in a Mouse Model.

Echovirus 30 (E30), a member of species B enterovirus, is associated with outbreaks of aseptic meningitis and has become a global health emergency. However, the pathogenesis of E30 remains poorly understood due to the lack of appropriate animal models. In this study, we established a mouse infection model to explore the pathogenicity of E30. The 2-day-old IFNAR-/- mice infected with E30 strain WZ16 showed lethargy and paralysis, and some died. Obvious pathological changes were observed in the skeletal muscle, brain tissue, and other tissues, with the highest viral load in the skeletal muscles. Transcriptome analysis of brain and skeletal muscle tissues from infected mice showed that significant differentially expressed genes were enriched in complement response and neuropathy-related pathways. Using immunofluorescence assay, we found that the viral double-stranded RNA (dsRNA) was detected in the mouse brain region and could infect human glioma (U251) cells. These results indicated that E30 affects the nervous system, and they provide a theoretical basis for understanding its pathogenesis. IMPORTANCE Echovirus 30 (E30) infection causes a wide spectrum of diseases with mild symptoms, such as hand, foot, and mouth disease (HFMD), acute flaccid paralysis, and aseptic meningitis and other diseases, especially one of the most common pathogens causing aseptic meningitis outbreaks. We established a novel mouse model of E30 infection by inoculating neonatal mice with clinical isolates of E30 and observed the pathological changes induced by E30. Using the E30 infection model, we found complement responses and neuropathy-related genes in the mice tissues at the transcriptome level. Moreover, we found that the viral dsRNA localized in the mouse brain and could replicate in human glioma cell line U251 rather than in the neuroblastoma cell line, SK-N-SH.

Pathological Features of Echovirus-11-Associated Brain Damage in Mice Based on RNA-Seq Analysis.

Echovirus 11 (E11) is a neurotropic virus that occasionally causes fatal neurological diseases in infected children. However, the molecular mechanism underlying the disease and pathological spectrum of E11 infection remains unclear. Therefore, we modelled E11 infection in 2-day-old type I interferon receptor knockout (IFNAR-/-) mice, which are susceptible to enteroviruses, with E11, and identified symptoms consistent with the clinical signs observed in human cases. All organs of infected suckling mice were found to show viral replication and pathological changes; the muscle tissue showed the highest viral replication, whereas the brain and muscle tissues showed the most obvious pathological changes. Brain tissues showed oedema and a large number of dead nerve cells; RNA-Seq analysis of the brain and hindlimb muscle tissues revealed differentially expressed genes to be abundantly enriched in immune response-related pathways, with changes in the Guanylate-binding protein (GBP) and MHC class genes, causing aseptic meningitis-related symptoms. Furthermore, human glioma U251 cell was identified as sensitive target cells for E11 infection. Overall, these results provide new insights into the pathogenesis and progress of aseptic meningitis caused by E11.

Acute meningoencephalitis associated with echovirus 9 infection in Sri Lanka, 2009.

The aetiology of acute meningoencephalitis in Sri Lankan children and adults is poorly understood. This study was carried out to determine pathogens responsible for meningoencephalitis in Sri Lanka. A hospital-based cross-sectional study was performed using cerebrospinal fluid samples (22 adult and 17 pediatric) collected from August to December 2009 from patients clinically diagnosed with acute meningoencephalitis at two tertiary care hospitals in Sri Lanka. Routine microbiology for bacterial pathogens together with in-house RT-PCR and PCR assays for the detection of dengue viruses, Japanese encephalitis virus, West Nile virus, chikungunya virus, enteroviruses, mumps virus, measles virus, herpes simplex viruses types 1 and 2, and varicella zoster virus were performed. Bacterial pathogens were not isolated from any patient specimens. However, from nine of the paediatric patients aged 1 month to 10 years (mean age 5.2 years) echovirus 9 (E-9; family Picornaviridae, genus Enterovirus,species Enterovirus B ) was detected by RT-PCR. All nine patients presented with fever, six had headache, and seven had vomiting. Neck stiffness indicating meningitis was present in six of the patients. Phylogenetic analysis of partial VP1 and VP4-VP2 genes showed these E-9 strains to be most closely related to E-9 strains detected in CSF from Korea and France in 2005 and 2006. The remaining patients were negative for all other viruses tested. E-9 was the most common cause of acute meningoencephalitis in the tested paediatric population from Sri Lanka in 2009, which likely reflects circulation of this E-9 strain between Europe and Asia over several years.

Persistent spiking fever in a child with acute myeloid leukemia and disseminated infection with enterovirus.

We here report a 7 year old acute myeloid leukemia patient with persistent spiking fever likely caused by chronic echovirus 20 infection. After immunoglobulin substitution fevers subsided and the virus was cleared. Enterovirus infection should be considered in immunocompromised patients with unexplained persistent fever.

An outbreak of echovirus 33 in schools in China in 2013.

Echovirus 33 (E33) has been infrequently detected and is less frequently associated with clinical diseases when compared with other types of enteroviruses (EVs) in China. An outbreak of E33 was identified in four schools in Hunan Province, China, in June 2013. For laboratory diagnosis, throat swabs and/or serum specimens were collected from 27 patients. E33 was isolated in cell culture and typed by molecular methods. Complete VP1 gene sequences were determined and analyzed. Specific E33 antibody was measured by virus neutralization testing. From June 3-20, 108 suspected cases were reported, and 19 were confirmed to be associated with E33 by laboratory testing, with seven virologically confirmed and 12 serologically confirmed cases. The suspected cases were in children aged 3-16 years (mean, 11 years), most of whom (94%, 102/108) were ≥6 years old. The majority of cases (98%, 106/108) presented as influenza-like illness (ILI), and two were clinically diagnosed as viral meningitis. Older children aged ≥12 years had a higher hospitalization rate (21%) than younger children (4%). A BLAST query of GenBank with the Hunan E33 strain VP1 gene sequence gave a close match to an E33 isolate from Pakistan, based on a partial VP1 gene sequence. Phylogenetic analyses of the complete E33 VP1 gene sequences from our study revealed an independent cluster with nucleotide sequences that diverge from E33 from other countries by >12%. Due to limited E33 VP1 gene sequence data in GenBank and passive EV surveillance in China and most other parts of the world (excepting hand, foot, and mouth disease surveillance in Asia), the approximate origin of Hunan E33 could not be determined.

Detection and identification of echovirus 7 from a child with gastro-enteritis.

BACKGROUND: Gastro-enteritis continues to be a significant cause of mortality in infants and young children in developing countries. Some previous studies have associated echoviruses with gastroenteritis. OBJECTIVE: To look for other viral agents causing gastro-enteritis in stool samples of infants and young children admitted with diarrhoea in an urban hospital in Kenya by electron microscopy. DESIGN: A cross sectional study. SETTING: Mbagathi District Hospital, Nairobi, Kenya. SUBJECTS: One hundred infants and young children admitted in the hospital due to gastro-enteritis and found to be negative for group A rotaviruses. RESULTS: We report a virus designated KE/CVR-99 which was recovered from the faeces of a one year old male child hospitalised for gastro-enteritis. Virus particles measuring 20-25 nm in diameter were detected by electron microscopy from the stool of the child hospitalised with gastro-enteritis. After injecting the viral particles intracerebrally in newborn suckling mice which were then observed daily for signs of illness, no sign of paralysis or any other form of illness was detected. Cytopathic effect was observed in rhabdomyosarcoma cells within six days of incubation whereas no cytopathic effect was observed in L-20 B cells. We identified the virus after typing against known anti-sera to a panel of enteroviruses. This virus was found to be Echovirus 7. CONCLUSION: This is the first case report of echovirus 7 in association with gastro-enteritis and detection by electron microscopy in Kenya.

Eruptive pseudoangiomatosis.

We describe two children with acute onset and spontaneous resolution of angioma-like papules during a viral illness. The biopsy specimens from both patients showed a unique histologic appearance consisting of dilated dermal blood vessels with plump, hobnail-shaped endothelial cells. On the basis of the natural history and the histopathologic features we suggest the diagnosis of eruptive pseudoangiomatosis.

Abnormalities of brain perfusion in echovirus type 30 meningitis.

From May to August 1998 an epidemic of aseptic meningitis (AM) due to echovirus type 30 (E30) occurred in Yamaguchi prefecture, Japan. We performed single-photon emission-computed tomography (SPECT) to evaluate cerebral perfusion during the acute stage in 27 patients with AM due to E30. Moreover, we measured the cerebrospinal fluid (CSF) concentrations of soluble tumor necrosis factor receptor (sTNF-R) and interleukin-1 beta (IL-1beta) in all 27 patients, and the serum concentration of soluble E-selectin (sE-selectin) in 19 of the 27 patients, which is responsible for vasculitis, by means of a sandwich enzyme-linked immunosorbent assay. In 20 of the 27 (74.1%) children, SPECT imaging revealed localized cerebral hypoperfusion without abnormal focal neurological findings or symptoms. Follow-up SPECT after about 1 month revealed no abnormalities. The CSF concentrations of sTNF-R and IL-1beta, and the serum concentration of sE-selectin in the group with abnormal findings on SPECT were significantly higher than those in the group without abnormal findings on SPECT and the control subjects. Our results indicate that transient reduced regional blood flow is a frequent finding in children with AM due to E30 infection and that this abnormal finding may be induced by cerebral vasculitis.

Acute transverse myelitis caused by ECHO virus type 18 infection.

UNLABELLED: A 14-year-old boy developed acute quadriplegia, associated with sensory impairment and bowel and urinary dysfunction. MRI of the cervical cord showed diffuse increased signal intensity on T2-weighted images with gadolinium-diethylenetriamine penta-acetic acid enhancement. Based on the clinical presentation and MRI findings, the diagnosis of acute transverse myelitis was made. Enterovirus RNA was amplified from CSF by the reverse transcriptase-polymerase chain reaction. Serum neutralizing antibody to ECHO virus type 18 rose from 1/4 on admission to 1/16 2 months later. CONCLUSION: This is the first reported case of acute transverse myelitis caused by ECHO virus type 18 infection.

Echovirus type 19 and herpes simplex type 2 infection in human placenta tissue explants

1. Light and electron microscopy have been used to characterize echovirus 19 and herpes simplex type 2 infection of human placenta tissue in vitro. Immunofluorescence, autoradiography and virus adsorption were used to determine virus replication in this system. 2. Placental tissue was permissive to echovirus 19. Trophoblast cells were lysed with liberation of mature virions. However, during the 48-h period of observation, few cells were damaged and the trophoblastic structure was maintained. 3. HSV-2 infection in placental tissue was aborted although trophoblastic cells allowed virus adsorption, penetration and uncoating. A characteristic cytopathic effect was observed in infected trophoblastic cells in spite of the abortive infection

Placental phagocytic cells infected with herpes simplex type 2 and echovirus type 19: virological and ultrastructural aspects.

Placental macrophage cells were kept in a short-term culture and infected with herpes simplex type 2 virus and echovirus type 19. These were observed under optical and electron microscopy. Immunofluorescence, virus titration and autoradiographic technique were used to determine if the virus was replicating in the system. The results showed that the placental phagocytic cells do not allow virus growth and that the virus particles are destroyed right after virus uptake, within 4 h post-infection. The increase of lipid bodies and other cellular alterations suggested the intensive action of these cells against viruses.

[Pathomorphology of uveitis caused by an echovirus]. / Patomorfologiia uveita, vyzvannogo virusom ECHO.

The monkey eyes infested by inoculation into the eye anterior chamber of the ECHO-19 virus from children with uveitis were studied morphologically. It was established electron microscopically that the inoculated virus is replicated in the capillary endothelium and stromal cells of the uveal tract. Crystal-like accumulation of virions and degenerative changes in the organelles are observed in these cells. Acute granulomatous alterative-exudative-hemorrhagic uveitis with the destruction of the iris, ciliary body and processes and secondary changes in the cornea and crystalline lens with the symptoms of keratitis and cataract develop in the anterior part of the eye as observed in the light microscope. The anterior and posterior goniosynechia develop. An acute inflammatory process is further transformed into a progressing autoimmune inflammation.

Fatal hepatoadrenal necrosis in the neonate associated with echovirus types 11 and 12 presenting as a surgical emergency.

Two neonates presented to our service with suspected intraabdominal surgical emergencies. Both subsequently were found to have hepatoadrenal necrosis due to overwhelming echoviral infection. Echovirus types 11 and 12 were isolated postmortem. The latter virus has not been associated previously with fulminant neonatal illness.