Powassan virus persistence after acute infection

Survivors of Powassan encephalitis often have persistent neurological disease. A new mouse model replicates some elements of the human disease and demonstrates the presence of viral RNA in the brain as well as myelitis more than 2 mo after the acute infection. The related tick-borne encephalitis and West Nile Neuroinvasive Disease (WNND) also have common neurological sequelae, and models for these better-studied diseases provide evidence for prolonged virus, RNA, and inflammation in some cases, in addition to damage from the acute encephalitic disease. A better understanding of the biological basis for persistent signs and symptoms after Powassan encephalitis, currently a rare disease, could benefit from further studies of the more prevalent flaviviral encephalitides.

Automated summary

A new mouse model has successfully replicated some features of human Powassan encephalitis, showing the presence of viral RNA and myelitis more than 2 months after acute infection. Similar neurological sequelae have been observed in tick-borne encephalitis and West Nile Neuroinvasive Disease, and models for these diseases have also provided evidence of prolonged virus, RNA, and inflammation. Understanding the biological basis for persistent symptoms after Powassan encephalitis could be improved by studying more prevalent flaviviral encephalitides.