Nipah virus encephalitis: serial MR study of an emerging disease.
ABSTRACT To report the serial magnetic resonance (MR) imaging findings of the Nipah virus.
Twelve patients underwent serial MR imaging. Eight patients were examined at the outbreak; 11, at 1 month; and seven, at 6 months. Contrast material-enhanced MR images, diffusion-weighted images, and single-voxel proton MR spectroscopic images were reviewed. Clinical and neurologic assessment, as well as analysis of the size, location, and appearance of brain lesions on MR images, were performed.
During the outbreak, all eight patients had multiple small foci of high signal intensity within the white matter on T2-weighted images. In six patients, cortical and brain stem lesions were also detected, and five patients had diffusion-weighted MR imaging-depicted hyperintensities. One month after the outbreak, five patients had widespread tiny foci of high signal intensity on T1-weighted images, particularly in the cerebral cortex. Diffusion-weighted images showed decreased prominence or disappearance of lesions over time. There was no evidence of progression or relapse of the lesions at 6-month follow-up. MR spectroscopy depicted reduction in N-acetylaspartate-to-creatine ratio and elevation of choline-to-creatine ratios.
The Nipah virus has findings unlike other viral encephalitides: small lesions that are primarily within the white matter, with transient punctate cortical hyperintensities on T1-weighted images.
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Article: Nipah and Hendra VirusesPerspectives in Medical Virology 01/2006; 16:179-199.
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ABSTRACT: Nipah virus (NiV) and Hendra (HeV) virus are emerging, biosafety level 4 paramyxoviruses responsible for fatal zoonotic infections of humans from pigs and horses, respectively, and are the prototypic members of a new Paramyxovirinae genus called Henipavirus. These enveloped, negative-sense RNA viruses infect cells through a pH-independent membrane fusion event mediated through the actions of their attachment (G) and fusion (F) envelope glycoproteins, which are also the principal antigens to which neutralizing antibodies are directed. Understanding the biological and functional features of the viral glycoproteins will help define the characteristics and properties of these novel viruses, and may provide insights into membrane fusion mechanisms, the virus infection process, and towards the development of therapeutics. Here, recombinant vaccinia virus vectors were generated to express the NiV and HeV glycoproteins. Glycoprotein functions and their cellular tropism characteristics were examined with a quantitative assay for membrane fusion. NiV and HeV glycoprotein-mediated fusion could be blocked by virus-specific antisera or synthetic peptides corresponding to the C-terminal alpha-helical heptad repeats of NiV or HeV F. Both F and G glycoproteins were required for membrane fusion and a broad species and cellular tropism pattern was observed for both HeV and NiV. Further, protease treatment of receptive host cells abolished viral glycoprotein-mediated fusion activity, suggesting a cell-surface protein serves as a receptor for these viruses. In addition, interactions between the glycoproteins of the paramyxoviruses have not been well defined, but studies reported here show the NiV and HeV glycoproteins are capable of a highly efficient heterotypic functional activity amongst themselves, but not with other related paramyxoviruses.
Article: MR imaging in Nipah virus infection[Show abstract] [Hide abstract]
ABSTRACT: Advanced diffusion weighted (DW) MRI of the brain in the fatal outbreak of Nipah viral encephalitis among pig workers in Malaysia and Singapore revealed a pattern similar to ischaemic infarction caused by obstruction of small cerebral blood vessels. However, relapse and late-onset cases in Malaysia, and other outbreaks of Nipah virus in Bangladesh and the Hendra virus infection in Australia, showed a different MRI pattern of predominantly confluent cortical lesions. MRI was useful in characterizing the disease in acute infection, as well as detection of spine abnormalities and subclinical infection.