virology blog
About viruses and viral disease
TWiV reviews the difficulties in predicting species susceptibility to SARS-CoV-2 infection by only examining the ACE2 protein, and the olfactory mucosa as a portal of entry into the central nervous system in COVID-19 patients.
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Download TWiV 690 (71 MB .mp3, 120 min)
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Amy joins the TWiV team to review evidence that enterovirus D68 is an etiologic agent of childhood paralysis, and her finding that the ability of the virus to infect cells of the nervous system is not a recently acquired property.
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Download TWiV 572 (73 MB .mp3, 121 min)
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The TWiV team summarizes the discovery of Sin Nombre virus, and presents evidence that neurotropic flaviviruses can cause intestinal dysmotility syndromes after systemic infection of mice.
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Download TWiV 527 (53 MB .mp3, 87 min)
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Intestinal dysmotility disorders such as irritable bowel syndrome affect 10-30% of humans in Western countries. Some of these diseases appear to correlate with viral infection. Inoculation of mice with neurotropic flaviviruses leads to injury and death of enteric neurons, inflammation, intestinal dilation and retarded bowel transit, providing a model for studying and treating these human intestinal disorders. [Read more…] about Viral infections of the enteric nervous system and intestinal dysmotility
From the Vector-Borne Viruses Symposium in Hamilton, Montana, Dickson and Vincent speak with Diane Griffin about her career and her work on understanding viral infections of the central nervous system.
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Download TWiV 453 (39 MB .mp3, 64 min)
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Evidence is mounting that Zika virus is neurotropic (able to infect cells of the nervous system) and neurovirulent (causes disease of the nervous system) in humans.
The most recent evidence comes from a case report of an 81 year old French man who developed meninogoencephalitis 10 days after returning from a 4 week cruise to New Caledonia, Vanuatu, Solomon Islands, and New Zealand (meningoencephalitis is infection of the meninges - the membranes that cover the brain - and the brain). His symptoms included fever, coma, paralysis, and a transient rash. A PCR test revealed Zika virus genomes in the cerebrospinal fluid, and infectious virus was recovered after applying the CSF to Vero cells in culture.
A second case report concerns a 15 year old girl in Guadeloupe who developed left hemiparesis (weakness of one side of the body), left arm pain, frontal headache, and acute lower back pain. After admission she developed dysuria (difficulty urinating) that required catheterization. PCR revealed the presence of Zika virus genomes in her serum, urine, and cerebrospinal fluid; other bacterial and viral infections were ruled out.
Until very recently Zika virus was believed to cause a benign infection comprising rash, fever, joint pain, red eyes, and headache. There is now strong evidence that the virus can cause congential birth defects, and growing evidence that the virus is neurotropic and neurovirulent. Previously the entire Zika virus genome was recovered from brain tissue of an aborted fetus.
Zika virus is classified in the family Flaviviridae, and other members are known to be neurotropic, including West Nile virus, Japanese encephalitis virus, and tick-borne encephalitis virus. West Nile virus infection may lead to acute flaccid paralysis, meningitis, encephalitis, and ocular manifestations. Examination of additional cases of Zika virus infection will be needed to document the full spectrum of illness caused by this virus.
Update: Neurotropism of Zika virus is also indicated by the findings that the virus infects human cortical neural progenitors.